A combined hydrometallurgical process for extracting battery metal elements

Abstract

This invention provides a combined hydrometallurgical process for extracting battery metal elements. It involves the combined hydrometallurgical extraction of metal elements from nickel-iron alloy and recycled ternary cathode powder. The process employs various methods to improve acid utilization and enhances iron recovery through the reuse of the back-extraction solution, yielding battery-grade iron phosphate, battery-grade nickel-cobalt-manganese sulfate solution, and battery-grade nickel sulfate solution. This process boasts high battery metal element recovery rates, high product purity, low waste residue, low auxiliary material usage, and high material recycling rate, demonstrating promising application prospects.

Description

Technical Field

[0001] This invention belongs to the field of hydrometallurgical technology and relates to a process for extracting battery metal elements by combined hydrometallurgical processes. Background Technology

[0002] In recent years, with the rapid development of the lithium battery new energy industry, the supply of nickel raw materials for battery materials has gradually become insufficient. Laterite nickel ore has become an important source of nickel in power battery materials in recent years. In the hydrometallurgical process of laterite nickel ore, a large amount of iron is difficult to utilize as a resource, resulting in waste. The pyrometallurgical process of laterite nickel ore is used to produce nickel-iron alloy, and then the hydrometallurgical process is used to prepare iron phosphate and nickel sulfate to realize the resource utilization of nickel-iron. However, the existing nickel-iron alloy processing technology not only produces a large amount of slag and has a low utilization rate of iron phosphate, but also has a low acid and alkali utilization rate and high production costs.

[0003] CN202111602206.8 discloses a method for preparing ferric phosphate from nickel-iron alloy, comprising: adding a prepared phosphoric acid solution and a sulfuric acid solution to the nickel-iron alloy, heating and stirring for a period of time to obtain a nickel-iron leachate, then adding a hydrogen peroxide solution and an ammonia solution, followed by aging, filtration, washing, and drying to obtain ferric phosphate dihydrate. However, this process does not involve mother liquor treatment, resulting in low utilization of residual acid in the mother liquor.

[0004] CN202210312490.3 discloses a method for separating and extracting nickel and iron from nickel-iron alloys, comprising leaching the nickel-iron alloy with a sulfuric acid solution, evaporating and concentrating the leachate to obtain a concentrated solution, cooling and crystallizing the concentrated solution, separating the solid and liquid to obtain crude ferrous sulfate crystals and a first solution, adding an oxidant and a phosphorus source to the first solution, adjusting the pH with alkali, heating the reaction, further adjusting the pH of the slurry after the reaction, and then separating the solid and liquid to obtain a nickel sulfate solution and ferric phosphate. Although this invention effectively improves the nickel-iron recovery rate, it results in a large amount of ferric phosphate slag, low acid and alkali utilization rate, underutilization of residual acid in the mother liquor, and high production costs.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The present invention aims to provide a combined hydrometallurgical process for extracting battery metal elements. This process improves the utilization rate of acid and iron in the nickel-iron mother liquor, while simultaneously extracting nickel, cobalt, and manganese elements from a nickel-cobalt-manganese solution, thereby increasing the purity of each extracted metal element. The process is simple, produces less waste residue, and requires less auxiliary materials.

[0007] To achieve the above objectives, the present invention provides a process for extracting battery metal elements using a combined hydrometallurgical process, comprising the following steps:

[0008] The mother liquor of nickel-iron is extracted to obtain the extract phase and the raffinate phase of the mother liquor of nickel-iron;

[0009] The nickel-cobalt-manganese oxide solution was subjected to a first extraction to obtain a first extract phase and a first raffinate phase.

[0010] The first raffinate phase is subjected to a second extraction to obtain the second raffinate phase;

[0011] The second raffinate phase is subjected to a third extraction to obtain a third extract phase and a third raffinate phase.

[0012] The residual phase of the nickel-iron mother liquor is mixed with sulfuric acid to obtain back-extraction agent one. The back-extraction agent one is used to back-extract the third extraction phase to obtain back-extraction solution one.

[0013] The pH of the first back-extraction solution is adjusted to 5-6 to carry out the first precipitation reaction. After solid-liquid separation and oil removal, a battery-grade nickel-cobalt-manganese sulfate solution is obtained.

[0014] The third raffinate phase is subjected to a fourth extraction to obtain a fourth raffinate phase;

[0015] The fourth raffinate phase is subjected to a fifth extraction to obtain a fifth extract phase;

[0016] The fifth extraction phase was back-extracted with sulfuric acid to obtain back-extraction solution II, which was then de-oiled to obtain a battery-grade nickel sulfate solution.

[0017] In some embodiments, the preparation of the nickel-iron mother liquor includes the following steps: after treating the nickel-iron alloy with inorganic acid leaching, solid-liquid separation is performed to obtain nickel-iron leachate;

[0018] The pH of the nickel-iron leaching solution is adjusted to 3.0-4.5, precipitation reaction two is carried out, solid-liquid separation is performed, and impurity-removed nickel-iron solution is obtained;

[0019] Oxidizing agent and phosphoric acid are added to the impurity-removing nickel-iron solution, and after an oxidation precipitation reaction, solid-liquid separation is performed to obtain the nickel-iron mother liquor and iron phosphate.

[0020] The iron phosphate is aged, filtered, and washed to obtain battery-grade iron phosphate.

[0021] In some embodiments, the nickel-iron mother liquor extract phase and the first extract phase are subjected to back-extraction three and back-extraction four, respectively, to obtain back-extraction solution three and back-extraction solution four, respectively; the back-extraction solution three and back-extraction solution four are mixed and deoiled to obtain recycled acid; the recycled acid is reused in the acid leaching treatment.

[0022] In some embodiments, the organic phase used for extraction includes a diluent and an extractant;

[0023] And / or, the diluent is at least one selected from sulfonated kerosene, kerosene, toluene, Escaid 110, hexane, heptane, and dodecane;

[0024] And / or, the extractants in the nickel-iron mother liquor extraction and the first extraction are at least one of P204, P507, C272 and P227, respectively;

[0025] And / or, the extractant in the third extraction is C272 or a combination of C272 and sec-nonyl-p-phenoxypropionic acid. In some embodiments, the stripping agent in the third and fourth strippings is phosphoric acid, with a molar concentration of 7-14 mol / L;

[0026] And / or, the H of the back-extraction agent one + The concentration is 1-2 mol / L.

[0027] In some embodiments, the pH adjuster for the first back-extraction solution and the pH adjuster for the nickel-iron leaching solution is nickel carbonate.

[0028] In some embodiments, the extractant in the nickel-iron mother liquor extraction and the first extraction has a percentage content of 15%-25% in the organic phase of the extraction;

[0029] And / or, when the nickel-iron mother liquor extraction and the first extraction are saponification extractions, the extracted organic phase is subjected to sodium soap followed by nickel soap, and the saponification rates of the sodium soap and the nickel soap are 30%-50% and 90%-100%, respectively.

[0030] And / or, the saponification rate of the extracted organic phase sodium soap in the first extraction is 30%-50%.

[0031] In some embodiments, when the extractant in the third extraction is C272, the percentage content of C272 in the extracted organic phase is 10%-30%.

[0032] And / or, when the extractant in the third extraction is a combination of C272 and the co-extractant sec-nonyl-p-phenoxypropionic acid, the percentage content of sec-nonyl-p-phenoxypropionic acid in the extractive organic phase is not higher than 10%, and the percentage content of C272 in the extractive organic phase is 10%-30%.

[0033] And / or, when the third extraction is a saponification extraction, the extracted organic phase is subjected to sodium soap, and the saponification rate of the sodium soap is 30%-50%.

[0034] In some embodiments, the extraction ratio O / A in the nickel-iron mother liquor extraction is 15:1-5, the number of extraction stages is 4-6, the number of washing times is 2-3, and the washing ratio O / A is 15-20:1.

[0035] And / or, the extraction ratio O / A in the third extraction is 10-12:1, and the number of extraction stages is 8-10;

[0036] And / or, the O / A ratio in the three back-extraction processes is 13-32:1;

[0037] And / or, in the back-extraction process, the O / A ratio is 10-15:1.

[0038] In some embodiments, the volume ratio of inorganic acid to recycled acid in the acid leaching treatment is 1:2-4;

[0039] And / or, the inorganic acid is at least one of sulfuric acid, hydrochloric acid and nitric acid.

[0040] The beneficial effects of this invention include:

[0041] This invention provides a combined hydrometallurgical process for extracting battery metal elements. The process involves back-extracting and degreasing the nickel-iron mother liquor extract phase and the first extract phase to obtain recycled acid, which is then reused in the acid leaching process. This improves the utilization of acid and iron in the process and reduces waste. The residual phase of the nickel-iron mother liquor is mixed with sulfuric acid for back-extraction, reducing the amount of acid and liquid alkali used and improving acid utilization. In the recovery of the nickel-cobalt-manganese oxide solution, C272 or a combination of C272 and sec-nonyl-p-phenoxypropionic acid is used as the extractant to separate nickel, calcium, magnesium, cobalt, manganese, and aluminum. Simultaneously, the gel-state aluminum slag is used to remove silicon, simplifying the process, reducing auxiliary material input, and decreasing the amount of aluminum slag. Through this combined hydrometallurgical process, battery-grade iron phosphate, battery-grade nickel-cobalt-manganese sulfate solution, and battery-grade nickel sulfate solution are obtained. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a process flow diagram of the combined hydrometallurgical extraction of battery metal elements provided in Embodiment 1 of the present invention;

[0044] Figure 2 This is a SEM image of battery-grade iron phosphate obtained in Example 1 of the present invention;

[0045] Figure 3 This is a SEM image of the battery-grade iron phosphate obtained in Example 1 of the present invention. Detailed Implementation

[0046] The following detailed description, with appropriate reference to the accompanying drawings, discloses a specific embodiment of a combined hydrometallurgical process for extracting battery metal elements according to the present invention. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of essentially the same structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0047] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. Specifically, "(", ")", "[", and "]" represent intervals, where "(" or ")" represents an open interval, meaning the endpoints of the interval are not included; and "[" and "]" represent a closed interval, meaning the endpoints of the interval are included. A range defined in this way can include endpoints or not, and can be arbitrarily combined, meaning any lower limit can be combined with any upper limit to form a range.

[0048] Specifically, for example, if the ranges 60-120 and 80-110 are listed for a specific parameter, it is understood that the ranges 60-110 and 80-120 are also expected. Furthermore, if the minimum range values ​​are listed as 1 and 2, and if the maximum range values ​​are listed as 3, 4, and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range “ab” represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range “0-5” means that all real numbers between “0-5” have been listed herein, and “0-5” is merely a shortened representation of these numerical combinations. Additionally, when a parameter is stated as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. If (10, 20) is listed, it is understood as any value in the interval 10-20 excluding 10 and 20; (10, 20] is understood as any value in the interval 10-20 excluding 10 but including 20.

[0049] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0050] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0051] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0052] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0053] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0054] In some embodiments, the nickel-iron mother liquor is extracted to obtain a nickel-iron mother liquor extract phase and a nickel-iron mother liquor raffinate phase.

[0055] The nickel-cobalt-manganese oxide solution was subjected to a first extraction to obtain a first extract phase and a first raffinate phase.

[0056] The first raffinate phase is subjected to a second extraction to obtain the second raffinate phase;

[0057] The second raffinate phase is subjected to a third extraction to obtain a third extract phase and a third raffinate phase.

[0058] The residual phase of the nickel-iron mother liquor is mixed with sulfuric acid to obtain back-extraction agent one. The back-extraction agent one is used to back-extract the third extraction phase to obtain back-extraction solution one.

[0059] The pH of the first back-extraction solution is adjusted to 5-6 to carry out the first precipitation reaction. After solid-liquid separation and oil removal, a battery-grade nickel-cobalt-manganese sulfate solution is obtained.

[0060] The third raffinate phase is subjected to a fourth extraction to obtain a fourth raffinate phase;

[0061] The fourth raffinate phase is subjected to a fifth extraction to obtain a fifth extract phase;

[0062] The fifth extraction phase was back-extracted with sulfuric acid to obtain back-extraction solution II, which was then de-oiled to obtain a battery-grade nickel sulfate solution.

[0063] In some embodiments, the nickel-cobalt-manganese oxide solution is subjected to a first extraction to remove iron, a second extraction to remove copper, a third extraction to separate nickel, calcium, and magnesium from cobalt, manganese, aluminum, silicon, and phosphorus, a fourth extraction to remove calcium and magnesium, a fifth extraction to remove nickel, and back-extraction to obtain a battery-grade nickel sulfate solution.

[0064] In some embodiments, the precipitation reaction yields a silicon-removing slag, which includes silicon slag, aluminum slag, and phosphorus slag.

[0065] In some embodiments, after the third extract phase is back-extracted, the resulting back-extract is adjusted for pH to remove phosphorus, silicon, and aluminum, and then deoiled to obtain a battery-grade nickel-cobalt-manganese sulfate solution. The process for obtaining battery-grade nickel sulfate solution and battery-grade nickel-cobalt-manganese sulfate solution uses fewer auxiliary materials, produces high-purity products, generates less waste residue, and has minimal environmental impact.

[0066] In some embodiments, the residual phase of the nickel-iron mother liquor is mixed with sulfuric acid to obtain a back-extraction agent, which is then used to back-extract the third extraction phase to obtain a back-extraction solution. Mixing the residual phase of the nickel-iron mother liquor with sulfuric acid to obtain the back-extraction agent improves the utilization rate of residual acid in the nickel-iron mother liquor, while saving the amount of acid and liquid alkali used in the back-extraction process. Furthermore, it can reduce the amount of impurity metal elements introduced into the nickel-cobalt-manganese solution by the back-extraction agent.

[0067] In some embodiments, the residual phase of the nickel-iron mother liquor is mixed with sulfuric acid to obtain a back-extraction agent, which is then used to back-extract the fifth extraction phase to obtain a battery-grade nickel-cobalt sulfate solution. Using the residual phase of the nickel-iron mother liquor as recycled acid introduces a certain amount of impurity elements, therefore, a precipitation reaction needs to be added, and further filtration and oil removal are required to obtain the battery-grade nickel-cobalt sulfate solution.

[0068] In some embodiments, the preparation of the nickel-iron mother liquor includes the following steps: after acid leaching of the nickel-iron alloy, solid-liquid separation is performed to obtain nickel-iron leaching solution and leaching residue. The leaching residue is nickel-iron alloy that has not been completely acid-leached, and it is returned to the acid leaching section for secondary acid leaching treatment.

[0069] In some embodiments, the raffinate phase of the nickel-iron mother liquor is mixed with sulfuric acid or sulfuric acid alone to obtain a second stripping agent. The second stripping agent is then used to strip the fifth extraction phase to obtain a second stripping solution. Since the raffinate phase of the nickel-iron mother liquor contains impurity metal elements, it is necessary to further add aluminum sulfate, followed by the addition of carbonic acid for precipitation reaction. After filtration and oil removal, silicon slag and battery-grade nickel-cobalt sulfate solution are obtained.

[0070] In some embodiments, after adjusting the pH of the nickel-iron leaching solution to 3.0-4.5, a second precipitation reaction is carried out to separate the solid and liquid phases, thereby obtaining a purified nickel-iron solution.

[0071] In some embodiments, the nickel-iron mother liquor extract phase and the first extract phase are subjected to back-extraction three and back-extraction four, respectively, to obtain back-extraction solution three and back-extraction solution four. The back-extraction solution three and back-extraction solution four are then mixed and deoiled to obtain recycled acid, which is reused in the acid leaching treatment. This improves the utilization rate of iron in the nickel-iron mother liquor and reduces the amount of waste residue; simultaneously, the H+ in the recycled acid... + and Fe 3+ Leaching of nickel-iron alloys reduces the use of acid.

[0072] In some embodiments, the extractants used in the nickel-iron mother liquor extraction and the first extraction are at least one of P204, P507, C272, and P227, respectively. Iron removal is performed at low pH using P204, P507, C272, and P227.

[0073] In some embodiments, the extractant in the third extraction is C272 or a combination of C272 and the co-extractant sec-nonyl-p-phenoxypropionic acid. The third extraction simplifies the separation process of nickel, calcium, and magnesium from cobalt, manganese, aluminum, silicon, and phosphorus.

[0074] In some embodiments, when the extractant for the third extraction is only C272, the aluminum extraction performance will decrease, and aluminum will be more difficult to separate from calcium and magnesium. When the extractant for the third extraction is a combination of C272 and the co-extractant sec-nonyl-p-phenoxypropionic acid, the aluminum extraction performance will be improved through the co-extraction effect of sec-nonyl-p-phenoxypropionic acid.

[0075] In some embodiments, the stripping agent in stripping step three and stripping step four is phosphoric acid, specifically PO4 in phosphoric acid. 3- with Fe 3+ Phosphoric acid undergoes a complexation reaction and exhibits better back-extraction performance than hydrochloric acid, sulfuric acid, and nitric acid. It can more effectively back-extract to obtain a regenerated organic phase, which can then be recycled, reducing the loss of the extracted organic phase and improving the utilization rate of the acid.

[0076] In some embodiments, the H of the back-extraction agent one + The concentration is 1-2 mol / L.

[0077] In some implementations, the molar concentration of phosphoric acid in the back-extraction is 7-14 mol / L. Too low a molar concentration of phosphoric acid will result in an excessively low concentration of nickel cobalt manganese sulfate.

[0078] In some embodiments, the pH adjuster for the first back-extraction solution and the pH adjuster for the nickel-iron leaching solution is nickel carbonate. During the first back-extraction process, the pH value is adjusted by nickel carbonate to remove aluminum and phosphorus; simultaneously, the adsorption properties of the gel-state aluminum slag are utilized to remove silicon from the solution, achieving a one-step removal of aluminum, silicon, and phosphorus from the first back-extraction solution, simplifying the process flow. This reduces the input of aluminum sulfate, lowers auxiliary material costs, and also reduces the amount of aluminum slag. Nickel carbonate is added to the nickel-iron leaching solution to carry out the second precipitation reaction, obtaining a cleaned nickel-iron solution and chromium slag. The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used without specified manufacturers are all conventional products that can be obtained commercially.

[0079] Please refer to the process flow diagram of the method. Figure 1 The features and performance of the present invention will be further described in detail below with reference to embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0080] Example 1:

[0081] Step 1: Acid leaching treatment of nickel-iron alloy

[0082] A nickel-iron alloy is subjected to acid leaching treatment. The nickel and iron in the nickel-iron alloy have mass fractions of 13% and 86%, respectively. Other metals include Co: 0.5%, Cr: 0.3%, and Si: 0.2%. The acid leaching acid consists of recycled acid after back-extraction and sulfuric acid, with a volume ratio of sulfuric acid to recycled acid of 1:2. The molar concentration of sulfuric acid is 0.5 mol / L. The pH of the acid leaching treatment is 1.5, the acid leaching temperature is 75℃, and the acid leaching time is 10 h, resulting in a nickel-iron leaching solution and leaching residue. The leaching residue is returned to the acid leaching process. The nickel-iron leaching solution contains the following metals: Ni: 21.7 g / L, Fe: 166 g / L, Co: 0.82 g / L, Cr: 0.66 g / L, and Si: 0.13 g / L.

[0083] Step 2: Chromium removal treatment via precipitation reaction

[0084] Nickel carbonate was added to the nickel-iron leaching solution to adjust the pH to 4.5, and the reaction was carried out at 60°C for 8 hours to obtain chromium slag (Ni: 1%, Fe: 1.6%, Cr: 15%, Si: 0.3%) and impurity-removed nickel-iron solution (Ni: 25 g / L, Fe: 166 g / L, Co: 0.82 g / L, Cr: 5 mg / L, Si: 0.12 g / L).

[0085] Step 3: Iron Oxidation and Preparing Battery-Grade Iron Phosphate

[0086] Hydrogen peroxide and phosphoric acid were added to the impurity-removed nickel-iron solution to carry out an oxidation and precipitation reaction. The amount of 30% hydrogen peroxide added was 27% of the volume of the impurity-removed nickel-iron solution, and the amount of 14 mol / L phosphoric acid solution added was 2.7% of the volume of the impurity-removed nickel-iron solution. The reaction was carried out at 95°C for 2 hours, with a pH of 0.5. After pressure filtration, iron phosphate and nickel-iron mother liquor were obtained. The nickel-iron mother liquor contained Ni: 19.3 g / L, Co: 0.73 g / L, Fe: 15 g / L, P: 0.6 g / L, and Si: 90 mg / L.

[0087] The iron phosphate is aged, filtered, washed, dried, and calcined to obtain battery-grade iron phosphate.

[0088] Step 4: Iron removal by extraction from nickel-iron mother liquor

[0089] Nickel-iron mother liquor extraction: The organic phase of the extract, composed of P227 and sulfonated kerosene, was subjected to 40% sodium soap treatment with 30% liquid alkali. Then, nickel sulfate solution was added to convert 100% of the organic phase after sodium soap treatment into nickel soap. This was then added to the nickel-iron mother liquor for extraction, yielding the nickel-iron mother liquor extract phase and the nickel-iron mother liquor raffinate phase. The volume ratio of sulfonated kerosene to P227 was 80%:20%, and the O / A ratio of the extract phase was 3:1. After five stages of extraction, the mixture was washed three times with 0.5 mol / L sulfuric acid, resulting in an O / A ratio of 20:1. The nickel-iron mother liquor raffinate phase contained Ni: 37.7 g / L, Co: 0.73 g / L, Fe < 5 mg / L, P: 0.52 g / L, Si: 85 mg / L, and pH 0.5.

[0090] Step 3: The nickel-iron mother liquor is extracted and back-extracted using a 7 mol / L phosphoric acid solution to obtain back-extraction solution three and a third regenerated organic phase. The O / A ratio of the back-extraction solution is 13:1, and five stages of back-extraction are performed. The Fe content of the third regenerated organic phase is 0.1 g / L. The third regenerated organic phase is recycled to step 4 for the sodium soap process. The Fe content of back-extraction solution three is 65 g / L, and the P content is 217 g / L. After degreasing, back-extraction solution three is recycled to the nickel-iron alloy acid leaching treatment.

[0091] Step 5: Extraction of iron and copper using nickel-cobalt-manganese oxide solution.

[0092] First extraction: Iron ions in the nickel-cobalt-manganese solution from the lithium battery recycling process were oxidized using hydrogen peroxide to obtain a nickel-cobalt-manganese oxide solution (Ni: 40 g / L, Co: 30 g / L, Mn: 30 g / L, Al: 2.85 g / L, Fe: 0.5 g / L, Ca: 0.22 g / L, Mg: 2.6 g / L, Cu: 1 g / L, pH 2.0). The organic phase of the extract, composed of P507 and sulfonated kerosene, was subjected to 40% sodium soap treatment with 30% liquid alkali. This oxidized nickel-cobalt-manganese solution was then extracted to obtain the first extract phase and the first raffinate phase. The volume ratio of sulfonated kerosene to P507 was 80%:20%, and the O / A ratio of the extract phase was 1:10. After five stages of extraction, the solution was washed three times with 0.5 mol / L sulfuric acid, resulting in an O / A ratio of 20:1. The first raffinate phase contained Ni: 38 g / L, Co: 28.5 g / L, Mn: 28.5 g / L, Al: 2.7 g / L, Fe: <5 mg / L, Cu: 2.5 g / L, Ca: 0.21 g / L, Mg: 2.5 g / L, and pH 2.0.

[0093] Step 4: Similar to step 4, step 3, the Fe content of the fourth regenerated organic phase is 0.1 g / L. The fourth regenerated organic phase is reused in the first extraction for the sodium soap process. The Fe content in step 4 is 65 g / L and the P content is 217 g / L. It is mixed into step 3 for the oil removal process.

[0094] Step 6: Extraction of copper with nickel-cobalt-manganese oxide solution

[0095] Second extraction: M5640 (N-phenyl-N,N'-di(2-ethylhexyl)dione oxime) and sulfonated kerosene were used as the extractable organic phase. The first raffinate phase was then subjected to a second extraction to obtain a second extractable phase and a second raffinate phase. The volume ratio of sulfonated kerosene to M5640 was 70%:30%, and the O / A ratio of the extractable phase was 1:2. After four stages of extraction and clarification using a first-stage clarifier, the second raffinate phase had the following composition: Ni: 38 g / L, Co: 28.5 g / L, Mn: 28.5 g / L, Al: 2.7 g / L, Fe: <5 mg / L, Cu: <1 mg / L, pH 1.0.

[0096] Extraction step 5: The second extract is back-extracted using a 2 mol / L sulfuric acid solution to obtain back-extract solution 5 and the fifth regenerated organic phase, wherein the O / A ratio of the back-extracted solution is 5:1, and 3-stage back-extraction is performed. The Cu content of the fifth regenerated organic phase is 0.1 g / L, and the fifth regenerated organic phase is reused in the second extraction. The Cu content in back-extract solution 5 is 25 g / L.

[0097] Step 7: Extraction of cobalt and manganese, extraction of calcium and magnesium, and extraction of nickel.

[0098] Third extraction: C272, sec-nonyl-p-phenoxypropionic acid, and sulfonated kerosene were prepared into a mixed extractable organic phase. After saponification with liquid alkali, the second raffinate phase was added for extraction, yielding a third extractable phase and a third raffinate phase. The volume ratio of C272, sec-nonyl-p-phenoxypropionic acid, and sulfonated kerosene was 20%:10%:70%, the saponification rate was 40%, and the O / A ratio of the extractable phase was 10:1. The extraction was performed in 8 stages, followed by 6 stages of washing with 0.5 mol / L sulfuric acid, with an O / A ratio of 40:1. The third raffinate phase contained: Ni: 37 g / L, Co: 2 mg / L, Mn: 2 mg / L, Al: 1 mg / L, Ca: 0.2 g / L, Mg: 2.4 g / L, and pH 4.0.

[0099] Back-extraction 1: Add concentrated sulfuric acid to the residual phase of the nickel-iron mother liquor from step 4 to prepare H... + The third extraction was back-extracted with a 1.5 mol / L acid solution to obtain back-extract solution one and a first regenerated organic phase, wherein the O / A ratio of the back-extracted solution was 12:1, and five-stage back-extraction was performed. The first regenerated organic phase was reused in the third extraction. The back-extract solution one contained Ni: 37 g / L, Co: 34.5 g / L, Mn: 34.2 g / L, Al: 2 g / L, P: 0.52 g / L, Si: 85 mg / L, and pH 3.0.

[0100] Fourth extraction: The organic phase composed of P507 and sulfonated kerosene was subjected to 40% sodium soap treatment with 30% liquid alkali, followed by extraction of the third raffinate phase, yielding a fourth extract phase and a fourth raffinate phase. The volume ratio of sulfonated kerosene to P507 was 80%:20%, and the O / A ratio of the extract phase was 1:1. After 10 stages of extraction, 18 stages of washing with 0.5 mol / L sulfuric acid were performed, with an O / A ratio of 10:1. The fourth raffinate phase contained Ni: 34.5 g / L, Ca: 1 mg / L, Mg: 1 mg / L, and pH 5.5.

[0101] Extraction step six: The fourth extraction step was performed by back-extraction with 4 mol / L hydrochloric acid solution to obtain back-extraction solution six and the sixth regenerated organic phase, wherein the O / A ratio of the back-extraction solution was 20:1, and eight-stage back-extraction was carried out. The Ca and Mg contents of the sixth regenerated organic phase were both less than 2 mg / L. The sixth regenerated organic phase was reused in the fourth extraction. The Ca content in back-extraction solution six was 4 g / L, and the Mg content was 48 g / L.

[0102] Fifth extraction: The organic phase composed of P507 and sulfonated kerosene was subjected to 50% sodium soap treatment with 30% liquid alkali, followed by extraction of the fourth raffinate phase, yielding a fifth extract phase and a fifth raffinate phase. The volume ratio of sulfonated kerosene to P507 was 80%:20%, and the O / A ratio of the extract phase was 3.45:1. After 10 stages of extraction, the phase was washed three times with 0.5 mol / L sulfuric acid, with an O / A ratio of 20:1. The fifth raffinate phase contained 10 mg / L Ni and had a pH of 6.5.

[0103] Second back-extraction: The fifth extraction was back-extracted using a 2 mol / L sulfuric acid solution to obtain a second back-extraction solution and a second regenerated organic phase, wherein the O / A ratio of the back-extraction solution was 10:1, and four stages of back-extraction were performed. The Ni content of the second regenerated organic phase was less than 5 mg / L, and the second regenerated organic phase was reused in the fifth extraction. The Ni content in the second back-extraction solution was 100 g / L, and the pH was 3.0. The second back-extraction solution was then de-oiled and finely filtered to obtain a battery-grade nickel sulfate solution.

[0104] Step 8: Obtain battery-grade nickel-cobalt-manganese sulfate solution

[0105] Precipitation reaction one: Nickel carbonate was added to the first stripping solution, and the pH of the solution was adjusted to 5.5 at 70℃. After reacting for 8 hours, the solution was filtered and deoiled to obtain slag and a battery-grade nickel-cobalt-manganese sulfate solution. Ni: 46 g / L, P ≤ 5 mg / L, Co: 34.5 g / L, Mn: 34.2 g / L, Al ≤ 1 mg / L, Si ≤ 10 mg / L. The slag was washed with 0.5 mol / L sulfuric acid to obtain desiliconized slag (Ni: 1%, Al: 10%, P: 2.6%, Si: 0.4%). The washing solution was then mixed into the nickel-cobalt-manganese sulfate solution.

[0106] Figure 2-3 The image shows a SEM image of battery-grade iron phosphate obtained in Example 1. Example 1 successfully prepared iron phosphate material with a thickness of approximately 10 μm.

[0107] Example 2:

[0108] The only difference between this embodiment and Example 1 is that in step 4: iron removal by nickel-iron mother liquor extraction, the phrase "using 30% liquid alkali to perform 40% sodium soap on the extraction organic phase composed of P227 and sulfonated kerosene, and then adding nickel sulfate solution to convert the sodium soap extraction organic phase into 100% nickel soap" is replaced with "using P204 and sulfonated kerosene to form the extraction organic phase". All other conditions and parameters are exactly the same as in Example 1.

[0109] Example 3:

[0110] The only difference between this embodiment and Embodiment 1 is that in step 4, back-extraction, "extracting and back-extracting the nickel-iron mother liquor with 7 mol / L phosphoric acid solution" is replaced with "extracting and back-extracting the nickel-iron mother liquor with 14 mol / L phosphoric acid solution". All other conditions and parameters are exactly the same as in Embodiment 1.

[0111] Example 4:

[0112] The difference between this embodiment and Example 1 lies only in step 7, the third extraction: "C272, sec-nonyl-p-phenoxypropionic acid, and sulfonated kerosene are mixed to form an extractable organic phase, which is then saponified with liquid alkali, and then added to the second raffinate phase for extraction, yielding a third extractable phase and a third raffinate phase. The volume ratio of C272, sec-nonyl-p-phenoxypropionic acid, and sulfonated kerosene is 20%:10%:70%, the saponification rate is 40%, the extraction phase O / A ratio is 10:1, and the process involves 8 stages of extraction and 6 stages of washing with 0.5 mol / L sulfuric acid." The original text, "The washing O / A ratio was 40:1", was replaced with "C272 and sulfonated kerosene were mixed to form an extractable organic phase, which was then saponified with liquid alkali. The second raffinate phase was then added for extraction to obtain a third extractable phase and a third raffinate phase. The volume ratio of C272 to sulfonated kerosene was 20%:80%, the saponification rate was 40%, the O / A ratio of the extractable phase was 12:1, and the process involved 8 stages of extraction followed by 8 stages of washing with 0.5 mol / L sulfuric acid, with an O / A ratio of 10:1". All other conditions and parameters were identical to those in Example 1.

[0113] Example 5:

[0114] The difference between this embodiment and Example 1 lies only in that, in step 7, the extraction of cobalt and manganese, the extraction of calcium and magnesium, and the extraction of nickel, the second back-extraction step involves using a 2 mol / L sulfuric acid solution to back-extract the fifth extraction, resulting in a second back-extraction solution and a second regenerated organic phase. The O / A ratio of the back-extraction solution is 10:1, and four stages of back-extraction are performed. The Ni content in the second regenerated organic phase is less than 5 mg / L, and this second regenerated organic phase is reused in the fifth extraction. The Ni content in the second back-extraction solution is 100 g / L, and the pH is... 3.0. The second back-extraction solution is degreased and finely filtered to obtain a battery-grade nickel sulfate solution. This is replaced with "Back-extraction II: Concentrated sulfuric acid is added to the residual phase of the nickel-iron mother liquor from step 4 to prepare a 1.5 mol / L sulfuric acid solution for back-extraction of the fifth extraction stage, yielding back-extraction solution II and a second regenerated organic phase. The O / A ratio of the back-extraction solution is 7.5:1, and five stages of back-extraction are performed. The Ni content of the second regenerated organic phase is less than 10 mg / L, and it is reused in the fifth extraction. The back-extraction solution II contains Ni: 112 g / L, Co: 0.6 g / L, P: 0.52 g / L, Si: 85 mg / L, and pH 3.0."

[0115] Precipitation reaction three: At 70℃, aluminum sulfate was added to the second back-extraction solution and stirred until the aluminum mass concentration reached 2.7 g / L. Nickel carbonate was then added, and the pH of the solution was adjusted to 5.5. After reacting for 8 hours, the solution was filtered, degreased, and finely filtered to obtain slag and a battery-grade nickel-cobalt sulfate solution. Ni: 112 g / L, P ≤ 5 mg / L, Co: 0.6 g / L, Al ≤ 1 mg / L, Si ≤ 10 mg / L. The slag was washed with 0.5 mol / L sulfuric acid to obtain desiliconized slag (Ni: 1.5%, Al: 10%, P: 2.6%, Si: 0.4%). The washing solution was then mixed into the nickel-cobalt sulfate solution. Other conditions and parameters were exactly the same as in Example 1.

[0116] Comparative Example 1:

[0117] Step 1: Acid leaching treatment of nickel-iron alloy

[0118] A nickel-iron alloy is subjected to acid leaching treatment, wherein the mass fractions of nickel and iron are 13% and 86%, respectively, and other metals include Co: 0.5%, Cr: 0.3%, and Si: 0.2%. The acid leaching acid consists of recycled acid after back-extraction and sulfuric acid, with a volume ratio of sulfuric acid to recycled acid of 1:2 and a molar concentration of sulfuric acid of 0.5 mol / L. The pH of the acid leaching treatment is 1.5, the acid leaching temperature is 75℃, and the acid leaching time is 10 h, resulting in a nickel-iron leaching solution and leaching residue. The leaching residue is returned to the acid leaching process. The nickel-iron leaching solution contains: Ni: 21.7 g / L, Fe: 166 g / L, Co: 0.82 g / L, Cr: 0.66 g / L, and Si: 0.13 g / L.

[0119] Step 2: Chromium removal treatment via precipitation reaction

[0120] Nickel carbonate was added to the nickel-iron leaching solution to adjust the pH to 4.5, and the reaction was carried out at 60°C for 8 hours to obtain chromium slag (Ni: 1%, Fe: 1.6%, Cr: 15%, Si: 0.3%) and impurity-removed nickel-iron solution (Ni: 25 g / L, Fe: 166 g / L, Co: 0.82 g / L, Cr: 5 mg / L, Si: 0.12 g / L).

[0121] Step 3: Iron Oxidation and Preparing Battery-Grade Iron Phosphate

[0122] Hydrogen peroxide and phosphoric acid were added to the impurity-removed nickel-iron solution to carry out an oxidation and precipitation reaction. The amount of 30% hydrogen peroxide added was 27% of the volume of the impurity-removed nickel-iron solution, and the amount of 14 mol / L phosphoric acid solution added was 2.7% of the volume of the impurity-removed nickel-iron solution. The reaction was carried out at 95°C for 2 hours, with a pH of 0.5. After pressure filtration, iron phosphate and nickel-iron mother liquor were obtained. The nickel-iron mother liquor contained Ni: 19.3 g / L, Co: 0.73 g / L, Fe: 15 g / L, P: 0.6 g / L, and Si: 90 mg / L.

[0123] The iron phosphate is aged, filtered, washed, dried, and calcined to obtain battery-grade iron phosphate.

[0124] Step 4: Recovery of nickel-iron mother liquor

[0125] Sodium carbonate was mixed with nickel-iron mother liquor, and the pH of the mixed solution was controlled at 5-5.5 to carry out the iron precipitation reaction.

[0126] Comparative Example 2:

[0127] The only difference between this comparative example and Example 1 is that in step 4, back-extraction three, the nickel-iron mother liquor is back-extracted using a 7 mol / L phosphoric acid solution to obtain back-extraction solution three and a third regenerated organic phase, wherein the O / A ratio of the back-extraction is 13:1, and five-stage back-extraction is performed. The Fe content of the third regenerated organic phase is 0.1 g / L. The third regenerated organic phase is recycled to step 4 for the sodium soap process. The Fe content of back-extraction solution three is 65 g / L, and the P content is 217 g / L. After degreasing, back-extraction solution three is recycled to the nickel-iron compound. "Gold acid leaching treatment" is replaced with "The nickel-iron mother liquor is extracted and back-extracted using a 7 mol / L sulfuric acid solution to obtain back-extraction solution three and a third regenerated organic phase, wherein the O / A ratio of the back-extraction solution is 2.1:1, and five-stage back-extraction is performed. The Fe content of the third regenerated organic phase is 0.5 g / L, and the third regenerated organic phase is recycled to step 4 for the sodium soap process. The Fe content of back-extraction solution three is 10 g / L. After degreasing, back-extraction solution three is recycled to the nickel-iron alloy acid leaching treatment." Other conditions and parameters are exactly the same as in Example 1.

[0128] Comparative Example 3:

[0129] Step 1: Acid leaching treatment of nickel-iron alloy

[0130] A nickel-iron alloy is subjected to acid leaching treatment, wherein the mass fractions of nickel and iron are 13% and 86%, respectively, and other metals include Co: 0.5%, Cr: 0.3%, and Si: 0.2%. The acid leaching acid consists of recycled acid after back-extraction and sulfuric acid, with a volume ratio of sulfuric acid to recycled acid of 1:2 and a molar concentration of sulfuric acid of 0.5 mol / L. The pH of the acid leaching treatment is 1.5, the acid leaching temperature is 75℃, and the acid leaching time is 10 h, resulting in a nickel-iron leaching solution and leaching residue. The leaching residue is returned to the acid leaching process. The nickel-iron leaching solution contains: Ni: 21.7 g / L, Fe: 166 g / L, Co: 0.82 g / L, Cr: 0.66 g / L, and Si: 0.13 g / L.

[0131] Step 2: Chromium removal treatment via precipitation reaction

[0132] Nickel carbonate was added to the nickel-iron leaching solution to adjust the pH to 4.5, and the reaction was carried out at 60°C for 8 hours to obtain chromium slag (Ni: 1%, Fe: 1.6%, Cr: 15%, Si: 0.3%) and impurity-removed nickel-iron solution (Ni: 25 g / L, Fe: 166 g / L, Co: 0.82 g / L, Cr: 5 mg / L, Si: 0.12 g / L).

[0133] Step 3: Iron Oxidation and Preparing Battery-Grade Iron Phosphate

[0134] Hydrogen peroxide and phosphoric acid were added to the impurity-removed nickel-iron solution to carry out an oxidation and precipitation reaction. The amount of 30% hydrogen peroxide added was 27% of the volume of the impurity-removed nickel-iron solution, and the amount of 14 mol / L phosphoric acid solution added was 2.7% of the volume of the impurity-removed nickel-iron solution. The reaction was carried out at 95°C for 2 hours, with a pH of 0.5. After pressure filtration, iron phosphate and nickel-iron mother liquor were obtained. The nickel-iron mother liquor contained Ni: 19.3 g / L, Co: 0.73 g / L, Fe: 15 g / L, P: 0.6 g / L, and Si: 90 mg / L.

[0135] The iron phosphate is aged, filtered, washed, dried, and calcined to obtain battery-grade iron phosphate.

[0136] Step 4: Iron removal by extraction from nickel-iron mother liquor

[0137] Nickel-iron mother liquor extraction: The organic phase of the extract, composed of P227 and sulfonated kerosene, was subjected to 40% sodium soap treatment with 30% liquid alkali. Then, nickel sulfate solution was added to convert 100% of the organic phase after sodium soap treatment into nickel soap. This was then added to the nickel-iron mother liquor for extraction, yielding the nickel-iron mother liquor extract phase and the nickel-iron mother liquor raffinate phase. The volume ratio of sulfonated kerosene to P227 was 80%:20%, and the O / A ratio of the extract phase was 3:1. After five stages of extraction, the mixture was washed three times with 0.5 mol / L sulfuric acid, resulting in an O / A ratio of 20:1. The nickel-iron mother liquor raffinate phase contained Ni: 37.7 g / L, Co: 0.73 g / L, Fe < 5 mg / L, P: 0.52 g / L, Si: 85 mg / L, and pH 0.5.

[0138] Step 3: The nickel-iron mother liquor is extracted and back-extracted using a 7 mol / L phosphoric acid solution to obtain back-extraction solution three and a third regenerated organic phase. The O / A ratio of the back-extraction solution is 13:1, and five stages of back-extraction are performed. The Fe content of the third regenerated organic phase is 0.1 g / L. The third regenerated organic phase is recycled to step 4 for the sodium soap process. The Fe content of back-extraction solution three is 65 g / L, and the P content is 217 g / L. After degreasing, back-extraction solution three is recycled to the nickel-iron alloy acid leaching treatment.

[0139] Step 5: Extraction of copper with nickel-cobalt-manganese oxide solution

[0140] Copper removal by extraction: Iron ions in the nickel-cobalt-manganese solution from the lithium battery recycling process are oxidized using hydrogen peroxide to obtain a nickel-cobalt-manganese oxide solution (Ni: 40 g / L, Co: 30 g / L, Mn: 30 g / L, Al: 2.85 g / L, Fe: 0.5 g / L, Ca: 0.22 g / L, Mg: 2.6 g / L, Cu: 1 g / L, pH 2.0). Second extraction: The nickel-cobalt-manganese oxide solution is subjected to a second extraction using M5640 (N-phenyl-N,N'-di(2-ethylhexyl)dione oxime) and sulfonated kerosene as the extractive organic phase, yielding a second extractive phase and a second raffinate phase. The volume ratio of sulfonated kerosene to M5640 is 70%:30%, and the O / A ratio of the extractive phase is 1:2. After four stages of extraction, a first-stage clarification is used.

[0141] Step 5: The second extract is back-extracted using a 2 mol / L sulfuric acid solution to obtain back-extract solution five and the fifth regenerated organic phase, wherein the O / A ratio of the back-extracted solution is 5:1, and three-stage back-extraction is performed. The fifth regenerated organic phase is reused in the second extraction.

[0142] Step 6: Remove iron and aluminum

[0143] Sodium carbonate was added to the second raffinate to adjust the pH to 5, precipitating iron and aluminum. After filtration, a solution containing copper, nickel, cobalt, and manganese, and iron and aluminum slag were obtained.

[0144] Step 7: Extraction of cobalt and manganese, extraction of calcium and magnesium, and extraction of nickel.

[0145] Third extraction: C272, sec-nonyl-p-phenoxypropionic acid, and sulfonated kerosene were prepared into a mixed extractable organic phase. After saponification with liquid alkali, the copper-, nickel-, cobalt-, and manganese-removing solution was added for extraction, yielding a third extractable phase and a third raffinate phase. The volume ratio of C272, sec-nonyl-p-phenoxypropionic acid, and sulfonated kerosene was 20%:10%:70%, the saponification rate was 40%, and the O / A ratio of the extract phase was 10:1. The process involved 8 stages of extraction followed by 6 stages of washing with 0.5 mol / L sulfuric acid, with an O / A ratio of 40:1 after each washing.

[0146] Back-extraction 1: Add concentrated sulfuric acid to the residual phase of the nickel-iron mother liquor from step 4 to prepare H... + A 1.5 mol / L acid solution was used for back-extraction of the third extract to obtain back-extraction solution one and a first regenerated organic phase, wherein the O / A ratio of the back-extraction solution was 12:1, and five stages of back-extraction were performed. The first regenerated organic phase was reused in the third extract.

[0147] Fourth extraction: The organic phase consisting of P507 and sulfonated kerosene was subjected to 40% sodium soap treatment with 30% liquid alkali, followed by extraction of the third raffinate phase, yielding a fourth extract phase and a fourth raffinate phase. The volume ratio of sulfonated kerosene to P507 was 80%:20%, and the O / A ratio of the extract phase was 1:1. After 10 stages of extraction, the mixture was washed with 0.5 mol / L sulfuric acid for 18 stages, with an O / A ratio of 10:1.

[0148] Extraction step six: The fourth extract is back-extracted using 4 mol / L hydrochloric acid solution to obtain back-extract solution six and the sixth regenerated organic phase, wherein the O / A ratio of the back-extracted solution is 20:1, and eight stages of back-extraction are performed. The sixth regenerated organic phase is reused in the fourth extraction.

[0149] Fifth extraction: The organic phase of extract composed of P507 and sulfonated kerosene was subjected to 50% sodium soap treatment with 30% liquid alkali, followed by extraction of the fourth raffinate phase to obtain the fifth extract phase and the fifth raffinate phase. The volume ratio of sulfonated kerosene to P507 was 80%:20%, and the O / A ratio of the extract phase was 3.45:1. After 10 stages of extraction, the mixture was washed three times with 0.5 mol / L sulfuric acid, with an O / A ratio of 20:1.

[0150] Back-extraction 2: The fifth extraction stage is back-extracted using a 2 mol / L sulfuric acid solution to obtain back-extraction solution 2 and a second regenerated organic phase, wherein the O / A ratio of the back-extraction solution is 10:1, and four stages of back-extraction are performed. The Ni content of the second regenerated organic phase is less than 5 mg / L, and the second regenerated organic phase is reused in the fifth extraction. The back-extraction solution 2 is then subjected to oil removal and fine filtration to obtain a battery-grade nickel sulfate solution.

[0151] Step 8: Obtain battery-grade nickel-cobalt-manganese sulfate solution

[0152] Precipitation reaction one: Aluminum sulfate was added to the first stripping solution to increase the aluminum concentration to 2 g / L. Nickel carbonate was then added to the solution, and the pH was adjusted to 5.5 at 70°C. After reacting for 8 hours, the solution was filtered and oil removed to obtain slag and a battery-grade nickel-cobalt-manganese sulfate solution. The slag was washed with 0.5 mol / L sulfuric acid to obtain desiliconized slag, and the washing solution was mixed into the nickel-cobalt-manganese sulfate solution.

[0153] Comparative Example 4:

[0154] The only difference between this comparative example and Example 1 is that in step 7: extraction of cobalt and manganese, extraction of calcium and magnesium, and extraction of nickel, the original description of "preparing C272, sec-nonyl-p-phenoxypropionic acid, and sulfonated kerosene into a mixed extractable organic phase, saponifying it with liquid alkali, and then adding the second raffinate phase for extraction to obtain a third extractable phase and a third raffinate phase. The volume ratio of C272, sec-nonyl-p-phenoxypropionic acid, and sulfonated kerosene phase is 20%:10%:70%" is replaced with "preparing sec-nonyl-p-phenoxypropionic acid and sulfonated kerosene into a mixed extractable organic phase, saponifying it with liquid alkali, and then adding the second raffinate phase for extraction to obtain a third extractable phase and a third raffinate phase. The volume ratio of sec-nonyl-p-phenoxypropionic acid and sulfonated kerosene phase is 15%:85%". All other conditions and parameters are exactly the same as in Example 1.

[0155] Experimental example:

[0156] The element concentrations in the residual phase of the nickel-iron mother liquor, the back-extraction solution, and the battery-grade nickel-cobalt-manganese sulfate solution in Examples 1-5 and Comparative Examples 2-4 were measured respectively. The iron element concentration in the nickel-iron mother liquor in Comparative Example 1 was measured. The slag volume and nickel-cobalt-manganese yield ratio, as well as the utilization rate of each element, were calculated. The results are shown in Table 1.

[0157] Among them, the concentration of iron in the raffinate phase of nickel-iron mother liquor was detected;

[0158] The concentrations of iron and phosphorus elements, as well as the hydrogen ion concentration, in the back-extraction solution were measured.

[0159] The ratios of nickel, cobalt, and manganese concentrations to calcium and magnesium concentrations in a battery-grade nickel-cobalt-manganese sulfate solution were determined and calculated.

[0160] The amount of slag produced per ton of nickel-cobalt-manganese is measured, where nickel-cobalt-manganese includes nickel in battery-grade nickel sulfate solution, and nickel, cobalt, and manganese in battery-grade nickel-cobalt-manganese sulfate solution; the amount of slag includes the sum of chromium slag, desiliconized slag, and iron-aluminum slag.

[0161] The utilization rate of each element is calculated using the ratio of product output to the total amount of raw materials and auxiliary materials. Products include battery-grade iron phosphate, battery-grade nickel-cobalt-manganese sulfate solution, battery-grade nickel sulfate solution, and battery-grade nickel-cobalt sulfate solution. Raw materials include nickel-iron alloy and nickel-cobalt-manganese oxide solution. Auxiliary materials include phosphoric acid and nickel carbonate.

[0162] Formula = Product output / (Raw material quantity + Auxiliary material quantity).

[0163] Table 1

[0164]

[0165]

[0166] As shown in the table above, the combined hydrometallurgical extraction process for battery metal elements provided by this invention in Examples 1-5 has low iron content in the raffinate phase of nickel-iron mother liquor, low calcium and magnesium content in battery-grade nickel-cobalt-manganese sulfate solution, and low slag production. At the same time, Fe, Ni, Co, Mn and P elements have extremely high utilization rates.

[0167] Compared with Example 1 of this invention, in the nickel-iron mother liquor extraction process of Example 2, iron removal without saponification was used, and the Fe content in the raffinate phase of the obtained nickel-iron mother liquor was ≤80mg / L, which is higher than the Fe content in the raffinate phase of the nickel-iron mother liquor in Example 1, thus reducing the utilization rate of iron in the nickel-iron alloy.

[0168] Compared with Example 1 of the present invention, Example 3 uses a higher concentration of phosphoric acid as the stripping agent in the back-extraction of the nickel-iron mother liquor extract phase, i.e., back-extraction three, resulting in higher concentrations of iron, phosphorus and acid in the obtained back-extraction solution three.

[0169] Compared with Example 1 of the present invention, in Example 4, only one type of extractant is used in the third extraction process, which leads to a reduction in the O / A ratio of the washing line and an increase in the amount of rewash.

[0170] Compared with Example 1 of this invention, Example 5 uses nickel-iron mother liquor to extract the residual phase in the fifth extraction back-extraction process. On the basis of utilizing the residual acid, impurity ions are introduced, and the back-extraction liquid needs to be further treated, which to some extent increases the amount of slag and auxiliary materials.

[0171] Compared with Example 1 of the present invention, the nickel-iron mother liquor recovery process of Comparative Example 1 mixes sodium carbonate with nickel-iron mother liquor to carry out an iron precipitation reaction to obtain iron slag, without recycling the iron in the nickel-iron mother liquor. The utilization rate of iron is reduced by 12%, and the generation of waste slag is increased.

[0172] Compared with Example 1 of the present invention, sulfuric acid was used in the back-extraction of Comparative Example 2. The antiferrervescence of sulfuric acid is far less than that of phosphoric acid, which increases the amount of acid used. At the same time, it leads to a higher iron content in the first regenerated organic phase. Long-term operation will cause the extractant to be poisoned and lose its extraction performance.

[0173] Compared to Example 1 of this invention, Comparative Example 3 changed the impurity removal sequence of the nickel-cobalt-manganese oxide solution. First, copper was removed from the oxidized nickel-cobalt-manganese solution by extraction, yielding a second raffinate phase. Then, sodium carbonate was mixed with the second raffinate phase to remove iron and aluminum, resulting in a copper-free nickel-cobalt-manganese solution and iron-aluminum slag. Since the addition of sodium carbonate removes impurities iron and aluminum simultaneously, aluminum sulfate needs to be added as an auxiliary material in the subsequent silicon removal process, increasing both the amount of auxiliary material used and the amount of slag generated.

[0174] Compared with Example 1 of the present invention, Comparative Example 4 changed the ratio of the extractant during the third extraction process, which made it impossible for cobalt and manganese to be effectively separated from calcium and magnesium, thus increasing the amount of calcium and magnesium impurities and slag in the battery-grade nickel cobalt manganese sulfate solution.

[0175] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A process for extracting battery metal elements using a combined hydrometallurgical method, characterized in that, Includes the following steps: The mother liquor of nickel-iron is extracted to obtain the extract phase and the raffinate phase of the mother liquor of nickel-iron; The nickel-cobalt-manganese oxide solution was subjected to a first extraction to obtain a first extract phase and a first raffinate phase. The first raffinate phase is subjected to a second extraction to obtain the second raffinate phase; The second raffinate phase is subjected to a third extraction to obtain a third extract phase and a third raffinate phase. The residual phase of the nickel-iron mother liquor is mixed with sulfuric acid to obtain back-extraction agent one. The back-extraction agent one is used to back-extract the third extraction phase to obtain back-extraction solution one. The pH of the first back-extraction solution is adjusted to 5-6 to carry out the first precipitation reaction. After solid-liquid separation and oil removal, a battery-grade nickel-cobalt-manganese sulfate solution is obtained. The third raffinate phase is subjected to a fourth extraction to obtain a fourth raffinate phase; The fourth raffinate phase is subjected to a fifth extraction to obtain a fifth extract phase; The fifth extraction phase was back-extracted with sulfuric acid to obtain back-extract solution II, which was then de-oiled to obtain a battery-grade nickel sulfate solution. The preparation of the nickel-iron mother liquor includes: treating the nickel-iron alloy with inorganic acid to obtain a nickel-iron leachate, and then removing impurities and precipitating iron from the nickel-iron leachate to obtain the nickel-iron mother liquor. The nickel-iron mother liquor extract phase and the first extract phase are subjected to back-extraction three and back-extraction four, respectively, to obtain back-extraction solution three and back-extraction solution four, respectively; the back-extraction solution three and back-extraction solution four are mixed and deoiled to obtain recycled acid; the recycled acid is reused in the acid leaching treatment.

2. The process for extracting battery metal elements by combined hydrometallurgical processing according to claim 1, characterized in that, The preparation of the nickel-iron mother liquor includes the following steps: after the nickel-iron alloy is treated with inorganic acid leaching, solid-liquid separation is performed to obtain nickel-iron leachate; The pH of the nickel-iron leaching solution is adjusted to 3.0-4.5, precipitation reaction two is carried out, solid-liquid separation is performed, and impurity-removed nickel-iron solution is obtained; Oxidizing agent and phosphoric acid are added to the impurity-removing nickel-iron solution, and after an oxidation precipitation reaction, solid-liquid separation is performed to obtain the nickel-iron mother liquor and iron phosphate. The iron phosphate is aged, filtered, and washed to obtain battery-grade iron phosphate.

3. The process for extracting battery metal elements by combined hydrometallurgical processing according to any one of claims 1 to 2, characterized in that, The organic phase used in extraction includes diluent and extractant; And / or, the diluent is at least one selected from sulfonated kerosene, kerosene, toluene, Escaid 110, hexane, heptane, and dodecane; And / or, the extractants in the nickel-iron mother liquor extraction and the first extraction are at least one of P204, P507, C272 and P227, respectively; And / or, the extractant in the third extraction is C272 or a combination of C272 and the co-extractant sec-nonyl-p-phenoxypropionic acid.

4. The process for extracting battery metal elements by combined hydrometallurgical processing according to claim 1, characterized in that, The stripping agent in stripping step three and stripping step four is phosphoric acid, and the molar concentration of phosphoric acid is 7-14 mol / L; And / or, the H+ concentration of the first stripping agent is 1-2 mol / L.

5. A process for extracting battery metal elements by combined hydrometallurgical smelting according to any one of claims 1 or 2, characterized in that, The pH adjuster for the first back-extraction solution and the pH adjuster for the nickel-iron leaching solution are nickel carbonate.

6. The process for extracting battery metal elements by combined hydrometallurgical smelting according to claim 3, characterized in that, The percentage content of the extractant in the nickel-iron mother liquor extraction and the first extraction in the organic phase is 15%-25%; And / or, in the nickel-iron mother liquor extraction, the extracted organic phase is subjected to sodium soap followed by nickel soap, and the saponification rates of the sodium soap and the nickel soap are 30%-50% and 90%-100%, respectively; And / or, the saponification rate of the extracted organic phase sodium soap in the first extraction is 30%-50%.

7. The process for extracting battery metal elements by combined hydrometallurgical processing according to claim 3, characterized in that, When C272 is used as the extractant in the third extraction, the percentage content of C272 in the extracted organic phase is 10%-30%. And / or, when the extractant in the third extraction is a combination of C272 and the co-extractant sec-nonyl-p-phenoxypropionic acid, the percentage content of sec-nonyl-p-phenoxypropionic acid in the extractive organic phase is not higher than 10%, and the percentage content of C272 in the extractive organic phase is 10%-30%; And / or, when the third extraction is a saponification extraction, the extracted organic phase is subjected to sodium soap, and the saponification rate of the sodium soap is 30%-50%.

8. A process for extracting battery metal elements by combined hydrometallurgical processing according to any one of claims 1 to 2, characterized in that, The extraction ratio O / A in the nickel-iron mother liquor extraction is 15:1-5, the number of extraction stages is 4-6, the number of washing times is 2-3, and the washing ratio O / A is 15-20:

1. And / or, the extraction ratio O / A in the third extraction is 10-12:1, and the number of extraction stages is 8-10; And / or, the O / A ratio in the three back-extraction processes is 13-32:1; And / or, in the back-extraction process, the O / A ratio is 10-15:

1.

9. The process for extracting battery metal elements by combined hydrometallurgical smelting according to claim 1, characterized in that, The volume ratio of inorganic acid to recycled acid in the acid leaching treatment is 1:2-4; And / or, the inorganic acid is at least one of sulfuric acid, hydrochloric acid and nitric acid.

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