Method for recycling valuable metal from aluminum-containing waste ternary battery positive electrode powder by using hazelnut shell powder

Abstract

The invention relates to a method for recovering valuable metals from aluminum-containing waste ternary battery positive electrode powder by using hazelnut shell powder. The method comprises the following steps: by using widely existing waste hazelnut shell powder as a reducing raw material, pyrolyzing at high temperature to generate various reducing gases (CH4, CO, H2 and the like) and reducing coke, and reducing the aluminum-containing ternary positive electrode material; and then leaching out Li through water leaching, and precipitating to obtain Li2CO3. Carrying out acid leaching on the water leaching residues, and transferring Al, Co, Ni and Mn elements to a liquid phase; kMnO4 is added into the acid liquor, and MnO2 is precipitated; then adding dimethylglyoxime (DMG) to obtain a nickel dimethylglyoxime precipitate; and adjusting the pH value of the cobalt-aluminum solution to 6-10, precipitating aluminum impurities, and evaporating, concentrating and crystallizing the cobalt-containing solution to obtain a CoSO4. 7H2O product. The waste hazelnut shell powder is used for reducing raw materials, wastes are used for treating wastes, the cost of the recycling process is effectively reduced, meanwhile, combination of aluminum and lithium is inhibited, the lithium recycling efficiency is improved, the cost of the recycling process can be effectively reduced, and good economic benefits and application prospects are achieved.

Description

Technical Field

[0001] The present invention relates to the field of valuable metal recovery, and particularly to a method for recovering valuable metals from aluminum-containing waste ternary battery cathode powder using hazelnut shell powder. Background Art

[0002] Ternary power batteries occupy a relatively high market share (≥35%) in the new energy vehicle field due to their high energy density, low self-discharge rate, and excellent voltage stability. The service life of such batteries is usually 5 - 8 years. After retirement, the high-value metal elements such as nickel, cobalt, manganese, and lithium contained in the cathode material give rise to significant resource utilization value.

[0003] In the field of ternary power battery cathode material recovery technology, the mainstream process adopts a collaborative treatment mode of pyrometallurgy and hydrometallurgy: First, high-valent metal oxides are converted into soluble low-valent states through high-temperature reduction decomposition, and then metal elements are efficiently purified through steps such as acid leaching extraction, precipitation separation, and solvent extraction. This combined process has become the key development direction of the industry due to its consideration of both recovery efficiency and industrial feasibility.

[0004] CN111430829A discloses a method for recycling and regenerating waste lithium battery cathode materials assisted by biomass waste. Biomass (a mixture of one or several of corn straw, rapeseed cake, rice husk, straw, sawdust, and sorghum distillers' grains), waste cathode powder are reduced and then separated by water leaching to obtain lithium carbonate. The water leaching residue is acid leached and then purified, and a ternary material precursor is prepared by coprecipitation; then, combined with lithium carbonate, a new ternary cathode material is prepared.

[0005] CN201711338941.6 discloses a method for recovering valuable metals in waste lithium nickel cobalt manganese oxide ternary battery cathode materials. The lithium nickel cobalt manganese oxide ternary battery cathode material is mixed with carbon powder and roasted for reduction, then acid leached, filtered, and the pH is adjusted to 7.0 - 10.0. After filtering and impurity removal, sodium carbonate is added to recover lithium metal elements.

[0006] CN202310938194.9 discloses a composite sulfur-based reducing agent for selectively extracting lithium from waste lithium-ion cathode materials and its application. The cathode material is mixed with iron sulfide and sodium thiosulfate for reduction roasting, and a lithium-rich solution is obtained by water leaching. The nickel cobalt manganese slag is roasted with sodium persulfate and then water leached to obtain a nickel cobalt manganese solution. The nickel cobalt manganese solution, lithium-rich solution, and ammonium oxalate are mixed in a molar ratio of 1:1.2:1 and then spray granulated to obtain a spherical nickel cobalt manganese regenerated cathode material.

[0007] CN201910859941.3 discloses a method for recovering valuable metals from the ternary cathode material of waste power batteries. The cathode material is subjected to high-temperature hydrogen reduction treatment, and the lithium-rich solution after water leaching is used to precipitate lithium carbonate. After acid leaching of the water leached residue, KMnO4 is added to precipitate MnO2. The separated cobalt-nickel solution is subjected to extraction to obtain a nickel-containing salt solution and a cobalt-containing salt solution.

[0008] CN202380011867.4 discloses a method for selectively extracting lithium from waste lithium-ion battery powder by aluminum-carbon synergistic reduction. A mixed solid composed of waste battery powder, carbon powder and aluminum powder is mixed with an alcohol substance and ball milled; after drying, it is calcined, and then carbonated water leaching is carried out for lithium extraction.

[0009] CN202410780655.9 discloses a method for recovering valuable metals from the ternary cathode material of aluminum-containing waste power batteries. Aluminum is directly used as a reducing agent for reduction. Subsequently, direct alkali leaching is carried out to remove most of the reduced aluminum metal and aluminum oxide. After acid leaching, a mixed solution containing nickel, cobalt, manganese, lithium and aluminum is obtained. Then, through precipitation, extraction, hydrolysis and precipitation in sequence, the target element compounds are separated.

[0010] In these above methods, using carbon powder, iron sulfide and sodium thiosulfate as reducing agents, their dosages are large, the cost is high, and the requirements for the use environment are high; using hydrogen as a reducing agent, the utilization rate is low, the energy consumption is large, and the safety hazard is large. And when directly using aluminum as a reducing agent, deep impurity removal treatment is still required in the later stage. Adopting aluminum-carbon synergistic reduction has extremely high requirements for the raw material ratio and mixing degree, and it is difficult to apply in practice. The biomass reduction method does not involve that the excessive aluminum content in the actual raw materials easily leads to the combination of aluminum and lithium, thereby affecting the lithium recovery rate. Therefore, there is an urgent need to find a recovery process with low cost, high efficiency and targeted at the actual aluminum-containing lithium-ion battery cathode material. Summary of the Invention

[0011] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for recovering valuable metals from aluminum-containing waste ternary battery cathode powder by using hazelnut shell powder. This method uses the widely existing waste hazelnut shell powder as a reducing raw material, and various reducing gases (CH4, CO, H2, etc.) and reducing coke can be generated by pyrolysis at high temperature, which can efficiently reduce the actual aluminum-containing ternary cathode material, reduce the recovery cost, inhibit the combination of aluminum and lithium, improve the lithium recovery efficiency, and release the trapped lithium resources.

[0012] To achieve this purpose, the present invention adopts the following technical solutions: Step 1: Crush the aluminum-containing ternary cathode material; Step 2: Mix the raw materials in Step 1 with hazelnut shell powder and carry out a sufficient reduction reaction; Step 3: Immerse the reduction product obtained in Step 2 in water to obtain a water immersion solution. The main element in the water immersion solution is Li. Add a sodium carbonate precipitant thereto, and filter to obtain a Li2CO3 product; Step 4: Acid-immerse the water immersion residue obtained in Step 3 to obtain an acid immersion solution. The main elements in the acid immersion solution are Al, Co, Ni, and Mn; Step 5: Add KMnO4 to the acid immersion solution obtained in Step 4, and filter and separate to obtain a cobalt-nickel-aluminum solution and MnO2; Step 6: Add dimethylglyoxime (DMG) to the cobalt-nickel-aluminum solution obtained in Step 5 to obtain a cobalt-aluminum solution and a dimethylglyoxime nickel precipitate; Step 7: Adjust the pH of the cobalt-aluminum solution obtained in Step 6 to 6-10 to precipitate aluminum impurities, obtain a cobalt-containing solution, evaporate, concentrate, and crystallize it to obtain a CoSO4·7H2O product.

[0013] A method for recovering valuable metals from aluminum-containing waste ternary battery cathode powder using hazelnut shell powder provided by the present invention.

[0014] This method uses widely existing waste hazelnut shell powder as a reduction raw material. Pyrolysis at high temperature can generate various reducing gases (CH4, CO, H2, etc.) and reducing coke. The reaction formula for the reduction process is: 2LiNi 0.5 Co 0.2 Mn 0.3 O2 + CH4 → Li2CO3 + Ni + 0.4CoO + 0.6MnO + 2H2O 2LiNi 0.5 Co 0.2 Mn 0.3 O2 + 2H2 → Li2O + Ni + 0.4CoO + 0.6MnO + 2H2O 2LiNi 0.5 Co 0.2 Mn 0.3 O2 + 2C → Li2O + Ni + 0.4CoO + 0.6MnO + 2CO LiNi 0.5 Co 0.2 Mn 0.3 O2 + 2CO → 0.5Li2O + 0.5Ni + 0.2CoO + 0.3MnO + CO2

[0015] Since CO2 is continuously generated during the reaction process, Li mainly exists in the form of Li2CO3 Li2O + CO2 → Li2CO3

[0016] And aluminum can also participate in the reduction reaction: 6LiNi0.5 Co 0.2 Mn 0.3 O2 + 2Al → 3Li2O + 3NiO + 1.2CoO + 1.8MnO + Al2O3

[0017] After reduction, due to the presence of CO2, the following reaction is continuously inhibited Li2CO3 + Al2O3 → 2LiAlO2 + CO2

[0018] To achieve the goal of inhibiting the combination of aluminum and lithium, improving the lithium recovery efficiency, and releasing the trapped lithium resources. The reduction reaction products are mainly lithium carbonate, metal oxides, elemental substances, a very small amount of lithium metaaluminate, and some aluminum elemental substances / oxides.

[0019] During the water leaching process, the water solubility of Li2CO3 is utilized for the separation of lithium.

[0020] After water leaching and filtration, acid leaching is carried out to efficiently dissolve the solid after water leaching. The reaction equations during the acid leaching process are as follows: 2LiAlO2 + 4H2SO4 → Al2(SO4)3 + 4H2O + Li2SO4 2Al + 3H2SO4 → Al2(SO4)3 + 3H2 Al2O3 + 3H2SO4 → Al2(SO4)3 + 3H2O Ni + H2SO4 → H2 + NiSO4 CoO + H2SO4 → H2O + CoSO4 MnO + H2SO4 → H2O + MnSO4

[0021] After acid leaching, the valuable elements are all transferred to the liquid phase. Then, by precipitating manganese and nickel, a cobalt-aluminum solution is obtained. After adjusting the pH to 6 - 10, it precipitates in the form of aluminum hydroxide. After filtration, the separated cobalt-containing solution is obtained, and through evaporation, concentration, and crystallization, the product CoSO4·7H2O is obtained.

[0022] According to the present invention, the aluminum content range of the raw material is 5% - 12%; for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, and 12% as well as specific point values between the above-mentioned values. Due to space limitations and for the sake of simplicity, the present invention does not list them all exhaustively.

[0023] Preferably, the particle size of the raw material after crushing is 80μm - 150μm; for example, it can be 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, and 150μm as well as specific point values between the above-mentioned values. Due to space limitations and for the sake of simplicity, the present invention does not list them all exhaustively.

[0024] According to the present invention, the reducing raw material is hazelnut shell powder, and the mass ratio of the reducing raw material to the positive electrode powder is 0.2:1 to 0.4:1; for example, it can be 0.2:1, 0.25:1, 0.3:1, 0.35:1, and 0.4:1, as well as specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0025] According to the present invention, the reduction reaction temperature is 600 to 700 °C; for example, it can be 600 °C, 650 °C, and 700 °C, as well as specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0026] According to the present invention, the reduction time is 3 to 6 h; for example, it can be 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, and 6 h, as well as specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0027] Preferably, the protective gas is one of argon or nitrogen.

[0028] According to the present invention, the water immersion stirring speed is 300 to 500 r / min; for example, it can be 300 r / min, 400 r / min, 500 r / min, as well as specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0029] According to the present invention, the water immersion stirring time is 1 to 3 h; for example, it can be 1 h, 1.5 h, 2 h, 2.5 h, and 3 h, as well as specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0030] According to the present invention, the liquid-solid ratio of the water immersion is 10:1 to 50:1 ml / g; for example, it can be 10:1 ml / g, 20:1 ml / g, 30:1 ml / g, 40:1 ml / g, and 50:1 ml / g, as well as specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0031] According to the present invention, the water immersion temperature is 0 to 25 °C; for example, it can be 0 °C, 5 °C, 10 °C, 15 °C, 20 °C, and 25 °C, as well as specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0032] According to the present invention, in the lithium precipitation process, the precipitation temperature is 95 to 105 °C; for example, it can be 95 °C, 100 °C, and 105 °C, as well as specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0033] According to the present invention, in the lithium precipitation process, the precipitation time is 0.5 to 2 h; for example, it can be 0.5 h, 1 h, 1.5 h, 2 h, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0034] According to the present invention, in the lithium precipitation process, the molar ratio of sodium carbonate added to lithium in the solution is 1:2 to 2:1; for example, it can be 1:2, 1:1, 2:1, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0035] According to the present invention, the stirring speed of the acid leaching is 350 to 550 r / min; for example, it can be 350 r / min, 450 r / min, 550 r / min, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0036] According to the present invention, the stirring time of the acid leaching is 4 to 6 h; for example, it can be 4 h, 4.5 h, 5 h, 5.5 h, 6 h, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0037] According to the present invention, the liquid-solid ratio of the acid leaching is 4:1 to 10:1 ml / g; for example, it can be 4:1 ml / g, 5:1 ml / g, 6:1 ml / g, 7:1 ml / g, 8:1 ml / g, 9:1 ml / g, 10:1 ml / g, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0038] According to the present invention, the temperature of the acid leaching is 50 to 90 °C; for example, it can be 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0039] Preferably, the acid leaching reagent is sulfuric acid.

[0040] Preferably, the concentration of the sulfuric acid is 1 to 5 mol / L; for example, it can be 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0041] According to the present invention, in the process of adding KMnO4 in step 5, the molar ratio of KMnO4 to Mn in the solution is 2:3.

[0042] According to the present invention, in the process of adding KMnO4 in step 5, the reaction time is 0.5 to 2 h; for example, it can be 0.5 h, 1 h, 1.5 h, 2 h, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0043] According to the present invention, in the process of adding KMnO4 in step 5, the temperature is 25 to 50 °C; for example, it can be 25 °C, 30 °C, 40 °C, 50 °C, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0044] According to the present invention, in the process of adding KMnO4 in step 5, the stirring speed is 200 to 500 r / min; for example, it can be 200 r / min, 300 r / min, 400 r / min, 500 r / min, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0045] According to the present invention, in the process of adding dimethylglyoxime in step 6, the molar ratio of dimethylglyoxime to Ni in the solution is 1:2.

[0046] According to the present invention, in the process of adding dimethylglyoxime in step 6, the reaction time is 1 to 3 h; for example, it can be 1 h, 2 h, 3 h, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0047] According to the present invention, in the process of adding dimethylglyoxime in step 6, the temperature is 25 to 50 °C; for example, it can be 25 °C, 30 °C, 40 °C, 50 °C, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0048] According to the present invention, in the process of adding dimethylglyoxime in step 6, the stirring speed is 200 to 500 r / min; for example, it can be 200 r / min, 300 r / min, 400 r / min, 500 r / min, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0049] According to the present invention, in the process of evaporation, concentration and crystallization in step 7, the cobalt-containing solution is evaporated to 30% to 60% of the original solution volume; for example, it can be 30%, 40%, 50%, 60%, and specific point values between the above values. Due to space limitations and for the sake of simplicity, the present invention will not list them all exhaustively.

[0050] According to the present invention, in the evaporation concentration crystallization process of step 7, the crystallization temperature is -10 to 0 °C; for example, it can be -10 °C, -5 °C, 0 °C, and specific point values between the above values. Limited by space and for the sake of simplicity, the present invention will not list them all exhaustively.

[0051] According to the present invention, in the evaporation concentration crystallization process of step 7, the addition amount of CoSO4·7H2O is 2% to 5% of the total Co molar amount in the solution; for example, it can be 2%, 3%, 4%, 5%, and specific point values between the above values. Limited by space and for the sake of simplicity, the present invention will not list them all exhaustively.

[0052] Compared with the prior art solutions, the present invention has at least the following beneficial effects: (1) The present invention uses the widely existing waste hazelnut shell powder as a reduction raw material, treating waste with waste, effectively reducing the cost of the recovery process while fully recycling waste resources; (2) The waste hazelnut shell powder can pyrolyze at high temperature to produce various reducing gases (such as CH4, CO, H2, etc.) and reducing coke, and the reduction product contains CO2, which can effectively inhibit the combination of aluminum and lithium and improve the lithium recovery efficiency; (3) The entire operation process of the present invention is simple and the production cost is low. The overall recovery rates of nickel, cobalt, manganese, and lithium can reach 97.0%, 93.8%, 99.1%, and 95.7% respectively, having good economic benefits and application prospects. Description of the Drawings

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary, and for those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained based on the provided drawings.

[0054] Figure 1 It is the process flow chart of a specific implementation. Detailed Embodiments

[0055] The following will further illustrate the technical solutions of the present invention in conjunction with the drawings and through specific embodiments.

[0056] As Figure 1 shown, the process flow provided by a specific embodiment of the present invention can be: Step 1: Crush the aluminum-containing ternary cathode material; Step 2: Mix the raw material in step 1 with hazelnut shell powder and then carry out a sufficient reduction reaction; Step 3: Immerse the reduction product obtained in Step 2 in water to obtain a water immersion solution. The main element in the water immersion solution is Li. Add a sodium carbonate precipitant thereto and filter to obtain a Li2CO3 product; Step 4: Acid-leach the water immersion residue obtained in Step 3 to obtain an acid leaching solution. The main elements in the acid leaching solution are Al, Co, Ni, and Mn; Step 5: Add KMnO4 to the acid leaching solution obtained in Step 4, and filter and separate to obtain a cobalt-nickel-aluminum solution and MnO2; Step 6: Add dimethylglyoxime (DMG) to the cobalt-nickel-aluminum solution obtained in Step 5 to obtain a cobalt-aluminum solution and a dimethylglyoxime nickel precipitate; Step 7: Adjust the pH of the cobalt-aluminum solution obtained in Step 6 to 6-10 to precipitate aluminum impurities, obtain a cobalt-containing solution, evaporate, concentrate, and crystallize it to obtain a CoSO4·7H2O product.

[0057] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, the typical but non-limiting embodiments of the present invention are as follows:

[0058] Example 1 Step 1: Crush a ternary cathode material containing 5% aluminum, and the particle size of the raw material after crushing is 80 μm; Step 2: Mix the raw material obtained in Step 1 with hazelnut shell powder and then carry out a sufficient reduction reaction; the mass ratio of the reduction raw material to the cathode powder is 0.2:1, the reduction reaction temperature is 600 °C, the reduction time is 3 h, and the protective gas is argon; Step 3: Immerse the reduction product obtained in Step 2 in water to obtain a water immersion solution. The stirring speed during water immersion is 300 r / min, the stirring time is 1 h, the liquid-solid ratio is 10:1 ml / g, and the temperature is 0 °C. During the lithium precipitation process, the precipitation temperature is 95 °C, the precipitation time is 0.5 h, the molar ratio of sodium carbonate added to lithium in the solution is 1:2, filter to obtain a Li2CO3 product, and the Li recovery rate is 97.2%; Step 4: Sulfuric acid-leach the water immersion residue obtained in Step 3, with a sulfuric acid concentration of 1 mol / L, an acid leaching stirring speed of 350 r / min, a stirring time of 4 h, a liquid-solid ratio of 4:1 ml / g, and a temperature of 50 °C to obtain an acid leaching solution. The main elements in the acid leaching solution are Al, Co, Ni, and Mn; Step 5: Add KMnO4 to the acid leaching solution obtained in Step 4, the molar ratio of KMnO4 to Mn in the solution is 2:3, the reaction time is 0.5 h, the temperature is 25 °C, the stirring speed is 200 r / min, filter and separate to obtain a cobalt-nickel-aluminum solution and MnO2, and the Mn recovery rate is 99.0%; Step 6: Add dimethylglyoxime (DMG) to the cobalt-nickel-aluminum solution obtained in Step 5. The molar ratio of dimethylglyoxime to Ni in the solution is 1:2. The reaction time is 1 h, the temperature is 25 °C, and the stirring speed is 200 r / min to obtain a cobalt-aluminum solution and nickel dimethylglyoxime precipitate. The Ni recovery rate is 96.4%; Step 7: Adjust the pH of the cobalt-aluminum solution obtained in Step 6 to 6 to precipitate aluminum impurities and obtain a cobalt-containing solution. Evaporate the cobalt-containing solution to 30% of the original solution volume. The crystallization temperature is -10 °C, and the addition amount of CoSO4·7H2O is 2% of the total Co molar amount in the solution to obtain CoSO4·7H2O product. The Co recovery rate is 95.4%.

[0059] Example 2 Step 1: Crush the ternary cathode material containing 12% aluminum. The particle size of the raw material after crushing is 150 μm; Step 2: Mix the raw material obtained in Step 1 with hazelnut shell powder and carry out a sufficient reduction reaction; the mass ratio of the reducing raw material to the cathode powder is 0.4:1, the reduction reaction temperature is 700 °C, the reduction time is 6 h, and the protective gas is nitrogen; Step 3: Leach the reduction product obtained in Step 2 with water to obtain a water leaching solution. The stirring speed for water leaching is 500 r / min, the stirring time is 3 h, the liquid-solid ratio is 50:1 ml / g, and the temperature is 25 °C. In the lithium precipitation process, the precipitation temperature is 105 °C, the precipitation time is 2 h, the addition amount of sodium carbonate and the molar ratio of lithium in the solution is 2:1, and filter to obtain Li2CO3 product. The Li recovery rate is 95.7%; Step 4: Acid leach the water leaching residue obtained in Step 3 with sulfuric acid. The sulfuric acid concentration is 5 mol / L, the stirring speed for acid leaching is 550 r / min, the stirring time is 6 h, the liquid-solid ratio is 10:1 ml / g, and the temperature is 90 °C to obtain an acid leaching solution. The main elements in the acid leaching solution are Al, Co, Ni, and Mn; Step 5: Add KMnO4 to the acid leaching solution obtained in Step 4. The molar ratio of KMnO4 to Mn in the solution is 2:3. The reaction time is 2 h, the temperature is 50 °C, and the stirring speed is 500 r / min, and filter and separate to obtain a cobalt-nickel-aluminum solution and MnO2. The Mn recovery rate is 99.1%; Step 6: Add dimethylglyoxime (DMG) to the cobalt-nickel-aluminum solution obtained in Step 5. The molar ratio of dimethylglyoxime to Ni in the solution is 1:2. The reaction time is 3 h, the temperature is 50 °C, and the stirring speed is 500 r / min to obtain a cobalt-aluminum solution and nickel dimethylglyoxime precipitate. The Ni recovery rate is 97.0%; Step 7: Adjust the pH of the cobalt-aluminum solution in Step 6 to 10 to precipitate aluminum impurities, obtaining a cobalt-containing solution. Evaporate the cobalt-containing solution to 60% of the original solution volume, with a crystallization temperature of 0 °C and the addition amount of CoSO4·7H2O being 5% of the total Co molar amount in the solution, obtaining CoSO4·7H2O product, and the Co recovery rate being 93.8%.

[0060] Comparative Example 1 Step 1: Crush the ternary cathode material containing 25% aluminum, and the particle size of the raw material after crushing is 150 μm; Step 2: Mix the raw material in Step 1 with hazelnut shell powder and conduct a sufficient reduction reaction; the mass ratio of the reducing raw material to the cathode powder is 0.4:1, the reduction reaction temperature is 700 °C, the reduction time is 6 h, and the protective gas is nitrogen; Step 3: Leach the reduction product in Step 2 with water to obtain a leachate. The leaching stirring speed is 500 r / min, the stirring time is 3 h, the liquid-solid ratio is 50:1 ml / g, and the temperature is 25 °C. During the lithium precipitation process, the precipitation temperature is 105 °C, the precipitation time is 2 h, the addition amount of sodium carbonate to the lithium molar ratio in the solution is 2:1, and filter to obtain Li2CO3 product, and the Li recovery rate is 83.2%; Step 4: Acid-leach the water-leached residue in Step 3 with sulfuric acid, with a sulfuric acid concentration of 5 mol / L, an acid-leaching stirring speed of 550 r / min, a stirring time of 6 h, a liquid-solid ratio of 10:1 ml / g, and a temperature of 90 °C to obtain an acid-leaching solution. The main elements in the acid-leaching solution are Al, Co, Ni, and Mn; Step 5: Add KMnO4 to the acid-leaching solution in Step 4, and the molar ratio of KMnO4 to Mn in the solution is 2:3. The reaction time is 2 h, the temperature is 50 °C, and the stirring speed is 500 r / min. Filter and separate to obtain a cobalt-nickel-aluminum solution and MnO2, and the Mn recovery rate is 98.0%; Step 6: Add dimethylglyoxime (DMG) to the cobalt-nickel-aluminum solution in Step 5, and the molar ratio of dimethylglyoxime to Ni in the solution is 1:2. The reaction time is 3 h, the temperature is 50 °C, and the stirring speed is 500 r / min to obtain a cobalt-aluminum solution and dimethylglyoxime nickel precipitate, and the Ni recovery rate is 96.0%; Step 7: Adjust the pH of the cobalt-aluminum solution in Step 6 to 10 to precipitate aluminum impurities, obtaining a cobalt-containing solution. Evaporate the cobalt-containing solution to 60% of the original solution volume, with a crystallization temperature of 0 °C and the addition amount of CoSO4·7H2O being 5% of the total Co molar amount in the solution, obtaining CoSO4·7H2O product, and the Co recovery rate being 94.0%.

[0061] Comparative Example 2 Step 1: Crush the ternary cathode material containing 12% aluminum, and the particle size of the raw material after crushing is 150 μm; Step 2: Mix the raw material described in Step 1 with hazelnut shell powder and carry out a full reduction reaction; the mass ratio of the reducing raw material to the cathode powder is 0.1:1, the reduction reaction temperature is 700 °C, the reduction time is 6 h, and the protective gas is nitrogen; Step 3: Immerse the reduction product described in Step 2 in water to obtain an immersion solution. The immersion stirring speed is 500 r / min, the stirring time is 3 h, the liquid-solid ratio is 50:1 ml / g, and the temperature is 25 °C. During the lithium precipitation process, the precipitation temperature is 105 °C, the precipitation time is 2 h, the addition amount of sodium carbonate to the lithium molar ratio in the solution is 2:1, and Li2CO3 product is obtained by filtration, and the Li recovery rate is 60.5%; Step 4: Acid-leach the water-immersed residue described in Step 3 with sulfuric acid, the sulfuric acid concentration is 5 mol / L, the acid-leaching stirring speed is 550 r / min, the stirring time is 6 h, the liquid-solid ratio is 10:1 ml / g, and the temperature is 90 °C to obtain an acid-leaching solution. The main elements in the acid-leaching solution are Al, Co, Ni, and Mn; Step 5: Add KMnO4 to the acid-leaching solution described in Step 4, and the molar ratio of KMnO4 to Mn in the solution is 2:3. The reaction time is 2 h, the temperature is 50 °C, and the stirring speed is 500 r / min. Filter and separate to obtain a cobalt-nickel-aluminum solution and MnO2, and the Mn recovery rate is 76.5%; Step 6: Add dimethylglyoxime (DMG) to the cobalt-nickel-aluminum solution described in Step 5, and the molar ratio of dimethylglyoxime to Ni in the solution is 1:2. The reaction time is 3 h, the temperature is 50 °C, and the stirring speed is 500 r / min to obtain a cobalt-aluminum solution and dimethylglyoxime nickel precipitate, and the Ni recovery rate is 68.0%; Step 7: Adjust the pH of the cobalt-aluminum solution described in Step 6 to 10 to precipitate aluminum impurities to obtain a cobalt-containing solution. Evaporate the cobalt-containing solution to 60% of the original solution volume, the crystallization temperature is 0 °C, and the addition amount of CoSO4·7H2O is 5% of the total Co molar amount in the solution to obtain CoSO4·7H2O product, and the Co recovery rate is 74.2%.

Claims

1. A method for recovering valuable metals from aluminum-containing waste ternary battery positive electrode powder using hazelnut shell powder, characterized in that: The method is: Step 1: crushing the aluminum-containing ternary positive electrode material; Step 2: Mix the raw materials in step 1 with hazelnut shell powder and perform a full reduction reaction; Step 3: soaking the reduction product in step 2 in water to obtain a water solution, wherein the main element in the water solution is Li, adding sodium carbonate precipitant thereto, and filtering to obtain a Li2CO3 product; Step 4: acid leaching the water leaching residue in step 3 to obtain an acid leaching solution, wherein the main elements in the acid leaching solution are Al, Co, Ni, and Mn; Step 5: Add KMnO4 to the acid leaching solution in step 4, and filter and separate to obtain a cobalt-nickel-aluminum solution and MnO2; Step 6: adding dimethylglyoxime (DMG) to the cobalt-nickel-aluminum solution described in step 5 to obtain a cobalt-aluminum solution and dimethylglyoxime nickel precipitate; Step 7: The cobalt-aluminum solution described in step 6 is adjusted to a pH of 6 to 10 to precipitate aluminum impurities to obtain a cobalt-containing solution, which is evaporated, concentrated and crystallized to obtain a CoSO4·7H2O product.

2. The method for recovering valuable metals from aluminum-containing waste ternary battery positive electrode powder using hazelnut shell powder according to claim 1, characterized in that: In step 1, the aluminum content of the raw material is in the range of 5% to 12%; Preferably, the particle size of the raw material after crushing is 80 μm to 150 μm.

3. The method for recovering valuable metals from aluminum-containing waste ternary battery positive electrode powder using hazelnut shell powder according to claim 1, characterized in that: In the step 2, the reducing raw material is hazelnut shell powder, the mass ratio of the reducing raw material to the positive electrode powder is 0.2:1 to 0.4:1, the reduction reaction temperature is 600 to 700° C., the reduction time is 3 to 6 hours, and the protective gas is one of argon or nitrogen.

4. The method for recovering valuable metals from aluminum-containing waste ternary battery positive electrode powder using hazelnut shell powder according to claim 1, characterized in that: In step 3, the water immersion stirring speed is 300-500 r / min, the stirring time is 1-3 h, the liquid-to-solid ratio is 10:1-50:1 ml / g, the temperature is 0-25° C., the lithium precipitation process, the precipitation temperature is 95-105° C., the precipitation time is 0.5-2 h, and the molar ratio of the amount of sodium carbonate added to the lithium in the solution is 1:2-2:

1.

5. The method for recovering valuable metals from aluminum-containing waste ternary battery positive electrode powder using hazelnut shell powder according to claim 1, characterized in that: In step 4, the acid leaching stirring speed is 350-550 r / min, the stirring time is 4-6 h, the liquid-solid ratio is 4:1-10:1 ml / g, and the temperature is 50-90° C.; Preferably, the acid leaching agent is sulfuric acid; Preferably, the concentration of sulfuric acid is 1 to 5 mol / L.

6. The method for recovering valuable metals from aluminum-containing waste ternary battery positive electrode powder using hazelnut shell powder according to claim 1, characterized in that: In the process of adding KMnO4 in step 5, the molar ratio of KMnO4 to Mn in the solution is 2:

3. The reaction time is 0.5 to 2 hours, the temperature is 25 to 50°C, and the stirring speed is 200 to 500 r / min.

7. The method for recovering valuable metals from aluminum-containing waste ternary battery positive electrode powder using hazelnut shell powder according to claim 1, characterized in that: In the process of adding diacetyl oxime in step 6, the molar ratio of diacetyl oxime to Ni in the solution is 1:

2. The reaction time is 1 to 3 hours, the temperature is 25 to 50° C., and the stirring speed is 200 to 500 r / min.

8. The method for recovering valuable metals from aluminum-containing waste ternary battery positive electrode powder using hazelnut shell powder according to claim 1, characterized in that: In the evaporation concentration crystallization process in step 7, the cobalt-containing solution is evaporated to 30% to 60% of the original solution volume, the crystallization temperature is -10 to 0°C, and the amount of CoSO4·7H2O added is 2% to 5% of the total Co molar amount in the solution.

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