Treatment of nickel-cobalt hydroxide

Abstract

The application provides a treatment method of nickel cobalt hydroxide, comprising the following steps: a first leaching process, reducing and acid leaching the nickel cobalt hydroxide to obtain a leaching solution; a neutralization process, adding a neutralizing agent to the leaching solution to obtain a neutralized solution; a first sulfuration process, adding a first sulfuration agent to the neutralized solution to obtain a first sulfuration solution; a second sulfuration process, adding a second sulfuration agent to the first sulfuration solution to obtain a second sulfuration precipitate; an ion exchange process, adding an ion exchange solution to the second sulfuration precipitate to obtain a third sulfuration precipitate; and a second leaching process, mixing the third sulfuration precipitate with a solvent and oxygen to perform pressurized leaching, and then obtaining a metal salt solution, wherein the metal salt comprises at least one of a nickel salt, a cobalt salt and a manganese salt. The treatment method provided in the embodiments of the application can remove metal impurities such as calcium and magnesium, so that a product containing nickel, cobalt and / or manganese is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nickel cobalt hydroxide treatment, and particularly relates to a treatment method of nickel cobalt hydroxide. BACKGROUND

[0002] With the rapid development of the new energy industry, the demand for lithium ion batteries is increasing. As an important metal raw material for lithium ion batteries, nickel, cobalt and manganese resources have become increasingly important.

[0003] Nickel cobalt hydroxide contains a large amount of metal elements such as nickel, cobalt and manganese, and is commonly used as a raw material for extracting nickel, cobalt and manganese metals. Since nickel cobalt hydroxide may also contain other impurity elements such as calcium and magnesium, a large number of impurity removal processes are required to obtain high-purity nickel, cobalt and manganese products, so that the obtained products can be directly used as nickel sources, cobalt sources and manganese sources for preparing lithium ion batteries.

[0004] However, in the related art, in the process of treating nickel cobalt hydroxide to obtain nickel, cobalt and manganese products, the environment is not friendly, the removal cost of impurities is high, and the obtained products still contain some impurities affecting their application. SUMMARY

[0005] The present application provides a treatment method of nickel cobalt hydroxide, which can extract nickel, cobalt and / or manganese from nickel cobalt hydroxide without using an extraction impurity removal process, and can also effectively remove impurities such as calcium and magnesium.

[0006] The present application provides a treatment method of nickel cobalt hydroxide, which can extract nickel, cobalt and / or manganese from nickel cobalt hydroxide without using an extraction impurity removal process, and can also effectively remove impurities such as calcium and magnesium.

[0007] The first leaching process reduces and acid leaches the nickel cobalt hydroxide to obtain a leaching solution and a leaching residue;

[0008] The neutralization process adds a neutralizing agent to the leaching solution to neutralize and precipitate iron, to obtain a neutralization precipitate and a neutralized solution;

[0009] The first sulfidation process adds a first sulfidation agent to the neutralized solution to sulfidize and precipitate copper and / or zinc, to obtain a first sulfidation precipitate and a first sulfidation solution;

[0010] The second sulfidation process adds a second sulfidation agent to the first sulfidation solution to sulfidize and precipitate the metals in the first sulfidation solution, to obtain a second sulfidation precipitate and a second sulfidation solution;

[0011] The ion exchange process adds an ion exchange solution to the second sulfidation precipitate to replace at least part of the impurities calcium and / or magnesium in the second sulfidation precipitate into the solution, and separates the solid and liquid to obtain a third sulfidation precipitate and a third sulfidation solution;

[0012] The second leaching process is to obtain a metal salt solution by subjecting the third sulfidation precipitate to pressure leaching after mixing with a solvent and oxygen, wherein the metal salt includes at least one of a nickel salt, a cobalt salt and a manganese salt.

[0013] The processing method of nickel-cobalt hydroxide provided by the embodiments of the present application can leach nickel, cobalt, manganese, iron, copper, zinc, calcium, magnesium and other elements in the nickel-cobalt hydroxide by reducing and acid leaching the nickel-cobalt hydroxide in the first leaching process; then, the addition of a neutralizing agent in the neutralizing process can make the leached iron precipitate to obtain a neutralization precipitate, i.e., iron residue; then, the addition of a first sulfidation agent to the neutralized solution in the first sulfidation process can make the leached copper and / or zinc precipitate to obtain a first sulfidation precipitate, i.e., copper residue and / or zinc residue; then, the addition of a second sulfidation agent to the first sulfidation solution in the second sulfidation process can make the leached nickel, cobalt, manganese, calcium, magnesium and other elements precipitate to obtain a second sulfidation precipitate; then, the addition of an ion exchange solution to the second sulfidation precipitate in the ion exchange process can displace the calcium and / or magnesium impurities in the second sulfidation precipitate into the solution, while the nickel, cobalt and manganese still exist in the third sulfidation precipitate in the form of solid; finally, the third sulfidation precipitate is subjected to pressure leaching, so that the nickel, cobalt and manganese in the third sulfidation precipitate are converted into a liquid metal salt form, so as to facilitate the direct application of nickel, cobalt and manganese products.

[0014] Therefore, according to the processing method provided by the embodiments of the present application, a metal salt product containing nickel, cobalt and / or manganese can be obtained, which can be used as a raw material for preparing lithium ion batteries. Moreover, the iron, copper, zinc, calcium, magnesium and other impurities can be removed during the processing of the nickel-cobalt hydroxide, the impurity removal process is simple, process abnormalities are less likely to occur, the environment is friendly, and the impurity removal cost is low.

[0015] In some embodiments of the present application, in the neutralizing process, the neutralizing agent includes at least one of calcium carbonate, sodium carbonate, sodium hydroxide, calcium hydroxide, ammonia, calcium oxide, potassium hydroxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, nickel carbonate, cobalt carbonate and manganese carbonate.

[0016] In some embodiments of the present application, the addition time of the neutralizing agent is 1h-2h.

[0017] In some embodiments of the present application, the reaction pH value of the neutralizing process is 4.5-5.5.

[0018] In some embodiments of the present application, the reaction temperature of the neutralizing process is 80℃-90℃, and the reaction time is 1h-1.5h.

[0019] In some embodiments of the present application, the first sulfidation process includes:

[0020] In the copper removal process, a first sulfidizing agent is added to the neutralized solution to sulfidize and precipitate copper, thereby obtaining copper residue and copper-removed solution;

[0021] In the zinc removal process, a first sulfidizing agent is added to the copper-removed solution to sulfidize and precipitate zinc, thereby obtaining first sulfidized precipitate and first sulfidized solution.

[0022] In some embodiments of the present application, the first sulfidizing agent comprises a sulfide.

[0023] In some embodiments of the present application, the sulfide comprises at least one of sodium sulfide and ammonium sulfide.

[0024] In some embodiments of the present application, the reaction pH value of the copper removal process is 1.0-1.2.

[0025] In some embodiments of the present application, the reaction temperature of the copper removal process is 20-30°C, and the reaction time is 1-1.5h.

[0026] In some embodiments of the present application, the reaction pH value of the zinc removal process is 2.0-2.5.

[0027] In some embodiments of the present application, the reaction temperature of the zinc removal process is 20-30°C, and the reaction time is 1-1.5h.

[0028] In some embodiments of the present application, in the second sulfidizing process, the second sulfidizing agent comprises a sulfide.

[0029] In some embodiments of the present application, the sulfide comprises at least one of sodium sulfide and ammonium sulfide.

[0030] In some embodiments of the present application, the reaction pH value of the second sulfidizing process is 3-5.

[0031] In some embodiments of the present application, the reaction temperature of the second sulfidizing process is 50-90°C, and the reaction time is 1-2h.

[0032] In some embodiments of the present application, in the ion exchange process, the ion exchange solution comprises a chloride salt solution.

[0033] In some embodiments of the present application, the chloride salt comprises at least one of nickel chloride, cobalt chloride and manganese chloride.

[0034] In some embodiments of the present application, the reaction temperature of the ion exchange process is 30-60°C, and the reaction time is 1-2h.

[0035] In some embodiments of the present application, the treatment method further comprises:

[0036] In the washing process, after the third sulfidized precipitate is mixed and washed with water, solid-liquid separation is performed to obtain washed residue and washed solution.

[0037] The washed residue is used to perform a second leaching process to obtain a metal salt solution.

[0038] In some embodiments of the present application, the washing temperature of the washing process is 30-60°C, and the washing time is 1-2h.

[0039] In some embodiments of the present application, in the second leaching process, the ratio of the amount of the washed residue to the solvent is 1-1.2g:2-25mL.

[0040] In some embodiments of the present application, the pressure of the pressure leaching is 1.0-1.5MPa.

[0041] In some embodiments of the present application, the temperature of the pressure leaching is 120-160°C, and the time is 3-4h.

[0042] In some embodiments of the present application, the treatment method further comprises:

[0043] A circulation process, in which the third sulfurized liquid is mixed with the first sulfurized liquid and then subjected to a second sulfurization process. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0045] Figure 1 A flow chart of the treatment method of nickel-cobalt hydroxide provided by some embodiments of the present application;

[0046] Figure 2 A flow chart of the treatment method of nickel-cobalt hydroxide provided by some embodiments of the present application;

[0047] Figure 3 A flow chart of the treatment method of nickel-cobalt hydroxide provided by some embodiments of the present application. DETAILED DESCRIPTION

[0048] 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 a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, 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" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[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] The term "or" is inclusive in this application, unless otherwise indicated. So for example, the phrase "A or B" means "A, B, or both A and B." More specifically, any of the following satisfy the condition "A or B": A is true (or present) and B is false (or not present); A is false (or not present) and B is true (or present); or both A and B are true (or present).

[0054] In this application, nickel-cobalt hydroxide (MHP) refers to a nickel intermediate product, which can be prepared by high-pressure acid leaching of laterite nickel ore, or prepared from battery black powder. Depending on the source, the nickel-cobalt hydroxide can contain metal elements such as nickel (Ni), cobalt (Co), manganese (Mn), iron (Fe), aluminum (Al), calcium (Ca), magnesium (Mg), copper (Cu), zinc (Zn), etc.

[0055] Liquid-solid ratio refers to the ratio of the volume of liquid (unit: milliliter) to the mass of solid (unit: gram), for example, the liquid-solid ratio can be 2ml:1g.

[0056] Ternary precursor refers to a nickel-cobalt-manganese hydroxide material, with a chemical formula of Ni x Co y Mn (1-x-y) (OH)2, where x, y can be adjusted according to the actual needs of nickel, cobalt, and manganese, and is generally used as a positive material for batteries.

[0057] Pure water generally refers to water with an electrical conductivity of less than or equal to 10 μS / cm, a total organic carbon of less than or equal to 20 mg / L, metal ions (Na, K, Ca, Mg, etc.) of less than or equal to 1000 μg / L, and other ions (Cl, NO3 - , etc.) of less than or equal to 2000 μg / L.

[0058] Referring to Figure 1 The application provides a treatment method for nickel-cobalt hydroxide, which comprises:

[0059] S100, a first leaching process, reducing and acid leaching the nickel-cobalt hydroxide to obtain a leaching solution and a leaching residue;

[0060] S200, a neutralization process, adding a neutralizing agent to the leaching solution to neutralize and precipitate iron, to obtain a neutralization precipitate and a neutralized solution;

[0061] S300, a first sulfidation process, adding a first sulfidation agent to the neutralized solution to sulfidize and precipitate copper and / or zinc, to obtain a first sulfidation precipitate and a first sulfidation solution;

[0062] S400, a second sulfidation process, adding a second sulfidation agent to the first sulfidation solution to sulfidize and precipitate the metals in the first sulfidation solution, to obtain a second sulfidation precipitate and a second sulfidation solution;

[0063] S500, an ion exchange process, adding an ion exchange solution to the second sulfidation precipitate to replace at least part of the impurities of calcium and / or magnesium in the second sulfidation precipitate into the solution, and obtaining a third sulfidation precipitate and a third sulfidation solution through solid-liquid separation;

[0064] S700, a second leaching process, mixing the third sulfidation precipitate with a solvent and oxygen to perform pressure leaching, and obtaining a metal salt solution through solid-liquid separation, wherein the metal salt includes at least one of a nickel salt, a cobalt salt and a manganese salt.

[0065] The processing method provided by the embodiment of the present application can leach the nickel, cobalt and manganese elements in the nickel-cobalt hydroxide by reducing and acid leaching the nickel-cobalt hydroxide in the first leaching process. Since the nickel-cobalt hydroxide can contain metal elements such as iron, aluminum, calcium, magnesium, copper and zinc, the metal ions such as iron, aluminum, calcium, magnesium, copper and zinc can also be leached in the reducing and acid leaching in the first leaching process, and thus the metal ions need to be removed. In the embodiment, the metal ions such as iron, aluminum, copper and zinc can be converted into a precipitated form by adding a neutralizing agent and a first sulfidation agent to the leaching solution, so as to remove the impurities of iron, aluminum, copper and zinc, thereby improving the purity of nickel, cobalt and manganese in the final product. The leached metal elements such as nickel, cobalt, copper, calcium and magnesium can be precipitated by adding a second sulfidation agent to the first sulfidation solution to react with the first sulfidation solution in the second sulfidation process, thereby obtaining a second sulfidation precipitate. Then, the second sulfidation precipitate is mixed with an ion exchange solution to perform ion exchange reaction. At this time, the ion exchange solution can react with calcium and magnesium in the second sulfidation precipitate to replace the calcium and magnesium into the solution, while the nickel, cobalt and manganese in the second sulfidation precipitate still exist in the form of solid. Then, the calcium and magnesium can enter the third sulfidation solution and the nickel, cobalt and manganese can enter the third sulfidation precipitate through solid-liquid separation. Finally, the third sulfidation precipitate is subjected to pressure leaching, thereby obtaining a metal salt product containing nickel, cobalt and manganese.

[0066] Therefore, according to the processing method of the nickel-cobalt hydroxide provided by the embodiment of the present application, the metal elements such as iron, aluminum, calcium, magnesium, copper and zinc can be removed by processing the nickel-cobalt hydroxide, thereby extracting a product containing nickel, cobalt and manganese. The product can be used as a raw material for preparing lithium ion batteries. Moreover, since the price of the nickel-cobalt hydroxide is low, the nickel, cobalt and manganese product obtained by the embodiment of the present application can be used as a raw material for lithium ion batteries, thereby reducing the cost of the raw material for lithium ion batteries.

[0067] In some embodiments, the first leaching process comprises: mixing the nickel-cobalt hydroxide with a solvent to form a slurry, and then mixing the slurry with an acid and a reducing agent to perform a reduction acid leaching, and then performing a solid-liquid separation to obtain a leaching solution and a leaching residue. The nickel, cobalt and manganese metals in the nickel-cobalt hydroxide can be fully leached by the reducing agent and the acid, so as to facilitate subsequent separation and extraction of the nickel, cobalt and manganese. The method of the solid-liquid separation can be any method known in the art for separating solids and liquids, for example, the solid-liquid separation can be performed by a centrifugal separation method, a tilting method, a filtration method, etc., and the solid-liquid separation herein can be performed by referring to the above methods.

[0068] In some embodiments, the amount of the nickel-cobalt hydroxide used in the first leaching process is 1 g-1.2 g, and the amount of the solvent used is 2 mL-2.5 mL, for example, the solvent can be water, etc. At this time, the nickel-cobalt hydroxide can be fully slurried, so that the nickel, cobalt and manganese metals in the nickel-cobalt hydroxide can fully react with the reducing agent and the acid, thereby maximizing the leaching rate of the nickel, cobalt and manganese metals.

[0069] In addition, in the first leaching process, by controlling the reaction conditions of the reduction acid leaching, it is also conducive to the reaction of the acid and the reducing agent with the nickel, cobalt and manganese metals. In some embodiments, the pH value of the reduction acid leaching is maintained at 1.5-2.0, and the temperature of the reduction acid leaching is 80-90°C. At this time, it can further help to quickly and fully leach the nickel, cobalt and manganese metals in the nickel-cobalt hydroxide.

[0070] In some embodiments, the acid used in the first leaching process includes at least one of sulfuric acid, hydrochloric acid and nitric acid. Sulfuric acid, hydrochloric acid and nitric acid are all common acids, widely available and low in cost, which are conducive to being used for reduction acid leaching.

[0071] In some embodiments, the reducing agent includes at least one of hydrogen peroxide, sulfur dioxide, sodium sulfite, sodium metabisulfite, ferrous sulfate, ferrous sulfide, sodium bisulfite, ammonium sulfite, ammonium bisulfite, sodium thiosulfate, calcium sulfite and sulfur. When the above reducing agents are selected, the nickel, cobalt and manganese metals in the nickel-cobalt hydroxide can be fully leached, so as to maximize the recovery of the nickel, cobalt and manganese in the nickel-cobalt hydroxide and improve the recovery rate of the nickel, cobalt and manganese.

[0072] In the neutralization process, the neutralizing agent is added mainly to remove the iron and aluminum impurities in the leaching solution. Specifically, the addition of the neutralizing agent can adjust the pH value of the leaching solution, so that the iron ions and aluminum ions undergo a hydrolysis reaction to convert into iron hydroxide and aluminum hydroxide precipitates, and then the solid-liquid separation can be performed to separate out the iron and aluminum impurities in the leaching solution.

[0073] In some embodiments, in the neutralization process, the neutralizing agent comprises at least one of calcium carbonate, sodium carbonate, sodium hydroxide, calcium hydroxide, ammonia, calcium oxide, potassium hydroxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, nickel carbonate, cobalt carbonate and manganese carbonate. The above neutralizing agents can be selected to adjust the pH value of the leaching solution and also to avoid introducing impurities that are difficult to remove in subsequent processes.

[0074] In some embodiments, the neutralizing agent is added for 1-2 hours. By controlling the continuous and slow addition of the neutralizing agent to the leaching solution, the precipitation of iron ions and aluminum ions can be avoided from precipitating too quickly and forming agglomerates, thereby avoiding the coating of nickel, cobalt and manganese ions when the agglomerates are formed, which reduces the recovery rate of nickel, cobalt and manganese.

[0075] In addition, the reaction conditions of the neutralization process are also conducive to the hydrolysis of iron ions and aluminum ions. In some embodiments, the reaction pH value of the neutralization process is 4.5-5.5, the reaction temperature of the neutralization process is 80-90°C, and the reaction time is 1-1.5 hours. Within the above pH value range, it can be ensured that iron and aluminum are fully precipitated, while nickel, cobalt and manganese do not precipitate; and completing the neutralization process within the above temperature and time range can further help to fully remove iron and aluminum from the leaching solution.

[0076] Please refer to Figure 2 In some embodiments, the first sulfidation process comprises:

[0077] S310, a copper removal process, a first sulfidation agent is added to the neutralized solution to sulfidize and precipitate copper, to obtain copper residue and copper-removed solution;

[0078] S320, a zinc removal process, a first sulfidation agent is added to the copper-removed solution to sulfidize and precipitate zinc, to obtain first sulfidation precipitate and first sulfidation solution.

[0079] In this embodiment, the impurity removal process is carried out in stages, so that copper and zinc impurities in the leaching solution can be gradually removed, which can make the impurity removal effect more thorough and help to reduce the content of copper and zinc impurities in nickel, cobalt and manganese products.

[0080] In some embodiments, the first sulfidation agent comprises a sulfide. In the first leaching process, copper and zinc metal impurities are leached and mainly exist in the leaching solution in the form of ions. By adding a sulfide in the copper removal process and the zinc removal process, the sulfide can react with the ions of copper and zinc metal to form corresponding copper sulfide and zinc sulfide precipitates. The possible chemical reactions include:

[0081] Cu 2+ +S 2- =CuS;

[0082] Zn 2+ +S 2-= ZnS.

[0083] By the above reaction, Cu 2+ , Zn 2+ ions in the first leaching process can be converted into sulfide form and precipitated, so as to remove copper and zinc impurities by solid-liquid separation, thereby obtaining high-purity nickel, cobalt and manganese products.

[0084] In some embodiments, the sulfide includes at least one of sodium sulfide and ammonium sulfide. The use of the above sulfide can convert copper and zinc ions into precipitates, thereby removing as much copper and zinc impurities as possible.

[0085] In the copper removal process, in order to avoid the reaction of nickel, cobalt and manganese ions with the first sulfidation agent, in some embodiments, the reaction pH value of the copper removal process can be controlled to be 1.0-1.2, thereby avoiding the precipitation of nickel, cobalt and manganese ions and causing loss.

[0086] In some embodiments, the reaction temperature of the copper removal process is 20-30°C, and the reaction time is 1-1.5h. Completing the copper removal process in the above temperature and time range can further help to precipitate copper ions sufficiently, thereby removing copper impurities sufficiently.

[0087] In the zinc removal process, in order to avoid the reaction of nickel, cobalt and manganese ions with the first sulfidation agent, in some embodiments, the reaction pH value of the zinc removal process can be controlled to be 2.0-2.5, thereby avoiding the precipitation of nickel, cobalt and manganese ions and causing loss.

[0088] In some embodiments, the reaction temperature of the zinc removal process is 20-30°C, and the reaction time is 1-1.5h. Completing the zinc removal process in the above temperature and time range can further help to precipitate zinc ions sufficiently, thereby removing zinc impurities sufficiently.

[0089] In some embodiments, in the second sulfidation process, the second sulfidation agent includes a sulfide. In the first leaching process, after the nickel, cobalt and manganese metals are leached, they mainly exist in the form of ions in the leaching solution. By adding a sulfide in the second sulfidation process, the sulfide can react with the ions of nickel, cobalt and manganese to generate corresponding nickel sulfide, cobalt sulfide and manganese sulfide. The possible chemical reactions include:

[0090] Ni 2+ + S 2- = NiS;

[0091] Co 2+ + S 2- = CoS;

[0092] Mn 2+ + S 2- = MnS;

[0093] Ca 2+ +S 2- = CaS;

[0094] Mg 2+ +S 2- = MgS.

[0095] Through the above reaction, the metal ions of Ni 2+ , Co 2+ , Mn 2+ , Ca 2+ , Mg 2+ , etc. leached in the first leaching process can be converted into sulfide form and precipitated, so as to facilitate the removal of calcium and magnesium impurities through the ion exchange process, thereby obtaining high-purity nickel, cobalt, and manganese products.

[0096] It should be noted that the second sulfidation agent can be the same sulfide as the first sulfidation agent, which can not only convert the ions of nickel, cobalt, and manganese into precipitates as much as possible to maximize the recovery rate of nickel, cobalt, and manganese, but also avoid introducing other impurities.

[0097] In addition, in the second sulfidation process, controlling the reaction conditions of the second sulfidation process is also conducive to the reaction of the ions of nickel, cobalt, and manganese with sulfides. In some embodiments, the reaction pH of the second sulfidation process is 3-5, the reaction temperature of the second sulfidation process is 50°C-90°C, and the reaction time is 1h-2h. By controlling the related parameters of the second sulfidation process within the above suitable range, the leached Ni 2+ , Co 2+ , Mn 2+ in the first leaching process can be precipitated sufficiently, thereby helping to improve the recovery rate of nickel, cobalt, and manganese.

[0098] When the second sulfidation agent is a sulfide such as sodium sulfide, the second sulfidation precipitate obtained through the second sulfidation process mainly contains nickel sulfide, cobalt sulfide, manganese sulfide, calcium sulfide, magnesium sulfide, and other metal sulfide forms, and at this time, the ion exchange process is needed to remove impurities such as calcium sulfide and magnesium sulfide.

[0099] In some embodiments, in the ion exchange process, the ion exchange solution includes a chloride salt solution. By mixing the second sulfidation precipitate with the chloride salt solution, the solubility difference of nickel sulfide, cobalt sulfide, manganese sulfide, calcium sulfide, and magnesium sulfide can be utilized to separate nickel sulfide, cobalt sulfide, and manganese sulfide from calcium sulfide and magnesium sulfide.

[0100] In some embodiments, the chloride salt includes at least one of nickel chloride, cobalt chloride, and manganese chloride. Since the solubility of nickel sulfide, cobalt sulfide, and manganese sulfide is much smaller than that of calcium sulfide and magnesium sulfide, when the nickel chloride, cobalt chloride, and / or manganese chloride solution is added, the added nickel ions, cobalt ions, and / or manganese ions are more likely to combine with the sulfur ions in the calcium sulfide and magnesium sulfide to form more difficultly soluble nickel sulfide, cobalt sulfide, and / or manganese sulfide, thereby causing the calcium sulfide and magnesium sulfide to be converted into soluble calcium ion and magnesium ion forms. Among them, the possible chemical reactions include:

[0101] CaS + NiCl2→ NiS + CaCl2;

[0102] MgS + NiCl2→ NiS + MgCl2;

[0103] CaS + CoCl2→ CoS + CaCl2;

[0104] MgS + CoCl2→ CoS + MgCl2;

[0105] CaS + MnCl2→ MnS + CaCl2;

[0106] MgS + MnCl2→ MnS + MgCl2.

[0107] Through the above reactions, the calcium sulfide and magnesium sulfide in the second sulfidation precipitate can be converted into soluble calcium chloride and magnesium chloride, while the nickel sulfide, cobalt sulfide, and manganese sulfide in the second sulfidation precipitate do not react with the chloride salt, so that the separation of nickel, cobalt, and manganese from calcium and magnesium can be achieved through solid-liquid separation, thereby effectively removing the calcium and magnesium impurities.

[0108] Moreover, when nickel chloride, cobalt chloride, and / or manganese chloride is used as the chloride salt added in the ion exchange process, no impurities other than nickel, cobalt, and manganese are introduced, which is conducive to obtaining nickel, cobalt, and manganese products with higher purity.

[0109] In some embodiments, the reaction temperature of the ion exchange process is 30-60°C, and the reaction time is 1-2h. At this time, sufficient replacement of calcium and magnesium impurities can be ensured, thereby converting as much calcium sulfide and magnesium sulfide as possible into soluble calcium chloride and magnesium chloride, which helps to reduce the calcium and magnesium impurity content of the nickel, cobalt, and manganese products.

[0110] To ensure that the calcium and magnesium impurities are sufficiently removed, an excess amount of chloride salt such as nickel chloride, cobalt chloride, and manganese chloride is generally added in the ion exchange process, and therefore, the third sulfidation solution may still contain nickel, cobalt, and manganese ions that have not reacted sufficiently. The nickel, cobalt, and manganese in this part can be recovered to improve the utilization rate of raw materials.

[0111] In some embodiments, the processing method further comprises a circulation process of mixing the third sulfidation post-liquid with the first sulfidation post-liquid and then performing the second sulfidation process. Through the above circulation process, the excessive nickel, cobalt and manganese ions in the ion exchange process can be recovered, and the problem of waste of chloride salt raw materials can be reduced.

[0112] Referring to Figure 3 In some embodiments, the processing method of the nickel-cobalt hydroxide further comprises:

[0113] S600, a washing process, the third sulfidation precipitate is mixed with water for washing, and then solid-liquid separation is performed to obtain washed residue and washed liquid; the washed residue is used to perform a second leaching process to obtain a metal salt solution.

[0114] When the chloride salt solution is added in the ion exchange process, a small amount of chloride ions may be entrained into the third sulfidation precipitate. In this embodiment, the third sulfidation precipitate is washed with water in the washing process, so that the small amount of chloride ions entrained in the third sulfidation precipitate can be removed, thereby avoiding the introduction of chloride ion impurities into the obtained nickel-cobalt-manganese product. After the washing process, nickel, cobalt and manganese mainly exist in the form of solids in the washed residue, i.e., the obtained washed residue can be used as a raw material for preparing lithium ion batteries.

[0115] In some embodiments, the washing temperature of the washing process is 30-60°C, and the washing time is 1-2h. The washing is completed within the above temperature and time range, which can further help to remove chloride ion impurities.

[0116] It can be understood that the washed liquid can also be obtained after the solid-liquid separation in the washing process. In order to avoid the loss caused by the entrainment of a small amount of nickel, cobalt and manganese in the washed liquid, in some embodiments, the washed liquid can be reused in the second sulfidation process to recover nickel, cobalt and manganese in the washed liquid, or the washed liquid can be reused in the ion exchange process to prepare an ion exchange solution.

[0117] In some cases, in order to facilitate the direct application of nickel, cobalt and manganese products, the washed residue needs to be further processed so that the nickel, cobalt and manganese in the washed residue are converted into liquid metal salt form. For example, the nickel sulfide, cobalt sulfide and manganese sulfide in the washed residue can be converted into liquid sulfate, and the obtained sulfate can be directly used to prepare a ternary precursor, so as to facilitate the preparation of corresponding lithium ion batteries. In this embodiment, by performing pressure leaching on the washed residue in the second leaching process, the nickel sulfide, cobalt sulfide and manganese sulfide in the washed residue can react with oxygen and a solvent such as water to be converted into a solution product of nickel sulfate, cobalt sulfate and manganese sulfate. In this way, a certain amount of nickel sulfate, cobalt sulfate and manganese sulfate can be supplemented into the obtained solution product to prepare a ternary precursor raw material meeting the target requirements, so that the iron, cobalt and nickel products obtained in this embodiment can be directly used to prepare a ternary precursor.

[0118] In some embodiments, in the second leaching process, the ratio of the amount of washed residue to solvent is 1 g-1.2 g: 2 mL-25 mL, which is conducive to the sufficient leaching of nickel, cobalt and manganese, so as to obtain nickel, cobalt and manganese products with higher purity.

[0119] In addition, in the second leaching process, by controlling the reaction conditions of the pressure leaching reaction, it is also conducive to the reaction of nickel sulfide, cobalt sulfide and manganese sulfide with oxygen and water. In some embodiments, the pressure of the pressure leaching is 1.0 MPa-1.5 MPa, the temperature of the pressure leaching is 120°C-160°C, and the time is 3h-4h. By controlling the related parameters of the pressure leaching within the above suitable range, it is conducive to the sufficient leaching of nickel, cobalt and manganese, so as to help improve the recovery rate of nickel, cobalt and manganese.

[0120] The following examples more specifically describe the disclosure of the present application, which are only used for illustrative purposes, because various modifications and changes within the scope of the disclosure of the present application are obvious to those skilled in the art. Unless otherwise stated, all parts, percentages and ratios reported in the following examples are based on mass, and all reagents and raw materials used in the examples are commercially available or synthesized according to conventional methods, and the instruments used in the examples are commercially available.

[0121] The composition of the nickel-cobalt hydroxide (MHP) raw material used in the following examples is shown in Table 1, and the judgment standard of battery-grade sulfate used for preparing ternary precursors is shown in Table 2.

[0122] Table 1, composition of nickel-cobalt hydroxide (MHP) raw material in the examples of the present application

[0123]

[0124] Table 2, judgment standard of battery-grade sulfate

[0125]

[0126] Example 1

[0127] The present embodiment provides a treatment method of nickel-cobalt hydroxide, comprising the following steps:

[0128] The first leaching process, first take 200g sample A MHP (composition see Table 1) in 1L beaker, add 400mL water according to liquid-solid ratio 2:1, slurry 10min. After slurry, the beaker is placed in a water bath to heat to 85℃ and add a certain amount of concentrated sulfuric acid to adjust the pH value of the slurry in the beaker to keep 1.5 unchanged. After the pH value of the slurry in the beaker is stable for 1h, continue to add a certain amount of sodium pyrosulfite and concentrated sulfuric acid for reduction acid leaching, until the slurry is clear, filtration to obtain the leaching liquid (leaching end point pH is 1.5) and a small amount of leaching residue.

[0129] The neutralization process, take the leaching liquid in a 1L beaker, and place the beaker in a water bath. When the temperature rises to 85℃, slowly add a certain amount of calcium carbonate to the leaching liquid until the pH value of the leaching liquid is 5.5 to carry out neutralization and iron removal reaction. The addition time of calcium carbonate is 1h, and the time of neutralization and iron removal reaction is 1.5h. During the neutralization and iron removal reaction, hydrolysis reaction occurs, and iron and aluminum are precipitated in the form of iron hydroxide and aluminum hydroxide, respectively. After the hydrolysis reaction is completed, solid-liquid separation is carried out to obtain the neutralized liquid, wherein the neutralized liquid is a nickel sulfate solution with iron and aluminum contents less than 1mg / L.

[0130] The copper removal process, take the neutralized liquid in a 1L beaker, add a certain amount of dilute sulfuric acid to the neutralized liquid to adjust the pH value to 1.0, and then add sodium sulfide to carry out sulfidation and copper removal reaction. The addition amount of sodium sulfide is 1.1 times the theoretical amount required for the complete precipitation of copper in the neutralized liquid. The sulfidation and copper removal reaction time is 1.5h, and the temperature is set to 20℃. After the reaction is completed, solid-liquid separation is carried out to obtain the copper-removed liquid, wherein the copper-removed liquid is a nickel sulfate solution with copper content less than 1mg / L.

[0131] The zinc removal process, take the copper-removed liquid in a 1L beaker, add a certain amount of sodium hydroxide to the copper-removed liquid to adjust the pH value to 2.0, and then add sodium sulfide to carry out sulfidation and zinc removal reaction. The addition amount of sodium sulfide is 1.2 times the theoretical amount required for the complete precipitation of zinc in the copper-removed liquid. The sulfidation and zinc removal reaction time is 1.5h, and the temperature is set to 20℃. After the reaction is completed, solid-liquid separation is carried out to obtain the first sulfidation liquid, wherein the first sulfidation liquid is a nickel sulfate solution with zinc content less than 5mg / L.

[0132] The second sulfidation process, take the first sulfidation liquid in a 1L beaker, add a certain amount of sodium hydroxide to the first sulfidation liquid to adjust the pH value to 4.0, and then add sodium sulfide to carry out sulfidation and precipitation reaction. The addition amount of sodium sulfide is 1.1 times the theoretical amount required for the complete precipitation of nickel, cobalt and manganese in the first sulfidation liquid. The sulfidation and precipitation reaction time is 1h, and the temperature is 50℃. After the reaction is completed, solid-liquid separation is carried out to obtain the second sulfidation precipitate and the second sulfidation liquid, wherein the second sulfidation precipitate is a sulfidation residue containing nickel sulfide, cobalt sulfide and manganese sulfide.

[0133] The ion exchange process is as follows: the second sulfidation precipitate is taken into a 1 L beaker, a certain amount of pure water is added according to the liquid-solid ratio of 2 ml:1 g, and nickel chloride is added for ion exchange. The amount of nickel chloride added is 1.1 times the theoretical amount required for the reaction with calcium and magnesium in the second sulfidation precipitate. The ion exchange temperature is 60 DEG C, and the time is 2 h. Then, solid-liquid separation is performed to obtain a third sulfidation liquid and a third sulfidation precipitate.

[0134] The washing process is as follows: the third sulfidation precipitate is taken into a beaker, a certain amount of pure water is added for washing, the washing temperature is set to 60 DEG C, and after the reaction temperature is reached, washing is performed for 2 h, followed by solid-liquid separation to obtain a washed liquid and a washed residue. In the washed residue, calcium, magnesium and chloride ions have been substantially removed, and the main elements are only nickel, cobalt and manganese.

[0135] The second leaching process is as follows: the washed residue is taken into a reaction container, a certain amount of pure water is added according to the liquid-solid ratio of 2 ml:1 g, the temperature is set to 160 DEG C, and the reaction container is pressurized with oxygen at 1.0 MPa for pressure leaching reaction for 3 h, followed by solid-liquid separation to obtain a metal salt solution containing nickel, cobalt and manganese. The obtained metal salt is a battery-grade sulfate salt (complying with the relevant standards in Table 2), which includes battery-grade nickel sulfate, cobalt sulfate and manganese sulfate. The contents of nickel, cobalt and manganese in the obtained metal salt are 96.16 g / L, 6.62 g / L and 15.21 g / L, respectively, and the contents of calcium and magnesium are 10.32 mg / L and 14.26 mg / L, respectively.

[0136] The obtained battery-grade sulfate salt can be mixed with a certain amount of nickel sulfate, cobalt sulfate and / or manganese sulfate and directly used for preparing a ternary precursor.

[0137] Example 2

[0138] The difference between this example and Example 1 is that the nickel-cobalt hydroxide raw material is selected from sample B, and the specific composition is shown in Table 1. The parameters of each process are different, and the specific parameters are shown in Table 3.

[0139] Example 3

[0140] The difference between this example and Example 1 is that only manganese chloride is added for ion exchange in the ion exchange process. The parameters of each process are different, and the specific parameters are shown in Table 3.

[0141] Example 4

[0142] The difference between this example and Example 1 is that only cobalt chloride is added for ion exchange in the ion exchange process. The parameters of each process are different, and the specific parameters are shown in Table 3.

[0143] Example 5

[0144] The embodiment differs from example 1 in that the third sulfidation post-liquid obtained by the ion exchange process is used to perform the second sulfidation process; the parameters of each process are different, and the specific parameters are shown in Table 3.

[0145] Table 3, parameters of each process in examples 2-5 and example 1

[0146]

[0147] Comparative example 1

[0148] The difference from example 1 is that after the zinc removal process is completed, ion exchange is performed using fluoride. In this comparative example, after the zinc removal process is completed, the following steps are specifically included:

[0149] The calcium and magnesium removal process takes the first sulfidation post-liquid in a 1L beaker, and sodium fluoride is added to the first sulfidation post-liquid to perform the calcium and magnesium removal reaction. The amount of sodium fluoride added is 1.2 times the theoretical amount required to precipitate all the calcium and magnesium in the first sulfidation post-liquid. The calcium and magnesium removal reaction time is 1.5 hours, and the temperature is set to room temperature. After the reaction is completed, solid-liquid separation is performed to obtain a calcium and magnesium removed post-liquid and a calcium and magnesium containing residue. The nickel, cobalt, and manganese contents in the calcium and magnesium removed post-liquid are 69.58 g / L, 5.47 g / L, and 13.41 g / L, respectively, and the calcium, magnesium, fluorine, and sodium contents are 13.43 mg / L, 15.03 mg / L, 201.32 mg / L, and 1334.42 mg / L, respectively.

[0150] The fluorine content in the obtained calcium and magnesium removed post-liquid exceeds the standard, and it cannot be used to prepare ternary precursors.

[0151] Comparative example 2

[0152] The difference from example 1 is that after the neutralization process is completed, impurity removal is performed using extraction. In this comparative example, after the neutralization process is completed, the following steps are specifically included:

[0153] The extraction impurity removal process takes the neutralized post-liquid and adds P204 extractant with a phase ratio of 3:1, mixes and stirs for 10 minutes, and then separates to obtain a cobalt extraction original liquid. The cobalt extraction original liquid is taken and P507 extractant is added with a phase ratio of 2:1, mixed and stirred for 10 minutes, and then separated to obtain a magnesium extraction original liquid. Cy272 extractant is added with a phase ratio of 1:2, stirred for 10 minutes, and then separated to obtain a crystallization original liquid. The crystallization original liquid is taken to an evaporator, the evaporation temperature is controlled at 150°C, the slurry volume is concentrated to 2 / 5, and then heating is stopped. After stirring at 52°C for 2 hours, solid-liquid separation is performed to obtain nickel sulfate crystals. After the nickel sulfate crystals are dissolved, a nickel sulfate solution is obtained. The nickel content in the obtained solution is 120.12 g / L, and the cobalt, manganese, calcium, and magnesium contents are 6.12 mg / L, 3.34 mg / L, 3.01 mg / L, and 2.12 mg / L, respectively.

[0154] The obtained nickel sulfate solution can be mixed with a certain amount of nickel sulfate, cobalt sulfate and / or manganese sulfate and directly used for preparing ternary precursors.

[0155] Table 4, comparison table of treatment methods of each example and comparative example

[0156]

[0157] Table 5, comparison table of final product compositions of each example and comparative example

[0158]

[0159]

[0160] As can be seen from Tables 1-5, after being treated by the treatment method provided in the present application, the nickel content in the final obtained nickel, cobalt and manganese product can reach 95 g / L or more, the cobalt content can reach 6.5 g / L or more, and the manganese content can reach 14 g / L or more, while the calcium content is only between 10 mg / L and 13 mg / L, and the magnesium content is only between 10 mg / L and 15 mg / L. Obviously, the calcium and magnesium impurity contents in the final product are extremely low, and it can be considered that there is almost no calcium and magnesium impurities. The obtained nickel, cobalt and manganese product meets the requirements of battery-grade sulfate, and can be directly used as a raw material for preparing ternary precursors, so as to prepare lithium ion batteries. Since the price of nickel-cobalt hydroxide is relatively low, the ternary precursor raw material obtained by the treatment method provided in the present application can reduce the raw material cost for preparing lithium ion batteries, which is conducive to the development of the lithium ion battery industry.

[0161] Moreover, in the present application, most of the calcium, magnesium and other impurities can be removed without using an extractant for extraction, the impurity removal process has low cost, simple process and operation, high safety and is more friendly to the environment, and is suitable for large-scale industrial application.

[0162] Comparing the experimental data of Comparative Example 1 and Example 1, in Comparative Example 1, fluoride is used for removing calcium and magnesium, and the final obtained product has a nickel content of only 69.58 g / L, which is much lower than the nickel content of the product obtained in Example 1. Moreover, the product obtained in Comparative Example 1 has a fluorine content of 201.32 mg / L and a sodium content of 1334.42 mg / L, which means that excessive fluorine and sodium impurities are introduced into the product, which limits the application field of the product, and the obtained product cannot be directly used for preparing lithium ion batteries. Moreover, the cost of fluoride used in Comparative Example 1 is high, while the impurity removal purpose can be achieved by the low-cost treatment process in Example 1.

[0163] Comparing the experimental data of Comparative Example 2 and Example 1, in Comparative Example 2, an extractant is added for impurity removal, and the final obtained product has a cobalt content of only 6.12 x 10 -3g / L, and the manganese content is only 3.34 x 10 -3 g / L, which is much lower than the cobalt content and the manganese content in the product obtained in Example 1, and it can be seen that the cobalt and manganese are not recovered in Comparative Example 1, while the cobalt and manganese in the nickel cobalt hydroxide raw material can be fully recovered in Example 1. In addition, the impurity removal operation in Comparative Example 1 is high in impurity removal cost, and the extraction process is complicated, and the extractant may volatilize organic matter, resulting in pollution to the production environment. The treatment method in the embodiments of the present application does not need to be extracted and removed, which can avoid the above problems, and effectively remove calcium, magnesium and other impurities to obtain iron, cobalt and nickel products meeting the requirements.

[0164] The technical features described above can be combined arbitrarily. Although all possible combinations of these technical features are not described, any combination of these technical features should be considered to be covered by the present specification, as long as there is no contradiction in such a combination.

[0165] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A process for the treatment of nickel cobalt hydroxide, characterized in that, The method comprises the following steps: A first leaching process, in which nickel-cobalt hydroxide is subjected to reduction acid leaching to obtain a leaching solution and a leaching residue; A neutralization process, in which a neutralizing agent is added to the leaching solution to neutralize and precipitate iron, thereby obtaining a neutralization precipitate and a post-neutralization solution, wherein the reaction pH value of the neutralization process is 4.5-5.5; A first sulfidation process, in which a first sulfidation agent is added to the post-neutralization solution to sulfidize and precipitate copper and zinc, thereby obtaining a first sulfidation precipitate and a first post-sulfidation solution; A second sulfidation process, in which a second sulfidation agent is added to the first post-sulfidation solution to sulfidize and precipitate metals in the first post-sulfidation solution, thereby obtaining a second sulfidation precipitate and a second post-sulfidation solution, wherein the reaction pH value of the second sulfidation process is 3-5; An ion exchange process, in which an ion exchange solution is added to the second sulfidation precipitate to replace at least part of impurities of calcium and / or magnesium in the second sulfidation precipitate into the solution, thereby obtaining a third sulfidation precipitate and a third post-sulfidation solution through solid-liquid separation; A second leaching process, in which the third sulfidation precipitate is mixed with a solvent and oxygen for pressurized leaching, and then solid-liquid separation is performed to obtain a metal salt solution, wherein the metal salt comprises nickel salt, cobalt salt and manganese salt; The first sulfidation process comprises: A copper removal process, in which a first sulfidation agent is added to the post-neutralization solution to sulfidize and precipitate copper, thereby obtaining a copper residue and a post-copper-removal solution, wherein the reaction pH value of the copper removal process is 1.0-1.2; and A zinc removal process, in which a first sulfidation agent is added to the post-copper-removal solution to sulfidize and precipitate zinc, thereby obtaining a first sulfidation precipitate and a first post-sulfidation solution, wherein the reaction pH value of the zinc removal process is 2.0-2.

5.

2. The treatment method according to claim 1, characterized in that, In the neutralization process, the neutralizing agent comprises at least one of calcium carbonate, sodium carbonate, sodium hydroxide, calcium hydroxide, ammonia, calcium oxide, potassium hydroxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, nickel carbonate, cobalt carbonate and manganese carbonate.

3. The treatment method according to claim 1 or 2, characterized in that, The neutralizing agent is added for 1-2 hours.

4. The treatment method according to claim 1 or 2, characterized in that, The reaction temperature of the neutralization process is 80-90°C, and the reaction time is 1-1.5 hours.

5. The treatment method of claim 1, wherein The first sulfidation agent comprises a sulfide, and the sulfide comprises at least one of sodium sulfide and ammonium sulfide.

6. The treatment method of claim 1, wherein The reaction temperature of the copper removal process is 20-30°C, and the reaction time is 1-1.5 hours.

7. The treatment method of claim 1, wherein The reaction temperature of the zinc removal process is 20-30°C, and the reaction time is 1-1.5 hours.

8. The treatment method of claim 1, wherein, In the second sulfidation process, the second sulfidation agent comprises a sulfide, and the sulfide comprises at least one of sodium sulfide and ammonium sulfide.

9. The treatment method of claim 1, wherein, The reaction temperature of the second sulfidation process is 50-90°C, and the reaction time is 1-2 hours.

10. The treatment method of claim 1, wherein The reaction temperature of the ion exchange process is 30-60°C, and the reaction time is 1-2 hours.

11. The treatment method of claim 1, wherein, The treatment method further comprises: A washing process, in which the third sulfidation precipitate is mixed with water for washing, and then solid-liquid separation is performed to obtain a washed residue and a washed solution; The washed residue is used for the second leaching process to obtain the metal salt solution.

12. The treatment method according to claim 11, characterized in that, The washing temperature of the washing process is 30-60°C, and the washing time is 1-2 hours.

13. The processing method of claim 11, wherein, In the second leaching process, the ratio of the washed residue to the solvent is 1g-1.2g: 2mL-25mL.

14. The treatment method according to claim 1 or 11, characterized by, The pressure of the pressure leaching is 1.0MPa-1.5MPa.

15. The treatment method according to claim 1 or 11, characterized by, The temperature of the pressure leaching is 120℃-160℃, and the time is 3h-4h.

16. The treatment method of claim 1, wherein, The treatment method further comprises: A circulation process, in which the third sulfurized liquid is mixed with the first sulfurized liquid and then subjected to the second sulfurization process.

Images