Process for extracting metal elements of battery by combining wet smelting

Abstract

According to the technology for extracting the metal elements of the battery by combining wet smelting, the nickel-iron alloy and the waste ternary positive electrode powder are recycled to combine with wet smelting of the metal elements, in the technology, the utilization rate of acid is increased by adopting multiple means, and the recovery rate of iron is increased through reutilization of strip liquor; battery-grade iron phosphate, a battery-grade nickel cobalt manganese sulfate solution and a battery-grade nickel sulfate solution are obtained; the process is high in battery metal element recovery rate, high in product purity, less in waste residue, less in auxiliary material consumption and high in material recycling rate in the process, and has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrometallurgy and relates to a process for extracting battery metal elements by combined hydrometallurgy. Background Art

[0002] In recent years, with the rapid development of the lithium battery new energy industry, the supply of nickel raw materials in battery materials has gradually become insufficient. Laterite nickel ore is an important source of nickel in power battery materials in recent years. In the wet smelting process of laterite nickel ore, a large amount of iron elements are difficult to realize resource utilization, resulting in waste; laterite nickel ore is smelted into nickel-iron alloy by pyrometallurgy, and then iron phosphate and nickel sulfate are prepared by wet process to realize the resource utilization of nickel-iron. However, the existing nickel-iron alloy processing process not only has a large amount of slag and low utilization rate of phosphorus and iron, but also has low acid and alkali utilization rate and high production cost.

[0003] CN202111602206.8 discloses a method for preparing ferric phosphate from a 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 leaching solution, and then adding a hydrogen peroxide solution and an ammonia solution, and then aging, filtering, washing, and drying to obtain ferric phosphate dihydrate. However, this process does not involve mother liquor treatment, and the utilization rate of the residual acid in the mother liquor is not high.

[0004] CN202210312490.3 discloses a method for separating and extracting nickel and iron from nickel-iron alloy, including leaching nickel-iron alloy with sulfuric acid solution, evaporating and concentrating the leachate to obtain concentrated liquid, cooling and crystallizing the concentrated liquid, solid-liquid separation to obtain crude ferrous sulfate crystals and the first solution, adding an oxidant and a phosphorus source to the first solution, and adding alkali to adjust pH, heating reaction, continuing to adjust the slurry pH after the reaction ends, and then solid-liquid separation to obtain nickel sulfate solution and ferric phosphate. Although the present invention effectively improves the nickel-iron recovery rate, the amount of ferric phosphate slag is large, the acid-base utilization rate is low, the mother liquor residual acid is not fully utilized, and the production cost is high.

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

[0006] The purpose of the present invention is to provide a process for extracting battery metal elements by combined hydrometallurgy, improve the utilization rate of acid and iron in nickel-iron mother liquor, and simultaneously extract nickel, cobalt and manganese elements in nickel-cobalt-manganese solution, thereby improving the purity of each metal element extracted, with a simple process flow, less waste residue and less auxiliary material consumption.

[0007] To achieve the above object, the present invention provides a process for extracting battery metal elements by combined hydrometallurgy, comprising the following steps:

[0008] Extracting the nickel-iron mother liquor to obtain a nickel-iron mother liquor extraction phase and a nickel-iron mother liquor raffinate phase;

[0009] Performing a first extraction on the nickel-cobalt-manganese oxide solution to obtain a first extraction phase and a first raffinate phase;

[0010] extracting the first raffinate phase for a second time to obtain a second raffinate phase;

[0011] extracting the second raffinate phase for the third time to obtain a third extract phase and a third raffinate phase;

[0012] The raffinate phase of the nickel-iron mother liquor and sulfuric acid are mixed to obtain a stripping agent 1, and the stripping agent 1 is used to strip the third extraction phase to obtain a stripping solution 1;

[0013] The pH of the stripping solution is adjusted to 5-6 to perform precipitation reaction one, and a battery-grade nickel-cobalt-manganese sulfate solution is obtained through solid-liquid separation and oil removal;

[0014] performing a fourth extraction on the third raffinate phase to obtain a fourth raffinate phase;

[0015] extracting the fourth raffinate phase for a fifth time to obtain a fifth extract phase;

[0016] The fifth extraction phase is stripped with sulfuric acid to obtain a second stripping solution, which is deoiled to obtain a battery-grade nickel sulfate solution.

[0017] In some embodiments, the preparation of the nickel-iron mother solution comprises the following steps: treating the nickel-iron alloy with an inorganic acid pickling treatment, and then separating the solid from the liquid to obtain a nickel-iron leaching solution;

[0018] The pH value of the nickel-iron leaching solution is adjusted to 3.0-4.5, and precipitation reaction 2 is performed, and solid-liquid separation is performed to obtain a nickel-iron liquid with impurities removed;

[0019] Adding an oxidant and phosphoric acid to the impurity-removing nickel-iron solution, performing an oxidation iron precipitation reaction, and performing solid-liquid separation to obtain the nickel-iron mother solution 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 extraction phase and the first extraction phase are subjected to stripping three and stripping four, respectively, to obtain stripping solution three and stripping solution four, respectively; the stripping solution three and stripping solution four are mixed and deoiled to obtain a reuse acid; and the reuse acid is reused in the acid leaching treatment.

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

[0023] and / or, the diluent is at least one of 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 respectively at least one of P204, P507, C272 and P227;

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

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

[0027] In some embodiments, the pH adjuster of the stripping solution 1 and the pH adjuster of the nickel-iron leaching solution are nickel carbonate.

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

[0029] And / or, when the nickel-iron mother liquor extraction and the first extraction are saponification extractions, the organic phase is extracted with sodium soap and then 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 sodium soap in the organic phase extracted in the first extraction is 30%-50%.

[0031] In some embodiments, when the extractant in the third extraction is C272, the percentage 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 a co-extractant, sec-nonyl-p-phenoxypropionic acid, the content of sec-nonyl-p-phenoxypropionic acid in the extracted organic phase is not higher than 10%, and the content of C272 in the extracted organic phase is 10%-30%;

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

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

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

[0036] And / or, in the stripping third, the stripping phase ratio O / A is 13-32:1;

[0037] And / or, in the stripping step, the stripping phase ratio O / A is 10-15:1.

[0038] In some embodiments, the volume ratio of the inorganic acid to the 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 the present invention include:

[0041] The present invention provides a process for extracting battery metal elements by combined hydrometallurgy, wherein the recycled acid obtained by stripping and degreasing the nickel-iron mother liquor extraction phase and the first extraction phase is recycled to the acid leaching treatment section, thereby improving the utilization of acid and iron in the process flow and reducing waste residue; the nickel-iron mother liquor raffinate phase is mixed with sulfuric acid for stripping, thereby reducing the amount of acid and liquid alkali used in stripping and improving the utilization rate of the acid; in the recovery of the nickel-cobalt-manganese oxide solution, C272 or a combination of C272 and secondary nonyl-p-phenoxypropionic acid is used as an extractant to separate nickel, calcium, magnesium and cobalt, manganese and aluminum, and the aluminum slag in a gel state is used for silicon removal, thereby simplifying the process flow, reducing the input of auxiliary materials, and reducing the amount of aluminum slag. By the process for extracting battery metal elements by combined hydrometallurgy provided by the present invention, battery-grade iron phosphate, battery-grade nickel-cobalt-manganese sulfate solution and battery-grade nickel sulfate solution are obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 A process flow chart of the combined hydrometallurgical process for extracting battery metal elements provided in Example 1 of the present invention;

[0044] Figure 2 This is a SEM image of the 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 DESCRIPTION

[0046] Below, with appropriate reference to the accompanying drawings, a specific embodiment of the process for extracting battery metal elements by combined hydrometallurgy provided by the present invention is described in detail. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following descriptions are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0047] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. In particular, "(", ")", "[" and "]" represent intervals, wherein "(" or ")" represents an open interval, i.e., the endpoint values ​​of the interval are not included; "[" and "]" represent a closed interval, i.e., the endpoints within the interval are included. The range defined in this way may be inclusive or exclusive of the end values, and may be arbitrarily combined, i.e., any lower limit may be combined with any upper limit to form a range.

[0048] Specifically, for example, if a range of 60-120 and 80-110 is listed for a particular parameter, it is understood that the range of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range "ab" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been fully listed in this article, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a certain parameter is expressed 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 between 10 and 20, excluding 10 and 20; (10, 20] is understood as any value between 10 and 20, excluding 10 but including 20.

[0049] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0050] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0051] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0052] If there is no special explanation, the "include" and "comprising" mentioned in this application represent open-ended or closed-ended expressions. For example, the "include" and "comprising" may represent that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0053] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": 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 subjected to nickel-iron mother liquor extraction to obtain a nickel-iron mother liquor extraction phase and a nickel-iron mother liquor raffinate phase;

[0055] Performing a first extraction on the nickel-cobalt-manganese oxide solution to obtain a first extraction phase and a first raffinate phase;

[0056] extracting the first raffinate phase for a second time to obtain a second raffinate phase;

[0057] extracting the second raffinate phase for the third time to obtain a third extract phase and a third raffinate phase;

[0058] The raffinate phase of the nickel-iron mother liquor and sulfuric acid are mixed to obtain a stripping agent 1, and the stripping agent 1 is used to strip the third extraction phase to obtain a stripping solution 1;

[0059] The pH of the stripping solution is adjusted to 5-6 to perform precipitation reaction one, and a battery-grade nickel-cobalt-manganese sulfate solution is obtained through solid-liquid separation and oil removal;

[0060] performing a fourth extraction on the third raffinate phase to obtain a fourth raffinate phase;

[0061] extracting the fourth raffinate phase for a fifth time to obtain a fifth extract phase;

[0062] The fifth extraction phase is stripped with sulfuric acid to obtain a second stripping solution, which is deoiled 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, magnesium from cobalt, manganese, aluminum, silicon, and phosphorus, a fourth extraction to remove calcium and magnesium, a fifth extraction to extract nickel, and stripping to obtain a battery-grade nickel sulfate solution.

[0064] In some embodiments, the precipitation reaction produces desiliconized slag, which includes silicon slag, aluminum slag and phosphorus slag.

[0065] In some embodiments, the third extraction phase is subjected to stripping one to obtain stripping solution one, which is subjected to pH adjustment to remove phosphorus, silicon and aluminum, and then deoiled to obtain a battery-grade nickel cobalt manganese sulfate solution. The process of obtaining a battery-grade nickel sulfate solution and a battery-grade nickel cobalt manganese sulfate solution uses less auxiliary materials, has high product purity, generates less waste residue, and has little impact on the environment.

[0066] In some embodiments, the raffinate phase of the nickel-iron mother liquor is mixed with sulfuric acid to obtain a stripping agent, and the third extraction phase is stripped one to obtain stripping solution one. The raffinate phase of the nickel-iron mother liquor is mixed with sulfuric acid to obtain a stripping agent, which improves the utilization rate of the residual acid in the nickel-iron mother liquor, while saving the amount of acid and liquid alkali used in the stripping process, and further reduces the impurity metal elements introduced by the stripping agent into the nickel-cobalt-manganese solution.

[0067] In some embodiments, the raffinate phase of the nickel-iron mother liquor is mixed with sulfuric acid to obtain a stripping agent, and the fifth extraction phase is stripped twice to obtain a battery-grade nickel-cobalt sulfate solution. Using the raffinate phase of the nickel-iron mother liquor as a recycled acid will introduce a certain amount of impurity elements, so it is necessary to increase the precipitation reaction, and further filter and remove oil to obtain a battery-grade nickel-cobalt sulfate solution.

[0068] In some embodiments, the preparation of the nickel-iron mother solution comprises the following steps: subjecting the nickel-iron alloy to acid leaching, and then separating the solid from the liquid to obtain a nickel-iron leaching solution and a leaching residue, wherein the leaching residue is the nickel-iron alloy that has not been completely acid leached, and is returned to the acid leaching stage for secondary acid leaching.

[0069] In some embodiments, the raffinate phase of the nickel-iron mother liquor is mixed with sulfuric acid or sulfuric acid is used alone to obtain a stripping agent 2, and the stripping agent 2 is used to strip the fifth extraction phase to obtain a stripping solution 2. Since the raffinate phase of the nickel-iron mother liquor includes impurity metal elements, aluminum sulfate needs to be further added, and then carbonic acid is added for precipitation reaction, and then filtered and deoiled to obtain silicon slag and battery-grade nickel-cobalt sulfate solution.

[0070] In some embodiments, after adjusting the pH value of the nickel-iron leaching solution to 3.0-4.5, a second precipitation reaction is performed, and solid-liquid separation is performed to obtain a nickel-iron liquid with impurities removed.

[0071] In some embodiments, the nickel-iron mother liquor extraction phase and the first extraction phase are subjected to stripping three and stripping four, respectively, to obtain stripping solution three and stripping solution four, respectively, and the stripping solution three and stripping solution four are mixed and deoiled to obtain recycling acid, and the recycling acid is recycled to the acid leaching treatment. The utilization rate of iron in the nickel-iron mother liquor is improved, and the amount of waste residue is reduced; at the same time, the H in the recycling acid + and Fe 3+ Leaching of nickel-iron alloys reduces acid usage.

[0072] In some embodiments, the extractants in the nickel-iron mother liquor extraction and the first extraction are at least one of P204, P507, C272 and P227. P204, P507, C272 and P227 are used to extract and remove iron at low pH.

[0073] In some embodiments, the extractant in the third extraction is C272 or a combination of C272 and a co-extractant, secondary nonyl-p-phenoxypropionic acid. The third extraction of cobalt, manganese and aluminum simplifies the separation process of nickel, calcium, magnesium and 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 be reduced, 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 synergistic extractant secondary nonyl phenoxy propionic acid, the aluminum extraction performance is improved through the synergistic effect of secondary nonyl phenoxy propionic acid.

[0075] In some embodiments, the stripping agent in the stripping three and the stripping four is phosphoric acid, and PO4 in phosphoric acid 3- with Fe 3+ The complex reaction occurs, and it has better stripping performance than hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid. It can strip more effectively to obtain the regenerated organic phase, and the regenerated organic phase after stripping can be recycled to reduce the loss of the extracted organic phase and improve the utilization rate of the acid.

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

[0077] In some embodiments, the molar concentration of phosphoric acid in stripping three is 7-14 mol / L. Too low a molar concentration of phosphoric acid will result in too low a concentration of nickel, cobalt and manganese sulfate metals.

[0078] In some embodiments, the pH regulator of the stripping solution one and the pH regulator of the nickel-iron leaching solution are nickel carbonate. During the stripping process, the reaction pH value is adjusted by nickel carbonate to remove aluminum and phosphorus; at the same time, the adsorption properties of the gel-state aluminum slag are used to remove silicon in the solution, so as to achieve a one-step method for removing aluminum, silicon and phosphorus from the stripping solution one, thereby simplifying the process flow. The input of aluminum sulfate is reduced, the cost of auxiliary materials is reduced, and the amount of aluminum slag is also reduced. Nickel carbonate is added to the nickel-iron leaching solution to carry out precipitation reaction two to obtain a nickel-iron liquid and chromium slag. The following describes the embodiments of the present application. The embodiments described below are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. If the specific techniques or conditions are not specified in the embodiments, they shall be carried out in accordance with the techniques or conditions described in the literature in the field or in accordance with the product instructions. The reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially.

[0079] Please refer to the process flow chart of the method Figure 1 The features and performance of the present invention are further described in detail below in conjunction with the examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0080] Embodiment 1:

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

[0082] The nickel-iron alloy is subjected to acid leaching treatment, wherein the mass fractions of nickel and iron in the nickel-iron alloy are 13% and 86% respectively, and other metals include Co: 0.5%, Cr: 0.3%, and Si: 0.2%. The acid leaching acid includes recycled acid and sulfuric acid after stripping and deoiling, and the volume ratio of sulfuric acid to recycled acid is 1:2, wherein 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°C, and the acid leaching time is 10 hours to obtain nickel-iron leaching solution and leaching residue, and the leaching residue is returned to the acid leaching process, wherein the nickel-iron leaching solution contains: metal 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: Precipitation reaction and chromium removal

[0084] Nickel carbonate is added to the nickel-iron leaching solution to adjust the pH value of the solution to 4.5, and the reaction is carried out at a temperature of 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: Oxidation reaction of iron precipitation and preparation of battery-grade iron phosphate

[0086] Hydrogen peroxide and phosphoric acid are added to the impurity-removed nickel-iron liquid to carry out an oxidation iron precipitation reaction, wherein the amount of 30% hydrogen peroxide added is 27% of the volume of the impurity-removed nickel-iron liquid, and the amount of 14 mol / L phosphoric acid solution added is 2.7% of the volume of the impurity-removed nickel-iron liquid. The reaction is carried out at 95° C. for 2 hours, the pH value is 0.5, and iron phosphate and nickel-iron mother liquor are obtained by filter pressing, wherein the nickel-iron mother liquor has 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 roasted to obtain battery-grade iron phosphate.

[0088] Step 4: Extraction and iron removal from nickel-iron mother liquor

[0089] Extraction of nickel-iron mother liquor: After 40% sodium soap is added to the extracted organic phase composed of P227 and sulfonated kerosene with 30% liquid alkali, nickel sulfate solution is added to convert the extracted organic phase after sodium soap into nickel soap 100%, and the nickel-iron mother liquor is added to mix and extract the nickel-iron mother liquor to obtain the nickel-iron mother liquor extraction phase and the nickel-iron mother liquor raffinate phase. Among them, the volume ratio of sulfonated kerosene to P227 is 80%:20%, the extraction phase O / A ratio is 3:1, after 5 levels of extraction, 0.5mol / L sulfuric acid is used for washing 3 times, and the washing O / A ratio is 20:1. The nickel-iron mother liquor raffinate phase contains Ni: 37.7g / L, Co: 0.73g / L, Fe<5mg / L, P: 0.52g / L, Si: 85mg / L, and pH is 0.5.

[0090] Stripping three: The nickel-iron mother liquor extract is stripped with 7 mol / L phosphoric acid solution to obtain stripping solution three and the third regenerated organic phase, wherein the stripping O / A ratio is 13:1, and 5-stage stripping is performed. The Fe content of the third regenerated organic phase is 0.1 g / L, and the third regenerated organic phase is reused in step 4 for the sodium soap process. The Fe content of stripping solution three is 65 g / L, and the P content is 217 g / L. After deoiling, the stripping solution three is reused for the nickel-iron alloy acid leaching treatment.

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

[0092] The first extraction: after oxidizing the iron ions in the nickel-cobalt-manganese solution in the process of recycling lithium batteries with hydrogen peroxide, 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) is obtained, and the organic phase composed of P507 and sulfonated kerosene is subjected to 40% sodium soap with 30% liquid alkali, and then the oxidized nickel-cobalt-manganese solution is extracted to obtain the first extraction phase and the first raffinate phase. The volume ratio of sulfonated kerosene to P507 is 80%:20%, the extraction phase O / A ratio is 1:10, and after 5-stage extraction, 0.5 mol / L sulfuric acid is used for washing 3 times, and the washing O / A ratio is 20:1. The first raffinate phase contains 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] Stripping four: Same as step 4 stripping three, the Fe content of the fourth regenerated organic phase is 0.1g / L, the fourth regenerated organic phase is recycled to the first extraction for the sodium soap process, the Fe: 65g / L, P: 217g / L in stripping solution four, added to stripping solution three for oil removal process.

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

[0095] Second extraction: M5640 (N-phenyl-N, N'-di(2-ethylhexyl) diketoxime) and sulfonated kerosene are used to form an organic phase for extraction, and the first raffinate phase is subjected to a second extraction to obtain a second extraction phase and a second raffinate phase. The volume ratio of sulfonated kerosene to M5640 is 70%:30%, the extraction phase O / A ratio is 1:2, and after 4-stage extraction; using 1-stage clarification, the second raffinate phase: Ni: 38g / L, Co: 28.5g / L, Mn: 28.5g / L, Al: 2.7g / L, Fe: <5mg / L, Cu: <1mg / L, pH 1.0.

[0096] Stripping 5: The second extraction phase was stripped with 2 mol / L sulfuric acid solution to obtain stripping solution 5 and the fifth regenerated organic phase, wherein the stripping O / A ratio was 5:1, and 3-stage stripping was performed. The Cu content of the fifth regenerated organic phase was 0.1 g / L, and the fifth regenerated organic phase was reused for the second extraction, and the Cu content of the stripping solution 5 was 25 g / L.

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

[0098] The third extraction: C272, secondary nonyl-p-phenoxypropionic acid and sulfonated kerosene are mixed into a mixed extraction organic phase, and after liquid alkali saponification, the second raffinate phase is added for extraction to obtain a third extraction phase and a third raffinate phase. Among them, the volume ratio of C272, secondary nonyl-p-phenoxypropionic acid and sulfonated kerosene phase is 20%: 10%: 70%, the saponification rate is 40%, the extraction phase O / A ratio is 10: 1, after 8 levels of extraction, 6 levels of 0.5 mol / L sulfuric acid washing, the washing O / A ratio is 40: 1. The third raffinate phase: Ni: 37g / L, Co: 2mg / L, Mn: 2mg / L, Al: 1mg / L, Ca: 0.2g / L, Mg: 2.4g / L, pH 4.0.

[0099] Stripping 1: Add concentrated sulfuric acid to the raffinate phase of nickel-iron mother liquor in step 4 to prepare H + The third extraction phase was back-extracted with an acid solution having a concentration of 1.5 mol / L to obtain a stripping solution 1 and a first regenerated organic phase, wherein the stripping O / A ratio was 12:1, and 5-stage stripping was performed. The first regenerated organic phase was reused for the third extraction, and the stripping solution 1 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] The fourth extraction: after using 30% liquid alkali to treat the organic phase composed of P507 and sulfonated kerosene with 40% sodium soap, the third raffinate phase is extracted to obtain the fourth extraction phase and the fourth raffinate phase. The volume ratio of sulfonated kerosene to P507 is 80%:20%, the extraction phase O / A ratio is 1:1, after 10 levels of extraction, 18 levels of 0.5 mol / L sulfuric acid washing are performed, and the O / A ratio of washing is 10:1. The fourth raffinate phase contains Ni: 34.5 g / L, Ca: 1 mg / L, Mg: 1 mg / L, and pH 5.5.

[0101] Stripping 6: The fourth extraction phase is stripped with 4 mol / L hydrochloric acid solution to obtain stripping solution 6 and the sixth regenerated organic phase, wherein the stripping O / A ratio is 20:1, and 8-stage stripping is performed. The Ca and Mg contents of the sixth regenerated organic phase are both less than 2 mg / L, and the sixth regenerated organic phase is reused for the fourth extraction, and the Ca in the stripping solution 6 is 4 g / L and the Mg is 48 g / L.

[0102] The fifth extraction: after 50% sodium soap is added to the organic phase composed of P507 and sulfonated kerosene using 30% liquid alkali, the fourth raffinate phase is extracted to obtain the fifth extraction phase and the fifth raffinate phase. The volume ratio of sulfonated kerosene to P507 is 80%:20%, the extraction phase O / A ratio is 3.45:1, and after 10 levels of extraction, 3 levels of 0.5 mol / L sulfuric acid washing are performed, and the O / A ratio of washing is 20:1. Ni in the fifth raffinate phase: 10 mg / L, pH 6.5.

[0103] Stripping 2: The fifth extraction phase is stripped with a 2mol / L sulfuric acid solution to obtain a stripping solution 2 and a second regenerated organic phase, wherein the stripping O / A ratio is 10:1, and a 4-stage stripping is performed. The Ni content of the second regenerated organic phase is less than 5mg / L, and the second regenerated organic phase is reused for the fifth extraction, and the Ni in the stripping solution 2 is 100g / L, and the pH is 3.0. The stripping solution 2 is deoiled and finely filtered to obtain a battery-grade nickel sulfate solution.

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

[0105] Precipitation reaction 1: Add nickel carbonate to stripping solution 1, adjust the solution pH to 5.5 at 70°C, react for 8 hours, filter and remove oil to obtain slag and battery-grade nickel cobalt manganese sulfate solution Ni: 46g / L, P≤5mg / L, Co: 34.5g / L, Mn: 34.2g / L, Al≤1mg / L, Si≤10mg / L. The slag is washed with 0.5mol / L sulfuric acid to obtain silicon-free slag (Ni: 1%, Al: 10%, P: 2.6%, Si: 0.4%), and the washing liquid is added to the nickel cobalt manganese sulfate solution.

[0106] Figure 2-3 This is a SEM image of battery-grade iron phosphate obtained in Example 1. Example 1 successfully prepared an iron phosphate material of about 10 μm.

[0107] Embodiment 2:

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

[0109] Embodiment 3:

[0110] The only difference between this embodiment and embodiment 1 is that, in step 4, stripping 3, "using 7 mol / L phosphoric acid solution to extract and strip the nickel-iron mother liquor" is replaced by "using 14 mol / L phosphoric acid solution to extract and strip the nickel-iron mother liquor", and other conditions and parameters are exactly the same as those in embodiment 1.

[0111] Embodiment 4:

[0112] The difference between this embodiment and embodiment 1 is that in the third extraction of step 7, "C272, secondary nonyl-p-phenoxypropionic acid and sulfonated kerosene are mixed into a mixed extraction organic phase, and after saponification with liquid alkali, the second raffinate phase is added for extraction to obtain a third extraction phase and a third raffinate phase. Among them, the volume ratio of C272, secondary nonyl-p-phenoxypropionic acid and sulfonated kerosene phase is 20%:10%:70%, the saponification rate is 40%, the extraction phase O / A ratio is 10:1, and after 8-stage extraction, 6-stage 0.5 mol / L sulfuric acid washing The method of Example 1 is as follows: "C272 and sulfonated kerosene are mixed into a mixed extraction organic phase, and after saponification with liquid alkali, the second raffinate phase is added for extraction to obtain a third extraction phase and a third raffinate phase. Among them, the volume ratio of C272 and sulfonated kerosene phase is 20%:80%, the saponification rate is 40%, the extraction phase O / A ratio is 12:1, after 8 levels of extraction, 8 levels of 0.5 mol / L sulfuric acid washing, the washing O / A ratio is 10:1", and the other conditions and parameters are exactly the same as those in Example 1.

[0113] Embodiment 5:

[0114] The difference between this embodiment and embodiment 1 is that in step 7, in the stripping second for extracting cobalt and manganese, extracting calcium and magnesium, and extracting nickel, "stripping second: using 2 mol / L sulfuric acid solution to extract the fifth extraction phase to obtain stripping solution 2 and the second regenerated organic phase, wherein the stripping O / A ratio is 10:1, and 4-stage stripping is performed. The Ni content of the second regenerated organic phase is less than 5 mg / L, and the second regenerated organic phase is reused for the fifth extraction, and the Ni in the stripping solution 2 is 100 g / L, and the pH is 1. 3.0. The stripping solution II is deoiled and finely filtered to obtain a battery-grade nickel sulfate solution", replaced by "Stripping II: Add concentrated sulfuric acid to the residual phase of the nickel-iron mother liquor in step 4 to prepare a 1.5 mol / L sulfuric acid solution to cross-extract the fifth extraction phase to obtain stripping solution II and a second regenerated organic phase, wherein the stripping O / A ratio is 7.5:1, and 5-stage stripping is performed. The Ni content of the second regenerated organic phase is less than 10 mg / L, which is reused for the fifth extraction. The stripping 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°C, aluminum sulfate was added to the stripping solution two and stirred until the mass concentration of aluminum was 2.7 g / L, then nickel carbonate was added to adjust the solution pH to 5.5. After reacting for 8 hours, slag and battery-grade nickel cobalt sulfate solution were obtained by filtration, oil removal and fine filtration. 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 silicon-free slag (Ni: 1.5%, Al: 10%, P: 2.6%, Si: 0.4%), and the washing solution was added to the nickel cobalt sulfate solution. The other conditions and parameters were exactly the same as those in Example 1.

[0116] Comparative Example 1:

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

[0118] The 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 includes recycled acid and sulfuric acid after stripping and deoiling, the volume ratio of sulfuric acid to recycled acid is 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°C, and the acid leaching time is 10 hours to obtain nickel-iron leaching solution and leaching residue, and the leaching residue is returned to the acid leaching process, wherein the nickel-iron leaching solution contains: metal 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: Precipitation reaction and chromium removal

[0120] Nickel carbonate is added to the nickel-iron leaching solution to adjust the pH value of the solution to 4.5, and the reaction is carried out at a temperature of 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: Oxidation reaction of iron precipitation and preparation of battery-grade iron phosphate

[0122] Hydrogen peroxide and phosphoric acid are added to the impurity-removed nickel-iron liquid to carry out an oxidation iron precipitation reaction, wherein the amount of 30% hydrogen peroxide added is 27% of the volume of the impurity-removed nickel-iron liquid, and the amount of 14 mol / L phosphoric acid solution added is 2.7% of the volume of the impurity-removed nickel-iron liquid. The reaction is carried out at 95° C. for 2 hours, the pH value is 0.5, and iron phosphate and nickel-iron mother liquor are obtained by filter pressing, wherein the nickel-iron mother liquor has 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 roasted to obtain battery-grade iron phosphate.

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

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

[0126] Comparative Example 2:

[0127] The difference between this comparative example and Example 1 is that in step 4, in the stripping step 3, "7 mol / L phosphoric acid solution is used to strip the nickel-iron mother liquor to obtain stripping solution 3 and the third regenerated organic phase, wherein the stripping O / A ratio is 13:1, and 5-stage stripping is performed. The Fe content of the third regenerated organic phase is 0.1 g / L, and the third regenerated organic phase is reused in step 4 for the sodium soap process. The Fe content of the stripping solution 3 is 65 g / L, and the P content is 217 g / L. After degreasing, the stripping solution 3 is reused to the nickel-iron synthesis process. Gold acid leaching treatment", is replaced by "using 7mol / L sulfuric acid solution to extract the nickel-iron mother liquor to obtain stripping solution three and a third regenerated organic phase, wherein the stripping O / A ratio is 2.1:1, and 5-stage stripping is performed. The Fe content of the third regenerated organic phase is 0.5g / L, and the third regenerated organic phase is reused in step 4 for the sodium soap process, and the Fe content of the stripping solution three is 10g / L. After deoiling, the stripping solution three is reused for nickel-iron alloy acid leaching treatment", and the other conditions and parameters are exactly the same as those in Example 1.

[0128] Comparative Example 3:

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

[0130] The 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 includes recycled acid and sulfuric acid after stripping and deoiling, the volume ratio of sulfuric acid to recycled acid is 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°C, and the acid leaching time is 10 hours to obtain nickel-iron leaching solution and leaching residue, and the leaching residue is returned to the acid leaching process, wherein the nickel-iron leaching solution contains: metal 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: Precipitation reaction and chromium removal

[0132] Nickel carbonate is added to the nickel-iron leaching solution to adjust the pH value of the solution to 4.5, and the reaction is carried out at a temperature of 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: Oxidation reaction of iron precipitation and preparation of battery-grade iron phosphate

[0134] Hydrogen peroxide and phosphoric acid are added to the impurity-removed nickel-iron liquid to carry out an oxidation iron precipitation reaction, wherein the amount of 30% hydrogen peroxide added is 27% of the volume of the impurity-removed nickel-iron liquid, and the amount of 14 mol / L phosphoric acid solution added is 2.7% of the volume of the impurity-removed nickel-iron liquid. The reaction is carried out at 95° C. for 2 hours, the pH value is 0.5, and iron phosphate and nickel-iron mother liquor are obtained by filter pressing, wherein the nickel-iron mother liquor has 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 roasted to obtain battery-grade iron phosphate.

[0136] Step 4: Extraction and iron removal from nickel-iron mother liquor

[0137] Extraction of nickel-iron mother liquor: After 40% sodium soap is added to the extracted organic phase composed of P227 and sulfonated kerosene with 30% liquid alkali, nickel sulfate solution is added to convert the extracted organic phase after sodium soap into nickel soap 100%, and the nickel-iron mother liquor is added to mix and extract the nickel-iron mother liquor to obtain the nickel-iron mother liquor extraction phase and the nickel-iron mother liquor raffinate phase. Among them, the volume ratio of sulfonated kerosene to P227 is 80%:20%, the extraction phase O / A ratio is 3:1, after 5 levels of extraction, 0.5mol / L sulfuric acid is used for washing 3 times, and the washing O / A ratio is 20:1. The nickel-iron mother liquor raffinate phase contains Ni: 37.7g / L, Co: 0.73g / L, Fe<5mg / L, P: 0.52g / L, Si: 85mg / L, and pH is 0.5.

[0138] Stripping three: The nickel-iron mother liquor extract is stripped with 7 mol / L phosphoric acid solution to obtain stripping solution three and the third regenerated organic phase, wherein the stripping O / A ratio is 13:1, and 5-stage stripping is performed. The Fe content of the third regenerated organic phase is 0.1 g / L, and the third regenerated organic phase is reused in step 4 for the sodium soap process. The Fe content of stripping solution three is 65 g / L, and the P content is 217 g / L. After deoiling, the stripping solution three is reused for the nickel-iron alloy acid leaching treatment.

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

[0140] Extraction and copper removal: After the iron ions in the nickel-cobalt-manganese solution in the process of recycling lithium batteries are oxidized by hydrogen peroxide, 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) is obtained. Second extraction: M5640 (N-phenyl-N, N'-di(2-ethylhexyl) diketoxime) and sulfonated kerosene are used to form an organic phase for extraction. After the nickel-cobalt-manganese oxide solution is subjected to a second extraction, a second extraction phase and a second raffinate phase are obtained. The volume ratio of sulfonated kerosene to M5640 is 70%:30%, the extraction phase ratio O / A is 1:2, and after 4-stage extraction; 1-stage clarification is used.

[0141] Stripping 5: The second extraction phase is stripped with 2 mol / L sulfuric acid solution to obtain stripping solution 5 and the fifth regenerated organic phase, wherein the stripping O / A ratio is 5:1, and three-stage stripping is performed. The fifth regenerated organic phase is reused for the second extraction.

[0142] Step 6: Remove iron and aluminum

[0143] Sodium carbonate is added to the obtained second raffinate phase, and the pH is adjusted to 5 to precipitate iron and aluminum. After filtration, a copper-nickel-cobalt-manganese removal solution and iron-aluminum slag are obtained.

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

[0145] The third extraction: C272, secondary nonyl-p-phenoxypropionic acid and sulfonated kerosene are mixed into a mixed extraction organic phase, and after saponification with liquid alkali, the copper, nickel, cobalt and manganese removal solution is added for extraction to obtain a third extraction phase and a third raffinate phase. Among them, the volume ratio of C272, secondary nonyl-p-phenoxypropionic acid and sulfonated kerosene phase is 20%:10%:70%, the saponification rate is 40%, the extraction phase O / A ratio is 10:1, after 8 levels of extraction, 6 levels of 0.5 mol / L sulfuric acid washing, the washing O / A ratio is 40:1.

[0146] Stripping 1: Add concentrated sulfuric acid to the raffinate phase of nickel-iron mother liquor in step 4 to prepare H + The third extraction phase is back-extracted with an acid solution having a concentration of 1.5 mol / L to obtain a first stripping solution and a first regenerated organic phase, wherein the stripping O / A ratio is 12:1, and 5-stage stripping is performed. The first regenerated organic phase is recycled to the third extraction.

[0147] The fourth extraction: after using 30% of liquid alkali to treat the organic phase composed of P507 and sulfonated kerosene with 40% sodium soap, the third raffinate phase is extracted to obtain a fourth extraction phase and a fourth raffinate phase. The volume ratio of sulfonated kerosene to P507 is 80%:20%, the extraction phase O / A ratio is 1:1, and after 10 levels of extraction, 18 levels of 0.5 mol / L sulfuric acid washing are performed, and the washing O / A ratio is 10:1.

[0148] Stripping 6: The fourth extraction phase is stripped with 4 mol / L hydrochloric acid solution to obtain stripping solution 6 and a sixth regenerated organic phase, wherein the stripping O / A ratio is 20:1, and 8-stage stripping is performed. The sixth regenerated organic phase is reused for the fourth extraction.

[0149] The fifth extraction: after 50% sodium soap is added to the organic phase composed of P507 and sulfonated kerosene using 30% liquid alkali, the fourth raffinate phase is extracted to obtain the fifth extraction phase and the fifth raffinate phase. The volume ratio of sulfonated kerosene to P507 is 80%:20%, the extraction phase O / A ratio is 3.45:1, and after 10 levels of extraction, 3 levels of 0.5 mol / L sulfuric acid washing are performed, and the washing O / A ratio is 20:1.

[0150] Stripping 2: Stripping the fifth extraction phase with 2 mol / L sulfuric acid solution to obtain stripping solution 2 and a second regenerated organic phase, wherein the stripping O / A ratio is 10:1, and 4-stage stripping is performed. The Ni content of the second regenerated organic phase is less than 5 mg / L, and the second regenerated organic phase is reused for the fifth extraction. The stripping solution 2 is deoiled and finely filtered to obtain a battery-grade nickel sulfate solution.

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

[0152] Precipitation reaction 1: Aluminum sulfate is added to the stripping solution 1 to increase the mass concentration of aluminum to 2g / L, and then nickel carbonate is added to the solution, and the pH of the solution is adjusted to 5.5 at 70°C. After reacting for 8 hours, the slag and battery-grade nickel cobalt manganese sulfate solution are obtained by filtration and oil removal. The slag is washed with 0.5mol / L sulfuric acid to obtain desiliconized slag, and the washing liquid is added to the nickel cobalt manganese sulfate solution.

[0153] Comparative Example 4:

[0154] The difference between this comparative example and Example 1 is that in step 7: extracting cobalt and manganese, extracting calcium and magnesium, and extracting nickel, "C272, secondary nonyl-p-phenoxypropionic acid and sulfonated kerosene are mixed into a mixed extraction organic phase, and after saponification with liquid alkali, the second raffinate phase is added for extraction to obtain a third extraction phase and a third raffinate phase. Among them, the volume ratio of C272, secondary nonyl-p-phenoxypropionic acid and sulfonated kerosene phase is 20%:10%:70%", is replaced by "secondary nonyl-p-phenoxypropionic acid and sulfonated kerosene are mixed into a mixed extraction organic phase, and after saponification with liquid alkali, the second raffinate phase is added for extraction to obtain a third extraction phase and a third raffinate phase. Among them, the volume ratio of secondary nonyl-p-phenoxypropionic acid and sulfonated kerosene phase is 15%:85%", and other conditions and parameters are exactly the same as those in Example 1.

[0155] Test example:

[0156] The element concentrations in the raffinate phase of the nickel-iron mother liquor, the stripping solution three and the battery-grade nickel-cobalt-manganese sulfate solution in Examples 1-5 and Comparative Examples 2-4 were detected respectively, the iron element concentration of the nickel-iron mother liquor in Comparative Example 1 was detected, and the slag amount and the nickel-cobalt-manganese output 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 is detected;

[0158] Detecting the concentrations of iron and phosphorus, as well as the concentration of hydrogen ions in the stripping solution 3;

[0159] Detect and calculate the ratio of the concentration of nickel, cobalt and manganese elements to the concentration of calcium and magnesium elements in battery-grade nickel-cobalt-manganese sulfate solution;

[0160] Detect the amount of slag produced per ton of nickel, cobalt and manganese, where nickel, cobalt and manganese include nickel in battery-grade nickel sulfate solution and nickel, cobalt and manganese in battery-grade nickel, cobalt and manganese sulfate solution; the slag amount includes the sum of chromium slag, silicon removal slag and iron and aluminum slag;

[0161] The utilization rate of each element is calculated by the ratio of product output to the sum of raw materials and auxiliary materials. The 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. The raw materials include nickel-iron alloy and nickel-cobalt-manganese oxide solution, and the auxiliary materials include phosphoric acid and nickel carbonate:

[0162] Formula = product output / (raw material quantity + auxiliary material quantity).

[0163] Table 1

[0164]

[0165]

[0166] It can be seen from the above table that in Examples 1-5, through the process of combined hydrometallurgy for extracting battery metal elements provided by the present invention, the iron content in the raffinate phase of the nickel-iron mother liquor is low, the calcium and magnesium contents in the battery-grade nickel-cobalt-manganese sulfate solution are low, the amount of slag generated by the process is small, and the utilization rates of Fe, Ni, Co, Mn and P elements are extremely high.

[0167] Compared with Example 1 of the present invention, in the extraction process of the nickel-iron mother liquor in Example 2, saponification-free iron removal is adopted, and Fe≤80mg / L in the raffinate phase of the obtained nickel-iron mother liquor is higher than Fe in the raffinate phase of the nickel-iron mother liquor in Example 1, and the utilization rate of iron in the nickel-iron alloy is reduced.

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

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

[0170] Compared with Example 1 of the present invention, in Example 5, the nickel-iron mother liquor raffinate phase is used in the fifth extraction back-extraction process. On the basis of the utilization of residual acid, impurity ions are introduced, and the second stripping liquor needs to be further processed, which causes an increase in the amount of slag and auxiliary materials to a certain extent.

[0171] Compared with Example 1 of the present invention, in the nickel-iron mother liquor recovery process of Comparative Example 1, sodium carbonate is mixed with the nickel-iron mother liquor to carry out iron precipitation reaction to obtain iron slag, and the iron in the nickel-iron mother liquor is not recycled, wherein 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 is used in the stripping step 3 in Comparative Example 2. The anti-iron property of sulfuric acid is far inferior to that of phosphoric acid. The amount of acid used is increased. At the same time, the iron content in the first regenerated organic phase is higher. Long-term operation will lead to poisoning of the extractant and loss of extraction performance.

[0173] Compared with Example 1 of the present invention, the order of removing impurities from the oxidized nickel-cobalt-manganese solution is changed in Comparative Example 3. First, the oxidized nickel-cobalt-manganese solution is extracted to remove copper to obtain a second raffinate phase; then sodium carbonate is mixed with the second raffinate phase to remove iron and aluminum to obtain a copper-removed nickel-cobalt-manganese solution and iron-aluminum slag. Since sodium carbonate is added to remove impurities iron and aluminum at the same time, an auxiliary material aluminum sulfate needs to be added in the subsequent silicon removal process, which increases the amount of auxiliary materials used and increases the amount of slag produced.

[0174] Compared with Example 1 of the present invention, in Comparative Example 4, the ratio of the extractant is changed during the third extraction process, so that cobalt and manganese cannot be effectively separated from calcium and magnesium, and the amount of calcium and magnesium impurities and slag in the battery-grade nickel sulfate cobalt and manganese solution is increased.

[0175] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A process for extracting battery metal elements by combined hydrometallurgy, characterized in that: The following steps are involved: Extracting the nickel-iron mother liquor to obtain a nickel-iron mother liquor extraction phase and a nickel-iron mother liquor raffinate phase; Performing a first extraction on the nickel-cobalt-manganese oxide solution to obtain a first extraction phase and a first raffinate phase; extracting the first raffinate phase for a second time to obtain a second raffinate phase; extracting the second raffinate phase for the third time to obtain a third extract phase and a third raffinate phase; The raffinate phase of the nickel-iron mother liquor and sulfuric acid are mixed to obtain a stripping agent 1, and the stripping agent 1 is used to strip the third extraction phase to obtain a stripping solution 1; The pH of the stripping solution is adjusted to 5-6 to perform precipitation reaction one, and a battery-grade nickel-cobalt-manganese sulfate solution is obtained through solid-liquid separation and oil removal; performing a fourth extraction on the third raffinate phase to obtain a fourth raffinate phase; extracting the fourth raffinate phase for a fifth time to obtain a fifth extract phase; The fifth extraction phase is stripped with sulfuric acid to obtain a second stripping solution, which is deoiled to obtain a battery-grade nickel sulfate solution.

2. A process for extracting battery metal elements by combined hydrometallurgy according to claim 1, characterized in that: The preparation of the nickel-iron mother solution comprises the following steps: subjecting the nickel-iron alloy to an inorganic acid pickling treatment, and then separating the solid from the liquid to obtain a nickel-iron leaching solution; The pH value of the nickel-iron leaching solution is adjusted to 3.0-4.5, and precipitation reaction 2 is performed, and solid-liquid separation is performed to obtain a nickel-iron liquid with impurities removed; Adding an oxidant and phosphoric acid to the impurity-removing nickel-iron solution, performing an oxidation iron precipitation reaction, and performing solid-liquid separation to obtain the nickel-iron mother solution and iron phosphate; The iron phosphate is aged, filtered and washed to obtain battery-grade iron phosphate.

3. A process for extracting battery metal elements by combined hydrometallurgy according to claim 2, characterized in that: The nickel-iron mother liquor extraction phase and the first extraction phase are subjected to stripping three and stripping four, respectively, to obtain stripping solution three and stripping solution four, respectively; the stripping solution three and stripping solution four are mixed and then deoiled to obtain recycling acid; and the recycling acid is recycled to the acid leaching treatment.

4. A process for extracting battery metal elements by combined hydrometallurgy according to any one of claims 1 to 3, characterized in that: The organic phase used for extraction includes a diluent and an extractant; and / or, the diluent is at least one of 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 respectively at least one of P204, P507, C272 and P227; And / or, the extractant in the third extraction is C272 or a combination of C272 and a co-extractant secondary nonyl-p-phenoxypropionic acid.

5. The process for extracting battery metal elements by combined hydrometallurgy according to claim 3 is characterized in that: The stripping agent in the stripping three and the stripping four is phosphoric acid, and the molar concentration of the phosphoric acid is 7-14 mol / L; And / or, the stripping agent H + The concentration is 1-2mol / L.

6. A process for extracting battery metal elements by combined hydrometallurgy according to any one of claims 1 or 2, characterized in that: The pH regulator of the stripping solution 1 and the pH regulator of the nickel-iron leaching solution are nickel carbonate.

7. The process for extracting battery metal elements by combined hydrometallurgy according to claim 4 is characterized in that: The percentage of the extractant in the nickel-iron mother liquor extraction and the first extraction in the extracted organic phase is 15%-25%; And / or, the nickel-iron mother liquor is extracted, and the extracted organic phase is subjected to sodium soap and then 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 sodium soap in the organic phase extracted in the first extraction is 30%-50%.

8. The process for extracting battery metal elements by combined hydrometallurgy according to claim 4 is characterized in that: When the extractant in the third extraction is C272, the percentage 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 a co-extractant secondary nonyl-p-phenoxypropionic acid, the percentage of the secondary nonyl-p-phenoxypropionic acid in the extracted organic phase is not higher than 10%, and the percentage of C272 in the extracted organic phase is 10%-30%; And / or, when the third extraction is a saponification extraction, sodium soap is applied to the extracted organic phase, and the saponification rate of the sodium soap is 30%-50%.

9. A process for extracting battery metal elements by combined hydrometallurgy according to any one of claims 1 to 8, characterized in that: The extraction phase O / A in the nickel-iron mother liquor extraction is 15:1-5, the extraction stage is 4-6, the number of washings is 2-3 times, and the washing phase O / A is 15-20:1; And / or, the extraction phase ratio O / A in the third extraction is 10-12:1, and the number of extraction stages is 8-10; And / or, in the stripping third, the stripping phase ratio O / A is 13-32:1; And / or, in the stripping step, the stripping phase ratio O / A is 10-15:

1.

10. The process for extracting battery metal elements by combined hydrometallurgy according to claim 3, characterized in that: The volume ratio of the inorganic acid to the 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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