System and method for removing contaminants from waste materials in ore concentrates
The method uses chemical reducing and oxidizing agents to selectively leach iron and sulfur from nickel ores at standard conditions, enhancing nickel recovery and reducing environmental impact, addressing the inefficiencies of current extraction methods.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- THE TRUSTEES OF COLUMBIA UNIV IN THE CITY OF NEW YORK
- Filing Date
- 2024-05-24
- Publication Date
- 2026-06-04
AI Technical Summary
Current methods for extracting nickel from sulfide ores are expensive, energy-intensive, and environmentally harmful, with low yields and inefficient use of lower-quality ores, posing challenges as high-quality deposits deplete and environmental impacts increase.
A method involving the use of chemical reducing agents like V(II) and Cr(II) to selectively leach iron and sulfur from nickel-containing concentrates, followed by chemical oxidizing agents like Ce(IV) to recover nickel, with electrochemical regeneration of agents for reuse, all conducted at standard temperatures and pressures.
This approach enhances nickel recovery from lower-quality ores, achieving high yields and reducing costs by transforming them into high-quality concentrates suitable for smelting, while minimizing environmental impact.
Smart Images
Figure 2026518258000001_ABST
Abstract
Description
Technical Field
[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 651,367, filed May 23, 2024, U.S. Provisional Patent Application No. 63 / 468,765, filed May 24, 2023, and U.S. Provisional Patent Application No. 63 / 539,901, filed September 22, 2023, which are hereby incorporated by reference in their entirety as if fully disclosed herein.
[0002] Statement Regarding Federally Sponsored Research and Development This invention was made with government support under grant number DE - AR0001706 awarded by the U.S. Department of Energy. The U.S. government has certain rights in this invention.
Background Art
[0003] The demand for nickel (Ni) is growing globally, mainly due to the expansion of the stainless - steel market. With the energy transition for climate change mitigation, the demand for nickel is predicted to increase by up to 5 - 10 times. In efforts to meet the increasing demand for high - quality raw materials, many processes and strategies have been developed for extracting and purifying Ni - containing products from naturally occurring ores and industrial by - products. The parameters for recovering nickel from natural and artificial sources depend on the grade and complexity of the Ni - containing sources.
[0004] Thermophilic bacteria have been used to improve the dissolution rate of precious metals, including copper and nickel. Bio - metallurgy is effective for Ni recovery and offers promising methods for future research and development. Ion exchange can also enable the improvement of nickel extraction and purification.
[0005] However, nickel is more expensive than other metals such as copper, and the latest nickel processing technologies are also less optimized than those for copper. Extracting nickel from sulfides is a major technical hurdle for cheaper Ni production. The main methods for extracting nickel are metallurgical methods, including dry metallurgy and wet metallurgy. These methods typically involve smelting, leaching, and refining. Smelting is used in mining to process desired metals such as copper, nickel, and cobalt, often obtained from sulfide minerals, into their pure final form. These dry metallurgical processes have been used since the beginning of ore smelting, but they are expensive, use large amounts of fuel, and can release harmful environmental toxins.
[0006] Base metals are typically found in sulfide and iron ore deposits. Ni sulfides such as pentlandite are typical sources of nickel. Previous studies have not found an effective and economical method for rapidly leaching Ni in high yield at room temperature. Current Ni production methods, using smelters or high-temperature autoclaves, utilize high temperatures, high pressure, and long residence times. While high pressure allows for processes exceeding 100°C, this results in more expensive reactors, increased energy costs, and higher total capital costs per unit of Ni recovered. Consequently, Ni yields are relatively low, hindering Ni production and creating harmful environmental impacts.
[0007] Investments in smelters can amount to billions of dollars, and therefore there is a strong incentive to extend their lifespan. Commercial operation of smelters derives significant profits from meticulous control of the raw materials for mineral concentrates, with prices set at least partially based on composition. In copper smelters, the weight percentages of Cu:Fe:S are kept within a certain range to operate efficiently. Similarly, nickel smelters maintain a weight percentage of Ni:Fe:S within a certain operating range to operate effectively.
[0008] As naturally occurring deposits of target metal-containing ore are depleted, the quality of the ore, i.e., the metal content in the ore, is expected to decrease significantly. This will have a major impact on the smelting process, which operates with the aforementioned tight ratios of metal to gangue. Smelting operations will be severely affected by the decline in ore grade. As resource grade declines, it may become difficult for miners to achieve their desired composition range (grade) targets without a significant decrease in yield (the proportion of important substances extracted from the ore), increased costs, and greater environmental impact. [Overview of the project]
[0009] Aspects of the present disclosure relate to methods for leaching one or more metals from sulfide-containing minerals. In some embodiments, the method comprises supplying a composition comprising one or more metal concentrates, wherein the composition comprises a certain concentration of iron, a certain concentration of sulfur, and a certain concentration of a target metal; reacting the metal concentrates with a first solution comprising one or more chemical reducing agents to form leached metal concentrates; separating a first leachate from the leached metal concentrates, wherein the first leachate comprises a higher concentration of iron, sulfur, or a combination thereof relative to the metal concentrates; and recovering the leached metal concentrates as a product concentrated with the target metal. In some embodiments, the method comprises treating the metal concentrates with one or more acids, wherein the one or more acids comprise approximately 0.1 M to approximately 1.0 M of H2SO4. In some embodiments, the method includes contacting the leached metal concentrate with a second solution containing one or more chemical oxidizing agents, separating the second leachate, wherein the second leachate contains a target metal, and separating the target metal product from the second leachate. In some embodiments, the method includes separating a certain concentration of reduced chemical oxidizing agent, supplying at least a portion of the reduced chemical oxidizing agent to an electrochemical device, oxidizing the reduced chemical oxidizing agent in the electrochemical device to a certain concentration of regenerated chemical oxidizing agent, and contacting at least a portion of the regenerated chemical oxidizing agent with the leached metal concentrate. In some embodiments, the method includes contacting the leached metal concentrate with an additional solution containing a certain concentration of ferric trivalent ions, and separating an additional leachate from the leached metal concentrate, wherein the additional leachate contains a higher concentration of copper relative to the leached metal concentrate. In some embodiments, the reaction of a metal concentrate with a first solution containing one or more chemical reducing agents to form a leached metal concentrate is carried out at approximately standard temperature, standard pressure, or a combination thereof. In some embodiments, the reaction of a metal concentrate with a first solution containing one or more chemical reducing agents to form a leached metal concentrate has a reaction time of approximately 1 minute to approximately 60 minutes.
[0010] In some embodiments, the metal concentrate includes pentlandite, pyrrhotite, copper tailings, or a combination thereof. In some embodiments, the target metal includes nickel, cobalt, or a combination thereof. In some embodiments, one or more chemical reducing agents include V(II), Cr(II), or a combination thereof. In some embodiments, one or more chemical oxidizing agents include Ce(IV), trivalent iron ions, or a combination thereof. In some embodiments, the metal concentrate further includes chalcopyrite.
[0011] Aspects of the present disclosure relate to systems for leaching one or more metals from sulfide-containing minerals. In some embodiments, the system includes a source of a composition comprising one or more metal concentrates, wherein the composition comprises a certain concentration of iron, a certain concentration of sulfur, and a certain concentration of a target metal; one or more reduction reactors communicating with the source of the composition and comprising a first solution comprising one or more chemical reducing agents; a first leachate discharge stream comprising a first leachate discharge stream comprising a high concentration of iron, sulfur, or a combination thereof relative to the metal concentrate; and a leached metal concentrate logistics stream comprising a product in which the target metal is concentrated relative to the metal concentrate. In some embodiments, the system includes an acid inlet stream in fluid communication with the reduction reactors, wherein the acid comprises approximately 0.1 M to approximately 1.0 M of H2SO4. In some embodiments, the system includes one or more oxidation reactors communicating with the leached metal concentrate logistics stream and comprising a second solution comprising one or more chemical oxidizing agents. In some embodiments, the system includes an electrochemical device in fluid communication with a reduction reactor, an oxidation reactor, or a combination thereof, and one or more regeneration streams configured to return a regenerated chemical reducing agent to the reduction reactor, a regenerated chemical oxidizing agent to the oxidation reactor, or a combination thereof. In some embodiments, the system includes an additional leachate discharge stream, the additional leachate discharge stream containing a high concentration of copper relative to the metal concentrate.
[0012] In some embodiments, the metal concentrate includes pentlandite, pyrrhotite, copper tailings, or a combination thereof. In some embodiments, the target metal includes nickel, cobalt, or a combination thereof. In some embodiments, one or more chemical reducing agents include V(II), Cr(II), or a combination thereof. In some embodiments, one or more chemical oxidizing agents include Ce(IV), trivalent iron ions, or a combination thereof. In some embodiments, the metal concentrate further includes chalcopyrite.
[0013] Aspects of the present disclosure relate to methods for leaching one or more metals from sulfide-containing minerals. In some embodiments, the method comprises supplying a composition containing a nickel concentrate; contacting the composition with an acid to form a treated composition, wherein the acid contains approximately 0.1 M to approximately 1.0 M of H2SO4; contacting the treated composition with a first solution containing one or more chemical reducing agents to form a leached nickel concentrate; separating a first leachate from the leached nickel concentrate, wherein the first leachate contains a high concentration of iron, sulfur, or a combination thereof relative to the nickel concentrate; contacting the leached nickel concentrate with a second solution containing one or more chemical oxidizing agents; separating a second leachate, wherein the second leachate contains a high concentration of nickel relative to the nickel concentrate; and separating a nickel metal product from the second leachate. In some embodiments, one or more chemical reducing agents include V(II), Cr(II), or a combination thereof, and one or more chemical oxidizing agents include Ce(IV), trivalent iron ions, or a combination thereof. In some embodiments, the nickel concentrate includes pentlandite, pyrrhotite, copper tailings, or a combination thereof.
[0014] The drawings illustrate embodiments of the subject matter disclosed for illustrative purposes of the present invention. However, it should be understood that this disclosure is not limited to the exact arrangements and fixtures shown in the drawings. [Brief explanation of the drawing]
[0015] [Figure 1] This is a chart of a method for leaching one or more metals from a sulfide-containing mineral according to embodiments of the present disclosure. [Figure 2A] This graph shows the preferential leaching of iron from a metal concentrate by reaction with a chemical reducing agent, according to embodiments of the present disclosure. [Figure 2B] This graph shows the preferential leaching of iron from a metal concentrate by reaction with a chemical reducing agent, according to embodiments of the present disclosure. [Figure 3] This graph shows the X-ray diffraction analysis of a solid metal concentrate leached from a solid produced by a reaction with a chemical reducing agent according to an embodiment of the present disclosure. [Figure 4A] This graph shows the preferential leaching of iron from a metal concentrate by reaction with a chemical reducing agent, according to embodiments of the present disclosure. [Figure 4B] This graph shows the preferential leaching of iron from a metal concentrate by reaction with a chemical reducing agent, according to embodiments of the present disclosure. [Figure 4C] This graph shows the X-ray diffraction analysis of a nickel-containing metal concentrate leached from a solid produced by reaction with a chemical reducing agent according to an embodiment of the present disclosure. [Figure 5] This graph shows the leaching of iron from a metal concentrate by reaction with a chemical reducing agent according to an embodiment of the disclosure. [Figure 6] This graph shows nickel leaching from a metal concentrate treated by reaction with a chemical oxidizing agent according to embodiments of the present disclosure. [Figure 7] This graph shows nickel leaching from a metal concentrate treated by reaction with a chemical oxidizing agent according to embodiments of the present disclosure. [Figure 8] This is a chart of a method for leaching one or more metals from a sulfide-containing mineral according to embodiments of the present disclosure. [Figure 9] This is a schematic diagram of a system for leaching one or more metals from sulfide-containing minerals. [Modes for carrying out the invention]
[0016] Referring to FIG. 1 here, some embodiments of the present disclosure are directed to a method 100 for leaching one or more metals from a sulfide-containing mineral. In some embodiments, the one or more metals include nickel, cobalt, or a combination thereof. In some embodiments, the one or more metals include copper. In some embodiments, the one or more metals include at least one of nickel and cobalt and further include copper. In some embodiments, the sulfide-containing mineral contains a certain concentration of nickel, cobalt, or a combination thereof. In some embodiments, the sulfide-containing mineral contains a certain concentration of copper. In some embodiments, the sulfide-containing mineral contains at least one of nickel and cobalt at a certain concentration and further contains a certain concentration of copper. In some embodiments, the sulfide-containing mineral contains one or more metal concentrates as will be described in more detail below.
[0017] In some embodiments, at 102, a composition is supplied. In some embodiments, the composition includes a solid mixture. In some embodiments, the composition includes one or more metal concentrates. As used herein, the term "metal concentrate" refers to a medium containing a certain concentration of a target metal, such as nickel, cobalt, copper, etc., the extraction of which is desired. In some embodiments, the metal concentrate is a metal-containing mineral or a combination of metal-containing minerals. In some embodiments, the composition is natural, artificial, or a combination thereof. In some embodiments, the metal concentrate is natural, artificial, or a combination thereof. In some embodiments, the composition includes a certain concentration of iron, a certain concentration of sulfur, a certain concentration of a target metal, or a combination thereof.
[0018] As described above, in some embodiments, the metal concentrate includes nickel, cobalt, or a combination thereof. In some embodiments, the metal concentrate includes copper. In some embodiments, the metal concentrate includes at least one of nickel and cobalt, and further includes copper. In some embodiments, the metal concentrate includes a certain concentration of iron, a certain concentration of sulfur, a certain concentration of a target metal, or a combination thereof. In some embodiments, the metal concentrate includes pentlandite, pyrrhotite, Cu tailings, or a combination thereof. In some embodiments, the metal concentrate includes chalcopyrite. In some embodiments, the metal concentrate includes at least one of pentlandite, pyrrhotite, and Cu tailings, and further includes chalcopyrite. In some embodiments, the sulfide-containing mineral includes a metal-containing substrate such as F1015, i.e., Cu tailings (0.7% Cu, 15.7% Ni, 30.6% S, 44.2% Fe).
[0019] In 104, at least a portion of the composition, such as a nickel concentrate, is contacted with a first solution configured to leach one or more target components therefrom. In some embodiments, the first solution comprises one or more chemical reducing agents. In some embodiments, at least a portion of the metal concentrate is reacted with the first solution, such as a chemical reducing agent. The reaction between the components of the metal concentrate and the chemical reducing agent forms a first leachate and a leached metal concentrate. In some embodiments, the first solution is contacted with the composition for approximately 1 hour, approximately 2 hours, approximately 3 hours, approximately 4 hours, approximately 5 hours, approximately 6 hours, approximately 7 hours, approximately 8 hours, more than approximately 8 hours, etc. In some embodiments, the first solution is contacted with the composition for between approximately 1 minute and approximately 60 minutes. In some embodiments, the one or more reducing agents comprise elemental vanadium, one or more vanadium compounds, elemental chromium, one or more chromium compounds, or combinations thereof. In some embodiments, the one or more chemical reducing agents comprise V(II), Cr(II), or combinations thereof. In some embodiments, the chemical reducing agent comprises vanadium(II) sulfate. In some embodiments, the chemical reducing agent comprises chromium(II) chloride. In some embodiments, the reducing agent is present at a concentration of approximately 0.1M to approximately 1.5M. In some embodiments, the metal concentrate is treated with one or more acids, for example, prior to contacting 104. In some embodiments, the one or more acids have a concentration of approximately 0.1M to approximately 1.0M. In some embodiments, the one or more acids comprise H2SO4.
[0020] In step 106, a first leachate is separated from the leached metal concentrate. In some embodiments, the first leachate contains high concentrations of iron, sulfur, or a combination thereof relative to the metal concentrate. In some embodiments, the first leachate contains iron, sulfur, or a combination thereof from the metal concentrate. Thus, steps 104 and 106 allow for the removal of undesirable iron and sulfur components from the metal concentrate source, while allowing the target metal, such as nickel, to remain in the leached metal concentrate. The first leachate may contain more than 85% of the total iron originally present in the composition. In some embodiments, at least one of steps 104 and 106 occurs at approximately standard temperature, standard pressure, or a combination thereof. Thus, the leached metal concentrate is concentrated with the target metal and may be useful as a substitute for conventional high-quality ore in downstream processes such as smelting, particularly when high-quality deposits are depleted in response to increasing demand. In step 108, the leached metal concentrate is recovered as a product concentrated with the target metal.
[0021] Referring here to Figures 2A and 2B, preferential leaching of iron from copper concentrates consistent with embodiments of the present disclosure is demonstrated. An exemplary tubular reactor setup was operated continuously to combine the copper concentrate with a VSO4 solution. In this embodiment, the use of VSO4 avoided the use of chlorides. After the reaction, H2S was discharged from the system and the solution was filtered. Copper concentrates from different sources demonstrated similar preferential iron leaching behavior in response to reaction with a chemical reducing agent consistent with embodiments of the present disclosure. The preferential leaching of iron from copper concentrates relative to copper and nickel components is demonstrated in Figure 2B. Figure 3 shows V 2+ The X-ray diffraction analysis of the solid leached metal concentrate after the leaching procedure is shown. As shown, the solid leached metal concentrate contains the final copper product (Cu or Cu2) and the intermediate copper product (Cu2S).
[0022] Referring here to Figures 4A and 4B, the preferential leaching of iron from nickel concentrates such as pentlandite, consistent with embodiments of the present disclosure, is also demonstrated. These figures show the leaching rates of Fe and Ni for various pentlandite loads over various reaction times, again demonstrating the preferential leaching of iron relative to the target metal (nickel in this case). Figure 4C shows X-ray diffraction analysis suggesting the presence of pentlandite and quartz throughout the reaction. Advantageously, embodiments of Method 100 can transform metal concentrates containing high concentrations of undesirable components such as iron and sulfur into starting materials, allowing for the preferential leaching of these components, thereby leaving a metal concentrate with a recognizable composition but enriched with one or more target metals, by removing the resulting leachate.
[0023] Referring again to Figure 1, at 110, the leached metal concentrate is brought into contact with a second solution. In some embodiments, the second solution is configured to leach one or more target components from the leached metal concentrate. In some embodiments, the second solution contains one or more chemical oxidizing agents. In some embodiments, the one or more chemical oxidizing agents include Ce(IV), iron trivalent ions, or a combination thereof. In some embodiments, at least a portion of the leached metal concentrate is reacted with the second solution, e.g., a chemical oxidizing agent. The reaction between the leached metal concentrate and the chemical oxidizing agent works to preferentially leach the target metal from the leached metal concentrate, after which the target metal can be recovered as a metal-concentrated leachate product. At 112, the second leachate is separated. In some embodiments, the second leachate contains the target metal. In some embodiments, at 114, the target metal product is separated from the second leachate.
[0024] Referring here to Table 1, exemplary embodiments of the method of the present disclosure were performed to demonstrate sequential selective leaching of Fe and Ni from pentland ore by vanadium treatment followed by cerium treatment. [Table 1] Table 1: Exemplary method demonstrating sequential selective leaching of iron and nickel from pentland ore
[0025] Referring here to Figure 5 and Table 2, chemical treatments consistent with the embodiments of this disclosure were performed to demonstrate the selective leaching of iron and nickel from the metal concentrate. These additional chemical treatments, indicated as "Chemical Treatment 1" and "Chemical Treatment 2," are shown in Table 3 below. Approximately 90% of the iron leached from the metal concentrate into the solution. The leached metal concentrate demonstrated that it was concentrated with nickel and had a lower concentration of iron (see Table 2 below). Indeed, the resulting leached nickel concentrate exhibited a composition similar to nickel matte, a traded nickel intermediate. [Table 2] Table 2: Concentration of components in nickel metal concentrate [Table 3] Table 3: Exemplary chemical reduction treatments for preferential leaching of iron and sulfur components from metal concentrates consistent with embodiments of the present disclosure.
[0026] Referring to Figure 6, the additional reaction with a chemical oxidizing agent resulted in the recovery of approximately 90% of the total nickel from the nickel metal concentrate in the second leachate. These metal recovery results were obtained when operating at room temperature and atmospheric pressure.
[0027] Referring here to Figure 7, a trivalent iron oxidizing agent at 80°C was demonstrated as a chemical oxidizing agent consistent with several embodiments of this disclosure. While not bound by theory, it was shown that the reaction rate is slower than that of cerium, and that high temperatures and reaction times of nearly 8 hours are utilized.
[0028] Referring again to Figure 1, in some embodiments, at 116, a reduced chemical oxidizing agent of a certain concentration is separated. In some embodiments, the reduced chemical oxidizing agent is produced as a result of the reaction in contact step 110. In some embodiments, at 118, at least a portion of the reduced chemical oxidizing agent is supplied to an electrochemical device. In some embodiments, at 120, the reduced chemical oxidizing agent in the electrochemical device is oxidized to a certain concentration of regenerated chemical oxidizing agent. The regenerated chemical oxidizing agent can then be reused to leach an additional amount of leached metal concentrate, which helps reduce the cost and waste of materials associated with embodiments of this disclosure. In some embodiments, at 122, at least a portion of the regenerated chemical oxidizing agent is brought into contact with the leached metal concentrate. In some embodiments (not shown), the oxidized chemical reducing agent is similarly electrochemically treated to produce a certain amount of regenerated chemical oxidizing agent, which can be used, for example, in contact step 104 to leach an additional metal concentrate.
[0029] In some embodiments, the leached metal concentrate is brought into contact with an additional solution containing a certain concentration of ferric trivalent ions. In some embodiments, an additional leachate is separated from the leached metal concentrate. In some embodiments, the additional leachate contains a high concentration of copper relative to the leached metal concentrate. More than 99% of the copper present in the metal concentrate can be recovered in the leachate stream utilizing chemical reducing agent / ferric trivalent ion leaching according to at least the embodiments of this disclosure. Thus, these embodiments can profitably recover a multitude of products from metal concentrates that might be considered "low quality," either as the product itself, e.g., a metal product, or as a concentrated raw material for use in other downstream processes, e.g., concentrated nickel-containing ore.
[0030] Referring here to Figure 8, some embodiments of the present disclosure relate to a method 800 for leaching one or more metals from sulfide-containing minerals. In some embodiments, in 802, a composition comprising a nickel concentrate is supplied. In some embodiments, the nickel concentrate comprises pentlandite, pyrrhotite, copper tailings, or a combination thereof. In 804, the composition is brought into contact with one or more acids. As described above, in some embodiments, the acid comprises approximately 0.1 M to approximately 1.0 M of H2SO4. In some embodiments, contact with the acid in 804 forms a treated composition. In some embodiments, in 806, the treated composition is brought into contact with a first solution. As described above, in some embodiments, the first solution comprises one or more chemical reducing agents. In some embodiments, the chemical reducing agents comprises V(II), Cr(II), or a combination thereof. The chemical reducing agents react with at least the nickel concentrate in the composition to form a first leachate comprising iron, sulfur, or a combination thereof from the nickel concentrate. The nickel concentration in this first leachate is high relative to the nickel concentrate. By contacting it (806), a nickel concentrate is also formed. In (808), the first leachate is separated from the nickel concentrate.
[0031] In some embodiments, in 810, the leached nickel concentrate is brought into contact with a second solution containing one or more chemical oxidizing agents. In some embodiments, the chemical oxidizing agents include Ce(IV), iron trivalent ions, or a combination thereof. The chemical oxidizing agents react with at least the leached nickel concentrate to form a second leachate containing nickel from the leached nickel concentrate. The nickel concentration in this second leachate is high relative to the nickel concentrate. In 812, the second leachate is separated. In 814, in some embodiments, the nickel metal product is separated from the second leachate by any preferred process, such as electrolytic extraction.
[0032] Referring here to Figure 9, some embodiments of the present disclosure relate to a system 900 for leaching one or more metals from sulfide-containing minerals, for example, to form concentrated metal concentrates, to recover metal products, etc., or for a combination thereof. In some embodiments, the system 900 includes a source 902 of a composition comprising one or more metal concentrates. As described above, in some embodiments, the composition comprises a certain concentration of iron, a certain concentration of sulfur, and a certain concentration of a target metal. In some embodiments, the target metal comprises nickel, cobalt, or a combination thereof.
[0033] In some embodiments, the source 902 is naturally occurring, artificial, or a combination thereof. In some embodiments, the metal concentrate is a metal-containing mineral or a combination of metal-containing minerals. In some embodiments, the metal concentrate is naturally occurring, artificial, or a combination thereof. In some embodiments, the metal concentrate includes pentlandite, pyrrhotite, copper tailings, or a combination thereof. In some embodiments, the metal concentrate also includes copper. In some embodiments, the metal concentrate also includes chalcopyrite.
[0034] In some embodiments, the system 900 includes one or more reduction reactors 904 in communication with a supply source 902. In some embodiments, the system 900 includes a plurality of reduction reactors 904. In some embodiments, the plurality of reduction reactors 904 are arranged in series. In some embodiments, the reduction reactors 904 are in fluid communication with one or more acid supply sources 906. In some embodiments, the supply source 902 is in direct communication with the acid supply source 906. In some embodiments, the system 900 includes an acid inlet stream 906A configured to bring the composition into contact with an acid from the acid supply source 906, for example, in a reduction reactor 904, in a supply source 902, in a separate reaction vessel (not shown), etc., or a combination thereof. In some embodiments, the acid, for example, the acid in the acid inlet stream 906A, includes approximately 0.1 M to approximately 1.0 M H2SO4.
[0035] In some embodiments, the reduction reactor 904 contains a first solution 908. As described above, in some embodiments, the first solution 908 contains one or more chemical reducing agents. In some embodiments, the one or more chemical reducing agents include V(II), Cr(II), or a combination thereof. In some embodiments, the system 900 contains a first leachate discharge stream 910. As described above, in some embodiments, the first leachate discharge stream contains, for example, a high concentration of iron, sulfur, or a combination thereof relative to the metal concentrate from the supply source 902. In some embodiments, the system 900 contains a leached metal concentrate stream 912 containing a product in which the target metal is concentrated relative to the metal concentrate. In some embodiments, the first leachate discharge stream 910 and the leached metal concentrate stream 912 are removed from the reduction reactor 904. In some embodiments, the first leachate discharge stream 910 and the leached metal concentrate stream 912 are separated via one or more filters 914.
[0036] In some embodiments, the system 900 includes one or more leachate reactors 916. In some embodiments, the leachate reactors 916 are in fluid communication with a leached metal concentration flow 912. In some embodiments, the leachate reactors 916 include a leachate solution 918 having a certain concentration of ferric trivalent ions. In some embodiments, the system 900 includes an additional leachate discharge flow 920. In some embodiments, the additional leachate discharge flow 920 contains a high concentration of copper to a supply 902. In some embodiments, the supply 902 contains chalcopyrite.
[0037] In some embodiments, the system 900 includes one or more oxidation reactors 922. In some embodiments, the oxidation reactor 922 is in fluid communication with a leached metal concentration flow 912. In some embodiments, the oxidation reactor 922 is in fluid communication with a leachate reactor 916. In some embodiments, the oxidation reactor 922 includes a second solution 924. In some embodiments, the second solution 924 includes one or more chemical oxidizing agents. In some embodiments, one or more chemical oxidizing agents include Ce(IV), iron trivalent ions, or a combination thereof. In some embodiments, the system 900 includes a second leachate discharge flow 926. In some embodiments, the second leachate discharge flow 926 contains a high concentration of nickel relative to the supply source 902.
[0038] In an exemplary embodiment of system 900, pentland ore is subjected to vanadium(II) and Ce(IV) leaching. First, raw pentland ore from, for example, source 902 is reacted with sulfuric acid, for example, via contact with acid inlet stream 906A. This solution is then filtered, for example, through filter 914, and then in reduction reactor 904 2+ The Ni-rich product is reacted with the pentland ore to leach iron, forming a first leachate discharge stream 910 that can be removed from the reduction reactor, for example, through another filter 914, leaving a Ni-rich product. The Ni-rich product is transported to the leachate reactor 916 as a leached metal concentration stream 912, where it is further treated with trivalent iron ions in the leachate solution 918. Copper in the Ni-rich product can be leached therefrom and removed as a copper-concentrated leachate discharge stream 920. The Ni-rich product is then transported to the oxidation reactor 922, where it can be contacted with a chemical oxidizing agent from a second solution 924. Nickel in the Ni-rich product can then be recovered as a second leachate discharge stream 926, which can be transported to an electrolytic extraction system (not shown) for recovering the nickel metal product.
[0039] In some embodiments, the system 900 includes an electrochemical device 928 communicating with a reduction reactor 904, an oxidation reactor 922, or a combination thereof. As described above, the electrochemical device 928 is configured to electrochemically replenish chemical reducing agents and chemical oxidizing agents for reuse in the reduction reactor 904 and the oxidation reactor 922, respectively. In some embodiments, the electrochemical device includes at least one pair of electrodes, e.g., a cathode and an anode, electrically communicating through one or more electrolytes, and a power supply configured to apply a potential between the electrodes. In some embodiments, the system 900 includes one or more regeneration streams 930 configured to return regenerated chemical reducing agents to the reduction reactor 904, return regenerated chemical oxidizing agents to the oxidation reactor 922, or a combination thereof.
[0040] The systems and methods of this disclosure favorably react metal concentrates with chemical reducing agents and chemical oxidizing agents to concentrate the metal concentrates with respect to a target metal such as nickel. As the demand for nickel-containing products increases, the availability of high-quality nickel-containing ore is decreasing. Lower-quality ore is still available but may not be suitable for use in conventional smelting systems, or may require long processing times, or may result in lower yields of metal products, increasing the associated costs of any nickel-containing product developed from the ore. Ni sulfide minerals can be treated with one or more acids and then contacted with one or more chemical reducing agents consistent with embodiments of this disclosure, e.g., V(II), to selectively leach a stream concentrated with iron and sulfur components from the mineral, leaving the concentrated mineral. In this way, minerals such as lower-quality pentlandite can be converted into higher-quality nickel concentrates desirable for use in smelting processes. The concentrated mineral can be further reacted with one or more chemical oxidizing agents, e.g., Ce(IV), to leach an additional stream concentrated with the target metal itself, e.g., nickel. It is also possible to further leach the copper product stream from the concentrated metal concentrate using trivalent iron ions. Embodiments of this disclosure can be carried out at reasonable pressures and temperatures compared to conventional methods, thus enabling higher yields and improved production methods of Ni metal and / or alternative Ni products. The selective removal process works well even with high loads of solids.
[0041] Subsequently, the metal products can be recovered from these additional flows, for example, by electrolytic extraction. Advantageously, both the chemical reducing agent and chemical oxidizing agent can be electrochemically replenished for reuse in subsequent reaction processes using additional metal concentrates, reducing the total cost and material waste associated with embodiments of this disclosure. These systems and methods enable domestic production of nickel as an alternative to dry metallurgy or autoclave processes, which have multiple environmental / climatic impacts, and are beneficial for implementations related to battery production, mining, clean technologies, and the like.
[0042] While the present invention has been described and illustrated with illustrative examples thereof, it will be understood by those skilled in the art that various other modifications, omissions, and additions described herein and thereto may be made without departing from the spirit and scope of the invention.
Claims
1. A method for leaching one or more metals from a sulfide-containing mineral, To supply a composition containing one or more metal concentrates, wherein the composition contains a certain concentration of iron, a certain concentration of sulfur, and a certain concentration of a target metal. The metal concentrate is reacted with a first solution containing one or more chemical reducing agents to form a leached metal concentrate. The separation of a first leachate from the leached metal concentrate, wherein the first leachate contains iron, sulfur, or a combination thereof in a high concentration relative to the metal concentrate. The process includes recovering the leached metal concentrate as a product in which the target metal is concentrated, A method wherein the metal concentrate comprises pentlandite, pyrrhotite, coarsely selected Cu tailings, or a combination thereof.
2. The method according to claim 1, wherein the target metal includes nickel, cobalt, or a combination thereof.
3. The method according to claim 1, wherein the one or more chemical reducing agents include V(II), Cr(II), or a combination thereof.
4. The process further comprises treating the metal concentrate with one or more acids, wherein the one or more acids are approximately 0.1 M to approximately 1.0 M H ２ SO ４ The method according to claim 1, including the method described in claim 1.
5. The leached metal concentrate is brought into contact with a second solution containing one or more chemical oxidizing agents. The separation of the second leachate, wherein the second leachate contains the target metal. The separation of the target metal product from the second leachate, The method according to claim 1, further comprising:
6. Separating a reduced chemical oxidizing agent at a certain concentration, The reduced chemical oxidizing agent is supplied to an electrochemical device, The electrochemical device oxidizes the reduced chemical oxidizing agent to a regenerated chemical oxidizing agent of a certain concentration, The process involves bringing at least a portion of the regenerated chemical oxidizing agent into contact with the leached metal concentrate, The method according to claim 5, further comprising:
7. The method according to claim 5, wherein the one or more chemical oxidizing agents include Ce(IV), iron trivalent ions, or a combination thereof.
8. The method according to claim 1, wherein the metal concentrate further comprises chalcopyrite.
9. The leached metal concentrate is brought into contact with an additional solution containing a certain concentration of ferric trivalent ions. The separation of an additional leachate from the leached metal concentrate, wherein the additional leachate contains a higher concentration of copper relative to the leached metal concentrate. The method according to claim 8, further comprising:
10. The method according to claim 1, wherein the metal concentrate is reacted with a first solution containing one or more chemical reducing agents to form an leached metal concentrate, at approximately standard temperature, standard pressure, or a combination thereof.
11. The method according to claim 1, wherein the metal concentrate is reacted with a first solution containing one or more chemical reducing agents to form an leached metal concentrate, the reaction time being approximately 1 minute to approximately 60 minutes.
12. A system for leaching one or more metals from sulfide-containing minerals, A source of a composition comprising one or more metal concentrates, wherein the composition comprises a certain concentration of iron, a certain concentration of sulfur, and a certain concentration of a target metal. One or more reduction reactors, which are in communication with a source of the composition and contain a first solution containing one or more chemical reducing agents, A first leachate discharge stream, the first leachate discharge stream containing high concentrations of iron, sulfur, or a combination thereof relative to the metal concentrate, A leached metal concentration logistics comprising a product in which the target metal is concentrated relative to the metal concentrate, A method wherein the metal concentrate comprises pentlandite, pyrrhotite, coarsely selected Cu tailings, or a combination thereof.
13. The system according to claim 12, wherein the target metal includes nickel, cobalt, or a combination thereof.
14. The system according to claim 12, wherein one or more chemical reducing agents include V(II), Cr(II), or a combination thereof.
15. The system further includes an acid inlet flow that is in fluid communication with the reduction reactor, wherein the acid is approximately 0.1 M to approximately 1.0 M H ２ SO ４ The system according to claim 12, including the above.
16. The system according to claim 12, further comprising one or more oxidation reactors communicating with the leached metal concentration logistics and containing a second solution, wherein the second solution contains one or more chemical oxidizing agents.
17. The system according to claim 16, wherein the one or more chemical oxidizing agents include Ce(IV), iron trivalent ions, or a combination thereof.
18. The reduction reactor, the oxidation reactor, or a combination thereof, and an electrochemical device in fluid communication with them, One or more regeneration streams configured to return the regenerated chemical reducing agent to the reduction reactor, return the regenerated chemical oxidizing agent to the oxidation reactor, or perform a combination thereof, The system according to claim 16, further comprising:
19. The system further includes an additional leachate discharge stream, the additional leachate discharge stream containing a high concentration of copper relative to the metal concentrate, The system according to claim 17, wherein the metal concentrate further comprises chalcopyrite.
20. A method for leaching one or more metals from a sulfide-containing mineral, To supply a composition containing nickel concentrate, The process involves contacting the aforementioned composition with an acid to form a treated composition, wherein the acid is approximately 0.1 M to approximately 1.0 M H ２ SO ４ Including forming, The treated composition is brought into contact with a first solution containing one or more chemical reducing agents to form an leached nickel concentrate. The separation of a first leachate from the leached nickel concentrate, wherein the first leachate contains iron, sulfur, or a combination thereof in a high concentration relative to the nickel concentrate. The leached nickel concentrate is brought into contact with a second solution containing one or more chemical oxidizing agents. The separation of the second leachate, wherein the second leachate contains a high concentration of nickel relative to the nickel concentrate. This includes separating nickel metal products from the second leachate, The one or more chemical reducing agents include V(II), Cr(II), or a combination thereof, and the one or more chemical oxidizing agents include Ce(IV), trivalent iron ions, or a combination thereof. A method wherein the nickel concentrate comprises pentlandite, pyrrhotite, coarse Cu tailings, or a combination thereof.