Methods for processing crushed solids with a liquid within a vessel
A method is provided in which solids, such as run-of-mine ore, are crushed and reacted with a liquid within a mass flow reactor as a substantially continuous process. The reaction can include dissolving at least one material out of the crushed solids and into solution with the liquid. Solid and liquid materials migrate through and are extracted from the mass flow reactor substantially under the influence of gravity alone and without the use of other relevant driving means or forces. The respective flows of solid and liquid materials through the mass flow reactor can be controlled so as to maintain generally constant levels of each therein. At least some of the reaction can occur under a predetermined hydrostatic head of the liquid. Further processing of the solid and liquid materials can be performed, including isolation of at least one material of interest extracted from the crushed solids.
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Many applications are known wherein a liquid is reacted with a particulated or crushed solid (“solids”) to enhance one or the other of the liquid or the solids (or both) for commercial benefit. One common application is to react a liquid “lixiviant” with a solid to extract a soluble compound from the solid by way of percolating or washing the solid with the liquid. (Accordingly, a “lixiviant” is a liquid used for this purpose.) This process is commonly described as “leaching”, and is known to various fields of endeavor. Typical examples include extracting valuable metals from ores containing the metals by contacting the ores with a lixiviant. The extracted metals will then be in solution with the lixiviant, and can be later removed from the lixiviant by known chemical processes, such as chemical precipitation, to render a relatively pure form of the extracted metals, or a form that can be subsequently processed to render a relatively pure form of the extracted metals. One example is to wash ore containing gold with a lixiviant containing cyanide to remove the gold from the ore. Other examples include washing oil shales with a solvent to extract petroleum from the shales, and washing coal with a sulfur-extracting liquid to remove sulfur from the coal. Yet another example includes contacting contaminated soil with a liquid-borne biological agent (or agents) to thereby decontaminate the soil.
In all of these processes the volumes of solids to be treated are typically considerable—on the order of tens to thousands of metric tons per day. In the case of ore leaching (to remove valuable metals from ores containing the metals), the most common process is to pile the ore into a “heap” on a leach pad, and then to introduce a lixiviant onto the top of the heap. After the lixiviant has passed through the ore heap via gravity, the lixiviant is collected and processed to remove the extracted metals from the lixiviant. The spent ore is then discarded (as for example by moving it to a spent ore pile), and new unprocessed ore is then placed on the leach pad, and the process repeated. Such leach pads often occupy areas covering many acres, and in some cases square miles. Due to the nature of the lixiviants used, and the metals being extracted from the ores, leach pads are typically subject to significant environmental controls to reduce the possibility of potential contamination of soil surrounding the leach pad. Further, the ore leaching process via ore heaps and leach pads is a slow process. Common leach times (i.e., the time between when the ore heap is initially formed and the lixiviant added to the ore heap, and the time when the ore is considered “spent” and is removed from the leach pad) are on the order of months. A six month leach time is not uncommon.
Other prior leaching methods and apparatus include: (1) batch tank leaching, (2) agitated vat leaching, (3) counter-current tank leaching, (4) permanent pad heap leaching (described briefly above), (5) re-usable pad heap leaching, and (6) bio-heap leaching. A common description for each of these methods and apparatus is a “leach circuit”.
The specific shortcomings of the prior art are as follows.
For agitated vat leaching, the basic operational concept is to provide an elevated contact rate of lixiviant and other additives to the surfaces of the ore particles by (a) increasing the surfaces of the ore which can be accessed by the lixiviant by grinding the ore to a particle size that exposes the desired metal or mineral value, (b) vigorously agitating the ore and lixiviant so as to provide an elevated level of contact between unconsumed reaction agents, and (c) to readily remove reaction outputs so as to maintain in majority concentration the unconsumed reaction agents.
The shortcomings of such a process include: (1) significant capital and operational costs are associated with grinding the ore to a small particle size and vigorously agitating such a dense media as an ore slurry; (2) the processing time required for the desired recovery level—as short as 24 hours in the typical case—in conjunction with the size limitations for a vessel which will afford reasonably good economic access of the agitation mechanical to the ore slurry, necessitates a large number of containment vessels, which in turn necessitates a plant of commensurate size to contain and support the operation of the containment vessels, all of which requires significant capital and real estate to construct; (3) small particle sizes typically present challenges for disposal of spent ore since special impoundments are typically required to de-water and stabilize it as permanent fill; (4) because of the relatively high capital and operating costs of such a leach process, the method is not economical for very low grade ores or ores which require leach times in excess of 24 hours to achieve economic recovery; (5) batch processing contains an inherent limitation in that there is wasted economic time between batch operations; and (6) because of the complexity of such a mechanically intensive process, design and construction times for the plant are relatively long (as compared to heap leaching, for example).
Heap leaching is an alternative to vat leaching and attempts to address the limitations of vat leaching with respect to low grade ores and ores that require longer leach recovery times (e.g., using certain oxides and certain sulfides). The basic operational concept of heap leaching is to trade-off leach recovery time for leach circuit processing size or volume by (1) secondary or tertiary crushing of the ore instead of grinding to a fine grain size, (2) agglomerating the ore into relatively uniform ore spheres to increase permeability of lixiviant and increase contact effectiveness rather than agitating the ore, (3) stacking in broad, relatively shallow piles on an impermeable layer instead of batching in expensive vessels, (4) sprinkling lixiviant on the ore, letting it trickle down under the action of gravity alone through the ore, and collecting the pregnant solution from perforated pipes on the bottom of the heap rather than submerging the ore within a vat or tank, (5) blowing air into the heap (as in the case of bio-heap leaching), and (6) removing the ore continuously from the pad as in the case of re-usable pads to make heap leaching a more continuous rather than a batch process.
Although heap leaching extends leaching technology to lower grade and harder-to-leach ores that are not economically done with vat leaching because of the implied processing volume required, heap leaching is less effective in extracting metals and the like from the ores, primarily due to the absence of submersion of the ore in the lixiviant and agitation of the ore (as in agitated vat leaching). Of particular concern in the use of a trickle-type application of lixiviant to a stack or pile of ore on a leach pad is channeling of the lixiviant, leaving significant portions of the leach pile without sufficient lixiviant to extract the theoretical maximum recoverable metals using the heap.
Another inherent shortcoming of heap leach is the inability to control environmental inputs such as temperature and oxygenation of the heap, which are critical factors in bio-heap leaching where the effectiveness of the bacteria is closely dependent on these variables.
Perhaps the greatest shortcoming of heap leaching is the capital and operating costs associated with large volumes of material, especially in the case of re-usable pads. Whereas in vat leaching the ore is transported in a slurry in pipe conduits, heap leaching, because of the large geometric extents of leach pads and complexity of stacking a stable heap, has been performed almost exclusively with conventional overland conveyors and specialized spreading and reclaim conveyors, which imply high capital and operating costs as compared to the compact plant piping of vat leaching.
What is needed then is an economical, efficient method and/or apparatus to react solids and liquids with one another that achieves the benefits to be derived from similar prior art apparatus and methods, but which avoid the shortcomings and detriments individually associated therewith.
SUMMARYOne embodiment provides for a method of processing selected solids with a selected liquid, the method including the steps of providing a vessel, and crushing the solids to not less than a predetermined median particle size. The crushed solids define, or are referred to herein, as crushed solids. The method also includes the step of reacting the crushed solids with the liquid within the vessel, such that a pregnant leach solution and post-reaction solids are derived. At least some of the reacting of the aforementioned step occurs under conditions of a predetermined hydrostatic head. The method further includes the step of migrating the pregnant leach solution and the post-reaction solids through the vessel substantially under the influence of gravity alone. Furthermore, the method includes the step of extracting the pregnant leach solution and the post reaction solids from the vessel.
Another embodiment provides for a method of processing a mine ore with a lixiviant, the method including the step of providing a reaction vessel, wherein the vessel defines solids outlet openings and liquid outlet openings. The method also includes the step of crushing the mine ore to not greater than a predetermined size, such that crushed ore is defined or derived. The method further includes the steps of reacting the crushed ore with the lixiviant within the reaction vessel, thus deriving a pregnant leach solution and post-reaction solids, and extracting at least some of the pregnant leach solution from the reaction vessel via the liquid outlet openings substantially under the influence of gravity alone. The method includes extracting the post-reaction solids and at least some of the pregnant leach solution from the reaction vessel via the solids outlet openings substantially under the influence of gravity alone.
These and other aspects and embodiments will now be described in detail with reference to the accompanying drawings, wherein:
DESCRIPTION OF THE DRAWINGS
In representative embodiments, the present teachings provide methods and apparatus for processing solids such as run-of-mine ore, in a substantially continuous manner, so that one or more materials of interest can be extracted or isolated from the ore and further processed to a condition deliverable to the market place.
The following terms are defined as used herein:
Run-of-Mine Ore: Refers to matter comprising at least one material of interest that is to be extracted or separated from the balance of the matter. Run-of-mine ore (or, interchangeably, ore) is in essentially the same condition as when it was removed from its natural or native source and, typically (but not exclusively), defines a substantially solid, chunk-like consistency and includes individual particles of substantially varying size. Non-limiting examples of materials of interest within such ore include gold, silver, platinum group metals, gallium, lead, germanium, refractory metals, molybdenum, copper, zinc, uranium, cobalt, nickel, light metals, crude oil, caregens, rare earth elements, etc. Other ores, comprising other respective materials of interest, can also be used. Examples of a native source for run-of-mine ore include, but are not limited to, a shaft mine, an open pit mine, a strip mine, etc.
Lixiviant: This refers to any of a number of chemical compounds, typically (but not necessarily) in a liquid state, which chemically reacts with run-of-mine ore so as to dissolve, or “leach”, one or more materials out of the ore and into solution with the lixiviant. Non-limiting examples of lixiviant include an aqueous solution of acid or acids, an aqueous solution of acid or acids including an oxidizing agent, an aqueous solution of an alkali or alkali's, sulfuric acid, a solution including sulfuric acid, an aqueous solution of an alkali or alkalis' including an oxidizing agent, an aqueous solution of cyanide including an oxidizing agent, an aqueous solution of sodium or calcium hypochlorite, an aqueous solution of ferrous or ferric sulfate, an aqueous solution of ferrous or ferric sulfate including an oxidizing agent, an aqueous solution including a bacterial catalyst, an aqueous solution of chlorine, an aqueous solution of hydrogen peroxide, a solution of ammonium thiosulfate, or an aqueous solution of air and sulfur dioxide and copper. Other suitable lixiviants can also be used. Various embodiments allow the use of a lixiviant (or lixiviants) of typically greater concentration than those used in known heap leaching operations. Furthermore, the concentration (and/or other characteristics) of a lixiviant can be controlled to tighter tolerances, if desired, during continuous mode operation of various embodiments, as compared to known heap leaching operations.
Pregnant Leach Solution (PLS): This refers to a liquid comprising a lixiviant—in some overall degree of chemical depletion or expenditure—and one or more materials dissolved into solution therewith. Thus, pregnant leach solution typically results from a chemical reaction between a solid material, such as crushed run-of-mine ore, and a pristine (new, fresh, or regenerated) lixiviant.
Post-Reaction Solids (PRS): This term refers to solids, typically in a crushed form, which have reacted with a lixiviant such that at least some amount of one or more materials are dissolved out of the solids. As used herein, post-reaction solids are usually defined by crushed run-of-mine ore that has reacted, to some degree, with a lixiviant as generally defined above. That is, such post-reaction solids are typically defined by crushed ore matter that has been depleted, to some extent, of one or more materials previously present in its original (pre-reaction) condition. In some cases, post-reaction solids (PRS) will include some quantity (i.e., trace or residual amounts, etc.) of pregnant leach solution (PLS) until and/or unless further treatments or processing steps are performed to remove (e.g., leach) such PLS borne by the PRS.
Barren Solution: Generally, this term refers to lixiviant that has been previously used within a leach process (i.e., was once a pregnant leach solution) and has been processed or otherwise sufficiently reconstituted (i.e., recycled) so as to be useful in one or more embodiments. Non-limiting examples of such recycling steps can include removal of the materials dissolved into solution with the PLS, reconstitution by gas injection or addition of new acid, etc. In one example, a barren solution is derived that can be used within a wash process in order to leach (soak, or free) another liquid out of a solid material, thus defining an aqueous leachate. In another example, a barren solution is defined by sufficiently recycling PLS so as to derive a lixiviant in substantially new condition, and which can be used as such.
Turning now to
The system 100 includes a supply of run-of-mine ore (ore) 102. The supply of ore 102 is typically piled in a covered or uncovered fashion to wait further processing, as described hereinafter.
The system 100 includes a crusher 104. The crusher 104 can be defined by any suitable means for crushing the ore 102 to a predetermined median (or, optionally, a mean, not-less-than, or not-to-exceed) size. In one embodiment, the crusher 104 is defined by a jaw mill. In other respective embodiments, the crusher 104 is defined by a gyratory type or SAG mill. One of ordinary skill in the mining engineering arts is aware of numerous such crushers 104 for suitably crushing run-of-mine ore 102, in accordance with the specific type of ore 102 and/or the desired median crushed size, and further elaboration is not required for purposes herein. In any case, the crusher 104 is suitably selected and used to crush the run-of-mine ore 102, thus deriving (i.e., defining) a supply (or stream) of crushed solids (i.e., crushed ore) 106.
The system 100 includes a supply of lixiviant 108. The lixiviant 108 can be defined by any suitable such lixiviant as defined above. The lixiviant 108 is reacted with the crushed solids 106 in order to derive one or more desired by-products (or effects) of the reaction such as, for example, a pregnant leach solution as defined above. For example, the lixiviant 108 can be suitably defined so as to react with the crushed solids 106 such that gold is leached out of the crushed solids 106 and into solution with the lixiviant 108. Other suitable lixiviants (i.e., liquids, etc.) 108 can also be used in accordance with the particular type of crushed solids 106, the desired reaction to occur therewith, etc. One of ordinary skill in the mining or chemical arts is aware of numerous such lixiviants 108 and their respective uses.
The system 100 of
The system 100 of
The mass flow reactor 110 of
The system 100 of
The system 100 includes pregnant leach solution process (PLS process) 116. The PLS process 116 can be defined by any suitable process (or combination of sub-processes) configured to receive the pregnant leach solution stream 114 from the mass flow reactor 110, the cooled/heated PLS stream 117 from the heat exchanger 115, and/or the PLS stream 134 (described hereinafter) and to separate (i.e., extract) one or more materials out of the residual pregnant leach solution. For example, a suitable PLS process 116 can be defined and used that causes gold to precipitate out of solution with the remaining PLS liquid advancing to the next stage. Non-limiting examples of process steps performed by the pregnant leach solution process 116 include any suitable one, or combination of, heating or cooling, clarification, filtration, bulk precipitation, pH modulation, solvent extraction, electrowinning, mercuric retorting, smelting, carbon column absorption, magnetic separation, cyclonic separation, etc. One of ordinary skill in the mining engineering arts is aware of numerous, well-established methods and materials for extracting particular materials out of pregnant leach solution and specific definition and elaboration is not required.
In any case, the pregnant leach solution process 116 includes suitable process steps resulting in the extraction and isolation of one or more minerals, metals, and/or other materials 118 in a condition suitable for provision to the market, or further processing, if desired. Also, the PLS process 116 can be defined and operated so as to reconstitute (i.e., recycle) the lixiviant within the PLS stream 114, 117 and/or 134, or some fraction thereof, so that a renewed lixiviant stream (or supply) 148 is derived. As depicted in
The system 100 of
As depicted in
The system 100 of
The system 100 also includes a barren solution (or water) wash 140. Typically, the barren solution wash 140 can be used to leach additional PLS (i.e., PLS 114) out of the (dried, or “dewatered”) fine solids 136. For example, some fine solids 136 include surface geometry, absorption characteristics, or other considerations that economically justify use of the barren solution wash 140 in order to recover additional material of interest (i.e., cyanide complexed gold, etc.) therefrom. In one embodiment, the barren solution wash is provided by way of a vessel substantially mechanically equivalent to the mass flow reactor 110. However defined and used, the barren solution (or water) wash 140 derives a stream (or supply) of aqueous leachate 142 borne by the (dried) fine solids as they exit the barren solution wash 140. In a sense, the fine solids 136 have been “rewetted” by way of soaking (leaching) within the barren solution wash 140 in the interest of recovering additional material of interest therefrom (e.g., dissolved copper, etc.). In some cases, the barren solution or water wash 140 is not used at all.
The system 100 also includes another centrifuge 144. The centrifuge 144 can be defined by any suitable apparatus configured to receive the stream of “rewetted” fine solids from the barren solution wash 140 and to separate the aqueous leachate 142 therefrom by way of centrifugal force. In this way, the centrifuge 144 derives a stream (or supply) of liquid aqueous leachate 146 and a stream (or supply) of re-dried (or “dewatered”) fine solids 145. As also depicted in
The system 100 includes a clarifying process 132. The clarifying process 132 can be defined by, or include, any suitable apparatus or processing step (or steps), if any, as desired or required, to remove solids from or otherwise handle the stream of pregnant leach solution 130 generated by the centrifuge process 128, and/or the aqueous leachate 146 generated by the centrifuge 144. For example, in a case where the PLS 130 contains 5000 ppm solids, reacted lixiviant and material of interest therein (e.g., dissolved copper, etc.), the clarifying process 132 can be suitably defined to remove a substantial fraction of the solids therefrom. In any case, the clarifying process 132 derives a stream (or supply) of pregnant leach solution 134 to be routed on to the PLS process 116 described above. In another embodiment of the system 100 (not shown), the clarifying process 132 is bypassed or omitted altogether. In yet another embodiment (not shown), the clarify process 132 can be suitably interconnected to the heat exchanger 115 so as to be heated or cooled thereby.
The system 100 of
The mass flow reactor 110 is also configured to receive the lixiviant 108 at a plurality of liquid entry points (or openings) 152 elevationally distributed within the MFR 110. While not specifically depicted in
The MFR 110 is also configured to permit the extraction of post-reaction solids 112 from one or more solids exit points (or openings) 154. Typically, at least one such solids exit point 154 is coincident with, or substantially proximate to, a bottom center “B” as defined by the mass flow reactor 110. Other respective suitable locations defined by the MFR 110 can also be used for locating the solids exits points 154. In any event, the mass flow reactor 110 is suitably equipped so as to throttle the flow of post-reaction solids 112 through each of the solids exit points 154 over some predetermined range, including complete shut off. The flow of post-reaction solids 112 can be independently controlled through each solids exit point 154, coupled (ganged) so as to throttle each exit point 156 flow in unison with the others, etc.
The MFR 110 is further configured to permit the extraction of pregnant leach solution 114 at a plurality of liquid exit points (or openings) 156 elevationally distributed within the MFR 110. It is to be understood that the mass flow reactor 110 is also suitably equipped so as to throttle (regulate) the flow of lixiviant pregnant leach solution 114 (i.e., liquid) through each of the liquid exit points 156 over some predetermined range, including complete shut off. The flow of PLS 114 can be independently controlled though each liquid exit point 156, ganged such that each liquid exit point 156 flow is throttled in unison with the others, etc.
It is important to note that the mass flow reactor 110 as depicted by
The mass flow reactor 110 of
As depicted in
The mass flow reactor 110 of
In another embodiment (not shown), a supply of inert solids is provided and selectively used so as to affect and/or stabilize one or more physical characteristics during reaction of solids with liquid(s) within a mass flow reactor (e.g., the MFR 110, etc.) such as, for example, increasing or decreasing heat conductivity, increasing or decreasing heat absorption, increasing or decreasing heat capacity, etc. Non-limiting examples of such inert solids (not shown) include steel spheres, etc.
In step 202 (
In step 204 (
In step 206 (
In step 208 (
In step 210 (
In step 212 (
Also in step 212 (
It is important to note that the respectively controlled flow rates of solids (i.e., crushed solids 106 and PRS 112) and liquids (i.e., lixiviant 108 and PLS 114) through the mass flow reactor 110 results in the reacting, or processing, of ore or other solid materials in a manner that is substantially continuous—rather than batch-like—in overall process operation. This means that once the desired depths (i.e., quantities) of solids “S” and liquid “L” are established in the MFR 110 (e.g., as in steps 204 and 206 above), such respective depths (or mass quantities, etc.) can be maintained essentially constant within the mass flow reactor 110, if desired, by way of appropriate solids and liquid flow control in to and out of (that is, through) the MFR 110. Once established, such continuous processing can be perpetuated for essentially any predetermined period of time (hours, days, weeks, months, etc.).
In step 214 (
In step 216 (
In step 218 (
In step 220 (
In step 222 (
In step 224 (
In the interest of understanding, at least some of the characteristics and advantages of the present teachings are summarized as follows:
a) The reaction of crushed solids with lixiviant (or other liquid) can be performed within a vessel, otherwise referred to as a mass flow reactor, as a substantially continuous process;
b) Solid and liquid materials migrate through, and are extracted from, a mass flow reactor substantially under the influence of gravity alone and without the use of other relevant mechanical means or forces such as, for example, driven paddles, augers, downward and/or upward liquid jetting, or vibrating, rocking, shaking, and/or rotating the mass flow reactor, and wherein gravity is not less than ninety percent of the migration-inducing force when gaseous pressure is present over the materials within the mass flow reactor;
c) At least some of the reaction of crushed solids with liquid within a mass flow reactor can be performed under conditions of a predetermined hydrostatic head of the liquid;
d) A flocculant can be used, if desired, to affect the permeability of crushed solids with respect to liquid within a mass flow reactor. In this way, liquid-on-solid contact, and the corresponding reaction between solids and liquids, can be suitably increased;
e) A gas can be injected into a mass flow reactor so as to oxidize or otherwise chemically affect compounds present during the reaction of crushed solids with liquid.
f) One or more physical and/or chemical variables can be suitably controlled within the mass flow reactor during processing, by any respectively suitable known means. Non-limiting examples of such variables include pH, Eh (i.e., electron potential in solution), temperature, viscosity, the concentration of a gas, the concentration of a liquid, etc.
g) A suitable inert solid can be used, if desired, to affect—increase, decrease or stabilize—one or more characteristics within a mass flow reactor during a reaction between solids and a liquid or liquids. Non-limiting examples of such characteristics include heat conductivity, heat absorption, etc.
It is anticipated that the invention will be embodied in other specific forms, not specifically described, that do not depart from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive, the scope of the invention being defined by the appended claims and equivalents thereof.
Claims
1. A method of processing solids with a liquid, comprising:
- providing a vessel;
- crushing the solids to not less than a predetermined median particle size, thus defining crushed solids;
- reacting the crushed solids with the liquid within the vessel, thus deriving a pregnant leach solution and post-reaction solids, wherein at least some of the reacting occurs under a predetermined hydrostatic head;
- migrating the pregnant leach solution and the post-reaction solids through the vessel substantially under the influence of gravity alone; and
- extracting the pregnant leach solution and the post-reaction solids from the vessel.
2. The method of claim 1, wherein the crushed solids define a permeability with respect to the liquid within the vessel, the method further comprising:
- controlling the permeability by way of at least one of: chemically flocculating fine particles of the crushed solids to form larger particles of the crushed solids within the vessel; agglomerating fine particles of the crushed solids to larger particles of the crushed solids prior to the reacting within the vessel; or removing fine particles of the crushed solids by way of at least one of dry screening, wet screening, or cyclonic separation of the crushed solids prior to the reacting within the vessel.
3. The method of claim 1, wherein the predetermined hydrostatic head is not less than 65 feet of the liquid.
4. The method of claim 1, wherein the reacting includes leaching at least one material out of the crushed solids and into solution with the liquid, thus deriving the pregnant leach solution and the post-reaction solids.
5. The method of claim 4, wherein the at least one material leached out of the crushed solids includes gold, silver, a platinum group metal, gallium, germanium, lead, copper, zinc, uranium, cobalt, nickel, a refractory metal, molybdenum, a light metal, sulfur, crude oil, caregens, or a rare earth element.
6. The method of claim 1, wherein the liquid includes an aqueous solution of acid or acids, an aqueous solution of acid or acids including an oxidizing agent, sulfuric acid, a solution including sulfuric acid, an aqueous solution of an alkali or alkali's, an aqueous solution of an alkali or alkalis including an oxidizing agent, an aqueous solution of cyanide including an oxidizing agent, an aqueous solution of sodium or calcium hypochlorite, an aqueous solution of ferrous or ferric sulfate, an aqueous solution of ferrous or ferric sulfate including an oxidizing agent, an aqueous solution including a bacterial catalyst, an aqueous solution of chlorine, an aqueous solution of hydrogen peroxide, a solution of ammonium thiosulfate, or an aqueous solution of air and sulfur dioxide and copper.
7. The method of claim 1, wherein the solids include one of gold-bearing ore, silver-bearing ore, ore bearing at least one platinum group metal, ore bearing rare earth elements, ore bearing gallium, ore bearing germanium, ore bearing light metals, ore bearing copper, ore bearing zinc, ore bearing molybdenum, ore bearing lead, ore bearing uranium, ore bearing cobalt, ore bearing nickel, ore bearing refractory metal, contaminated soil, solids containing coal, solids containing oil sands, and solids containing oil shales.
8. The method of claim 1, and further comprising adding the liquid into the vessel at a first flow rate, wherein the pregnant leach solution is extracted from the vessel at a second flow rate, and wherein the adding the liquid and the extracting the pregnant leach solution are performed simultaneously for a predetermined period of time.
9. The method of claim 8, wherein the first and second flow rates are at least one of essentially equal or essentially constant for the predetermined period of time.
10. The method of claim 8, wherein the predetermined period of time is not less than 3 hours.
11. The method of claim 1, and further comprising adding the crushed solids into the vessel at a first flow rate, wherein the post-reaction solids are extracted from the vessel at a second flow rate, and wherein the adding the crushed solids and the extracting the post-reaction solids are performed simultaneously for a predetermined period of time.
12. The method of claim 11, wherein the first and second flow rates are at least one of essentially equal or essentially constant for at least the predetermined period of time.
13. The method of claim 11, wherein the predetermined period of time is not less than 3 hours.
14. The method of claim 1, wherein the post-reaction solids are extracted from the vessel proximate a bottom of the vessel.
15. The method of claim 1, wherein the post-reaction solids are extracted from the vessel substantially under the influence of gravity alone.
16. The method of claim 1, wherein the pregnant leach solution is extracted from the vessel substantially under the influence of gravity alone.
17. The method of claim 1, and further comprising separating at least some of the post-reaction solids into at least two distinct groups, wherein each group corresponds to a predetermined median particle size of post-reaction solid.
18. The method of claim 1, and further comprising removing pregnant leach solution from at least some of the post-reaction solids.
19. The method of claim 18, including centrifuging at least some of the post-reaction solids to remove at least some of the pregnant leach solution.
20. The method of claim 18, including passing at least some of the post-reaction solids along a screen to remove at least some of the pregnant leach solution.
21. The method of claim 18, including leaching at least some of the post-reaction solids in a barren solution wash, thus deriving an aqueous leachate.
22. The method of claim 21, wherein the vessel is a first vessel, the method further comprising:
- providing a second vessel;
- performing the leaching of at least some of the post-reaction solids in the barren solution wash within the second vessel, thus deriving the aqueous leachate and post-leaching solids; and
- extracting the aqueous leachate and the post-leaching solids from the second vessel.
23. The method of claim 1, and further comprising extracting at least one material from the pregnant leach solution.
24. The method of claim 23, wherein the at least one material includes gold, silver, a platinum group metal, gallium, germanium, molybdenum, lead, copper, zinc, uranium, cobalt, nickel, a refractory metal, a light metal, crude oil, sulfur, or a rare earth element.
25. The method of claim 23, wherein the extracting includes at least one of using a solvent extraction, chemical precipitation, or electrolytic precipitation.
26. The method of claim 1, and further comprising controlling at least one of pH, Eh, temperature, a gas concentration, or a liquid concentration within the vessel during the reacting the crushed solids with the liquid.
27. The method of claim 1, wherein the vessel is a first vessel and the liquid is a first liquid and the pregnant leach solution is a first leach solution and the post-reaction solids are first post-reaction solids, the method further comprising:
- providing a second vessel; and
- reacting at least some of the post-reaction solids with a second liquid within the second vessel, thus deriving a second pregnant leach solution and second post-reaction solids.
28. The method of claim 1, and further comprising injecting a gas into the vessel during at least some of the reacting the crushed solids with the liquid.
29. The method of claim 28, wherein the gas is defined by an oxidizing gas.
30. The method of claim 1, wherein the crushed solids within the vessel define a permeability with respect to the liquid, the method further comprising:
- providing at least one essentially inert solid within the vessel during the reacting so as to increase the permeability of the crushed solids with respect to the liquid.
31. A method of processing mine ore with a lixiviant, comprising:
- providing a reaction vessel defining solids outlet openings and liquid outlet openings;
- crushing the mine ore to not greater than a predetermined size, thus defining crushed ore;
- reacting the crushed ore with the lixiviant within the reaction vessel, thus deriving a pregnant leach solution and post-reaction solids;
- extracting at least some of the pregnant leach solution from the reaction vessel via the liquid outlet openings substantially under the influence of gravity alone; and
- extracting the post-reaction solids and at least some of the pregnant leach solution from the reaction vessel via the solids outlet openings substantially under the influence of gravity alone.
32. The method of claim 31, wherein the predetermined size is such that at least 80 percent of the crushed ore is not greater than 6 inches in size.
33. The method of claim 31, and further comprising removing solids of less than 0.15 millimeters from the crushed ore prior to the reacting the crushed ore with the lixiviant within the reaction vessel, the removed solids defining fine solids.
34. The method of claim 33, and further comprising removing at least one material from the fine solids by way of leaching the fine solids.
35. The method of claim 31, wherein:
- the reacting includes dissolving at least one material out of the crushed ore and into solution with the lixiviant, thus deriving the pregnant leach solution; and
- the at least one material includes gold, silver, a platinum group metal, gallium, lead, germanium, copper, molybdenum, zinc, uranium, cobalt, nickel, a refractory metal, a light metal, sulfur, crude oil, or a rare earth element.
36. The method of claim 31, wherein the lixiviant includes an aqueous solution of acid or acids, an aqueous solution of acid or acids including an oxidizing agent, sulfuric acid, a solution including sulfuric acid, an aqueous solution of a base or bases, an aqueous solution of a base or bases including an oxidizing agent, an aqueous solution of cyanide including an oxidizing agent, an aqueous solution of sodium or calcium hypochlorite, an aqueous solution of ferrous or ferric sulfate, an aqueous solution of ferrous or ferric sulfate including an oxidizing agent, an aqueous solution including a bacterial catalyst, an aqueous solution of chlorine, an aqueous solution of hydrogen peroxide, a solution of ammonium thiosulfate, a lixiviant for leaching uranium, or an aqueous solution of air and sulfur dioxide and copper.
37. The method of claim 31, wherein the crushed ore includes gold-bearing ore, silver-bearing ore, ore bearing at least one platinum group metal, ore bearing rare earth elements, ore bearing gallium, ore bearing germanium, ore bearing light metals, ore bearing copper, ore bearing zinc, ore bearing molybdenum, ore bearing lead, ore bearing uranium, ore bearing cobalt, ore bearing nickel, ore bearing refractory metals, solids containing coal, solids containing oil sands, or solids containing oil shales.
38. The method of claim 31, and further comprising introducing the lixiviant into the reaction vessel at a first flow rate, wherein the pregnant leach solution is extracted from the reaction vessel at a second flow rate, and wherein the first and second flow rates are simultaneous.
39. The method of claim 38, wherein the first and second flow rates are essentially equal, essentially constant, or essentially equal and constant.
40. The method of claim 31, and further comprising introducing the crushed ore into the reaction vessel at a first flow rate, wherein the post-reaction solids are extracted from the reaction vessel at a second flow rate, and wherein the first and second flow rates are simultaneous.
41. The method of claim 40, wherein the first and second flow rates are essentially equal, essentially constant, or essentially equal and constant.
42. The method of claim 31, and further comprising separating at least two predetermined sizes of solids from at least some of the post-reaction solids.
43. The method of claim 31, and further comprising removing pregnant leach solution from at least some of the post-reaction solids, wherein the removing the pregnant leach solution includes at least one of:
- centrifuging at least some of the post-reaction solids;
- passing at least some of the post-reaction solids through a filter;
- passing at least some of the post-reaction solids along a screen; or
- leaching at least some of the post-reaction solids in barren solution wash, thus deriving an aqueous leachate.
44. The method of claim 31, and further comprising separating at least one dissolved material out of the pregnant leach solution, wherein the at least one dissolved material includes gold, silver, a platinum group metal, gallium, germanium, copper, zinc, uranium, cobalt, molybdenum, nickel, lead, a refractory metal, a light metal, crude oil, caregens, or a rare earth element.
45. The method of claim 31, and further comprising controlling at least one of temperature, pH, Eh, a gas concentration, or liquid concentration, within the reaction vessel during the reacting the crushed ore with the lixiviant.
Type: Application
Filed: Nov 28, 2005
Publication Date: May 31, 2007
Applicant:
Inventors: Matthew Russell (Spokane, WA), Robert Russell (Kellogg, ID), James Moore (Gilbert, AZ)
Application Number: 11/287,779
International Classification: C22B 15/00 (20060101);