Mining system

Information

  • Patent Grant
  • 6796616
  • Patent Number
    6,796,616
  • Date Filed
    Wednesday, June 26, 2002
    22 years ago
  • Date Issued
    Tuesday, September 28, 2004
    20 years ago
Abstract
A method for extracting mineral deposits. First, a predetermined surface is contour mined in a mineral seam, such as a mountain, to provide an elongate active mining area and a highwall. Next, a sealable intake and return canopy is placed at substantially opposing ends of the mineral seam. A continuous miner then successively cuts a mineral seam in the elongate active mining area. Roof supports are advanced after each respective successive cut to support a roof of the elongate active mining area. After formation of an air seal and introduction of a conveyor in the elongate active mining area, either longwall or shortwall mining techniques may be used to cut a face of the mineral seam via a miner. Material cut from the face of the mineral seam is then discharged onto the conveyor. The intake and return canopies are then configured to allow ventilation of the active mining area by the introduction of air along the face of the mineral seam while the miner advances along the mineral seam. The roof supports and conveyor are advanced into the mineral seam after cutting, with the material cut being conveyed to an area outside of the active mining area. The miner is then removed, reverse-oriented, and re-inserted into the active mining area to allow further cutting of the mineral seam.
Description




FIELD OF THE INVENTION




The present invention relates, in general, to a mining system for extracting mineral deposits, and more specifically, but without limitation, to a mining system utilizing a combination of surface contour mining and underground shortwall or longwall mining systems.




BACKGROUND OF THE INVENTION




Conventional surface mining systems have devastating environmental results. In hilly or mountainous regions, surface contour mining is accomplished by removing timber and clearing the area to be mined, making a strip cut to form a substantially horizontal bench and a vertical highwall that exposes the seam of mineral deposits to be removed. Another technique is to simply remove the entire top portion of the mountain to extract the minerals deposited below.




Underground mining systems are less damaging to the environment, but more costly and inefficient with lower production rates. When underground mining systems are used to extract mineral or coal deposits from a mineral or coal reserve


10


, the reserve


10


is divided into panels


12


as shown in

FIG. 1

which are laid out and developed for both shortwall mining and longwall mining operations. Coal reserves conducive to mining adjacent parallel panels (Panels


1


to


8


as shown in

FIG. 1

) are most desirable because they facilitate panel development and allow shorter equipment moves. As can be seen, the panels


12


are generally rectangular in shape having gate entries


14


(a headgate and tailgate) extending along each length, and are all connected at one end by main entries


16


. In modern mining systems, these panels


12


are developed using continuous miner units. In modern longwall mining systems, panels typically range from 400 to 1200 feet in width and from 4,000 to 15,000 feet in length. In modern shortwall mining systems, the shortwall panels typically range from 100 to 200 feet in width and from 2,000 to 4,000 feet in length. Production of coal or other sedimentary deposits begins at one end of the panel


12


, the starter entry


18


, to mine the seam along its face or wall in the direction indicated by the arrow


19


.




Referring more specifically to

FIG. 2

, panel


1


of

FIG. 1

is shown in more detail as panel


20


having headgate entries


22




a-c


, collectively the headgate


22


, and the tailgate entries


24




a-c


, collectively the tailgate


24


, referred to above. While the direction of mining proceeds in the direction indicated by the arrow


19


, production or plowing of the coal always proceeds from the headgate


22


to the tailgate


24


in the direction shown by the arrow


25


for both longwall and shortwall mining systems as will be described below in more detail. A “three-entry” development system utilizes the three maingate entries


16




a-c


, collectively the maingate


16


, the three headgate entries


22




a-c


, and the three tailgate entries


24




a-c


that are commonly used to provide the necessary airways and escapeways and other functions. The system permits installation of belt and track in the center entry, and allows one outer entry to be used as a return airway. This system is complex and expensive to develop, and is well-known in the mining business.




Upon completing development of the panels


12


, the longwall or shortwall mining of the panel


20


commences as shown in

FIGS. 3 and 4

, respectively. Referring more specifically to

FIG. 3

, longwall machinery


30


and miners are protected by roof supports


32


,


33


designed to withstand tremendous overburden pressures. The material containing the minerals is cut from the face of the seam by a plough or shearer


34


of the longwall machinery


30


and drops onto an armored chain conveyor system (not shown) for transport to a main conveyor system


36


, which in turn transports the material to the surface. As successive cuts are made along the face of the seam from the headgate


22


to the tailgate


24


in the direction of production indicated by the arrow


25


, the roof supports


32


,


33


and armored chain conveyor are advanced into the seam in the direction of mining indicated by the arrow


19


, allowing the overburden to collapse or cave-in behind the roof supports


32


,


33


to form what is known as a gob


38


of loosely-packed material. The roof supports


32


,


33


not only advance in the mining direction, but also are extendable as known in the art with the supports


32


being shown in the extended configuration and the supports


33


being shown in the retracted configuration.




Referring more specifically to

FIG. 4

, shortwall machinery


40


and miners are also protected by roof supports


42


,


43


designed to withstand tremendous overburden pressures. Unlike the longwall miner which ploughs the seam parallel to its face, a shortwall miner cutting head


44


of the shortwall machinery


40


which is approximately 10 to 12 feet in width plows in a direction generally perpendicular to the face of the seam and drops the material onto an armored chain conveyor system (not shown) for transport to a main conveyor systems


46


, which in turn transports the material to the surface. As successive cuts are made along the face of the seam from the headgate


22


to the tailgate


24


in the direction of production indicated by the arrow


25


, the roof supports


42


,


43


and armored chain conveyor are advanced into the seam in the direction of mining indicated by the arrow


19


, allowing the overburden to collapse or cave behind the roof supports


42


,


43


forming the gob


48


. The roof supports not only advance in the mining direction as shown by supports


42




a


and


42




b


, but also are extendable as known in the art with supports


42


being shown in the extended configuration and supports


43


being shown in the retracted configuration. The shortwall mining system requires significantly less capital and is more flexible in handling geological conditions that vary through the mineral reserve. The only significant disadvantage of the shortwall mining system is that the production rate is somewhat lower as compared to the longwall mining system.




It should be apparent from the above, the primary problem associated with underground longwall and shortwall mining systems is the cost and time associated with developing and creating the panels, and then moving either system from panel to panel underground to mine the entire mineral reserve


10


. The moves from panel to panel result in many days of downtime at a high cost to the mining operation. The ingress and egress entries and ventilation associated with the system are all expensive. Time travel to the seam face for the miners is also a significant cost associated with these systems.




Moreover, federal legislation (e.g., Clean Water Act) restricts the use of waste rock produced by large scale surface mining systems as “fill material” legitimately disposed of at other locations. Recent court decisions have held that excess spoil generated by mining operations is waste that does not qualify as fill material that can disposed of as valley fills. Thus, the disposal of excess spoil is a significant problem.




SUMMARY OF THE INVENTION




Apparatus and method for extracting mineral deposits is provided by combining surface contour mining with underground longwall or shortwall mining techniques. More specifically, such apparatus and method uses surface contour mining to create a staging bench and highwall for inserting either shortwall or longwall mining equipment into the seam of a mineral reserve to commence a continuous mining operation without the need for developing separate underground panels. The highwall formed at the point of insertion, the insertion highwall, extends between opposing highwalls formed on either side of the insertion highwall and generally in parallel to the direction of production and perpendicular to the direction of mining. A continuous miner is used to develop a starter entry cut into the seam extending along the entire length of the insertion highwall. Roof supports are advanced into the starter entry cut as formed by the continuous miner across the insertion highwall, and are then covered with spoil as they advance into the starter entry cut to form a starter passage sealed at both ends by a canopy. The longwall or shortwall mining commences inside the starter passage moving in either direction between the opposing highwalls that operate as “endgates” and function as either a headgate or a tailgate for the mining system depending upon the direction of production travel.




The above-identified problems are solved because the mining system is easily inserted, accessed and extracted from the surface by means of stable opposing highwalls and bench area created by contour surface mining. In addition to reducing the move time, such apparatus and method nearly eliminates travel time of the miners to the face of the seam and eliminates the need for developing panels and entries to the panels. Ingress and egress entries and ventilation entries are all much simpler and more efficient because they are provided at the opposing highwalls formed above ground on the bench rather than underground moving with successive passages formed therebetween by the face of the seam, the roof support, and the gob as the mining progresses into the seam.




Additionally, the mining operation is not restricted to production from the headgate to the tailgate, but can be adapted to move back and forth in both directions between the opposing highwalls on both sides of the ridge or mountain with full seam extraction across the entire length of the face. This eliminates the need for development entries and permanent roof supports and simplifies face ventilation. Furthermore, roof supports can be easily added or removed from the mining system to accommodate changes in the face width of the entire mineral deposit of the mineral reserve. The instant invention also reduces the volume of excess spoil that must be disposed of as a result of the mining operation.











BRIEF DESCRIPTION OF THE DRAWINGS




A more complete understanding of the method and apparatus of the present invention may be obtained by reference to the following Detailed Description when taken in conjunction with the accompanying Drawings wherein:





FIG. 1

is a top plan view of an exemplary mineral reserve layed out in parallel panels;





FIG. 2

is an enlarged top plan view of one of the panels of the mineral reserve of

FIG. 1

;





FIG. 3

is an enlarged top plan, partial view of the panel of

FIG. 2

after the commencement of longwall mining;





FIG. 4

is an enlarged top plan, partial view of the panel of

FIG. 2

after the commencement of shortwall mining;





FIG. 5

is an enlarged top plan view of the mining system according to one embodiment of the present invention;





FIG. 5A

is a cross-sectional view taken along line


5


A—


5


A of

FIG. 5

;





FIG. 6

is an enlarged top plan view of the mining system of

FIG. 5

during an initial setup and equipment insertion phase according to one embodiment of the present invention;





FIG. 6A

is a cross-sectional view taken along line


6


A—


6


A of

FIG. 6

;





FIGS. 7A and 7B

are respective front and side views of an embodiment of an intake canopy; and





FIGS. 8A and 8B

are respective front and side views of an embodiment of an exhaust canopy.





FIG. 9

is a top plan view of an initial production phase according to one embodiment of the present invention, which follows the initial setup and equipment insertion phase of

FIG. 6

;





FIG. 9A

is a cross-sectional view taken along line


9


A—


9


A of

FIG. 9

;





FIG. 10

is a top plan view of an exemplary initial system reversal phase according to one embodiment of the present invention, which follows the initial production phase of

FIG. 9

;





FIG. 10A

is a cross-sectional view taken along line


10


A—


10


A of

FIG. 10

;





FIG. 11

a top plan view of a full production phase according to one embodiment of the present invention, which follows the initial system reversal phase of

FIG. 10

;





FIG. 11A

is a cross-sectional view taken along line


11


A—


11


A of

FIG. 11

;





FIG. 12

is a top plan view of an equipment extraction phase according to one embodiment of the present invention, which follows the full production phase of

FIG. 11

;





FIG. 12A

is a cross-sectional view taken along line


12


A—


12


A of

FIG. 12

;





FIG. 13

is a top plan view of an embodiment of the present invention utilizing a longwall miner; and





FIG. 13A

is a cross-sectional view taken along line


13


A—


13


A of FIG.


13


.











DETAILED DESCRIPTION OF THE PRESENT INVENTION




The present invention provides an economical, convenient mining system adapted to quickly and efficiently remove mineral deposits from a mineral reserve with minimal downtime Apparatus and methods for extracting the mineral deposits are provided by combining surface contour mining with underground longwall or shortwall mining techniques. Referring more specifically to a mineral reserve


501


in

FIG. 5

, the mining system of the present invention utilizes surface contour mining to create a stable highwall


502


and bench area


503


around the mineral reserve


501


to allow insertion of the mining system underground. The surface contour mining, however, is conducted in stages commencing with mining area A between lines a and a′, then mining area B advancing to lines b and b′, followed by subsequent surface contour cuts advancing in increments of about 200 feet to 500 feet for each mining area to the end of the mineral reserve


501


. The bench area


503


is typically between 80 to 100 feet wide.




Referring also to

FIG. 5A

, the mining system commences by using surface contour mining to make the initial surface contour cut in mining area A by creating (i) a bench for supporting mining equipment, the staging bench


510


, and (ii) a stable highwall to allow insertion of the equipment into a seam


504


of the mineral reserve


501


underground, the insertion highwall


520


, to commence a continuous mining operation without the need for developing separate underground panels


12


(see FIG.


1


). Although a longwall or shortwall mining system can be used, a shortwall continuous mining operation is disclosed in complete detail, and a longwall mining operation is disclosed (

FIGS. 13 and 13A

) to the extent different from the shortwall operation. Material excavated from the initial cut in mining area A will be disposed of on an existing bench or used as excess spoil fill. The height of the insertion highwall


520


may be about 40 feet with a safety bench


530


cut above the insertion highwall


520


. It is important that this initial cut be laid out as straight as possible to eliminate any problems with equipment insertion underground.




Referring back to

FIG. 5

, the insertion highwall


520


is generally perpendicular to the direction that the mining will advance as indicated by the arrow M and generally parallel to the direction of mineral production as indicated by the double arrow P. With respect to shortwall mining, the cutting bits of the shortwall miner will be oriented in a direction generally perpendicular to arrow M. The initial surface contour cut includes a stable highwall and bench area on both sides of the staging area, i.e., the bench


550


and opposing highwall


555


on one side, and the bench


560


with opposing highwall


565


on the other side. The insertion highwall


520


extends between the opposing highwalls


555


,


565


. Although the system as described above proceeds generally in the direction indicated by arrow M, in certain situations, it may be necessary to shift the direction of production P may need to change as indicated by the double arrow P′ so that the production path is as short as possible. The opposing highwalls


555


,


565


are still generally perpendicular to the shifted direction of mining as indicated by the arrow M′. It is appreciated that this system provides for shifts in relatively any direction, and therefore is completely adaptable to the changes in the mineral seam


504


in a selected region. Because the system is designed for quick relocation, a user can appreciate the advantages of the present system.




As the mining system advances into the mineral seam


504


(FIG.


5


A), with changes in production direction being implemented in a manner as described above when necessary, contour mining continues in advance of production until the end of the mineral seam


504


is reached. The contour mining establishes an exit bench


590


, which has been formed in accordance with the principles discussed above with respect to the staging bench


510


. An equipment extraction highwall


540


has also been formed, and is made in accordance with the insertion highwall


520


and shown in FIG.


5


A. As the miner makes its final cut through the mineral seam


504


, the mining equipment is removed from the mineral reserve


501


in a manner described in more detail below. Note that the entire mineral reserve


501


does not have to be completed (i.e., the mining operation could commence with mining area A and move to mining area Z to avoid any destruction of mining area X in accordance with ordinary mining design methods).




Referring now to

FIGS. 6-12A

in general, there is shown differing phases for the use of the mining system according to the principles of the present invention as described above and utilizing exemplary shortwall mining techniques. Referring specifically to

FIG. 6

, a top plan view of the initial setup and equipment insertion phase


600


for an exemplary shortwall mining system is shown. A staging bench


610


is first formed after contour mining the mineral seam


604


in accordance with the principles discussed above. An equipment staging area


615


is formed at an insertion highwall


620


. As described above, the contour mining includes a stable highwall, which are also referred to as endwalls, and bench area on both sides of the equipment staging area


615


, i.e. the bench


650


and highwall


655


on one side, and the bench


660


and highwall


665


on the other side. The opposing highwalls


655


,


665


in the area being mined operate as endgates, and may function as either a headgate or a tailgate, described hereinabove, for the mining system depending on the direction of production travel. This is an important advantage, as the invention described herein eliminates the necessity of independent headgates or tailgates required by prior art systems, which reduces mining costs considerably. A power substation


670


may be set up in the equipment staging area


615


to provide power to various parts of the system.




In the equipment insertion phase


600


, a continuous miner


675


makes initial cuts in the mineral seam


604


to form a starter entry


680


. After several successive cuts are made beginning at the starter entry


680


, and moving from one highwall


655


to the opposing highwall


665


, an insertion passage


685


is formed. Shield carrier


672


is allowed to insert roof supports


674


behind the area mined by the continuous miner


675


. The roof supports


674


are shown in the equipment staging area


615


after being placed in the starter entry


680


and starter passage


685


, and also ready for placement by the shield carrier


672


. An intake canopy


700


and an exhaust canopy


800


are placed at the substantially opposing highwalls


655


,


665


as defined by the insertion highwall


620


.




Mine spoil


720


developed during creation of the access benches


650


,


660


is placed on and around the roof supports


674


to complete the formation of the starter passage


685


. This use of excess mine spoil


720


, which effectively seals the starter passage


685


and creates a ventilation pathway within the starter passage


685


eliminates the need to transport the mine spoil


720


to disposal locations. This expedient use of the mine spoil


720


complies with recent court decisions, particularly those involving the Clean Water Act, by providing an immediate use for the mine spoil


720


, as opposed to prior systems which typically dispose of mine spoil


720


within valley fills. Accordingly, an immediate benefit of the present invention is to eliminate the need for disposal locations by placement and use of the mine spoil


720


generated during the mining process.




Referring now to

FIG. 6A

, a cross-section of the phase


600


taken along lines


6


A—


6


A of

FIG. 6

is shown. The staging bench


610


is shown formed below the equipment insertion highwall


620


. A safety bench


630


is shown formed adjacent the equipment insertion highwall


620


and the existing mountaintop


601


. The mine spoil


720


is shown surrounding the starter passage


685


adjacent the roof supports


674


as the continuous miner


675


(

FIG. 6

) completes cuts between the highwall


655


and opposing highwall


665


(FIG.


6


). The mine spoil


720


creates an effective seal of the starter passage


685


, which allows proper ventilation of the starter passage


685


and successive cuts into the mineral seam


604


. Roof supports


674


are shown in the starter passage


685


adjacent to the mineral seam


604


and supporting the safety bench


630


in the area adjacent the equipment insertion highwall


620


. As can be seen, the roof supports


674


have been advanced into the area mined by the continuous miner


675


(FIG.


6


).




Referring now to

FIGS. 7A-7B

, and

FIGS. 8A-8B

, the intake canopy


700


and exhaust canopy


800


are shown in exemplary front and side views, respectively. The placement of the intake canopy


700


and exhaust canopy


800


during mining operations facilitates ventilation during operation of the present invention, and provides a convenient location for insertion and removal of the continuous miner


675


, and also provides for safe ingress and egress into the mining area as required by the Mine Safety and Health Administration (MSHA). Accordingly, it is preferable that both the intake canopy


700


and exhaust canopy


800


allow air to flow between the intake canopy


700


and exhaust canopy


800


in order to facilitate ventilation of the area between the intake canopy


700


and exhaust canopy


800


.




The intake canopy


700


includes a roof


750


, preferably comprised of steel plating, support columns


755


coupled to the roof


750


, at least one door


760


for sealing the canopy


700


. The door


760


may be coupled to the intake canopy


700


via hinges


765


or other suitable coupling means. A base


770


is coupled to the columns


755


opposite the roof


750


. A mining belt


775


may be coupled to the doors and extending along the base


770


to facilitate an air seal during operation to insure proper ventilation. The exhaust canopy


800


includes a roof


812


, preferably comprised of steel plating, a base


814


, and columns


816


coupling the roof


812


to the base


814


. In certain preferred embodiments, the columns are I-beams comprised of steel. Likewise, the roof


812


and base


814


may be I-beams for structural integrity.




Although not specifically shown, the exhaust canopy may include doors in a manner described above. Because the intake canopy


700


, exhaust canopy


800


, and mine spoil


720


(

FIGS. 6 and 6A

) create an effective air seal, the intake canopy


700


and, if desired, the exhaust canopy


800


may be provided with a reversible ventilation fan such that the direction of ventilation may be reversed or re-oriented depending on the production direction. The ventilation fan is described in more detail hereinbelow.




Referring now to

FIG. 9

, a top plan view of an initial production phase


900


, which follows the initial setup and equipment insertion phase


600


for the exemplary mining system of

FIG. 6

is shown. In the instant production phase


900


, the starter passage


685


has been completed and mine spoil


720


has been placed in the manner described above to form an air seal between substantially opposing highwalls


655


,


665


. A ventilation fan


910


is shown attached to the intake canopy


700


to effectively ventilate the cutting area between the intake canopy


700


and exhaust canopy


800


. A conveyor system


920


is shown at one end of the roof supports


674


for conveying mined material to the exhaust canopy


800


, and is coupled to a second conveyor system


930


for transport of the mined material to an outside stockpile


940


. The intake canopy


700


and exhaust canopy


800


are shown advanced forward along the outside of the mineral seam


604


relative to

FIG. 6

, but such advancement is not required during this phase


900


. The continuous miner


675


advances into the mineral seam


604


and moving from one highwall


655


to the opposing highwall


665


. The roof supports


674


behind the continuous miner


675


advance from highwall


655


in the direction indicated by arrow M after the continuous miner


675


has advanced into mineral seam


604


towards highwall


665


in the direction indicated by arrow P


1


. The continuous miner


675


may have a boom


950


or the like to transport mined material to the conveyor system


920


. The mine spoil


720


has been placed along substantially opposing highwalls


655


,


665


at the immediate area previously mined during creation of the starter passage


685


, and after advancement of the intake canopy


700


and exhaust canopy


800


.




Referring now to

FIG. 9A

, a cross-section of the phase


900


taken along line


9


A—


9


A of

FIG. 9

is shown. The mine spoil


720


is shown surrounding the roof supports


674


to facilitate the formation of the air seal along the equipment insertion highwall


620


and between opposing highwalls


655


,


665


, which allows the ventilation fan


910


to effectively ventilate the area between the intake canopy


700


and the exhaust canopy


800


(FIG.


9


).




Referring now to

FIG. 10

, a top plan view of the second production phase


1000


, which follows the initial production phase


900


of

FIG. 9

is shown. In this phase


1000


, gob


1010


behind the roof supports


674


has collapsed in the area behind the roof supports


674


. The continuous miner


675


has progressed through the mineral seam


604


to the exhaust canopy


800


at the endgate area adjacent highwall


665


to complete a first production passage


1020


, and, turned around as designated by the dashed-line path R, and has re-entered the mineral seam


604


for a second production cut in the direction of arrow P


2


. Because the mining equipment does not need to be removed and repositioned at highwall


655


due to the innovations of the present invention, significant cost savings and efficiency increases are realized through the elimination of downtime, the reduction in manpower, and the existing location for beginning of the second production cut indicated by arrow P


2


. In accordance with these advantages, the exhaust canopy


800


has been moved from position A to position B to account for the first production cut (

FIGS. 10 and 10A

) through the mineral seam


604


. The roof supports


674


behind the continuous miner


675


have advanced into the mineral seam


604


in the direction indicated by arrow M to support the roof in the area behind the continuous miner


675


. The ventilation fan


910


is reversed upon re-entry of the continuous miner


675


to facilitate ventilation in the proper direction. Mine spoil


720


continues to be placed along the opposing highwalls


655


,


665


in the area recently mined to maintain the air seal.




Referring now to

FIG. 10A

, a cross-section of the second production phase


1000


taken along line


10


A—


10


A of

FIG. 10

is shown. The original air seal created by the mine spoil


720


is shown in the same position relative to the equipment insertion highwall, however, the gob


1010


is shown collapsed behind the roof supports


674


. The collapse of the gob


1010


behind the roof supports


674


further facilitates formation of an air seal between the intake canopy


700


and exhaust canopy


800


adjacent the mineral seam


604


where the continuous miner


675


is operating. In this regard, it can be appreciated that no mountaintop removal is required, as the mountaintop collapses to form the gob


1010


, with strata above the gob


1010


bending or breaking but not completely collapsing, thereby eliminating the need to transport portions of the mountaintop that are removed in prior systems. This in combination with continual use of the mine spoil


720


as the continuous miner


675


advances into the mineral seam


604


equates to tremendous reductions in environmental impact, yet complete or almost complete recovery of the mined material.




Referring now to

FIG. 11

, a top plan view of a continuing production phase


1100


, which follows the second production phase


1000


of

FIG. 10

is shown. The continuous miner


675


has advanced significantly into the mineral seam


604


at this point of the phase


1100


in the direction indicated by arrow M. Production occurs in the direction of the line indicated by arrow P


x


. Mine spoil


720


has been used to backfill the equipment insertion highwall


620


adjacent the equipment staging area


615


and along opposing highwalls


655


,


665


up to the area recently mined to allow reclamation of the mining area with minimal environmental impact. The backfilling will continue as the continuous miner


675


advances further into the mineral seam


604


. For example, in this phase


1100


mine spoil


720


has been placed along opposing highwalls


655


,


665


to facilitate formation of the air seal and deposit the fill material thereby allowing recovery in short


200


′ to


500


′ sections to approximate original contour without creating waste. Accordingly, recent legislative and judicial decisions restricting the types of waste created no longer apply to the present invention, unlike prior systems. The present invention thus accounts not only for mountaintop removal waste through the allowability of gob collapse behind areas recently mined by the continuous miner


675


, but also accounts for mine spoil


720


created by providing a placement and use which improves mining efficiency and production. The intake canopy


700


and exhaust canopy


800


have each been advanced along substantially opposing highwalls


655


,


665


of the mineral seam


604


. The gob


1010


has formed due to overburden collapse rather than removal and fill, as required in prior systems in the areas behind the roof supports


674


recently mined by the continuous miner


675


, thereby offering significantly less environmental impact than prior systems.




Referring now to

FIG. 11A

, a cross-section of the continuing production phase


1100


taken along line


11


A—


11


A of

FIG. 11

is shown. The gob


1010


, which represents material that did not have to be removed during the mining operation is shown as collapsed in the area behind the roof supports


674


. The continuous miner


675


, roof supports


674


, and conveyor system


920


are shown as advanced into the mineral seam


604


in the direction indicated by arrow M.




Referring now to

FIG. 12

, a top plan view of an equipment extraction phase


1200


, which follows the continuing production phase


1100


of

FIG. 11

is shown. In the extraction phase


1200


, the continuous miner


675


has reached an equipment extraction highwall


540


, adjacent an equipment extraction area


590


between endgate


1210


and endgate


1220


. The canopies


700


,


800


have been advanced to endgates


1210


,


1220


to assist in ventilation and removal and repositioning of the continuous miner


675


. During this phase


1200


, the continuous miner


675


makes its final cut through the mineral seam


604


and exits the mineral seam


604


via the exhaust canopy


800


. It is contemplated that the orientation of the final cut may be reversed, depending on the size of the mineral seam


604


and the position of the continuous miner


675


in the next-to-last cut. The gob


1010


is completely collapsed and re-fills the recently mined area, and mine spoil


720


continues to be used to reclaim the area recently mined. Strata above the gob


1010


may break and bend, but does not completely collapse. In fact, when viewed from the surface, external surfaces of the mountaintop show little to no signs of underground mining operations conducted in accordance with the principles of the present invention. The power substation


670


has advanced with the continuous miner


675


to provide a continuous power supply to the system. It can clearly be seen that the removal of the continuous miner


675


may be achieved with little effort due to the location of the intake canopy


700


, exhaust canopy


800


, and methods as described above. Tremendous cost savings and increases in production efficiency are thus achievable with little to no environmental impact.




Referring now to

FIG. 12A

, a cross-section of the phase


1200


taken along line


12


A—


12


A of

FIG. 12

is shown. The roof supports


674


are shown supporting the equipment extraction highwall


540


and safety bench


1230


during the final cut and removal of the continuous miner


675


, conveyor


920


and roof supports


674


.




Referring specifically to

FIG. 13

, a top plan view of an first production cut


1300


for an exemplary longwall mining system is shown. As described above, the longwall mining system shares many similarities to the shortwall mining system discussed above. For example, prior to the first production cut


1300


, a staging bench


1310


is first formed after contour mining the mineral seam


1304


in accordance with the principles discussed above. An equipment staging area


1315


is formed at an insertion highwall


1320


. As described above, the contour mining includes a stable highwall, which are also referred to as endwalls, and bench area on both sides of the equipment staging area


1315


, i.e. the bench


1350


and highwall


1355


on one side, and the bench


1360


and highwall


1365


on the other side. The opposing highwalls


1355


,


1365


in the area being mined operate as endgates, and may function as either a headgate or a tailgate, described hereinabove, for the mining system depending on the direction of production travel. This is an important advantage, as the invention described herein eliminates the necessity of independent headgates or tailgates required by prior art systems, which reduces mining costs considerably. A power substation


1370


may be set up in the equipment staging area


1315


to provide power to various parts of the system.




Prior to the first production cut


1300


of the longwall mining system, a continuous miner (not shown) makes initial cuts in the mineral seam


1304


to form a starter entry


1380


in the manner described above with respect to the shortwall mining system. After several successive cuts are made beginning at the starter entry


1380


, and moving from one highwall


1355


to the opposing highwall


1365


, an insertion passage


1385


is formed. Roof supports


1374


are placed behind the area mined by the continuous miner in a manner described above. An intake canopy


1400


and an exhaust canopy


1500


are placed at the substantially opposing highwalls


1355


,


1365


as defined by the insertion highwall


1320


.




Mine spoil


1420


developed during creation of the access bench


1350


,


1360


is placed on and around the roof supports


1374


to complete the formation of the starter passage


1385


. This use of excess mine spoil


1420


, which effectively seals the starter passage


1385


and creates a ventilation pathway within the starter passage


1385


eliminates the need to transport the mine spoil


1420


to disposal locations. This expedient use of the mine spoil


1420


complies with recent court decisions, particularly those involving the Clean Water Act, by providing an immediate use for the mine spoil


1420


, as opposed to prior systems which typically dispose of mine spoil


1420


within valley fills. Accordingly, an immediate benefit of the present invention is to eliminate the need for disposal locations by placement and use of the mine spoil


1420


generated during the mining process.




In the first production cut


1300


, after the starter passage


1385


has been created in the manner described above, a longwall miner


1375


is placed within the starter passage


1385


and proceeds to cut into the mineral seam


1304


in the direction indicated by arrow M


1


, but in smaller increments than that for the continuous miner described above, into the mineral seam


1304


. Production occurs in a direction indicated by arrow P


L


. Cutting bits on the longwall miner


1375


are oriented in a direction parallel to M


1


. As successive cuts are made into the mineral seam


1304


, the roof supports


1374


are advanced into the recently mined area. Ventilation is provided through the use of a ventilation fan


1440


coupled to the intake canopy


1400


. Ventilation thus occurs between opposing highwalls


1355


,


1365


beginning at endgate


1450


and proceeding towards endgate


1460


. It is appreciated that ventilation orientation may be reversed, depending on the circumstances. Because the longwall miner


1375


, upon reaching endgate


1450


, does not have to leave the cutting area of the mineral seam


1304


, once the first production cut


1300


has been completed, additional cuts may be made with decreases in downtime due to the elimination of equipment relocation.




Referring now to

FIG. 13A

, a cross-section of the first production cut


1300


taken along lines


13


A—


13


A of

FIG. 13

is shown. The staging bench


1310


is shown formed below the equipment insertion highwall


1320


. A safety bench


1330


is shown formed adjacent the equipment insertion highwall


1320


and the existing mountaintop


1301


. The mine spoil


1420


is shown surrounding the starter entry


1380


adjacent the roof supports


1374


as the longwall miner


1375


completes cuts between the highwall


1355


and opposing highwall


1365


(FIG.


13


). The mine spoil


1420


creates an effective seal of the starter passage


1385


, which allows proper ventilation of the starter passage


1385


and successive cuts into the mineral seam


1304


. Roof supports


1374


are shown in the starter passage


1385


adjacent to the mineral seam


1304


and supporting the safety bench


1330


in the area adjacent the equipment insertion highwall


1320


. As can be seen, the roof supports


1374


have been advanced into the area mined by the longwall miner


1375


.




The present invention provides many advantages over prior mining systems. These include advantages as compared to conventional underground longwall/shortwall systems and advantages as compared to conventional surface mining operations. With respect to conventional underground longwall/shortwall systems, the mining system of the present invention operates from continuous surface access, and does not require panel formation, headgate and tailgate entries, shuttle cars, roof bolter, scoop and a personnel carrier. Estimated capital cost reductions of about 25-30% over conventional longwall systems and about 15-20% reduction over conventional shortwall systems of equivalent production capacity may be realized. Second, directly proportional to the reduction in equipment requirements discussed above is a reduction in manpower requirements, which results in an estimated personnel cost reduction of about 30-40% over conventional longwall systems and about 20-30% over conventional shortwall systems of equivalent production capacity. Third, due to the reductions in personnel requirements, the reduction in travel time to the mineral seam and the elimination of panel moves results in about a 10-15% increase in production. Finally, through the unique and novel combination of surface and underground mining technologies and the elimination of underground development entries, the present invention may achieve nearly 100% recovery of the mineable resources, a tremendous improvement in the typical 75-85% overall recovery achieved in conventional longwall and shortwall systems.




As compared to conventional surface mining operations, similar efficiency increases and production increases are realized. First, the present invention requires a relatively small bench area due to the relatively small earthmoving equipment as compared to the larger equipment required in conventional surface mining operations. Second, manpower requirements are greatly reduced due to the reduction in equipment requirements as compared to the conventional large-scale surface mining operations, which results in about a 10-20% personnel cost reduction over conventional surface mining systems of equivalent production capacity and resource recovery potential. This results in a proportional increase in productivity (on a tons per man-hour basis) of about 10-20%. Fourth, because the present invention may achieve about 100% recovery of the mineable resource, this is equivalent to recovery achieved by large-scale mountain top removal operations and significantly better than the typical 65-85% recovery achieved in conventional surface/auger or surface/highwall-miner systems. Finally, because of the small surface mining bench requirement which is subsequently completely reclaimed to approximate original contour, the surface disturbance and associated environmental impacts are significantly less than those associated with typical large-scale surface mining (especially mountain top removal) operations. Such improvement results in about a 70% reduction in total surface area disturbance as compared to mountain top removal operations.




Other advantages include the elimination of the need for large valley fills and in-stream sediment ponds. If blasting is necessary, the number and size of blasts are greatly reduced. Safety is ensured through the use of the roof supports, canopies or other shields.




Importantly, federal legislation (i.e. the Clean Water Act) and judicial decisions have raised concerns of many miners in the industry due to, among other things, restrictions placed on waste removal operations at the mining site. The present invention offers an economical, efficient and highly productive system which complies with federal legislation and judicial systems by imposing little to no environmental impact at the mining area. This is accomplished through the principles discussed above, with particular emphasis on the elimination of unused mine spoil, which in the present invention is used to facilitate creation of an air seal and re-contour the exterior surface of the mine. This is further accomplished through the collapsing of the gob behind the longwall or shortwall miner, which eliminates the need to remove the gob after mining. Finally, it is important to note that the system of the present invention accomplishes these goals and advantages without compromising miner safety.




The previous description is of preferred embodiments for implementing the invention, and the scope of the invention should not necessarily be limited by this description. The scope of the present invention is instead defined by the following claims.



Claims
  • 1. A method for extracting mineral deposits in a mineral reserve accessible from a sloping surface, comprising:mining the sloping surface to create a bench and highwall for providing access to the mineral reserve; forming a surface in the highwall generally perpendicular to a desired direction of mining the mineral reserve to create an insertion highwall between opposing endwalls of the highwall extending therefrom; cutting a starter entry into the mineral reserve across the entire length of the insertion highwall from one endwall to the other; inserting roof supports into the starter entry and backfilling the starter entry with spoil to form a starter passage from one endwall to the other; mining the mineral reserve in the starter passage moving along the insertion highwall from one end wall to the other in a direction of production to extract mineral deposits therefrom; successively mining the mineral reserve moving from one endwall to the other in the direction of production to continue extracting mineral deposits therefrom thereby forming at least one successive passage advancing in the direction of mining; and providing roof support for successive passages resulting from the extraction of mineral deposits from the mineral reserve.
  • 2. The method of claim 1, wherein the direction of production reverses direction between the endwalls for successive passages.
  • 3. The method of claim 1, wherein the roof support for successive passages is provided by advancing the roof supports inserted into the starter entry, whereby the roof collapses behind the roof support to form the next successive passage.
  • 4. The method of claim 1, wherein mining the mineral reserve along the insertion highwall is accomplished by shortwall mining in the direction of production.
  • 5. The method of claim 1, wherein mining the mineral reserve along the insertion highwall is accomplished by longwall mining in the direction of production.
  • 6. The method of claim 1, wherein the bench and highwall extend a first predetermined distance from the endwall to form a first mining stage for mining a first predetermined number of successive passages, and further comprising:mining the mineral reserves using the first mining stage to extract mineral deposits from the first predetermined number of successive passages through the mineral reserve.
  • 7. The method of claim 6, further comprising:extending the bench and highwall a second predetermined distance from the first predetermined distance to form a second mining stage for mining a second predetermined number of successive passages; and backfilling the first mining stage to recontour the surface with spoil resulting from mining the sloping surface of the second mining stage.
  • 8. The method of claim 7, wherein the steps of extending the bench and highwall and backfilling the first mining stage are repeated until a desired termination point of the mineral reserve is reached.
  • 9. The method of claim 8, wherein the repeated steps of extending the bench and highwall and backfilling the first mining stage are conducted in stages.
  • 10. The method of claim 1, further comprising:ventilating the starter passage at one of the endwalls and at least one of the successive passages at one of the endwalls for each passage.
  • 11. The method of claim 1, further comprising:positioning one canopy at one endwall and another canopy at the other end wall to provide safe access to the passage.
  • 12. The method of claim 11, wherein one canopy is sealed and further comprising:ventilating the passage from the unsealed canopy.
  • 13. The method of claim 10, further comprising:coupling a reversible ventilation fan to at least one of the canopies.
  • 14. The method of claim 11, wherein the ventilation fan is coupled to the unsealed canopy.
  • 15. The method of claim 11, further comprising:reversing the reversible ventilation fan after creation of each successive passage.
  • 16. The method of claim 11, wherein one canopy is positioned at one end of the starter passage adjacent an endwall, and one canopy is positioned at the other end of the starter passage adjacent the other endwall.
  • 17. The method of claim 9, wherein the canopies are mobile.
  • 18. The method of claim 17, wherein the step of successively mining the mineral reserve is accomplished by a miner, and further comprising:removing the miner from the successive passage through one of the canopies at one of the endwalls after creation of the successive passage; reversing the orientation of the miner; reversing the orientation of the ventilation; and re-inserting the miner into the mineral reserve adjacent the completed successive passage through the one of the canopies at one of the endwalls.
  • 19. The method of claim 18, further comprising:advancing the canopies along the endwalls after creation of the successive passage.
  • 20. The method of claim 18, further comprising:backfilling the created successive passages with spoil.
  • 21. The method of claim 1, further comprising:allowing gob behind the roof supports to collapse in an area behind the roof supports after the step of providing roof support for successive passages.
  • 22. The method of claim 1, further comprising:forming a surface in the highwall generally perpendicular to the desired direction of mining the mineral reserve to create an extraction highwall between opposing endwalls of the highwall extending therefrom, the extraction highwall being on a generally opposite side of the mineral reserve from the insertion highwall.
  • 23. The method of claim 22, further comprising:mining the mineral reserve moving from one endwall to the other in the direction of production to continue extracting mineral deposits therefrom thereby forming an extraction passage; removing mining equipment from the extraction passage; and re-contouring an extraction highwall formed adjacent the extraction passage to proximate an original contour of the sloping surface.
  • 24. The method of claim 1, further comprising:manually advancing the roof supports in the direction of mining after the creation of each successive passage.
  • 25. The method of claim 1, wherein the step of mining the sloping surface is accomplished by contour mining.
  • 26. The method of claim 1, wherein the bench is adapted to support mining equipment.
  • 27. The method of claim 1, further comprising:creating at least one power substation disposed on the bench to provide power to mining equipment.
  • 28. The method of claim 27, wherein the at least one power substation is mobile.
  • 29. The method of claim 27, further comprising:advancing the at least one power substation in the direction of mining relative to the step of successively mining the mineral reserves.
  • 30. The method of claim 1, wherein the roof supports are inserted via a shield carrier.
  • 31. The method of claim 1, further comprising:forming a safety bench above the insertion highwall and parallel to the bench.
  • 32. The method of claim 1, further comprising:conveying the mineral deposits from the mineral reserve to a stockpile.
  • 33. The method of claim 1, wherein the backfilling occurs along the roof supports and endwalls.
  • 34. The method of claim 33, wherein the backfilling creates an air seal along the insertion highwall between opposing endwalls.
  • 35. The method of claim 1, wherein the insertion highwall is generally straight between the opposing endwalls.
  • 36. A method for extracting mineral deposits in a mineral reserve accessible from a sloping surface, comprising:mining the sloping surface to create a bench and highwall for providing access to the mineral reserve; forming a surface in the highwall generally perpendicular to a desired direction of mining the mineral reserve to create an insertion highwall between opposing endwalls of the highwall extending therefrom; cutting a starter entry into the mineral reserve across the entire length of the insertion highwall from one end wall to the other; inserting roof supports into the starter entry and backfilling the starter entry with spoil to form a starter passage from one endwall to the other; mining the mineral reserve with a shortwall miner in the starter passage moving along the insertion highwall from one end wall to the other in a direction of production to extract mineral deposits therefrom; successively mining the mineral reserve with a shortwall miner moving from one endwall to the other in the direction of production to continue extracting mineral deposits therefrom thereby forming at least one successive passage advancing in the direction of mining; and providing roof support for successive passages resulting from the extraction of mineral deposits from the mineral reserve.
  • 37. The method of claim 36, wherein the direction of production reverses direction between the endwalls for successive passages.
  • 38. The method of claim 36, wherein the roof support for successive passages is provided by advancing the roof supports inserted into the starter entry, whereby the roof collapses behind the roof support to form the next successive passage.
  • 39. The method of claim 36, wherein the bench and highwall extend a first predetermined distance from the endwall to form a first mining stage for mining a first predetermined number of successive passages, and further comprising:mining the mineral reserves using the first mining stage to extract mineral deposits from the first predetermined number of successive passages through the mineral reserve.
  • 40. The method of claim 39, further comprising:extending the bench and highwall a second predetermined distance from the first predetermined distance to form a second mining stage for mining a second predetermined number of successive passages; and backfilling the first mining stage to recontour the surface with spoil resulting from mining the sloping surface of the second mining stage.
  • 41. The method of claim 36, further comprising:ventilating the starter passage at one of the endwalls and at least one of the successive passages at one of the endwalls for each passage.
  • 42. The method of claim 36, further comprising:positioning one canopy at one endwall and another canopy at the other endwall to provide safe access to the passage.
  • 43. The method of claim 42, wherein one canopy is sealed and further comprising:ventilating the passage from the unsealed canopy.
  • 44. The method of claim 42, wherein one canopy is positioned at one end of the starter passage adjacent an endwall, and one canopy is positioned at the other end of the starter passage adjacent the other endwall.
  • 45. The method of claim 42, further comprising:coupling a reversible ventilation fan to at least one of the canopies.
  • 46. The method of claim 45, wherein the ventilation fan is coupled to the sealed canopy.
  • 47. The method of claim 45, further comprising:reversing the reversible ventilation fan after creation of each successive passage.
  • 48. The method of claim 42, wherein the canopies are mobile.
  • 49. The method of claim 48, further comprising:removing the shortwall miner from the successive passage through one of the canopies at one of the endwalls after creation of the successive passage; reversing the orientation of the shortwall miner; reversing the orientation of the ventilation; and re-inserting the shortwall miner into the mineral reserve adjacent the completed successive passage through the one of the canopies at one of the endwalls.
  • 50. The method of claim 49, further comprising:advancing the canopies along the endwalls after creation of the successive passage.
  • 51. The method of claim 49, further comprising:backfilling the created successive passages with spoil.
  • 52. The method of claim 36, further comprising:allowing gob behind the roof supports to collapse in an area behind the roof supports after the step of providing roof support for successive passages.
  • 53. The method of claim 36, further comprising:forming a surface in the highwall generally perpendicular to the desired direction of mining the mineral reserve to create an extraction highwall between opposing endwalls of the highwall extending therefrom, the extraction highwall being on a generally opposite side of the mineral reserve from the insertion highwall.
  • 54. The method of claim 53, further comprising:mining the mineral reserve moving from one endwall to the other in the direction of production to continue extracting mineral deposits therefrom thereby forming an extraction passage; removing the shortwall miner and roof supports from the extraction passage; and re-contouring an extraction highwall formed adjacent the extraction passage to proximate an original contour of the sloping surface.
  • 55. The method of claim 36, further comprising:manually advancing the roof supports in the direction of mining after the creation of each successive passage.
  • 56. The method of claim 36, wherein the step of mining the sloping surface is accomplished by contour mining.
  • 57. The method of claim 36, wherein the steps of extending the bench and highwall and backfilling the first mining stage are repeated until a desired termination point of the mineral reserve is reached.
  • 58. The method of claim 57, wherein the repeated steps of extending the bench and highwall and backfilling the first mining stage are conducted in stages.
  • 59. The method of claim 36, wherein the bench is adapted to support mining equipment.
  • 60. The method of claim 36, further comprising:creating at least one power substation disposed on the bench to provide power to mining equipment.
  • 61. The method of claim 60, wherein the at least one power substation is mobile.
  • 62. The method of claim 61, further comprising:advancing the at least one power substation in the direction of mining relative to the step of successively mining the mineral reserves.
  • 63. The method of claim 36, wherein the roof supports are inserted via a shield carrier.
  • 64. The method of claim 36, further comprising:forming a safety bench above the insertion highwall and parallel to the bench.
  • 65. The method of claim 36, further comprising:conveying the mineral deposits from the mineral reserve to a stockpile.
  • 66. The method of claim 36, wherein the backfilling occurs along the roof supports and endwalls.
  • 67. The method of claim 66, wherein the backfilling creates an air seal along the insertion highwall between opposing endwalls.
  • 68. The method of claim 36, wherein the insertion highwall is generally straight between the opposing endwalls.
  • 69. A method for extracting mineral deposits in a mineral reserve accessible from a sloping surface, comprising:mining the sloping surface to create a bench and highwall for providing access to the mineral reserve; forming a surface in the highwall generally perpendicular to a desired direction of mining the mineral reserve to create an insertion highwall between opposing endwalls of the highwall extending therefrom; cutting a starter entry into the mineral reserve across the entire length of the insertion highwall from one endwall to the other; inserting roof supports into the starter entry and backfilling the starter entry with spoil to form a starter passage from one endwall to the other; mining the mineral reserve with a longwall miner in the starter passage moving along the insertion highwall from one endwall to the other in a direction of production to extract mineral deposits therefrom; successively mining the mineral reserve with a longwall miner moving from one endwall to the other in the direction of production to continue extracting mineral deposits therefrom thereby forming at least one successive passage advancing in the direction of mining; and providing roof support for successive passages resulting from the extraction of mineral deposits from the mineral reserve.
  • 70. The method of claim 69, wherein the direction of production reverses direction between the endwalls for successive passages.
  • 71. The method of claim 69, wherein the roof support for successive passages is provided by advancing the roof supports inserted into the starter entry, whereby the roof collapses behind the roof support to form the next successive passage.
  • 72. The method of claim 69, wherein the bench and highwall extend a first predetermined distance from the endwall to form a first mining stage for mining a first predetermined number of successive passages, and further comprising:mining the mineral reserves using the first mining stage to extract mineral deposits from the first predetermined number of successive passages through the mineral reserve.
  • 73. The method of claim 72, further comprising:extending the bench and highwall a second predetermined distance from the first predetermined distance to form a second mining stage for mining a second predetermined number of successive passages; and backfilling the first mining stage to recontour the surface with spoil resulting from mining the sloping surface of the second mining stage.
  • 74. The method of claim 69, further comprising:ventilating the starter passage at one of the endwalls and at least one of the successive passages at one of the endwalls for each passage.
  • 75. The method of claim 69, further comprising:positioning one canopy at one endwall and another canopy at the other endwall to provide safe access to the passage.
  • 76. The method of claim 75, wherein one canopy is sealed and further comprising:ventilating the passage from the unsealed canopy.
  • 77. The method of claim 75, wherein one canopy is positioned at one end of the starter passage adjacent an endwall, and one canopy is positioned at the other end of the starter passage adjacent the other endwall.
  • 78. The method of claim 75, further comprising:coupling a reversible ventilation fan to at least one of the canopies.
  • 79. The method of claim 78, wherein the ventilation fan is coupled to the unsealed canopy.
  • 80. The method of claim 78, further comprising:reversing the reversible ventilation fan after creation of each successive passage.
  • 81. The method of claim 75, wherein the canopies are mobile.
  • 82. The method of claim 81, further comprising:removing the longwall miner from the successive passage through one of the canopies at one of the endwalls after creation of the successive passage; reversing the orientation of the longwall miner; reversing the orientation of the ventilation; and re-inserting the longwall miner into the mineral reserve adjacent the completed successive passage through the one of the canopies at one of the endwalls.
  • 83. The method of claim 82, further comprising:advancing the canopies along the endwalls after creation of the successive passage.
  • 84. The method of claim 82, further comprising:backfilling the created successive passages with spoil.
  • 85. The method of claim 69, further comprising:allowing gob behind the roof supports to collapse in an area behind the roof supports after the step of providing roof support for successive passages.
  • 86. The method of claim 69, further comprising:forming a surface in the highwall generally perpendicular to the desired direction of mining the mineral reserve to create an extraction highwall between opposing endwalls of the highwall extending therefrom, the extraction highwall being on a generally opposite side of the mineral reserve from the insertion highwall.
  • 87. The method of claim 86, further comprising:mining the mineral reserve moving from one endwall to the other in the direction of production to continue extracting mineral deposits therefrom thereby forming an extraction passage; removing the longwall miner and roof supports from the extraction passage; and recontouring an extraction highwall formed adjacent the extraction passage to proximate an original contour of the sloping surface.
  • 88. The method of claim 69, further comprising:manually advancing the roof supports in the direction of mining after the creation of each successive passage.
  • 89. The method of claim 69, wherein the step of mining the sloping surface is accomplished by contour mining.
  • 90. The method of claim 69, wherein the steps of extending the bench and highwall and backfilling the first mining stage are repeated until a desired termination point of the mineral reserve is reached.
  • 91. The method of claim 90, wherein the repeated steps of extending the bench and highwall and backfilling the first mining stage are conducted in stages.
  • 92. The method of claim 69, wherein the bench is adapted to support mining equipment.
  • 93. The method of claim 69, further comprising:creating at least one power substation disposed on the bench to provide power to mining equipment.
  • 94. The method of claim 93, wherein the at least one power substation is mobile.
  • 95. The method of claim 94, further comprising:advancing the at least one power substation in the direction of mining relative to the step of successively mining the mineral reserves.
  • 96. The method of claim 69, wherein the roof supports are inserted via a shield carrier.
  • 97. The method of claim 69, further comprising:forming a safety bench above the insertion highwall and parallel to the bench.
  • 98. The method of claim 69, further comprising:conveying the mineral deposits from the mineral reserve to a stockpile.
  • 99. The method of claim 69, wherein the backfilling occurs along the roof supports and endwalls.
  • 100. The method of claim 99, wherein the backfilling creates an air seal along the insertion highwall in the starter passage between opposing endwalls.
  • 101. The method of claim 69, wherein the insertion highwall is generally straight between the opposing endwalls.
  • 102. The method of claim 69, wherein the step of cutting is accomplished by a shortwall miner.
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4505517 Seddon et al. Mar 1985 A
4952000 Lipinski et al. Aug 1990 A
5033795 Farrar et al. Jul 1991 A
5782539 Peterson Jul 1998 A
6086159 Peterson Jul 2000 A
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