Patent Application
20250034667
The present invention relates in general to the field of production of materials. More specifically, the present invention is directed to a method of making or otherwise producing a metal from a metal-ore using mechanical energy with a pure element selected from energy of formation data of the ore forms of each chemical comminution. Even more specifically, an iron powder is produced directly from iron ore powder. Further and more specifically, the present invention is directed to a method of making or otherwise producing a pure iron powder from iron ore powder that eliminates the need for carbon to reduce the iron. As such, the present invention dramatically reduces the carbon footprint, as well as associated energy and costs. As a result, the present invention reduces detrimental sulphur.
Currently iron is reduced from iron ore by using a specially manufactured metallurgical coke which is inserted with the iron ore in a large high temperature furnace (often oxygen blast furnace with high capital investments) and the carbon in the coke creates CO2 directly liberating the iron in the molten bath which is then poured into ingots making Pig iron. The Pig iron contains a lot of carbon often 3-4 wt. %. This is the highest greenhouse gas producing industry not only for the intensive energy needs but directly produces CO2 gas (as well as other greenhouse gases) in the process.
Iron ore (often an iron oxide concentration of about 65 wt. %) is molten in a large oxygen blast furnace with additions of metallurgical coke (source of more impurities) and high temperature that cause the carbon in the coke to form greenhouse gases such as CO2 reducing the iron but solutionizes a large amount of carbon and impurities. The molten iron is then poured into ingots creating what is known as Pig iron.
Currently the iron industry is spending billions of dollars trying to reduce their carbon footprint, but most efforts concentrate on incremental reductions such as on reduced greenhouse gas emissions (more use of natural gas for example), reduction of energy requirements, and increasing efficiencies of current processes, consisting of oxygen blast furnaces that produces molten iron which is put into ingots directly. There are other processes than oxygen blast furnaces in use but this is still the vast majority of production. Many of these other processes still rely on direct production of greenhouse gases such as CO2 to reduce the iron ore.
Changing the silicon powder, as other elements work such as calcium but that has issues in terms of availably, and is very corrosive and toxic, as pure iron oxide was milled with calcium previously. However, under inert environment the prior art used only some pure oxides (not any ores) and never attempted the use of silicon. Based on the Ellingham diagram other elements that can be used include: magnesium, aluminum, titanium, manganese, chromium, and zinc observed in one particular diagram, although other materials could be used. The pure oxides and pure elements studied by in the prior art are provided in Table 1. The reactions studied in the prior art are shown in Table 2 all under an argon environment, work here has shown this process can be done in an air environment drastically cutting costs.
CuO + Ca
CuO + Mg
Cu + MgO
CdO + Ca
ZnO + Ca
A block diagram showing a traditional method of making iron is shown in
What is needed is another method of making iron that is superior to previous methods, including a method creating a similar iron product without the need for carbon which in turn reduces the carbon footprint and associated energy and costs.
By way of summary, the present invention is directed to an inventive method of producing pure iron powder, that can reduce the amount of carbon needed, which in turn minimizes the carbon footprint as well as associated costs and energy. The invention is directed to a new method of making iron from iron ore using chemical comminution. The inventive method was developed based in part on review of Ellingham diagrams to determine the potential elements especially targeting silicon to use. The first experiment netted positive results. There are numerous benefits to the claimed process including that the method drastically reduces the carbon footprint in typical iron making processes by no longer needing metallurgical coke (a form of processed coal) and large energy intensive blast furnaces which directly produces CO2 which is one of the highest greenhouse gas producing industrial processes. More importantly, the present invention makes it possible to apply this process using current comminution infrastructure of the iron ore processing which would add to the reduction of greenhouse gases since iron ore would no longer have to be transported. However, a much smaller amount of silicon would have to be transported (less than 50% of iron ore weight) unless locally created using chemical comminution or other methods of reduction of silicon, the second most abundant element in the Earth's crust.
These, and other aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
A clear conception of the advantages and features constituting the present invention, and of the construction and operation of typical mechanisms provided with the present invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the drawings accompanying and forming a part of this specification:
In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
The present invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments described in detail in the following description.
An appendix is provided that discloses further aspects of the present invention.
The present invention includes the components of iron ore powder, silicon powder (available as a waste product of semiconductor industry), and mechanical means to provide activation energy.
It is possible to use equipment that already exists in iron ore processing, which also uses comminution, for the present invention but it may be beneficial to look at changes or modifications to the various mills that may improve efficiency.
All of the powder ingredients, including iron ore concentrate and silicon, in some type of mechanical mill (ball, SPEX, rod, attritor, planetary, etc.) or other mechanical means to achieve activation energy. The mechanical energy imparted to the powders changes the structure by a reduction in size (hence increase in surface area important to reactions), increase in defects, atoms on grain boundaries. This reduces the activation energy to initiate the spontaneous reaction to create pure iron and silicon oxide as silicon oxide has a lower Gibbs energy of formation than iron oxide based on Ellingham diagrams (this can be applied to any ionic based compound as well), so any metal that has an oxide (or others) with a lower energy of formation can be used to reduce any particular oxide, carbide, nitride, boride, etc. Therefore, silicon will take away oxygen from the iron ore leaving pure iron and silicon oxide. Additionally, the silicon oxide forms an amorphous phase that appears to be a collection bin for other elements present in the iron ore concentrate (often about 65 wt. % of the ore) essentially forming a slag.
Any method to impart mechanical energy could potentially be used. Typically, common milling methods such as SPEX, rod, attritor, planetary, ball, etc. can be used but a new type of mill or way to impart mechanical energy to the powders to initiate the reaction is possible. Whatever is needed to get it over the activation barrier (which is reduced as the particle size is reduced, defect density increases, and atoms at the boundaries increases: i.e. free surfaces).
Dry milling in air will now be described. A process called Mechanonanosynthesis was developed based off modified mechanical alloying where elements like carbon or nitrogen (as well as others) can create in situ dispersoids that are nanometer in size by milling with a surfactant (or air to get nitrogen) and creating a reaction with metals in the powder and the volume fraction of these compounds is simply a function of milling time. Based off this process, the first experiment, using wet milling with hexanes (others can be used) as a process control agent, demonstrated that pure iron can be produced along with iron carbides. It should be noted that the optimized process produced iron and carbon powder content ratios similar to Pig iron (iron from blast furnace operation but contains impurities needing further refinement). Importantly, this dry milling in air process appears to produce just pure iron with no added carbon (or minimal) which can be another benefit as the carbon in Pig iron being about 3-4 wt. % and a reduction of carbon is required for steels since carbon contents are typically just above zero to about 1 wt. %.
The present invention directly reduces iron ore powder to iron powder. Ultimately, if the iron can be extracted this new method of producing (relatively) carbon-free iron from iron ore extracted from the earth having huge potential reductions in energy and both direct and indirect reductions in greenhouse gas emissions.
The present invention includes a simple, less energy intensive process to make iron directly from iron ore concentrate using a highly available silicon (second most abundant element in the earth's crust) that is also a waste product of the semiconductor industry. Dramatic reductions in direct (zero) production of greenhouse gas emissions as well as possible reductions in energy requirements. Additionally, costs may be reduced based on the fact that iron ore manufacturers can use current comminution equipment (mills) for this new process, and there is no need to create metallurgical coke which is becoming more difficult to obtain and produce, a needed step to further reduce the high sulphur content in the coal. Furthermore, a reduced need to sinter and transport iron ore (about 65 wt. % of the total ore weight), while silicon would need to be transported, the weight requirement per pound of ore is less than about half. However, with silicon being so abundant it can also be locally refined.
In developing the present invention, the separation of the iron from the powder agglomerate consisting of basically iron and an amorphous sand mix which appears to collect other elements present was challenging. Given the large amount of iron present it might be possible to just melt the material and the iron will agglomerate. Initial attempts were tried in an arc-melter which requires a conductive sample (this sample has a large amount of nonconductive sand); however, despite not fully melting there are regions of pure iron in the composite nugget after attempts suggesting that melting could be a very simple solution to separating the iron.
The present invention is directed to a new way to make iron from iron ore, consisting of using current comminution equipment in production of iron ore, ingredients consisting basically of silicon and iron ore powder, imparted with sufficient mechanical energy to achieve a reduction in the activation barrier for the reaction.
The present process developed can be done in air, which significantly reduces costs, with ores, as well as silicon. Based on the Ellingham diagram other elements that can be used include: magnesium, aluminum, titanium, manganese, chromium, and zinc observed in one particular diagram, although other diagrams could identify other elements to be used. The present invention only requires a vessel with powders of pure element, ore, under sufficient mechanical energy. This could be applied to any ore system not just iron ore.
The present process makes iron which is one of the most important and widely-used structural materials in the world, of most importance steels and cast irons.
The present invention allows for dramatic reductions in the carbon footprint. In fact, this could lead to zero carbon emissions in an industry that using current technology cannot achieve. The present invention may also reduce costs of production due largely in part to the removal of the need to use metallurgical coke, as well as reduction in transportation, making use of existing mills, no need for capital intensive blast furnaces to melt ore, and the key ingredient silicon is a waste product of the semiconductor industry as well as other sources due to the vast amount of silicon based materials.
The process to form Pig iron has impurities along with large amounts of carbon, these impurities include phosphorus, silicon, manganese, sulphur (majority from the coke), etc. These impurities are a result of the high liquidus temperatures during iron making which increases solutionization of elements present in the ore. Under the current invention it can be expected that solutionization is dramatically reduced due to the near room temperature processing. It is important to point out silicon is often beneficial to the properties, as typically others can be detrimental and are minimized by extra processing. Hot metal (molten Pig iron) is directly reduced by oxidation (at liquid temperatures) and removing most of the residual impurities present in the system that can be trapped in the iron as described above. Common steels typically have between just above zero to about 1 wt. % carbon, and the carbon in the Pig iron must be reduced. Sulphur is a problem but manganese is present to make MnS to tie up the sulphur reducing the detrimental effects up to the maximum amount tolerable. Additional processing that use fluxes and magnesium is required to reduce sulphur levels to adequate levels (typically maximum of 0.05 wt. %) in iron alloys but can only be tolerated up to a maximum of about 0.29 wt. %. While this has not been explored as of yet it is quite possible that these elements (those present in the iron ore) are tied up in the amorphous sand producing a much purer iron (near-room temperature reduces solutionization of these detrimental elements), this would reduce other steps needed in the steel making process as well as enhance properties. More important, a vast majority of sulphur typically comes from the metallurgical coke and therefore would not be expected to be present any longer (or dramatically reduced), thus reducing the need to alloy with manganese. Preliminary chemical analysis of an area of iron from the partially melted processed powder showed no presence of sulphur.
If the dry chemical comminution process can be scaled-up, and especially make use of existing iron ore comminution equipment, then huge reductions in costs as well as greenhouse gases emissions can be realized. Additionally, this could lead to sulphur free (or reduced) iron and may reduce other impurities as well as reduce the amount of carbon using the dry chemical comminution process. The issue here is the science in not well understood as it appears the reaction here is spontaneous and appears to occur simultaneously and the mechanism has yet to be explored but there clearly is some type of activation barrier to overcome. The severe milling reduces materials to their size limit (thus increasing surface area important to a reduction in activation energy), as well as large defect densities (store mechanical energy reducing activation energy), and large number of atoms up to 50% on grain boundary regions (act like a free surface very reactive reducing activation energy), thus allowing for a variety of reactions to occur at near-room temperature. The wet method (inserting process control liquid hexanes or other organic liquids or waxes) the reactions occur based on a well behaved linear milling time (slopes are variable based on milling parameters). This will also produce iron with large amounts of carbon (iron carbide) but with higher processing cost. The present method can be scaled-up. Thus providing the ability to directly produce steels to cast iron binary alloys directly with the possibility of silicon additions.
The inventive method is further illustrated in the block diagram contained in
Although the best mode contemplated by the inventors of carrying out the present invention is disclosed above, practice of the present invention is not limited thereto. It will be manifest that various additions, modifications and rearrangements of the features of the present invention may be made without deviating from the spirit and scope of the underlying inventive concept.
Moreover, the individual components need not be assembled in the disclosed configuration, but could be provided in virtually any configuration. Furthermore, all the disclosed features of each disclosed embodiment can be combined with, or substituted for, the disclosed features of every other disclosed embodiment except where such features are mutually exclusive.
It is intended that the appended claims cover all such additions, modifications and rearrangements. Expedient embodiments of the present invention are differentiated by the appended claims.
This present application claims priority on U.S. Provisional Patent Application Ser. No. 63/529,210, filed on Jul. 27, 2023 and entitled Iron Making Process—Chemical Comminution, the entire contents of which are hereby expressly incorporated by reference into the present application.
| Number | Date | Country | |
|---|---|---|---|
| 63529210 | Jul 2023 | US |
