Patent Application
20250130028
Aspects of the present disclosure relate to systems, apparatuses, methods, and processes for delivering or loading explosive compositions into a set of boreholes in accordance with one or more programmably or selectably configurable densities or density profiles/distributions, for instance, such that multiple distinct segments of a given borehole and/or different boreholes across a multi-borehole array can have distinct or different programmably specified densities and/or density profiles/distributions.
It may be well known that when bulk emulsion explosives containing greater than approximately 50% emulsion phase and which are sensitized with gas bubble voids reside in boreholes/blastholes, the bulk emulsion explosive acts as a fluid medium, and the size and distribution of the sensitising voids are affected by hydrostatic pressure that is proportional to the depth of the void in the borehole/blasthole column. A consequence of constant sensitising agent feed mass fraction level, and the generation of a hydrostatic gradient in the bulk emulsion explosive, is that there is a higher bulk density of explosive composition product at the base of the borehole/blasthole, and a lower bulk density of the explosive composition product at the top of the borehole/blasthole. For a given emulsion explosive composition product, the corresponding consequence of this hydrostatic gradient is a higher ideal energy (e.g., relative bulk strength (RBS)) for the explosive composition product at the base of the borehole/blasthole, and a lower ideal energy (e.g., RBS) at the top of the borehole/blasthole.
In chemically sensitised bulk explosive compositions where gas bubble voids are used for sensitisation, the in-situ bulk explosive composition density can be changed by changing the stoichiometry of the chemical sensitising agent(s) in the part of the borehole/blasthole where density change is desired. One desirable aspect of this can be to reduce the energy level at the base of the borehole/blasthole column by increasing the sensitising agent concentration in that section of bulk explosive composition product, and/or adding less sensitising agent in the bulk explosive composition product at the top of the borehole/blasthole to increase the energy of the explosive composition product at the top of the borehole/blasthole.
Systems, apparatuses, and processes by which explosive composition product densities can be adjusted or changed in a flexible manner, and which are readily and/or inexpensively retrofittable to or integratable with existing explosive composition delivery systems, are desired.
It is desired to address or ameliorate one of more limitations or problems in the prior art, or to at least provide a useful alternative.
Disclosed herein is a system/apparatus (for delivering or loading explosive compositions having one or more programmably or selectably configurable densities or density profiles/distributions into boreholes, and for outputting into the borehole the explosive composition having the selected (e.g., programmably specified) density or density profile/distribution at the outlet structure of the conduit/hose) including:
In some embodiments, the introduction of the set of sensitizing agents (e.g., a set of chemical sensitizing agents) occurs by way of at least one sensitizing agent introduction site (including a sensitizing agent injection site, location, or structure, e.g., at least one chemical sensitizing agent introduction site) that is away from the outlet structure of the conduit/hose, including wherein each sensitizing agent introduction site is not proximate to the outlet structure of the conduit/hose, including:
In some embodiments:
In some embodiments, the sensitizing agents are selectively introduced at mutually different concentrations/flow rates, or in accordance with different concentration/flow rate functions, at respective different times, to provide the concentration profile/distribution in a manner intended or expected to serially or sequentially produce explosive compositions (“different-density explosive compositions”) having respectively the different densities or density profiles/distributions.
In some embodiments, the introduction of the set of sensitizing agents at the sensitizing agent introduction site at the different concentrations/flow rates, or in accordance with different concentration/flow rate functions, at the different times, gives rise to different lengthwise segments of conduit/hose material contents corresponding to the different-density explosive compositions such that at least two different along-conduit/along-hose or in-conduit/in-hose material contents or masses, volumes, or inventories of chemical compositions/substances/species or explosive composition products exist (along the length of the conduit/hose), each of which corresponds to:
In some embodiments, if during a first time interval the set of sensitizing agents was introduced at a first concentration/flow rate or a first function therefor to facilitate or enable the production of a first density explosive composition, and during a successive second time interval (e.g., immediately after the first time interval) the set of sensitizing agents was introduced at a distinct or different second concentration/flow rate or a second function therefor to facilitate or enable the production of a distinct or different second density explosive composition, then:
In some embodiments, the at least one control system or control unit is configured for automatically managing, coordinating, or controlling the introduction and flow/conveyance of explosive composition constituents into and/or along (specific) portions of the system/apparatus, as well as the formulation or production and output of different-density explosive compositions in and/or among the set of boreholes in accordance with a blast plan, including wherein the control system is configured for automatically selectively managing, controlling, monitoring, establishing, changing, adjusting, modifying, and/or varying the concentration(s)/flow rate(s) of, or concentration/flow function(s) for, the set of sensitizing agents introducible or introduced at the sensitizing agent introduction site (away from the outlet structure of the conduit/hose) in a pre-scheduled manner with respect to the generation of a sequence or series of the in-conduit/in-hose masses, volumes, or inventories that will be output by the outlet structure to produce explosive compositions having intended densities or density profiles/distributions within one or more segments of individual boreholes/blastholes and/or across particular boreholes/blastholes, as indicated, established, or defined by the blast plan.
In some embodiments, the at least one control system or control unit is configured for following a borehole loading sequence involving a current borehole under consideration/being loaded and a next-in-sequence borehole to be loaded, including after loading a final or last segment of the current borehole under consideration with a final explosive composition having an intended or target density or density profile/distribution (e.g., a target in-hole average density for the final borehole segment), loading any remaining in-conduit/in-hose mass, volume, or inventory corresponding to this intended or target density or density profile/distribution into an initial or first segment of a next-in-sequence borehole to be loaded.
In some embodiments, the density or density profile/distribution of the final explosive composition (currently intended to be output or being output from the conduit/hose outlet structure into a final segment of a borehole currently being loaded) and the density or density profile/distribution of an initial explosive composition that will be output into the initial or first segment of the next-in-sequence borehole to be loaded can each be selected, set, established, defined (e.g., preset or predefined) as a (particular) default or neutral density (e.g., an identical or essentially identical neutral density) or neutral density value, or default or neutral density profile/distribution, respectively (wherein the default or neutral density is defined as an explosive composition density that can enhance or maximize the likelihood of or ensure reliable explosive composition detonation in a blasthole, e.g., following an explosive initiation event produced by a borehole-resident explosive initiation device that properly operates/initiates), wherein the default or neutral density, or neutral density value, or default or neutral density profile/distribution defines at least one presettable or preset sensitizer concentration/flow rate for the sensitizing agents, and/or a presettable or preset neutral density voidage of the explosive composition.
In some embodiments, the default or neutral density, or neutral density value, or default or neutral density profile/distribution includes: values of substantially 0.80-1.25 g/cc or g/cm3, including between substantially 0.90 and substantially 1.2 g/cc, including less than or equal to 1 g/cc, or substantially 1 g/cc.
In some embodiments, the control system or control unit and/or a blast design system (configured for generating the blast plan) is configured for automatically verifying and/or ensuring or requiring that when a final segment of a given borehole to be loaded is not intended to receive or is not capable of receiving the entire in-conduit/in-hose material contents between the sensitizing agent introduction site and the outlet structure, each of the final segment of the given borehole to be loaded as well as the first segment of a next borehole to be loaded will be or are loaded (e.g., in serial order) to include or contain an explosive composition having an identical neutral density, or using the same neutral density function (e.g., the same continuous neutral density function), such that a density of an uppermost amount of explosive composition in the given borehole/blasthole and the density of a lowermost amount of explosive composition in the next borehole to be loaded have the same or essentially the same neutral density value.
In some embodiments, the control system or control unit is configured to establish at the sensitizing agent introduction site at least one sensitizing agent concentration/flow rate or concentration/flow rate function that corresponds to or which will implement the selected explosive composition density or density profile/distribution, after the in-conduit/in-hose explosive composition constituents corresponding to the selected density or density profile/distribution have flowed away from the sensitizing agent introduction site through the conduit/hose and are output from the outlet structure thereof, based on one or more of:
In some embodiments, the control system or control unit maintains a given sensitizing agent concentration/flow rate or concentration/flow rate function across a selected/specified (e.g., automatically determined) time interval that will subsequently produce a target volume of explosive composition having the selected density or density profile/distribution across or along a target segment of the borehole when this explosive composition is output into the borehole, including optionally across or along a target length or depth of the borehole for boreholes having an approximately uniform or essentially constant diameter, wherein the target segment/target length of the borehole corresponds to or is specified by the blast plan data corresponding to this borehole.
In some embodiments, the control system or control unit is configured to utilize one or more mathematical functions and/or lookup table values to establish the sensitizing agent concentration/flow rate or function corresponding to the selected explosive composition density or density profile/distribution.
In some embodiments, the control system or control unit is configured for introducing or programmably/selectively/selectably introducing a set of void size stabilization agents at or into one or more (particular, structural) portions of an explosive composition loading system or apparatus (e.g., by way of at least one automatically actuatable/controllable valve and/or pump associated with at least one port), in a manner that introduces the set of stabilization agents into the explosive composition (which facilitates or enables improved or more reliable predictability or management/control, e.g., on a selective or programmable basis, of the size distribution(s) of sensitizing voids that will be or which are generated in the explosive composition by way of a set of sensitizing agents).
In some embodiments, the void size stabilization agent includes a chemical agent that facilitates void (e.g., gas bubble) size management, predictability, or controllability (e.g., by way of reducing or preventing void coalescence associated with or attributed to Ostwald ripening and/or diffusion).
In some embodiments, the void size stabilization agent include or is a surface-active chemical composition that is soluble in an organic phase and is capable of one or more of: lowering the interfacial tension of a fuel, enhancing foaming, and increasing foam stability in the organic phase (e.g., a surface-active chemical composition that can reduce surface tension within aqueous/organic interfaces in high internal phase water-in-oil emulsions), optionally including a fluoro-aliphatic esther (e.g., EXSOL (Energy extending SOLution) available through Orica International Pte Ltd (Singapore)).
In some embodiments, the void size stabilization agents are introduced at one or more void size stabilization agent introduction sites positioned before, essentially at or at, and/or after the (chemical) sensitizing agent introduction site.
Described herein is a method/process (for delivering or loading explosive compositions having with one or more programmably or selectably configurable densities or density profiles/distributions into boreholes, and for outputting into the borehole the explosive composition having the selected (e.g., programmably specified) density or density profile/distribution at the outlet structure of the conduit/hose) including: changing (including adjusting, modifying, or varying) a concentration/flow rate (which may be in accordance with a concentration/flow function, e.g., mathematical function or algorithm, such as a flow rate function) of a set of sensitizing agents (e.g., at least one chemical sensitizing agent, such as at least one chemical gassing agent) for an explosive composition, wherein the sensitizing agents are introduced at or into at least one (particular, structural) portion of an explosive composition loading system or apparatus (e.g., by way of a set of automatically actuatable/controllable valves and/or pumps associated with at least one port corresponding to the system or apparatus) in a manner that facilitates or enables (customizable, programmable, selectable, or variable) generation of two or more explosive compositions having at least one density profile/distribution (including across successive explosive composition sequences, e.g., corresponding to one or more borehole loading sequences), wherein the changing of the concentration/flow rate provides the sensitizing agents with a concentration profile/distribution within and along a conduit/hose during flow of the explosive compositions toward and prior to the explosive compositions reaching a distal end portion of the conduit/hose that is fluidically coupled to an outlet structure (of the conduit/hose), wherein the concentration profile/distribution corresponds to the density profile/distribution, (including such that multiple distinct segments of a given borehole and/or different boreholes across a multi-borehole array can have distinct or different programmably specified densities and/or density profiles/distributions).
Described herein is system/apparatus (for delivering or loading explosive compositions having with one or more programmably or selectably configurable densities or density profiles/distributions into boreholes) including: at least one control system or control unit configured for introducing or programmably/selectively/selectably introducing a set of void dimension/size stabilization agents at or into one or more (particular, structural) portions of an explosive composition loading system or apparatus (e.g., by way of at least one automatically actuatable/controllable valve and/or pump associated with at least one port), in a manner that introduces the stabilization agents into the explosive composition (which facilitates or enables improved or more reliable predictability or management/control, e.g., on a selective or programmable basis, of the size distribution(s) of sensitizing voids that will be or which are generated in the explosive composition by way of a set of (chemical) sensitizing agents).
In some embodiments, the void size stabilization agent includes a chemical agent that facilitates void (e.g., gas bubble) size management, predictability, or controllability (e.g., by way of reducing or preventing void coalescence associated with or attributed to Ostwald ripening and/or diffusion).
In some embodiments, the void size stabilization agent include or is a surface-active chemical composition that is soluble in an organic phase and is capable of one or more of: lowering the interfacial tension of a fuel, enhancing foaming, and increasing foam stability in the organic phase (e.g., a surface-active chemical composition that can reduce surface tension within aqueous/organic interfaces in high internal phase water-in-oil emulsions), optionally including a fluoro-aliphatic esther.
In some embodiments, the void size stabilization agents are introduced at one or more void size stabilization agent introduction sites that are optionally positioned before, essentially at or at, and/or after a sensitizing agent introduction site.
In some embodiments, each void size stabilization agent introduction site is located:
In some embodiments, the control system or control unit is configured for selectively or selectably (e.g., on a programmable basis) establishing, adjusting, or varying a concentration/flow rate or function of a set of void size stabilization agents that are introduced into the explosive composition or constituents thereof by way of at least one void size stabilization agent introduction site, such that explosive compositions output from the outlet structure of the conduit/hose can contain distinct or different void size stabilization agent concentrations and/or types, and different or distinct lengthwise segments of a given borehole/blasthole, and/or different boreholes/blastholes in a borehole/blasthole array can contain explosive compositions with distinct or different void size stabilization agent concentrations and/or types (e.g., on a selective or selectable basis).
In some embodiments, the control system or control unit is configured to manage or control concentration(s)/flow rate(s) or function(s) of a set of void size stabilization agents into the void size stabilization agent introduction site(s) at particular times, including in accordance with a blast plan
Described herein is a method/process (for delivering or loading explosive compositions having with one or more programmably or selectably configurable densities or density profiles/distributions into boreholes) including:
Some embodiments of the present invention are hereinafter further described with reference to the accompanying drawings in which the following figures appear.
The reference herein to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that such prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavor to which this specification relates. Herein, unless the context stipulates or requires otherwise, any use of the word “comprise,” and variations such as “comprises” and “comprising,” imply the inclusion of a stated element or procedure/step or group of elements or procedures/steps but not the exclusion of any other element or procedures/step or group of elements or procedures/steps. Reference to one or more embodiments, e.g., as various embodiments, many embodiments, several embodiments, multiple embodiments, some embodiments, certain embodiments, particular embodiments, specific embodiments, or a number of embodiments, need not or does not mean or imply all embodiments. Reference to a number of embodiments means at least one embodiment.
As used herein, the term “set” corresponds to or is defined as a non-empty finite organization of elements that mathematically exhibits a cardinality of at least 1 (i.e., a set as defined herein can correspond to a unit, singlet, or single element set, or a multiple element set), in accordance with known mathematical definitions (for instance, in a manner corresponding to that described in An Introduction to Mathematical Reasoning: Numbers, Sets, and Functions, “Chapter 11: Properties of Finite Sets” (e.g., as indicated on p. 140), by Peter J. Eccles, Cambridge University Press (1998)). Thus, a set includes at least one element. In general, an element of a set can include or be one or more portions of a structure, an object, a process, a composition, a physical parameter, or a value depending upon the type of set under consideration. The presence of “/” in a FIG. or text herein is understood to mean “and/or” unless otherwise indicated. The recitation of a particular numerical value or value range herein is understood to include or be a recitation of an approximate numerical value or value range, for instance, within +/−20%, +/−15%, +/−10%, +/−5%, +/−2.5%, +/−2%, +/−1%, +/−0.5%, or +/−0%. The term “essentially all” or “substantially” can indicate a percentage greater than or equal to 90%, for instance, greater than 92.5%, 95%, 97.5%, 99%, or 100%. The term “significant fraction” can indicate a percentage greater than or equal to 20%, for instance, greater than 25%, 50%, 75%, 80%, or 100%.
In the context of the present disclosure, reference to a selective and/or selectable basis and direct conceptual variations thereof (e.g., selectively/selectably defined) encompass a preferential or programmably specified, defined, established, or selected basis (e.g., an automatically or semi-automatically specified or selected basis, such as by way of a data processor, for instance, at least one microprocessor/microcontroller, configured for executing one or more memory-resident program instruction sets).
Herein, an energetic material or explosive composition can refer to a chemical composition that includes an oxidizer/oxidizing phase and a fuel phase, which can be explosively initiated and under appropriate conditions detonated. Depending upon embodiment details, the oxidizer/oxidizing phase an include or be a supersaturated solution of ammonium nitrate (AN) and/or one or more other oxidizing agents; and the fuel phase can include one or more types of oils, in a manner understood by individuals having ordinary skill in the relevant art. In various embodiments, a fluid or liquid energetic material/material composition or explosive composition can be analogous or correspond to or include or be an emulsion explosive composition (e.g., a water-in-oil or melt-in-oil emulsion explosive composition), such as an ammonium nitrate emulsion (ANE) based explosive composition that includes an emulsifier, and which can be fluidically conveyed or pumped, as individuals having ordinary skill in the relevant art will also understand. An emulsion explosive composition can include or be mixed with AN prills or ammonium nitrate fuel oil (ANFO), in a manner that individuals having ordinary skill in the relevant art further comprehend. Non-limiting representative types of emulsion explosive compositions suitable for use in various embodiments in accordance with the present disclosure are available from Orica International Pte Ltd, Singapore.
In order to render an emulsion explosive composition sensitive to explosive initiation/detonation, one or more types of sensitizing agents are introduced into and mixed with the emulsion explosive composition to produce a distribution of sensitizing voids therein, in a manner understood by individuals having ordinary skill in the relevant art. Depending upon embodiment details, sensitizing voids can be introduced or produced in an emulsion explosive composition by way of sensitizing agents, including chemical sensitizing agents (e.g., chemical gassing agents) and/or non-chemical sensitizing agents (e.g., solid sensitizing agents). Thus, the introduction or delivery of sensitizing voids into an emulsion explosive composition can include the introduction or delivery of (a) chemical sensitizing agents that produce gas bubbles in the emulsion explosive composition by way of chemical reaction(s); and/or (b) sensitizing agents per se (e.g., gas bubbles and/or hollow microspheres/microballoons that are directly introduced into the emulsion explosive composition).
Sensitization of an unsensitized explosive composition by way of introducing and/or producing sensitizing voids therein generates a sensitized explosive composition having a density that is less than that of the unsensitized explosive composition. Thus, the density of a void-sensitized (e.g., gas bubble sensitized) explosive composition decreases as an amount or quantity of sensitizing voids generated therein increases, as individuals having ordinary skill in the relevant art understand.
With respect to chemical sensitization, after a set of chemical sensitization agents or chemical gassing agents has been introduced into the emulsion explosive composition or constituents thereof and mixed therewith, chemical sensitization or gassing reactions occur over a period of time (e.g., between approximately 5-60 minutes depending upon embodiment details), as individuals having ordinary skill in the relevant art comprehend. For instance, one or more chemical gassing agents can be soluble in an inorganic oxidizer salt or discontinuous phase of an emulsion explosive composition, and can chemically react in the oxidizer salt phase under appropriate pH conditions to produce a dispersion of gas bubbles (e.g., nitrogen bubbles) distributed in the emulsion explosive composition, thereby producing an initially-sensitized emulsion explosive composition that becomes essentially fully-sensitized or fully-sensitized over a period of time (e.g., as such chemical reactions proceed to completion). When chemical gassing agents are used, sensitizing voids per se are not directly introduced or delivered into the emulsion explosive composition. Rather, droplets of chemical gassing solution(s) are introduced or delivered into the emulsion explosive composition, with chemical gassing of the emulsion explosive composition taking place subsequently (e.g., primarily or overwhelmingly after the emulsion explosive composition has been output from and no longer resides in an explosive composition loading system or apparatus) because the gas-generating reaction is not instantaneous. The effect is still essentially the same or the same in terms of achieving a desired distribution of voids in the sensitized emulsion explosive composition produced.
Sensitizing voids and/or chemicals that can react to produce sensitizing voids are typically introduced into an explosive composition in association with, during, or as part of loading the explosive composition into a borehole. Herein, the term “borehole” can refer to an elongate hole formed in or drilled into a portion of a geologic formation, which can be or is being loaded with an explosive composition (e.g., an initially-sensitized or preliminarily-sensitized explosive composition, which relative to chemical sensitization can be defined as an explosive composition that has had its chemical sensitizing agents thoroughly mixed and distributed therein, and which will thus become fully sensitized by way of chemical reactions while resident in the borehole) in association with a particular commercial blasting operation. The term “blasthole” can refer to a borehole that has been loaded with or at least partially loaded with an initially sensitized or sensitized explosive composition that can be explosively initiated/detonated. Each of a borehole and a blasthole includes an opening at a collar thereof; at least one cross-sectional area or diameter along an overall length or depth of the borehole or blasthole; and a toe portion corresponding or reaching to a terminal end of the borehole that establishes a maximum extent, length, or depth of the borehole or blasthole in the portion of the geologic formation in which the borehole or blasthole resides. Herein, the reference to an explosive composition density corresponding to a given portion, segment, or section of a borehole/blasthole can represent or be an average density for that borehole/blasthole portion, segment, or section, in a manner understood by individuals having ordinary skill in the relevant art.
As further elaborated upon below, for a given explosive composition and a particular set of sensitizing agents under consideration (e.g., which includes at least one chemical sensitizing agent), an explosive composition loading system in accordance with an embodiment of the present disclosure is configurable or configured for introducing, delivering, or injecting at a sensitization agent introduction site (e.g., a chemical sensitizing agent introduction site) the set of sensitizing agents (e.g., a set of chemical sensitizing agents) relative to or across a range of sensitizing agent concentrations/flows (e.g., chemical sensitizing agent concentrations/flow rates), for instance, between a first or minimum useable sensitization agent concentration/flow rate (e.g., which can produce a highest useable explosive composition density that is below the explosive composition's critical density) and a second or maximum useable sensitization agent concentration/flow rate (e.g., which can produce a lowest useable explosive composition density). In various embodiments, a set of sensitizing agents can include or be a set of chemical sensitizing agents, and can be referred to as such in the description herein for purpose of brevity and clarity. However, embodiments in accordance with the present disclosure need not be limited to chemical sensitizing agents; for instance, depending upon embodiment details, sensitizing voids can be produced by way of the introduction of gas bubbles (e.g., already-formed gas bubbles) and/or hollow microspheres/microballoons directly into an explosive composition or constituents thereof.
A blast/loading plan or design (e.g., which is generated by a blast/loading plan or design system configured for executing blast design software that includes program instruction sets which are executable by at least one data processing unit, such as a microprocessor, of the blast design system) can establish for each borehole/blasthole within an array of boreholes/blastholes a set of target explosive composition densities within individual boreholes/blastholes, and/or across boreholes/blastholes of the array, in a manner understood by individuals having ordinary skill in the relevant art.
Further in view of the foregoing, multiple embodiments in accordance with the present disclosure are applicable to fluidically conveyable or liquid explosive compositions other than emulsion explosive compositions, such as slurry, water gel, or suspension explosive compositions. However, for purpose of simplicity, brevity, and clarity, various portions of the description below focus on emulsion explosive compositions.
Embodiments in accordance with the present disclosure are directed to systems, apparatuses, methods, and processes for delivering, loading, or producing explosive compositions having programmably configurable/configured or selectably definable/defined physical or compositional characteristics or properties, such as programmably configurable/configured or selectably definable/defined densities and/or density profiles/distributions (e.g., multiple, several, or many distinct or different densities and/or density profiles/distributions), along or within distinct or different portions, segments, or sections of a borehole, and/or across at least some boreholes of a multi-borehole array. An intended density or profile/distribution of explosive composition(s) physical characteristics or properties (e.g., an intended density or density profile/distribution) within a given borehole, and/or across a multi-borehole array, can be established or defined (e.g., programmably defined or pre-defined) in accordance with a blast plan.
Explosive composition constituents or components (e.g., which can include an unsensitized or a partially-sensitized/semi-sensitized explosive composition) are combinable or combined or mixed (e.g., well-mixed/thoroughly mixed) such that they can be output or loaded into a borehole to produce an initially-sensitized or sensitized explosive composition (e.g., an initially-sensitized explosive composition that transitions to an essentially fully-sensitized or fully-sensitized explosive composition by way of chemical reactions that occur over a period of time). Explosive composition constituents can be conveyed (e.g., flowably and/or fluidically conveyed, for instance, by way of a pump) along an elongate conduit/hose structure (e.g., a set of conduits coupled to or which includes a flexible hose) toward an output or outlet structure of the conduit/hose structure, for instance, as the conduit/hose structure is withdrawn from a borehole (e.g., in association with borehole loading). The outlet structure is configured for outputting, dispensing, releasing, or ejecting the explosive composition, which includes explosive composition constituents that have been well-mixed/thoroughly with the set of sensitizing agents under consideration, into the borehole. The outlet structure includes a distal or terminal end portion having a distal or terminal output, and in various embodiments includes a mixing apparatus or device (e.g., at least one static mixer), for instance, which is disposed adjacent to or which forms a portion of its distal output, in a manner understood by individuals having ordinary skill in the relevant art. In some embodiments, the outlet structure (e.g., its distal output) can possibly include or correspond to a terminal narrow(ed) aperture or valve (e.g., a narrow(ed) exit aperture or valve, disposed post-mixer) configured for increasing explosive composition viscosity (e.g., by way of homogenization), for instance, as the explosive composition flows therethrough into the borehole, which individuals having ordinary skill in the relevant art will also comprehend. Hereafter, for purpose of brevity and clarity, a conduit/hose structure can simply be referred to as a conduit/hose.
Various embodiments in accordance with the present disclosure are configurable or configured for changing, adjusting, modifying, or varying a concentration/flow (e.g., flow rate) of, or a concentration/flow function (e.g., mathematical function or algorithm, such as a flow rate function) for, a set of sensitizing agents (e.g., at least one chemical sensitizing agent, such as at least one chemical gassing agent) introduced at or into at least one particular structural portion of an explosive composition loading system or apparatus (e.g., by way of a set of automatically actuatable/controllable valves and/or pumps associated with at least one port corresponding to the system or apparatus), in a manner that facilitates or enables the customizable, programmable, selectable, or variable generation of successive explosive composition sequences within and along a conduit/hose that have different sensitizing agent concentrations corresponding to different densities or density profiles/distributions, in association with or during the flow of the explosive composition toward the outlet structure of the conduit/hose. For purpose of brevity and simplicity, in the description hereafter a concentration/flow can be referred to as a concentration/flow rate, and a concentration/flow function can be referred to as a concentration/flow rate function. Once in the conduit/hose, the concentration/flow rate or the concentration/flow function defines a least one concentration profile/distribution corresponding to the desired/designed at least one density profile/distribution.
More particularly, in various embodiments:
1. The introduction of the set of sensitizing agents (e.g., a set of chemical sensitizing agents) occurs by way of at least one sensitizing agent introduction/injection site, location, or structure (e.g., at least one chemical sensitizing agent introduction site) that is away from the outlet structure of the conduit/hose (e.g., at least one chemical sensitizing agent introduction site is not proximate to the outlet structure of the conduit/hose, and can be one or more meters, such as multiple, several, many, tens, or multiple tens of meters away from the outlet structure depending upon embodiment details). Additionally/alternatively, the at least one sensitizing agent introduction/injection site, location, or structure may be out of the borehole when the conduit/hose is extended substantially into the borehole. Additionally/alternatively, the at least one sensitizing agent introduction/injection site, location, or structure may be closer to a collar of the borehole than to a toe of the borehole when the conduit/hose is extended substantially to the toe of the borehole.
For purpose of brevity and simplicity, the description hereafter considers a single sensitizing agent introduction site (e.g., a single chemical sensitizing agent introduction site), although certain embodiments can include multiple sensitizing agent introduction sites. For instance, the sensitizing agent introduction site can be (a) prior to, essentially at, or at a suction side or inlet or input of a pump by which explosive composition constituents, which can include the unsensitized or partially sensitized explosive composition, are conveyed; (b) just after, essentially at, or at a pump throat associated with or corresponding to an outlet or output of the pump; or (c) proximate to, essentially at, or at a pump-facing input coupling structure corresponding to the (flexible) conduit/hose, such as a rotary union structure relative to which the flexible hose can be coupled. The conduit/hose can be carried by or wound around a hose reel or wheel (e.g., a mechanized or automated hose reel) in a retractable/withdrawable manner, as individuals having ordinary skill in the art. The outlet structure of the conduit/hose can correspond to or be a distal or terminal end portion of the flexible hose, in a manner also understood by individuals having ordinary skill in the relevant art.
2. At the sensitizing agent introduction site, which is away from the outlet structure of the conduit/hose as set forth above, the set of sensitizing agents can be selectively introduced at different concentrations/flow rates, or in accordance with different concentration/flow rate functions, at respective different times, to provide the concentration profile/distribution in a manner intended or expected to serially or sequentially produce explosive compositions having different densities or density profiles/distributions. A given explosive composition density or density profile/distribution thus corresponds to a particular concentration/flow rate or concentration/flow rate function for the set of sensitizing agents during a particular time interval. For purpose of brevity and clarity, the sensitizing agent introduction site and the set of sensitizing agents can be referred to hereafter as the (chemical) sensitizing agent introduction site and the set of (chemical) sensitizing agents, respectively, without loss of generality or applicability to embodiments in which already-formed gas bubbles and/or solid sensitizing agents (e.g., microspheres/microballoons) are introducible or introduced at the sensitizing agent introduction site (or elsewhere within the system).
3. The introduction of the set of (chemical) sensitizing agents at its introduction site at different concentrations/flow rates, or in accordance with different concentration/flow rate functions, at different times gives rise to different lengthwise segments of conduit/hose material contents corresponding to different-density explosive compositions. Thus, in association with or during borehole loading operations in which the conduit/hose outlet structure outputs an explosive composition as the conduit/hose is withdrawn from a borehole, in response to at least one change in or adjustment to a concentration/flow rate or concentration/flow rate function of at least one (chemical) sensitizing agent at the (chemical) sensitizing agent introduction site, between the (chemical) sensitizing agent introduction site and the outlet structure of the conduit/hose, along the length of the conduit/hose at least two different along-conduit/along-hose or in-conduit/in-hose material contents or masses, volumes, or inventories of chemical compositions/substances/species or explosive composition products exist, each of which corresponds to (i) a specific (chemical) sensitizing agent concentration/flow rate or function therefor that was established at a particular prior time, and (ii) a distinct or different explosive composition density, density function, or density profile/distribution (e.g., a different average in-hole explosive composition density or density profile/distribution), which is correlated with the (chemical) sensitizing agent concentration/flow rate or function therefor. For purpose of brevity and simplicity, along-conduit/along-hose material contents or masses, volumes, or inventories can be referred to hereafter as in-conduit/in-hose material contents or masses, volumes, or inventories, respectively. Depending on the application/mine site/geology, and the types of blasts required, the density profile/distribution may be designed/selected to include: (i) a gradient, optionally including a monotonic increase in density to compensate for hydrostatic pressure in the borehole; (ii) a mathematical function with a non-zero average, including a sinusoidal function, a square wave function, or a triangular wave function, to provide customizable, programmable, selectable, or variable selection of velocity of detonation (VoD) in the sensitized explosive composition; and/or (iii) two or mutually distinct or different programmably specified densities corresponding to two or more respective rock types in the borehole or from the borehole to a next borehole.
4. If during a first time interval the set of (chemical) sensitizing agents was introduced at a first concentration/flow rate or a first function therefor to facilitate or enable the production of first density explosive composition, and during a successive second time interval (e.g., immediately after the first time interval) the set of (chemical) sensitizing agents was introduced at a distinct or different second concentration/flow rate or a second function therefor to facilitate or enable the production of a distinct or different second density explosive composition, then (i) a first lengthwise segment of the conduit/hose that is closer to the outlet structure carries a first in-conduit/in-hose mass, volume, or inventory corresponding to the first density explosive composition; and (ii) a second lengthwise segment of the conduit/hose, which is rearward of the first segment of the conduit/hose and hence further from the outlet structure and closer to the (chemical) sensitizing agent introduction site than the first segment of the conduit/hose carries a second in-conduit/in-hose mass, volume, or inventory corresponding to the second density explosive composition.
5. Thus, with respect to reaching and being output from the outlet structure of the conduit/hose, the first in-conduit/in-hose mass, volume, or inventory corresponding to the first density explosive composition physically and temporally leads the second in-conduit/in-hose mass, volume, or inventory corresponding to the second density explosive composition. Stated analogously, the second in-conduit/in-hose mass, volume, or inventory corresponding to the second density explosive composition physically and temporally lags the second in-conduit/in-hose mass, volume, or inventory corresponding to the first density explosive composition. Hence, the first in-conduit/in-hose mass, volume, or inventory corresponding to the first density explosive composition must be cleared from the conduit/hose before the second density explosive composition can be output from the outlet structure of the conduit/hose (e.g., before the second density explosive composition can be loaded into one or more boreholes). Stated analogously, until the first density explosive composition is cleared or entirely dispensed from the outlet structure (e.g., by way of loading the first density explosive composition into portions of at least one borehole), the second density explosive composition cannot reach and be output from the outlet structure.
6. An explosive composition loading system or apparatus in accordance with multiple embodiments of the present disclosure includes at least one control system or control unit configured for automatically managing, coordinating, or controlling the introduction and flow/conveyance of explosive composition constituents into and/or along specific portions of the system or apparatus, as well as the formulation or production and output of different-density explosive compositions in and/or among a set of boreholes, for instance, in accordance with a blast plan. In view of the foregoing, in various embodiments the control system is configured for automatically selectively managing, controlling, monitoring, establishing, changing, adjusting, modifying, and/or varying the concentration(s)/flow rate(s) of, or concentration/flow function(s) for, a set of (chemical) sensitizing agents introducible or introduced at a (chemical) sensitizing agent introduction site away from an outlet structure of a conduit/hose in a “forward looking” or “pre-scheduled” manner with respect to the generation of a sequence or series of in-conduit/in-hose masses, volumes, or inventories that will be output by the outlet structure to produce explosive compositions having intended densities or density profiles/distributions within one or more segments of individual boreholes/blastholes and/or across particular boreholes/blastholes, as indicated, established, or defined by the blast plan.
7. Further in view of the foregoing, with respect to a borehole loading sequence involving a current borehole under consideration/being loaded and a next-in-sequence borehole to be loaded, after loading a final or last segment of the current borehole under consideration with an explosive composition having an intended or target density or density profile/distribution (e.g., a target in-hole average density for the final borehole segment) is complete, any remaining in-conduit/in-hose mass, volume, or inventory corresponding to this target density or density profile/distribution will be loaded into an initial or first segment of a next-in-sequence borehole to be loaded, unless the borehole loading sequence is interrupted/delayed and such remaining in-conduit/in-hose material content is output elsewhere (e.g., and likely undesirably wasted, such as by way of being output onto the ground or into a waste explosive composition receptacle) before loading of the next-in-sequence borehole begins. Stated analogously, unless the entirety of the in-conduit/in-hose material contents between the (chemical) sensitizing agent introduction site and the outlet structure is loaded into the final segment of the current borehole, the first segment of the next-in-sequence borehole to be loaded will contain at least some explosive composition having the target density or density profile/distribution of the previously loaded borehole's final segment if the borehole loading sequence remains uninterrupted/undelayed, for instance, in accordance with an intended, desired, or planned (e.g., most time, material mass, and cost efficient) borehole loading sequence.
However, with respect to a given borehole to be loaded, the number and volumetric sizes of borehole segments along the borehole's length that are intended to be loaded with explosive compositions having distinct or different densities or density profiles/distributions may preclude loading the entirety of the in-conduit/in-hose material contents between the (chemical) sensitizing agent introduction site and the outlet structure into that borehole's final segment.
In various embodiments, (a) the density or density profile/distribution of an explosive composition currently intended to be output or being output from the conduit/hose outlet structure into a final segment of a borehole currently being loaded, and (b) the density or density profile/distribution of an explosive composition that will be output into the first segment of a next borehole to be loaded can each be selected, set, established, defined (e.g., preset or predefined) as a particular default or neutral density (e.g., an identical or essentially identical neutral density) or neutral density value, or default or neutral density profile/distribution, respectively. A default or neutral density can be defined as an explosive composition density that can enhance or maximize the likelihood of or ensure reliable explosive composition detonation in a blasthole (e.g., following an explosive initiation event produced by a borehole-resident explosive initiation device that properly operates/initiates).
Herein, for purpose of brevity a default or neutral density (e.g., a neutral density value) can simply be referred to as a neutral density. A particular neutral density can fall within an acceptable neutral density range. For instance, depending upon embodiment, situational, and/or explosive composition details, a neutral density can range between or fall within values of approximately or substantially 0.80-1.25 g/cc or g/cm3 (e.g., between substantially 0.90 and substantially 1.2 g/cc), inclusive, or less than or equal to 1 g/cc, or substantially 1 g/cc. In some embodiments, a neutral density is a programmable, selectable or presettable/preset density, such as a cup density that can be indicated/specified/confirmed by way of a user interface (e.g., established before explosive composition loading into a borehole and/or across a multi-borehole array begins). A concentration/flow rate for a set of (chemical) sensitizing agents that will produce a particular neutral density explosive composition (e.g., an explosive composition having a particular or specific neutral density that falls within an acceptable neutral density range) can be categorized or defined as a neutral density sensitizer concentration/flow rate. A presettable or preset neutral density value thus corresponds to a presettable or preset sensitizer concentration/flow rate. Additionally, a quantity or relative quantity of sensitizing voids within a neutral density explosive composition can be categorized or defined as a neutral density voidage. An explosive composition having a presettable or preset neutral density will thus correspond to or exhibit a presettable or preset neutral density voidage.
In various embodiments, the control system and/or a blast design system configured for generating the blast plan can be configured for automatically verifying and/or ensuring or requiring that when the final segment of a given borehole to be loaded is not intended to receive or is not capable of receiving the entire in-conduit/in-hose material contents between the (chemical) sensitizing agent introduction site and the outlet structure, each of the final segment of the given borehole to be loaded as well as the first segment of a next borehole to be loaded will be or are loaded (e.g., in serial order) to include or contain an explosive composition having an identical neutral density, or using the same neutral density function (e.g., the same continuous neutral density function), such that the density of an uppermost amount of explosive composition in the given borehole/blasthole and the density of a lowermost amount of explosive composition in the next borehole to be loaded have the same or essentially the same neutral density value. A consequence of this is that the toe of a borehole loaded with a neutral density explosive composition can or will typically have at least a small column of low(er) density explosive composition therein prior to loading one or more high(er) density additional explosive compositions (e.g., such as main explosive charge) above the borehole's toe, which can ensure enhanced or greater explosive composition initiation/detonation sensitivity in the toe of the borehole in or near which at least one explosive initiation device resides.
8. With respect to a given borehole under consideration, for outputting into the borehole an explosive composition having a selected (e.g., programmably specified) density or density profile/distribution at the outlet structure of the conduit/hose, based on at least some of: (a) current or most-recent system configuration data, including one or more of the set of (chemical) sensitizing agents under consideration; the explosive composition under consideration; the explosive composition's critical density or a highest usable (e.g., reliably detonable) density; a selected or preset neutral density or neutral density range for the explosive composition; a pump speed; a diameter of the flexible hose and/or outlet structure; and the diameter of the borehole; and (b) current or most-recent borehole data (e.g., borehole condition data), such as whether the borehole is a wet hole (e.g., contains water) or a dry hole, and a final/pre-loading blasthole depth measurement, the control system can establish at the (chemical) sensitizing agent introduction site at least one (chemical) sensitizing agent concentration/flow rate or concentration/flow rate function that corresponds to or which will implement the selected explosive composition density or density profile/distribution after the in-conduit/in-hose explosive composition constituents corresponding to the selected density or density profile/distribution have flowed away from the (chemical) sensitizing agent introduction site through the conduit/hose and are output from the outlet structure thereof. The control system can maintain a given (chemical) sensitizing agent concentration/flow rate or concentration/flow rate function across a selected/specified (e.g., automatically determined) time interval that will subsequently produce a target volume of explosive composition having the selected density or density profile/distribution across or along a target segment of the borehole, and more particularly, across or along a target length or depth of the borehole for boreholes having an approximately uniform or essentially constant diameter, when this explosive composition is output into the borehole. The target segment/target length of the borehole can correspond to or be specified by blast plan data corresponding to this borehole. The control system can utilize one or more mathematical functions and/or lookup table values to establish a (chemical) sensitizing agent concentration/flow rate or function therefor corresponding to the selected explosive composition density or density profile/distribution, in a manner understood by individuals having ordinary skill in the relevant art.
In addition or as an alternative to the foregoing, multiple embodiments in accordance with the present disclosure can be configurable or configured for introducing or programmably/selectively/selectably introducing a set of void size (or “dimension”) stabilization agents at or into one or more particular structural portions of an explosive composition loading system or apparatus (e.g., by way of at least one automatically actuatable/controllable valve and/or pump associated with at least one port), in a manner that introduces the void size stabilization agent(s) into an explosive composition and which facilitates or enables improved or more reliable predictability or management/control (e.g., on a selective or programmable basis) of the size distribution(s) of sensitizing voids that will be or which are generated in the explosive composition by way of the set of (chemical) sensitizing agents. A void size stabilization agent can be a chemical agent that facilitates void (e.g., gas bubble) size management, predictability, or controllability by way of reducing or preventing void coalescence associated with or attributed to “Ostwald ripening” and/or diffusion. In several embodiments, a void size stabilization agent can include or be a surface-active chemical composition, which is soluble in an organic phase and is capable of at least some of lowering the interfacial tension of a fuel, enhancing foaming, and increasing foam stability in the organic phase (e.g., a surface-active chemical composition that can reduce surface tension within aqueous/organic interfaces in high internal phase water-in-oil emulsions). The void size stabilization agent can be referred to as a bubble size stabilization agent or bubble stabilization enhancer (e.g., particularly in embodiments in which the sensitizing voids include or are gas bubbles), and can be of a form described in U.S. Pat. No. 4,594,118. In a non-limiting representative implementation, a suitable bubble size stabilization agent can include or be a fluoro-aliphatic esther, for instance, EXSOL (Energy extending SOLution) available through Orica International Pte Ltd (Singapore).
Depending upon embodiment details, the void size stabilization agent(s) can be introduced at one or more void size stabilization agent introduction sites positioned before, essentially at or at, and/or after the (chemical) sensitizing agent introduction site. In multiple embodiments, each void size stabilization agent introduction site is located away from and hence is not proximate to the outlet structure of the conduit/hose (e.g., each void size stabilization agent introduction site is one or more meters, such as multiple, several, many, tens, or multiple tens of meters away from the outlet structure, in a manner analogous to that described above). However, in at least some embodiments, at least one void size stabilization introduction site can be proximate to, essentially at, or at the outlet structure of the conduit/hose, in which case at least one void size stabilization agent can be introduced into explosive composition constituents or an explosive composition in an “end-of-hose” manner, such as by way of an end-of-hose conduit/hose structure (e.g., which can be analogous, similar, generally identical, or essentially identical to an end-of-hose conduit/hose apparatus, structure, or nozzle device such as that described in U.S. Pat. No. 6,397,754, which can be configured for receiving/carrying and introducing the void size stabilization agent(s) into an explosive composition proximate to or at the end of the conduit/hose).
In view of the foregoing, certain embodiments in accordance with the present disclosure are configurable or configured for selectively or selectably (e.g., on a programmable basis) establishing, adjusting, or varying a concentration/flow rate or function therefor of a set of void size (or “dimension”) stabilization agents which are introduced into an explosive composition or constituents thereof by way of at least one void size stabilization agent introduction site, such that explosive compositions output from the outlet structure of the conduit/hose can contain distinct or different void size stabilization agent concentrations and/or types, and different or distinct lengthwise segments of a given borehole/blasthole, and/or different boreholes/blastholes in a borehole/blasthole array can contain explosive compositions with distinct or different void size stabilization agent concentrations and/or types (e.g., on a selective or selectable basis). The control system can manage or control the concentration(s)/flow rate(s) or function(s) therefor of a set of void size stabilization agents into the void size stabilization agent introduction site(s) at particular times, for instance, in accordance with a blast plan. In embodiments in which one or more void stabilization agent introduction sites are located away from the outlet structure of the conduit/hose in a manner analogous to that set forth above, the control system is configurable or configured for managing or controlling the introduction of at least one void size stabilization agent into a set of void size stabilization introduction sites at particular times such that distinct or different lengthwise segments of the conduit/hose (e.g., which are also away from the outlet structure of the conduit/hose) can carry or contain distinct or different in-conduit/in-hose void size stabilization agent concentrations and/or types.
The following description details aspects of particular non-limiting representative embodiments of systems, apparatuses, and processes configurable or configured for loading explosive compositions into boreholes such that multiple distinct (e.g., distinguishable) or different segments of a given borehole and/or different boreholes across a multi-borehole/blasthole array can be loaded with or contain explosive compositions having corresponding distinct (e.g., distinguishable) or different physical or compositional characteristics or properties. Programmably or selectively/selectably defined explosive composition physical or compositional characteristics or properties can include programmably or selectively defined: (a) densities or density profiles/distributions, for instance, such that multiple distinct segments of a given borehole/blasthole and/or different boreholes/blastholes across a multi-borehole array can be loaded with or contain distinct or different programmably or selectably defined explosive composition densities or density profiles/distributions (e.g., where such borehole/blasthole segments and/or different boreholes/blastholes across the multi-borehole array correspond to different concentrations, concentration profiles, flow rates, or flow rate profiles of a set of sensitizing agents, such as one or more chemical sensitizing agents); and/or (b) void size stabilization agent concentration(s) and/or types, for instance, such that one or more segments of a given borehole/blasthole and/or different boreholes/blastholes across a multi-borehole array can be loaded with or contain one or more particular void size stabilization agent concentrations or types.
Further in view of the foregoing, in accordance with such systems, apparatuses, and processes, the loading of any particular borehole from the borehole's toe toward the borehole's collar with an explosive composition having distinct or different compositional characteristics (e.g., densities or density profiles/distributions) progressively occurs in an automated or semi-automated manner by way of a control system configurable or configured for facilitating or enabling the physical production and temporal sequencing of in-conduit/in-hose material contents which (a) correspond to distinct or different explosive composition physical characteristics (e.g., densities or density profiles/distributions), and (b) are away from and not proximate to the outlet structure of the conduit/hose (e.g., one or more meters, such as multiple, several, many, tens, or multiple tens of meters away from the outlet structure), such that specific distinct or different lengthwise segments of the conduit/hose that are away from the outlet structure can carry or contain explosive composition constituents corresponding to different or distinct explosive composition physical characteristics (e.g., densities or density profiles/distributions) which will be output into the borehole. Such physical and temporal sequencing of in-conduit/in-hose material contents can occur by way of the control system changing, adjusting, or establishing concentration/flow rates of or concentration/flow rate functions for (a) a set of (chemical) sensitizing agents, and/or (b) a set of void size stabilization agents at particular times.
Additionally, in accordance with embodiments of the present disclosure, the loading of a given borehole with an explosive composition is intended or expected to be directly followed by the loading of a next borehole (e.g., a next-in-sequence borehole) without an intermediate procedure in which remaining mass contents of the conduit/hose corresponding to the compositional characteristics (e.g., density or density profile/distribution) of the explosive composition loaded into the final segment of the given borehole would be emptied from the conduit/hose structure prior to the start of loading the next borehole. Such direct borehole-to-borehole loading can be facilitated or enabled under the direction of the control system by way of in-conduit/in-hose production of an explosive composition having a neutral density or neutral density profile, which is intended to be loaded into each of the final portion of a given borehole as well as the toe portion of a next-in-sequence borehole.
In an embodiment, the system 10 includes at least one AN/ANE source, reservoir, or vessel 100, such as an AN/ANE bin or hopper 100; possibly an additive bin or tank 110 and an associated additive feeder 112; in some embodiments a fuel oil tank 120 and an associated fuel oil pump 122; and in some embodiments a bubble size stabilization agent (BSSA) tank 130 and an associated BSSA pump 132, which are fluidically coupled such that AN/ANE, possibly one or more additives (e.g., aluminum powder and/or glass microspheres/microballoons), in some embodiments fuel oil, and in some embodiments a BSSA can be combined, mixed, or blended together to produce a first material stream 1010. Outputs of each of the fuel pump 122 and the BSSA pump 132 can be fluidically coupled to a first control valve apparatus/device 140. Outputs of each of the AN/ANE hopper 100, the additive feeder 112, and the first control valve apparatus/device 140 (e.g., a solenoid type valve device) can be coupled to inputs of a mixing or blending apparatus/device 145, and an output thereof can provide the first material stream 1010. In embodiments in which the additive tank 110 and the additive feeder 112 do not add or feed solid sensitizing agents (e.g., glass microspheres/microballoons) into the AN/ANE, the first material stream 1010 is unsensitized; and in embodiments in which the additive tank 110 and the additive feeder 112 add or feed solid sensitizing agents into the AN/ANE, the first material stream 1010 can be defined as partially-sensitized.
The system 10 also includes a first chemical gassing agent (CGA) tank 150 that carries or contains a first CGA or first CGA composition/solution (e.g., aqueous CGA solution); and a second CGA tank 154 that carries or contains a second CGA or second CGA composition/solution (e.g., aqueous CGA solution). The first and second CGAs, when thoroughly mixed with an explosive composition (e.g., an emulsion explosive composition), can chemically react therewith such that chemical gassing of the explosive composition occurs. In a non-limiting representative embodiment, the first CGA can include one or more ammonium species, such as ammonium chloride, ammonium nitrate, ammonium chlorate, ammonium sulphate, ammonium thiocyanate, or combinations thereof; and the second CGA can include one or more alkaline earth nitrite and/or alkali metal nitrite species, in a manner understood by individuals having ordinary skill in the relevant art. Each of the first CGA tank 150 and the second CGA tank 154 has an output coupled to a first CGA pump 152 and a second CGA pump 156, respectively. The first and second CGA pumps 152, 156 have outputs that are coupled to inputs of a second control valve apparatus/device 160 (e.g., another solenoid type valve device), which itself has an output that provides a second material stream 1020.
The system 10 further includes a product pump/mixer 170, which has an inlet 172 configured for receiving the first material stream 1010, and an input port/port structure 174 that corresponds to or which provides the CGA introduction site and which is thus configured for receiving the second material stream 1020. The product pump/mixer 170 is configured for pumping and typically to at least some extent mixing (e.g., progressively/further mixing) the first and second material streams 1010, 1020 as the pumped and progressively/further mixed first and second material streams 1010, 1020 are conveyed toward an output or outlet 176 of the product pump/mixer 170. Because the second material stream 1020 contains the first and second CGAs, as the first and second material streams 1010, 1020 are pumped and progressively/further mixed by the product pump/mixer 170, the first and second CGAs provided by the second material stream 1020 are mixed to at least some extent with the explosive composition constituents provided by the first material stream 1010 in the product pump/mixer 170.
The output 176 of the product pump/mixer 170 is fluidically coupled, such as by way of a coupling structure 210 (e.g., a rotary union structure) corresponding to a hose reel or hose wheel 200, to an input structure or input of a hose 300 for providing the pumped and at least somewhat mixed first and second material streams 1010, 1020 thereto. As indicated above, a distal or terminal end portion of the hose 300 is fluidically coupled to or includes an outlet structure that includes a mixer 310 (e.g., a static mixer). The mixer 310 is configured for thoroughly mixing the explosive composition constituents and the set of chemical gassing agents that pass therethrough, such that an initially or preliminarily sensitized explosive composition can be output from the outlet structure 310 and loaded into a borehole 5.
Portions of the hose 300 and the outlet structure, including the mixer 310, can be selectively/selectably lowered into and withdrawn from a borehole to facilitate loading of a sensitized explosive composition therein, in a manner understood by individuals having ordinary skill in the relevant art. In multiple embodiments, the hose 300 is carried by a hose reel or wheel 200, such that rotary motion of the hose reel 200 in a first direction facilitates or enables feeding portions of the hose 300 and the mixer 310 into a borehole 5 under consideration; and rotary motion of the hose reel 200 in an opposite second direction facilitates or enables retraction or withdrawal of the hose and the mixer 310 out of the borehole 5.
The system 10 additionally includes a control system or control unit 190 configured for managing or controlling the operation of the fuel oil pump 122, the BSSA pump 132, the first CGA pump 152, the second CGA pump 156, possibly or typically the first and second control valve apparatuses/devices 140, 160, and the product pump/mixer 170. The control system 190 can include at least one data processing unit (e.g., a microprocessor or microcontroller) and a memory wherein program instruction sets reside, which are executable by the data processing unit for managing or controlling the operation of such system components. The control system 190 can include one or more types of data/signal communication units, such as wireless signal communication units configured for wireless signal communication (e.g., radio frequency (RF) signal communication) with one or more other systems, such as a remote blast design/planning system by which blast plans can be generated and stored. The control system 190 can establish, select, or control pumping rates, including that of the product pump/mixer 170; and can facilitate or enable the management or control of the rotational speed (and direction) of the hose reel 200, for instance, such that hose withdrawal from the borehole 5 can be coordinated or matched with the rate at which the initially-sensitized explosive composition is loaded into the borehole 5 (e.g., corresponding to a current level or depth of borehole filling), in a manner understood by individuals having ordinary skill in the relevant art. The control system 190 can automatically or semi-automatically manage or control the system 10 such that individual boreholes 5 which are successively or serially loaded can contain explosive compositions having an approximately identical neutral density or neutral density profile/distribution with respect to a final loaded segment of a given blasthole 5 and a first loaded segment of a next successively or serially loaded borehole/blasthole 5, such as in a manner indicated above.
As indicated above, in alternative embodiments the sensitizing agent introduction site 174 can be located at or on different portions of the system 10. That is, the sensitizing agent introduction site need not be located at or on a portion of the product pump/mixer 170. For instance, the chemical agent introduction site 174 can be located proximate to or near the input of the hose 300, as further detailed hereafter.
As indicated in
In this representative borehole loading scenario, a first borehole 5a is to be loaded with, or is loaded with, four sequentially-introduced explosive composition product decks or segments S1-S4, which are contiguous with each other. That is, the first borehole 5a contains four explosive composition product segments identified as S1-S4 in Table 1. After the first borehole 5a has been loaded, a second borehole 5b is to be loaded with, or is loaded with, four sequentially-introduced explosive composition product decks or segments S5-S8, which are contiguous with each other; and after the second borehole 5b has been loaded, a third borehole 5c is to be loaded with, or is loaded with, four sequentially-introduced explosive composition product decks or segments S9-S12, which are contiguous with each other. Thus, the second borehole 5b contains four explosive composition product segments identified in Table 1 as S5-S8; and the third borehole 5c contains four explosive composition product segments identified as S9-S12 in Table 1. For each of segments S1-S12, Table 1 indicates the segment's loaded explosive composition mass; average along-segment or in-segment explosive composition density; and segment length or depth.
In this representative borehole loading scenario, the first, second, and third boreholes 5a-c are to be loaded with, or are loaded with, a chemically sensitizable or sensitized explosive composition by way of: (i) at a first in-field hose location (e.g., a second on-bench location), the introduction of a hose 200 into the first borehole 5a, and the output of initially-sensitized explosive compositions corresponding to segments S1-S4, which can differ in their particular selected or programmably specified densities, from an outlet portion of the hose 200 as the hose 200 is withdrawn from the first borehole 5a; (ii) at a second in-field hose location (e.g., a second on-bench location), the introduction of the hose 200 into the second borehole 5b, and the output of initially-sensitized explosive compositions corresponding to segments S5-S8, which can differ in their particular selected or programmably specified densities, from the outlet portion of the hose 200 as the hose 200 is withdrawn from the second borehole 5b; and (iii) at a third in-field hose location (e.g., a third on-bench location), the introduction of the hose 200 into the third borehole 5c, and the output of initially-sensitized explosive compositions corresponding to segments S9-S12, which can differ in their particular selected or programmably specified densities, from the outlet portion of the hose 200 as the hose 200 is withdrawn from the third borehole 5c.
In this representative borehole loading sequence, each borehole 5a-5c can be a wet hole (e.g., each borehole 5a-5c contains at least some water); each borehole 5a-c is to be loaded with an emulsion explosive composition that is sensitized by way of a set of chemical sensitizing agents (e.g., in a manner indicated above); and each borehole 5a-5c is defined to have a diameter of 229 millimeters (mm). Additionally, the neutral density for each borehole 5a-5c corresponds to or is selected or set as a cup density of approximately 0.9 g/cc, which can be defined as a neutral cup density. A representative hose withdrawal rate from each borehole 5a-c can be approximately 0.2 m/s.
Each individual borehole 5a-5c has an overall explosive composition loading length or depth corresponding to the cumulative length or depth of the individual segments S within that borehole 5a-5c. Per Table 1, the overall explosive composition loading length or depth of the first and second boreholes 5a,b is approximately 20.6 meters (m), and the overall explosive composition loading length or depth of the third borehole 5c is approximately 20.5 m.
Based on Table 1, the first borehole 5a can be defined to have an overall target explosive composition density across all of its segments S1-S4 (e.g., where the overall target density can be defined as an average density across the entirety of segments S1-S4) of approximately 1.04 g/cc. For instance, an overall target explosive composition density for the first borehole 5a can be defined or calculated as ((3.8 m*1.15 g/cc)+(6.8 m*1.02 g/cc)+(8.0 m*1.02 g/cc)+(2.0 m*0.99 g/cc))/(3.8 m+6.8 m+8.0 m+2.0 m)=approximately 1.04 g/cc. Similarly, the second borehole 5b can be defined to have an overall target explosive composition density across all of its segments S5-S8 of approximately 1.04 g/cc. The third borehole 5c can be defined to have an overall target explosive composition density across all of its segments S9-S12 of approximately 1.22 g/cc.
As indicated in
Aspects of System Operation Associated with the Representative Borehole Loading Scenario
In association with positioning or transferring the hose 200 at hose location 1 corresponding to the first borehole 5a, the control system 190 initiates or directs the manufacture of an explosive composition using settings that facilitate or enable the generation of an explosive composition product that fills the in conduit/in-hose explosive composition product inventory, which includes the explosive composition product inventory extending between the chemical sensitizing agent introduction site 174 and the full length of the hose 200 (e.g., up to or including the mixer 310 at the outlet structure of the hose 200). In this representative blasthole loading scenario, this in-conduit/in-hose explosive composition product inventory in the product pump/mixer 170 plus the hose 200 totals to approximately 178 kg and is manufactured to have a neutral cup density of approximately 0.90, which “primes” the system 10 with an initial explosive composition product inventory from the chemical sensitizing agent introduction site 174 to the output end of hose 200. This initial or as-primed explosive composition product inventory is intended to be delivered into the first segment S1 of the first borehole 5a. The hose 200 is lowered down into the first segment S1 of the first borehole 5a accordingly.
The control unit 190 changes the flow rate(s) of the set of chemical sensitizing agents from the neutral density in response to the predicted physical conditions and expected pressures to establish/maintain the target density corresponding to the second segment S2 in the first blasthole 5a. The control unit 190 begins to produce the required mass of explosive composition product within the system 10 for the second segment S2 in the first borehole 5a as (i) the hose is progressively withdrawn through the first segment S1 in the first borehole 5a, and (ii) the previously manufactured neutral density product is delivered into the first segment S1 in the first borehole 5a. It can be noted that an explosive composition product having a neutral cup density can have a different (e.g., higher or significantly higher) in-segment borehole-resident density due to the effects of hydrostatic pressure, in a manner understood by individuals having ordinary skill in the relevant art. By the time the initial explosive composition product inventory of 178 kg manufactured to have a neutral cup density has been delivered into the first segment S1 in the first borehole 5a and the first segment S1 in the first borehole 5a is completely loaded, approximately 178 kg of the explosive composition product destined for and ready for loading into the second segment S2 in the first borehole 5a will have been manufactured within the system 10, and thus will have filled the product pump/mixer 170 and the hose 200, and is accordingly ready for delivery into the second segment S2 of the first borehole 5a.
As indicated in Table 1, the control system 190 is configured to direct the manufacture of approximately 284 kg of explosive composition product having an average in-segment density of approximately 1.02 g/cc for the second segment S2 in the first borehole 5a. As described above, approximately 178 kg of explosive composition product had been manufactured as of the completion of the loading of the first segment S1 in the first borehole 5a. As the hose 200 is progressively withdrawn from the first borehole 5a along and through the second segment S2 thereof, the explosive composition product destined for this second segment S2 accordingly begins to be delivered into the first borehole 5a. While this is being performed, the control system 190 directs the further manufacture of approximately 106 kg of explosive composition product at unchanged, most-current, or same addition rate(s) or flow rate(s) for the set of chemical gassing agents, and directs the delivery of this additional 106 kg of explosive composition product into the second segment S2 of the first borehole 5a. In this representative borehole loading scenario, with a hose withdrawal rate of approximately 0.2 m/s, the full loading of Segment 2 will be accomplished in approximately 1.5 seconds. Once the total mass of approximately 284 kg required for the second segment S2 in the first borehole 5a has been manufactured within the system 10, the control system 190 again changes the chemical gassing agent addition or flow rate(s) in response to the predicted physical conditions and expected pressures to establish/maintain the target density of 1.02 g/cc for the third segment S3 in the first borehole 5a, and the explosive composition product corresponding to this third segment S3 accordingly begins to be manufactured within the system 10.
Table 1 above indicates that a total of approximately 336 kg of explosive composition product should be manufactured for the third segment S3 of the first borehole 5a. In a manner similar or analogous to that described above with respect to loading the second segment S2 of the first borehole 5a, approximately 178 kg of explosive composition product destined for and ready for loading into the third segment S3 of the first borehole 5a has been manufactured within the system 10 by the time the loading of the second segment S2 of the first borehole 5a has been completed. The hose 200 is progressively withdrawn through the third segment S3 of the first borehole 5a, and explosive composition product for this third segment S3 begins to be delivered therein. While this is being performed, the control system 190 directs the manufacture of approximately 158 kg of additional explosive composition product at an identical, most-current, or same chemical sensitization agent addition or flow rate, and continues to direct the delivery of such additional explosive composition product into the third segment S3 of the first borehole 5a. Once the total mass of approximately 336 kg required for this third segment S3 has been manufactured within the system 10, the control system 190 again changes the addition or flow rate(s) of the set of chemical sensitization agents in response to the predicted physical conditions and expected pressures to establish/maintain the target density for the fourth segment S4 of the first borehole 5a, and the required mass of product destined for this fourth segment S4 begins to be produced at those conditions as the hose 200 is progressively withdrawn through the third segment S3 of the first borehole 5a.
The flow rates of the chemical sensitisation agent in this example, and in others disclosed herein, may be calculated based on the gas voidage present (Vg) at a position within each deck, and the gas voidage (Vg) may be calculated based on the in-hole density (ρ) of the deck and the volume of solid in the explosive matrix (Vm) as indicated in equation below, where the basis for the calculation is 1 kg of explosives product:
The amount of gas moles (Ng) available within the aforementioned volume (Vg) may calculated using the ideal gas law as follows:
where (R) is the universal gas constant, Kco=273.15 K and (g) is the gravitational constant (ms−2).
The absolute pressure, P, may be calculated at the point of interest in the blasthole, accounting for hydrostatic effects of explosives products, and any stemming materials.
The moles of gas partitioning into the oil and aqueous phase may be calculated using the Henry's law equations, including:
where:
The total moles of gas Nt available at the above location may be then calculated by adding the moles dissolved in the aqueous and oil phase due to the hydrostatic pressure based on the following relationship:
Since the chemical sensitising agent is added on the surface, it is desired to deduct the gas moles that will be dissolved in the aqueous and oil phase under atmospheric conditions, which is achieved by substituting Patm for P in Eq 3 & 4 to obtain Naqs, Noils and final gas moles Nf as indicated below:
The mass flow delivery rate of the gasser (%gasser) may be then calculated by converting molar flow rates in Eq 6 via the applicable molecular weight and the composition of the sensitising agent.
The gasser flow rate for the position within the deck may be then calculated based on the following relationship:
where {dot over (m)}bulk is the mass flow rate of the bulk product (kg/min), and {dot over (m)}gasser is the mass flow rate of the gasser flow (kg/min).
The uppermost explosive product composition segment in the first borehole 5a, i.e., the fourth segment S4 of this borehole 5a, is intended to contain explosive composition product manufactured to have a neutral cup density. Such an explosive composition product can: (i) act as a layer that resists floating in water when in-situ; (ii) be used safely for “top up” requirements, if needed; and, since the within-system or system-resident explosive product inventory of approximately 178 kg is greater than the as-designed or intended explosive product composition mass of approximately 82 kg for the fourth segment S4 of the first blasthole 5a Segment 4, (iii) be used to load some of the explosive composition product that will be pumped into the fifth segment S5 at the toe or base of the second borehole 5b.
In a manner similar or analogous to that described above for loading the third segment S3 of the first borehole 5a, approximately 178 kg of the neutral density (e.g., neutral cup density) product has been manufactured by the time the loading of the third segment S3 of the first borehole 5a has been completed. The hose 200 is progressively withdrawn through the fourth segment S4 of the first borehole 5a the neutral density explosive composition product begins to be delivered therein. However, the blast plan calls for only approximately 82 kg of this neutral density explosive composition product to be delivered into the fourth segment S4 of the first borehole 5a. Thus, when the total explosive composition product mass of approximately 82 kg for this fourth segment S4 has been delivered therein, the loading of the first borehole/blasthole 5a with explosive composition product is complete. It should be understood that while the delivery of approximately 82 kg of explosive composition product into the fourth segment S4 of the first blasthole 5a is being performed, additional explosive composition product has been manufactured at the identical, most-current, or same chemical sensitizing agent addition or flow rate(s), leaving a within-system inventory of approximately 178 kg of neutral cup density explosive composition product. The hose 200 is removed from Location 1 corresponding to the first borehole 5a; moved to Location 2 corresponding to the second borehole 5b; and lowered into the second borehole 5b and positioned in the fifth segment S5 thereof.
Approximately 178 kg of explosive composition product manufactured to have a neutral cup density should be delivered into Segment 5. With respect to the explosive composition product manufacturing activities described above with reference to loading the fourth segment S4 of the first blasthole 5a, upon the completion of loading this fourth segment S4, there is a full within-system explosive composition product inventory that was manufactured to have a neutral cup density. The control system 190 thus changes the addition or flow rate(s) for the set of chemical sensitizing agents in response to the predicted physical conditions and expected pressures to establish/maintain the target density for the sixth segment S6 in the second borehole 5b, and the required mass of explosive composition product will begin to be produced at these manufacture conditions (eventually totaling approximately 284 kg as indicated in Table 1), as the hose 200 is progressively withdrawn through the fifth segment S5 in the second borehole 5b, thereby delivering the 178 kg of neutral density explosive composition product into and completing the loading of the fifth segment S5 in the second borehole 5b.
At the commencement of the loading of the sixth segment S6 of the second borehole 5b, the within-system explosive composition product inventory is approximately 178 kg, which has been manufactured in accordance with the set of chemical sensitizing agent addition or flow rate(s) that will or which is expected to produce the in-segment density corresponding to this sixth segment S6. The hose 200 is progressively withdrawn through this sixth segment S6, and the explosive composition product destined for this sixth segment S6 begins to be delivered therein. The blast plan for this sixth segment S6 requires approximately 284 kg of explosive composition product, so while the first 178 kg of explosive composition product is being delivered into this sixth segment S6, the control system 190 oversees the further manufacture of approximately 106 kg of explosive composition product at the identical, most-recent, or same chemical sensitization agent addition or flow rate(s), and the continued delivery of such explosive composition product into the sixth segment S6 of the second borehole 5a. Once the total explosive composition product mass of approximately 284 kg for this sixth segment S6 has been manufactured, the control system 190 again changes the addition or flow rate(s) of the set of chemical sensitizing agents in response to the predicted physical conditions and expected pressures to establish/maintain the target density for the seventh segment S7 of the second borehole 5b, and explosive composition product for this seventh segment S7 will accordingly begin to be manufactured within the system 10 to fill the within-system inventory.
Table 1 indicates that approximately 336 kg of product should be manufactured for the seventh segment S7 of the second borehole 5b. In a manner similar or analogous to that described above with respect to loading the sixth segment S6 of the second borehole 5b, approximately 178 kg of explosive composition product destined for and ready for loading into the seventh segment S7 of the second borehole 5b has been manufactured within the system 10 by the time the loading of the sixth segment S6 of the second borehole 5b has been completed. The hose 200 is progressively withdrawn through the seventh segment S7 of the second borehole 5b, and explosive composition product manufactured for this seventh segment S7 begins to be delivered therein. While this is performed, the control system 190 directs the further manufacture of approximately 158 kg of explosive composition product with the identical, most-current, or same addition or flow rate(s) for the set of chemical sensitizing agents, and oversees the continued delivery of this approximately 158 kg of explosive composition product into the seventh segment S7 of the second blast hole 5b. Once the total explosive composition product mass for the seventh segment S7 of the second borehole 5b has been manufactured in-system, the control system 190 gain changes the addition or flow rate(s) for the set of chemical sensitization agents in response to the predicted physical conditions and expected pressures to establish/maintain the target density for the eighth segment S8 of the second borehole 5b, and the required mass of explosive composition product of approximately 82 kg corresponding to this eighth segment S8 begins to be produced within the system 10 at these manufacturing conditions as the hose 200 is progressively withdrawn through the seventh segment S7 of the second borehole 5b.
The uppermost explosive product composition segment in the second borehole 5b, i.e., the eighth segment S8 of this borehole 5a, is intended to contain approximately 82 kg of explosive composition product that was manufactured to have a neutral cup density, in a manner analogous to that described above with respect to the fourth segment S4 of the first borehole 5a. As per the blast/loading plan or design, once the total explosive composition product mass of approximately 82 kg for the eighth segment S8 of the second borehole 5b has been manufactured within the system 10, the control system 190 adjusts or changes the addition or flow rate(s) of the set of chemical sensitizing agents to manufacture approximately 178 kg of explosive composition product that will or is expected to provide an in-hole average density for the ninth segment S9 of the third borehole 5c of approximately 1.22, as indicated in Table 1. After the aforementioned 82 kg of explosive composition has been delivered into the eighth segment S8 of the second borehole 5b, the loading of the second borehole/blasthole 5b with explosive composition product is complete, and the within-system inventory is approximately 178 kg of explosive composition product that has been manufactured to produce an in-hole average density of that indicated in Table 1 for the ninth segment S9 of the third borehole 5c. The hose 200 is removed from Location 2 corresponding to the second borehole 5b; moved to Location 3 corresponding to the third borehole 5c; and lowered into the third borehole 5c and positioned in the ninth segment S9 thereof.
Approximately 178 kg of explosive composition product should be delivered into the ninth segment S9 of the third borehole 5c. From description above directed to the loading of the eight segment S8 of the second borehole 5b, there is a full within-system inventory of approximately 178 kg of explosive composition product in the system 10, which has been manufactured such that it will or is expected to produce an average in-hole density within the ninth segment S9 of the third borehole 5c of approximately 1.22. The design intent in this case is for a higher density product to be delivered to the toe of the third borehole 5c, i.e., into the ninth segment S9 thereof, with higher level of compression compared to that the first segment S1 at the toe of the first borehole 5a and the fifth segment S5 at the toe of the second borehole 5b, and as such a shorter segment length is noted. Upon the start of delivery of the approximately 178 kg of explosive composition product into the ninth segment S9 of the third borehole 5c, the control system 190 adjusts or changes the addition or flow rate(s) of the set of chemical sensitization agents in response to the predicted physical conditions and expected pressures to establish/maintain the target density for the tenth segment S10 of the third borehole 5c, and the required mass of explosive composition product destined for this tenth segment S10 will begin to be produced within the system at those manufacturing conditions.
It should be noted that the blast/loading plan or design stipulates or calls for a total of approximately 150 kg of explosive composition product in the tenth segment S10 of the third borehole 5c, which is approximately 28 kg less than of the within system explosive product inventory quantity of approximately 178 kg, so the control system 190 once again adjusts or changes the addition or flow rate(s) for the set of chemical sensitizing agents to correspond to the density for the eleventh segment S11 of the third borehole 5c after the approximately 150 kg of explosive composition product destined for the tenth segment S10 of the third borehole 5c has been manufactured in-system. The hose 200 is progressively withdrawn through the ninth segment S9 of the third borehole 5c during delivery of approximately 178 kg of explosive composition product having the indicated in-hole density therein, which completes the loading of this ninth segment S9.
At the commencement of the loading of the tenth segment S10 of the third borehole 5c, the within-system inventory is approximately 150 kg of the explosive composition product for this tenth segment S10, plus approximately 28 kg of explosive composition product destined for the eleventh segment S11 of the third borehole 5c. The hose 200 is progressively withdrawn through the tenth segment S10 of the third borehole 5c, and the explosive composition product manufactured and destined for this tenth segment S10 is delivered therein. While the total mass of approximately 150 kg of explosive composition product for this tenth segment S10 is being delivered, the control unit 190 continues to direct the production of explosive composition product under the density conditions corresponding to the explosive composition product destined for the eleventh segment S11 of the third borehole 5c. Upon completion of the loading of the tenth segment S10 of the third borehole 5c, the within-system system inventory is approximately 178 kg of explosive composition product that has been manufactured for providing the in-hole target density for the eleventh segment S11 of the third borehole 5c.
Table 1 indicates that a total mass of 350 kg of explosive composition product should be manufactured for the eleventh segment S11 of the third borehole 5c. As indicated above with reference to the tenth segment S10 of the third borehole 5c, approximately 178 kg of explosive composition product destined for the eleventh segment S11 of the third borehole 5c has been manufactured within the system 10 by the time the loading of the tenth segment S10 of the third borehole 5c has been completed. The hose 200 is progressively withdrawn through the eleventh segment S11 of the third borehole 5c and explosive composition product manufactured for delivery into this eleventh segment S11 begins to be delivered therein. While this is performed, the control system 190 directs the further manufacture of approximately 172 kg of explosive composition product at the identical, most-recent, or same addition or flow rate(s) for the set of chemical sensitizing agents, where this approximately 172 kg of additional explosive composition product will continue to be delivered into the eleventh segment S11 of the third borehole 5c. When the total explosive composition product mass of approximately 350 kg for this eleventh segment S11 has been manufactured in-system, the control system 190 again adjusts or changes the addition or flow rate(s) for the set of chemical sensitizing agents in response to the predicted physical conditions and expected pressures to establish/maintain the target density for the twelfth segment S12 of the third borehole 5c, and the required mass of explosive composition product destined for this twelfth segment S12 begins to be produced in the system at the appropriate manufacturing conditions as the hose 200 is progressively withdrawn through the eleventh segment S11 of the third borehole 5c.
The uppermost segment of the third borehole 5c, i.e., the twelfth segment S12 of this borehole 5c, is intended to contain approximately 350 kg of explosive composition product having an in-segment average density of approximately 1.22 g/cc. In this representative blasthole loading scenario, this uppermost segment need not or does not contain an explosive composition product that was manufactured to have a neutral cup density. For instance, in this situation the blast/loading plan or design need not or does not anticipate an explosive composition product manufactured to have a neutral cup density to be loaded into the base or toe of a subsequent borehole. It may be desirable for the completion of the loading of the twelfth segment S12 of the third borehole 5c to at least generally coincide with emptying of the within-system explosive composition product inventory to reduce or minimize waste handling issues.
Per the blast/loading plan or design, the total explosive composition product mass of approximately 350 kg for the twelfth segment S12 of the third borehole 5c is manufactured at a density that is not limited by the need to correspond to or operate at the neutral density, but can support other design intentions or needs (such as a particular target as-delivered energy level). The hose 200 is removed from Location 3 once the required explosive composition product mass has been delivered into the twelfth segment S12 of the third borehole/blasthole 5c, and the loading sequence is thus complete.
It can be noted that in some embodiments, additional or other manners of establishing or adjusting/changing the amount and/or mass of within-system explosive composition product inventory, such as changing hose geometry (length and/or diameter), changing hopper geometries, and/or changing pump volumes can be employed, in a manner understood by individuals having ordinary skill in the relevant art.
As indicated above, in certain embodiments the control system 190 can also be configured for selectively or programmably establishing or adjusting/changing the introduction of a set of void size stabilization agents (e.g., a BSSA) into explosive composition products that are delivered into a borehole 5 or across a multi-borehole array. For instance, Table 2 indicates blast/loading plan or design parameters corresponding to Table 1, which further include BSSA percentages for the selective establishment or adjustment of particular percentages (e.g., mass percentages as set forth above) of BSSA introducible or introduced into different segments S1-S12 of the first through third boreholes 5a-c corresponding to the representative borehole loading scenario described above.
The control system 190 can be configured for establishing or adjusting the introduction of the BSSA into the explosive composition product corresponding to each of borehole segments S1-S12 in accordance with the BSSA percentages set forth in Table 2.
With reference to the example from Table 2, it is possible to selectively or programmably adjust the delivery of void size stabilization agents to affect the blast performance of the explosive. Using Segment S1 within Borehole ID 5a as an example, the graph in
In contrast, if the similar product is loaded using void size stabilization agents corresponding to Condition (2), (3.1), or (3.2) from the graph of
It is known in the art that for similar conditions of bulk density of emulsion-based explosives, changes in void bubble length can influence the Velocity of Detonation (VoD) of the bulk explosive within blast holes, e.g., as described in Hattori et al. (Hattori, K., Fukatsu, Y., and Sakai, H., (1982), “Effect of the Size of Glass Microballoons on the Detonation Velocity of Emulsion Explosives,” J. Ind. Explos. Soc. Japan 43, 295-309); Edamura, et al. (Edamura, K., Hirosaki, Y., Sakai, K., Hattoriand, K., and Sakurai, T, (1985) “Effect of Balloon Size on Detonation Velocity of Water-in-Oil Emulsion Explosives,” Nippon Oil and Fats Co., Ltd., Japan); and/or Lee (Lee, J., (1987), The Effect of Microballoon size on Detonation Behaviour of Emulsion Explosives, MSc-Metallurgy Thesis, New Mexico Institute of Mining and Technology, Socorro, New Mexico, April 1987). While the specific relationship between void bubble length and VoD is influenced by factors such as the type of material being blasted (e.g., the confinement), the VoD can monotonically and non-linearly decrease with increasing void bubble length. For the comparison in the above example in Segment S1 between Conditions 1 and 3 (void bubble length from 380 μm to 80 μm), VoD could conservatively increase from approximately or substantially 5.0 km·s−1 at 380 μm to approximately or substantially 5.5 km·s−1 at 80 μm2.
One industry measure of explosive performance in blastholes is the borehole pressure (Pb) or explosion pressure, e.g., as described in Rustan, A., (Ed), (2011), Mining and Rock Construction Technology Desk Reference—Rock Mechanics, Drilling, Blasting, CRC Press/Balkema, Leiden, The Netherlands, p 50. For similar conditions of bulk density of emulsion-based explosives, it would be further understood that Pb is proportional to VoD2. Consequently, for the example described above, a Pb in S1 based on the predicted VoD at 80 μm void bubble length would be 21% higher than the Pb for the 380 μm void bubble length. The value of the ability to vary the borehole pressure within blastholes by selectively or programmably adjusting the in-situ void bubble length, through the manipulation of the void size stabilization agents, and therefore affect the blast performance of the explosive, would be evident to blast designers.
In view of the description herein and the FIGs. corresponding thereto, an explosive composition loading system, apparatus, or process/method can be configured for selectively or programmably (a) manufacturing explosive composition products (i) corresponding to different sensitizing agent concentrations/densities, and/or (ii) having different BSSA concentrations/percentages therein as distinct, distinguishable, or different within-system or system-resident explosive composition product inventories (e.g., distinct, distinguishable, or different in-conduit/in-hose explosive composition product inventories, which are disposed relative to each other along a conduit/hose in a sequential, serial, or in-line adjacent manner); and (b) sequentially or serially delivering such within-system or system-resident explosive composition product inventories into different segments of a given borehole 5 and/or into different boreholes 5 across a multi-borehole array. An explosive composition loading system, apparatus, or process/method can further be configured for (c) manufacturing within-system or system-resident explosive composition product inventory having a neutral density (e.g., a neutral cup density), and delivering such neutral density explosive product inventory into each of an uppermost portion of a given borehole to be loaded or being loaded as well as a lowermost portion of a sequentially or serially next borehole to be loaded (e.g., such that upon completion of the loading of the given borehole, the loading of the sequentially or serially next borehole can begin or occur without purging such within-system or system-resident explosive composition inventory from the conduit/hose prior to the loading of the sequentially or serially next borehole).
The above description details aspects of particular systems, apparatuses, devices, methods, processes, and procedures in accordance with particular non-limiting representative embodiments of the present disclosure. It will be readily understood by a person having ordinary skill in the relevant art that modifications can be made to one or more aspects or portions of these and related embodiments without departing from the scope of the present disclosure.
The present application is related to U.S. Patent Application No. 63/239,546, filed in the United States of America on 1 Sep. 2021, the originally filed specification of which is hereby incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/SG2022/050636 | 9/1/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63239546 | Sep 2021 | US |
