A method for co-recycling waste lithium-ion battery materials and high-grade nickel matte

Abstract

This invention provides a method for the co-recycling of waste lithium-ion battery materials and high-grade nickel matte, comprising the following steps: (1) mixing waste lithium-ion battery materials with high-grade nickel matte to obtain a mixture; (2) calcining the mixture to obtain a co-calcined solid product; (3) leaching the solid product with deionized water to obtain a lithium-containing aqueous leachate and a leachate residue; (4) acid-dissolving the leachate residue to obtain an acidic leachate; after precipitation, impurity removal, and extraction separation, the leachate yields a metal sulfate; (5) purifying the lithium-containing aqueous leachate to obtain lithium carbonate. This invention achieves priority lithium extraction from retired lithium-ion batteries and atmospheric pressure acid leaching of high-grade nickel matte to prepare nickel sulfate, converting valuable metals in lithium batteries into water-insoluble forms, achieving a lithium leaching rate of over 92% and efficient separation of valuable metals.

Description

Technical Field

[0001] This invention belongs to the fields of solid waste recycling and metallurgical technology, and particularly relates to a method for the co-recycling of waste lithium-ion battery materials and high-grade nickel matte. Background Technology

[0002] In recent years, with the promotion of electric vehicles worldwide, the market demand for lithium-ion batteries has increased rapidly. Ternary cathode materials, due to their excellent cycle performance, high conductivity, and high energy density, have become the preferred cathode material for electric vehicle power batteries. The rapid development of the power battery field has also led to high market demand for lithium carbonate and nickel sulfate. Developing technologies for recycling valuable metals from retired lithium-ion batteries can help alleviate the shortage of lithium and nickel resources.

[0003] For the priority lithium extraction from retired lithium-ion batteries, a combined pyrometallurgical and hydrometallurgical process is currently the main method. Due to the significant differences in the physicochemical properties between different metal elements, neither pyrometallurgical nor hydrometallurgical processes alone are efficient at recovering lithium from powder waste. The combined pyrometallurgical and hydrometallurgical process first selectively converts lithium in the powder waste into soluble lithium compounds such as LiCl, Li₂CO₃, LiNO₃, Li₂SO₄, and LiOH, while other metals such as nickel, cobalt, and manganese form water-insoluble elemental forms or oxides during roasting. For the leaching residue after lithium extraction, inorganic acids and hydrogen peroxide are commonly used to leach and recover the remaining metal elements. This method avoids the lithium loss caused by traditional pyrometallurgical processes and significantly reduces wastewater and acidic waste generation compared to hydrometallurgical processes.

[0004] High-grade nickel matte is an intermediate product of pyrometallurgical nickel ore production. Traditionally, nickel sulfate is prepared from high-grade nickel matte using a staged pressure acid leaching process. However, this process requires sophisticated equipment, consumes high energy, produces a variety of impurity ions in the leaching solution, and poses certain safety hazards. The common process of dissolving metallic nickel in sulfuric acid and then evaporating and crystallizing it to obtain nickel sulfate is too costly due to the complexity of the metallic nickel production process. Therefore, it is necessary to develop a low-cost, easy-to-operate, and readily industrializable method for preparing nickel sulfate to achieve the rational utilization of high-grade nickel matte resources.

[0005] Chinese patent CN112111651B discloses a pyrometallurgical recovery process for recovering valuable metals from retired lithium-ion batteries using sulfate sulfation roasting. The process involves mixing powdered waste with sulfate and roasting it to convert lithium into lithium sulfate. The lithium sulfate is then converted to lithium carbonate or lithium bicarbonate through alkaline leaching with carbon dioxide. Lithium carbonate is obtained through evaporation, and the leaching residue is further leached with sulfuric acid. While this method can selectively leach lithium, the sulfate used contains sodium or potassium ions, making separation difficult and affecting the purity of the lithium carbonate.

[0006] Chinese patent CN114574705A discloses a method for separating lithium and valuable metals from powder waste containing positive and negative electrodes of retired ternary lithium-ion batteries using concentrated sulfuric acid through sulfation roasting. The method mainly involves mixing the positive and negative electrode powders with a certain amount of sulfuric acid and deionized water, drying the mixture, ball milling it, and roasting it under an inert atmosphere to convert lithium into lithium sulfate. The lithium-containing aqueous extract is then obtained by water leaching, and after impurity removal, it is used to prepare high-purity lithium carbonate. While this method achieves preferential lithium extraction, the use of concentrated sulfuric acid in the roasting process affects the lithium extraction rate. Uneven mixing of sulfuric acid and powder is also prone to occur during the mixing process, and the method places high demands on the corrosion resistance of the equipment, posing certain safety hazards.

[0007] Chinese patent application CN114959252A discloses a method for producing nickel sulfate using high-nickel matte through oxidative roasting. The method involves oxidizing and roasting high-nickel matte, converting the metallic elements into oxides. The roasted product is then sequentially leached with sulfuric acid, undergoes multi-stage impurity removal, and concentration crystallization to obtain the nickel sulfate product. This method achieves a direct production of nickel sulfate from high-nickel matte, enabling the roasting of nickel disulfide to form oxides, and can be better applied to wet processes in different systems. However, while this method has strong advantages, it generates acidic tail gas and wastewater during the process, resulting in resource waste and potential environmental pollution risks if not properly treated.

[0008] Chinese patent application CN114892001A discloses a method for preparing nickel sulfate through a three-stage leaching process using high-grade nickel matte. The method involves atmospheric pressure leaching, a first oxygen pressure leaching process with progressively increasing temperature and pressure, and a second oxygen pressure leaching process, achieving effective separation of nickel. This method converts sulfur into sulfate ions during the oxygen pressure leaching process, producing no harmful gases. However, the process involves too many steps, making it inconvenient to operate and reducing costs. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the background art above and to provide a method for the co-recycling of waste lithium-ion battery materials and high-grade nickel matte.

[0010] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0011] A method for the co-recycling of waste lithium-ion battery materials and high-grade nickel matte includes the following steps:

[0012] (1) Mix the waste lithium-ion battery material with high-grade nickel matte to obtain a mixture;

[0013] (2) The mixture obtained in step (1) is roasted to obtain a co-roasted solid product;

[0014] (3) The solid product obtained in step (2) is leached with deionized water to obtain lithium-containing water leaching solution and water leaching residue;

[0015] (4) The water leaching residue obtained in step (3) is acid-dissolved to obtain an acidic leachate; after precipitation to remove impurities and extraction separation, the leachate is used to obtain metal sulfates.

[0016] (5) The lithium-containing aqueous solution obtained in step (3) is purified to obtain lithium carbonate.

[0017] This invention proposes a novel process to preferentially extract lithium from retired lithium-ion batteries and prepare nickel sulfate by high-grade nickel matte acid leaching under normal pressure. Through synergistic roasting, lithium is selectively reacted to generate water-soluble lithium sulfate, and the metals such as nickel, cobalt, manganese, aluminum, and copper contained in the lithium battery are converted into water-insoluble forms.

[0018] Preferably, the lithium content of the waste lithium-ion battery material in step (1) is 1 to 7 wt%.

[0019] Preferably, the waste lithium-ion battery material is a positive electrode material or a mixture of positive and negative electrode materials from retired lithium-ion batteries, and the retired lithium-ion battery positive electrode material or positive and negative electrode material contains lithium and one or more of graphite, manganese, nickel, cobalt, copper, aluminum, phosphorus or fluorine.

[0020] Furthermore, the cathode material or positive / negative electrode material of the retired lithium-ion battery is one or more of lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt manganese oxide, or lithium nickel cobalt aluminum oxide.

[0021] Preferably, the high-grade nickel matte in step (1) is an intermediate product of nickel metallurgy, which contains one or more of the main elements Ni and S, as well as Cu, Fe or Co.

[0022] Preferably, the high-grade nickel matte in step (1) includes nickel sulfide as the main component and one or more of copper, cobalt or iron, with a nickel content of 40-70 wt% and a sulfur content of 20-35 wt%.

[0023] Preferably, the molar ratio of Li in the waste lithium-ion battery material and S in high-grade nickel matte in step (1) is 2:1 to 2:3.

[0024] Preferably, the roasting temperature in step (2) is 550-750℃ and the roasting time is 0.5-3 h.

[0025] Preferably, the thickness of the mixture during the roasting process is 3mm to 30mm.

[0026] Preferably, in step (3), the deionized water and the solid product obtained by roasting are mixed at a solid-liquid ratio of 1:3 to 1:10 g / mL, the water immersion temperature is 20 to 90°C, and the immersion time is 0.5 to 3 hours.

[0027] Preferably, the acid leaching solution used in step (4) is one or more of sulfuric acid, hydrochloric acid, or nitric acid, wherein the acid solution [H + The concentration is greater than 0.1 mol / L. The water-leached residue and acid leaching solution are mixed at a solid-liquid ratio of 1:5 to 1:20 g / mL. The acid leaching temperature is 20 to 90℃ and the leaching time is 0.5 to 3 hours.

[0028] Furthermore, the metal sulfate is one or more of nickel sulfate, cobalt sulfate, or manganese sulfate.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] (1) This invention uses high-grade nickel matte to co-calcine retired lithium-ion battery powder waste, which simply and efficiently achieves a lithium leaching rate of over 92% and efficient separation of valuable metals, providing a guarantee for the subsequent preparation of high-purity lithium carbonate and battery-grade nickel / cobalt / manganese sulfate.

[0031] (2) Based on the fact that the metal elements in the retired lithium-ion battery powder waste are almost identical to the common impurity metals (cobalt, copper, iron, aluminum, etc.) in high-grade nickel matte raw materials, this invention uses high-grade nickel matte as an additive. By controlling appropriate conditions, nickel, cobalt, manganese and copper in the powder waste are converted into corresponding metal oxides or metals, and nickel sulfide in high-grade nickel matte forms nickel oxide after roasting, thus innovatively realizing the coupling of the retired lithium-ion battery with the valuable metal in high-grade nickel matte through atmospheric pressure acid leaching process.

[0032] (3) The present invention converts lithium in the raw material into soluble substances under appropriate conditions through synergistic roasting, so as to preferentially extract lithium element in the subsequent water leaching process; this technology can separate lithium from other metal elements, thereby making the subsequent acid leaching treatment more efficient.

[0033] (4) The process flow of the present invention has strong adaptability to raw materials and is suitable for the recycling of various retired lithium-ion battery materials; the process flow is simple and easy to implement, and the loss of valuable metals during the recycling process is small, providing a reliable technical guarantee for the large-scale and efficient recycling of valuable metals in retired lithium-ion batteries.

[0034] (5) The advantages of this invention are that it avoids the high temperature and high pressure acid leaching conditions required for the traditional high-grade nickel matte to nickel sulfate production process, and realizes the coupling of nickel, cobalt and manganese recovery in the leaching residue after priority lithium extraction with the recovery of nickel in high-grade nickel matte. It opens up a new and efficient process technology for high-grade nickel matte-assisted priority lithium extraction and direct production of short-range high-efficiency leaching, which is suitable for large-scale process production and has broad application value and development prospects. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a process flow diagram of the comprehensive recycling of valuable metals from spent lithium-ion battery powder waste in this embodiment of the invention. Detailed Implementation

[0037] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0038] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0039] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0040] Example 1:

[0041] A method for the co-recycling of waste lithium-ion battery materials and high-grade nickel matte is illustrated in the following process flow diagram: Figure 1 As shown, it includes the following steps:

[0042] (1) 5g of retired lithium-ion battery powder waste (lithium content 3%) and 2.6g of high nickel matte (sulfur content 26%) were mixed at a molar ratio of n(Li):n(S)=1:1. After thorough mixing, the mixture was spread evenly in an alumina crucible with a material layer thickness of 10mm. The alumina crucible was placed in a high-temperature furnace and co-calcined in an air atmosphere. The air flow rate in the furnace was 600 mL / min, the reaction temperature was 600℃, and the reaction time was 120min to obtain a solid product.

[0043] (2) The solid product obtained in step (1) is subjected to water leaching at a temperature of 50°C for 0.5 h and a solid-liquid ratio of 1:5 (g / mL) to obtain lithium-containing water leaching solution and leaching residue.

[0044] (3) The lithium-containing water leaching solution obtained in step (2) is evaporated and concentrated, and the pH of the water leaching solution is adjusted to 11 with 2 mol / L NaOH solution. After precipitation and impurity removal, impurity-removed residue and impurity-removed solution are obtained.

[0045] (4) The leaching residue obtained in step (2) and the impurity-removed residue obtained in step (3) are directly leached with sulfuric acid solution to dissolve the filter residue and obtain acidic leachate.

[0046] (5) Add the purified liquid obtained in step (3) to a saturated Na2CO3 solution (the molar amount of Na2CO3 is about twice the molar amount of lithium in the raw material) to precipitate Li2CO3. Filter to obtain solid Li2CO3. Wash the solid Li2CO3 with hot water to remove residual sodium ions and obtain lithium carbonate with a purity greater than 99.5%.

[0047] (6) After the nickel, cobalt and manganese leaching solution obtained in step (4) is subjected to deep purification steps such as extraction and back-extraction, battery-grade nickel / cobalt / manganese sulfate is obtained; it can be used for the preparation of ternary precursors.

[0048] Calculations show that in this embodiment, the lithium leaching rate reaches 93.40%, and the leaching rates of nickel, cobalt, and manganese in the acidic leaching solution reach 99.99%, 99.81%, and 99.94%, respectively.

[0049] Example 2:

[0050] A method for the co-recycling of waste lithium-ion battery materials and high-grade nickel matte is illustrated in the following process flow diagram: Figure 1 As shown, it includes the following steps:

[0051] (1) 5g of retired lithium-ion battery powder waste (lithium content 5%) and 3.9g of high nickel matte (sulfur content 26%) were mixed at a molar ratio of n(Li):n(S)=2:1.5. After thorough mixing, the mixture was spread evenly in an alumina crucible with a material layer thickness of 5mm. The alumina crucible was placed in a high-temperature furnace and co-calcined in an air atmosphere. The air flow rate in the furnace was 600 mL / min, the reaction temperature was 650℃, and the reaction time was 180min to obtain a solid product.

[0052] (2) The solid product obtained in step (1) is subjected to water leaching at a leaching temperature of 25°C for 1 hour and a solid-liquid ratio of 1:5 (g / mL) to obtain lithium-containing water leaching solution and leaching residue.

[0053] (3) The lithium-containing water leaching solution obtained in step (2) is evaporated and concentrated, and the pH of the water leaching solution is adjusted to 11 with 2 mol / L NaOH solution. After precipitation and impurity removal, impurity-removed residue and impurity-removed solution are obtained.

[0054] (4) The leaching residue obtained in step (2) and the impurity-removed residue obtained in step (3) are directly leached with sulfuric acid solution to dissolve the filter residue and obtain acidic leachate.

[0055] (5) Add the purified liquid obtained in step (3) to a saturated Na2CO3 solution (the molar amount of Na2CO3 is about twice the molar amount of lithium in the raw material) to precipitate Li2CO3. Filter to obtain solid Li2CO3. Wash the solid Li2CO3 with hot water to remove residual sodium ions and obtain lithium carbonate with a purity greater than 99.5%.

[0056] (6) After the nickel, cobalt and manganese leaching solution obtained in step (3) is subjected to deep purification steps such as extraction and back-extraction, battery-grade nickel / cobalt / manganese sulfate is obtained; it can be used for the preparation of ternary precursors.

[0057] Calculations show that in this embodiment, the leaching rate of lithium reaches 92.63%, and the leaching rates of nickel, cobalt, and manganese in the acidic leaching solution reach 99.86%, 98.11%, and 98.26%, respectively.

[0058] Example 3:

[0059] A method for the co-recycling of waste lithium-ion battery materials and high-grade nickel matte is illustrated in the following process flow diagram: Figure 1 As shown, it includes the following steps:

[0060] (1) 5g of retired lithium-ion battery powder waste (lithium content 7%) and 3.7g of high nickel matte (sulfur content 26%) were mixed at a molar ratio of n(Li):n(S)=2:1.2. After thorough mixing, the mixture was spread evenly in an alumina crucible with a material layer thickness of 5mm. The alumina crucible was placed in a high-temperature furnace and co-calcined in an air atmosphere. The air flow rate in the furnace was 600 mL / min, the reaction temperature was 550℃, and the reaction time was 180min to obtain a solid product.

[0061] (2) The solid product obtained in step (1) is subjected to water leaching at a leaching temperature of 25°C for 0.5 h and a solid-liquid ratio of 1:10 (g / mL) to obtain lithium-containing water leaching solution and leaching residue.

[0062] (3) The lithium-containing water leaching solution obtained in step (2) is evaporated and concentrated, and the pH of the water leaching solution is adjusted to 11 with 2 mol / L NaOH solution. After precipitation and impurity removal, impurity-removed residue and impurity-removed solution are obtained.

[0063] (4) The leaching residue obtained in step (2) and the impurity-removed residue obtained in step (3) are directly leached with sulfuric acid solution to dissolve the filter residue and obtain acidic leachate.

[0064] (5) Add the purified liquid obtained in step (3) to a saturated Na2CO3 solution (the molar amount of Na2CO3 is about twice the molar amount of lithium in the raw material) to precipitate Li2CO3. Filter to obtain solid Li2CO3. Wash the solid Li2CO3 with hot water to remove residual sodium ions and obtain lithium carbonate with a purity greater than 99.5%.

[0065] (6) After the nickel, cobalt and manganese leaching solution obtained in step (3) is subjected to deep purification steps such as extraction and back-extraction, battery-grade nickel / cobalt / manganese sulfate is obtained; it can be used for the preparation of ternary precursors.

[0066] Calculations show that the leaching rate of lithium in this embodiment reaches 93.28%, and the leaching rates of nickel, cobalt, and manganese in the acidic leaching solution reach 98.28%, 98.23%, and 98.69%, respectively.

[0067] Example 4:

[0068] A method for the co-recycling of waste lithium-ion battery materials and high-grade nickel matte is illustrated in the following process flow diagram: Figure 1 As shown, it includes the following steps:

[0069] (1) 20g of retired lithium-ion battery powder waste (lithium content 3%) and 7.9g of high nickel matte (sulfur content 26%) were mixed at a molar ratio of n(Li):n(S)=2:1.5. After thorough mixing, the mixture was spread evenly in an alumina crucible with a material layer thickness of 20mm. The alumina crucible was placed in a high-temperature furnace and co-calcined in an air atmosphere. The air flow rate in the furnace was 600 mL / min, the reaction temperature was 650℃, and the reaction time was 120min to obtain a solid product.

[0070] (2) The solid product obtained in step (1) is subjected to water leaching at a temperature of 50°C for 0.5 h and a solid-liquid ratio of 1:5 (g / mL) to obtain lithium-containing water leaching solution and leaching residue.

[0071] (3) The lithium-containing water leaching solution obtained in step (2) is evaporated and concentrated, and the pH of the water leaching solution is adjusted to 11 with 2 mol / L NaOH solution. After precipitation and impurity removal, impurity-removed residue and impurity-removed solution are obtained.

[0072] (4) The leaching residue obtained in step (2) and the impurity-removed residue obtained in step (3) are directly leached with sulfuric acid solution to dissolve the filter residue and obtain acidic leachate.

[0073] (5) Add the purified liquid obtained in step (3) to a saturated Na2CO3 solution (the molar amount of Na2CO3 is about twice the molar amount of lithium in the raw material) to precipitate Li2CO3. Filter to obtain solid Li2CO3. Wash the solid Li2CO3 with hot water to remove residual sodium ions and obtain lithium carbonate with a purity greater than 99.5%.

[0074] (6) After the nickel, cobalt and manganese leaching solution obtained in step (3) is subjected to deep purification steps such as extraction and back-extraction, battery-grade nickel / cobalt / manganese sulfate is obtained; it can be used for the preparation of ternary precursors.

[0075] Calculations show that the leaching rate of lithium in this embodiment reaches 93.03%, and the leaching rates of nickel, cobalt, and manganese in the acidic leaching solution reach 98.86%, 99.14%, and 99.72%, respectively.

[0076] Example 5:

[0077] A method for the co-recycling of waste lithium-ion battery materials and high-grade nickel matte is illustrated in the following process flow diagram: Figure 1 As shown, it includes the following steps:

[0078] (1) 5g of retired lithium-ion battery powder waste (lithium content 5%) and 6.6g of high nickel matte (sulfur content 26%) were mixed at a molar ratio of n(Li):n(S)=2:3. After thorough mixing, the mixture was spread evenly in an alumina crucible with a material layer thickness of 10mm. The alumina crucible was placed in a high-temperature furnace and co-calcined in an air atmosphere. The air flow rate in the furnace was 600 mL / min, the reaction temperature was 550℃, and the reaction time was 180min to obtain a solid product.

[0079] (2) The solid product obtained in step (1) is subjected to water leaching at a leaching temperature of 25°C for 0.5 h and a solid-liquid ratio of 1:5 (g / mL) to obtain lithium-containing water leaching solution and leaching residue.

[0080] (3) The lithium-containing water leaching solution obtained in step (2) is evaporated and concentrated, and the pH of the water leaching solution is adjusted to 11 with 2 mol / L NaOH solution. After precipitation and impurity removal, impurity-removed residue and impurity-removed solution are obtained.

[0081] (4) The leaching residue obtained in step (2) and the impurity-removed residue obtained in step (3) are directly leached with sulfuric acid solution to dissolve the filter residue and obtain acidic leachate.

[0082] (5) Add the purified liquid obtained in step (3) to a saturated Na2CO3 solution (the molar amount of Na2CO3 is about twice the molar amount of lithium in the raw material) to precipitate Li2CO3. Filter to obtain solid Li2CO3. Wash the solid Li2CO3 with hot water to remove residual sodium ions and obtain lithium carbonate with a purity greater than 99.5%.

[0083] (6) After the nickel, cobalt and manganese leaching solution obtained in step (3) is subjected to deep purification steps such as extraction and back-extraction, battery-grade nickel / cobalt / manganese sulfate is obtained; it can be used for the preparation of ternary precursors.

[0084] Calculations show that the leaching rate of lithium in this embodiment reaches 92.80%, and the leaching rates of nickel, cobalt, and manganese in the acidic leaching solution reach 99.59%, 98.30%, and 98.63%, respectively.

[0085] Example 6:

[0086] A method for the co-recycling of waste lithium-ion battery materials and high-grade nickel matte is illustrated in the following process flow diagram: Figure 1 As shown, it includes the following steps:

[0087] (1) 5g of retired lithium-ion battery powder waste (lithium content 3%) and 1.6g of high nickel matte (sulfur content 26%) were mixed at a molar ratio of n(Li):n(S)=2:1.2. After thorough mixing, the mixture was spread evenly in an alumina crucible with a material layer thickness of 5mm. The alumina crucible was placed in a high-temperature furnace and co-calcined in an air atmosphere. The air flow rate in the furnace was 600 mL / min, the reaction temperature was 700℃, and the reaction time was 180min to obtain a solid product.

[0088] (2) The solid product obtained in step (1) is subjected to water leaching at a leaching temperature of 25°C for 2 hours and a solid-liquid ratio of 1:5 (g / mL) to obtain lithium-containing water leaching solution and leaching residue.

[0089] (3) The lithium-containing water leaching solution obtained in step (2) is evaporated and concentrated, and the pH of the water leaching solution is adjusted to 11 with 2 mol / L NaOH solution. After precipitation and impurity removal, impurity-removed residue and impurity-removed solution are obtained.

[0090] (4) The leaching residue obtained in step (2) and the impurity-removed residue obtained in step (3) are directly leached with sulfuric acid solution to dissolve the filter residue and obtain acidic leachate.

[0091] (5) Add the purified liquid obtained in step (3) to a saturated Na2CO3 solution (the molar amount of Na2CO3 is about twice the molar amount of lithium in the raw material) to precipitate Li2CO3. Filter to obtain solid Li2CO3. Wash the solid Li2CO3 with hot water to remove residual sodium ions and obtain lithium carbonate with a purity greater than 99.5%.

[0092] (6) After the nickel, cobalt and manganese leaching solution obtained in step (3) is subjected to deep purification steps such as extraction and back-extraction, battery-grade nickel / cobalt / manganese sulfate is obtained; it can be used for the preparation of ternary precursors.

[0093] Calculations show that the leaching rate of lithium in this embodiment reaches 94.80%, and the leaching rates of nickel, cobalt, and manganese in the acidic leaching solution reach 99.59%, 98.00%, and 98.63%, respectively.

[0094] Comparative Example 1: Roasting time was too long

[0095] (1) 5g of retired lithium-ion battery powder waste (lithium content 3%) and 2.0g of high nickel matte (sulfur content 26%) were mixed at a molar ratio of n(Li):n(S)=2:1.5. After thorough mixing, the mixture was spread evenly in an alumina crucible with a material layer thickness of 5mm. The alumina crucible was placed in a high-temperature furnace and co-calcined in an air atmosphere. The air flow rate in the furnace was 500 mL / min, the reaction temperature was 600℃, and the reaction time was 480min to obtain a solid product.

[0096] (2) The solid product obtained in step (1) is subjected to water leaching at a leaching temperature of 60°C for 1 hour and a solid-liquid ratio of 1:10 (g / mL) to obtain a lithium-containing water leaching solution and leaching residue containing impurity ions such as Ni and Mn.

[0097] (3) The lithium-containing water leaching solution obtained in step (2) is evaporated and concentrated, and the pH of the water leaching solution is adjusted to 11 with 2 mol / L NaOH solution. After precipitation and impurity removal, impurity-removed residue and impurity-removed solution are obtained.

[0098] (4) The leaching residue obtained in step (2) and the impurity-removed residue obtained in step (3) are directly leached with sulfuric acid solution to dissolve the filter residue and obtain acidic leachate.

[0099] (5) Add the purified liquid obtained in step (3) to a saturated Na2CO3 solution (the molar amount of Na2CO3 is about twice the molar amount of lithium in the raw material) to precipitate Li2CO3. Filter to obtain solid Li2CO3. Wash the solid Li2CO3 with hot water to remove residual sodium ions and obtain lithium carbonate with a purity greater than 99.5%.

[0100] (6) After the nickel, cobalt and manganese leaching solution obtained in step (3) is subjected to deep purification steps such as extraction and back-extraction, battery-grade nickel / cobalt / manganese sulfate is obtained; it can be used for the preparation of ternary precursors.

[0101] Calculations show that the leaching rates of lithium, nickel, and manganese in the aqueous leaching solution in this comparative example are 92.03%, 5.12%, and 10.25%, respectively, while the leaching rates of nickel, cobalt, and manganese in the acidic leaching solution are 93.89%, 99.66%, and 88.54%, respectively.

[0102] In this comparative co-calcination process, the calcination time was too long, causing some Ni and Mn in the raw materials to be converted into sulfates and enter the water leaching solution, affecting the lithium separation effect. Therefore, the longer the reaction time, the less the entire process can be coupled properly, making it impossible to achieve selective separation of Li, Ni, Co, and Mn. At the same time, the ionic composition of the water leaching solution becomes more complex, increasing the difficulty of impurity removal and reducing the recovery rate of each element.

[0103] Comparative Example 2: Excessive Addition of High-Grain Nickel

[0104] (1) 5g of retired lithium-ion battery powder waste (lithium content 3%) and 5.3g of high nickel matte (sulfur content 26%) were mixed at a molar ratio of n(Li):n(S)=1:2. After thorough mixing, the mixture was spread evenly in an alumina crucible with a material layer thickness of 15mm. The alumina crucible was placed in a high-temperature furnace and co-calcined in an air atmosphere. The air flow rate in the furnace was 500 mL / min, the reaction temperature was 600℃, and the reaction time was 120min to obtain a solid product.

[0105] (2) The solid product obtained in step (1) is subjected to water leaching at a leaching temperature of 60°C for 1 hour and a solid-liquid ratio of 1:10 (g / mL) to obtain a lithium-containing water leaching solution and leaching residue containing impurity ions such as Ni, Co, and Mn.

[0106] (3) The lithium-containing water leaching solution obtained in step (2) is evaporated and concentrated, and the pH of the water leaching solution is adjusted to 11 with 2 mol / L NaOH solution. After precipitation and impurity removal, impurity-removed residue and impurity-removed solution are obtained.

[0107] (4) The leaching residue obtained in step (2) and the impurity-removed residue obtained in step (3) are directly leached with sulfuric acid solution to dissolve the filter residue and obtain acidic leachate.

[0108] (5) Add the purified liquid obtained in step (3) to a saturated Na2CO3 solution (the molar amount of Na2CO3 is about twice the molar amount of lithium in the raw material) to precipitate Li2CO3. Filter to obtain solid Li2CO3. Wash the solid Li2CO3 with hot water to remove residual sodium ions and obtain lithium carbonate with a purity greater than 99.5%.

[0109] (6) After the nickel, cobalt and manganese leaching solution obtained in step (3) is subjected to deep purification steps such as extraction and back-extraction, battery-grade nickel / cobalt / manganese sulfate is obtained; it can be used for the preparation of ternary precursors.

[0110] Calculations show that the leaching rates of lithium, nickel, cobalt, and manganese in the aqueous leaching solution in this comparative example were 95.90%, 13.93%, 15.29%, and 21.43%, respectively. The leaching rates of nickel, cobalt, and manganese in the acidic leaching solution were 85.53%, 84.61%, and 77.86%, respectively.

[0111] In this comparative co-calcination process, due to the excessive addition of high-grade nickel matte, some Ni, Co, Mn, Al, and Cu in the raw materials were converted into sulfates and entered the leaching solution during calcination, affecting the lithium separation effect. Therefore, excessive use of high-grade nickel matte prevents the entire process from being well coupled, making it impossible to achieve selective separation of Li, Ni, Co, and Mn. At the same time, it complicates the ionic composition of the leaching solution, increasing the difficulty of impurity removal and reducing the recovery rate of each element.

[0112] Comparative Example 3: Calcination temperature too low

[0113] (1) 5g of retired lithium-ion battery powder waste (lithium content 3%) and 2.6g of high nickel matte (sulfur content 26%) were mixed at a molar ratio of n(Li):n(S)=1:1. After thorough mixing, the mixture was spread evenly in an alumina crucible with a material layer thickness of 10mm. The alumina crucible was placed in a high-temperature furnace and co-calcined in an air atmosphere. The air flow rate in the furnace was 500 mL / min, the reaction temperature was 400℃, and the reaction time was 180min to obtain a solid product.

[0114] (2) The solid product obtained in step (1) is subjected to water leaching at a temperature of 60°C for 1 hour and a solid-liquid ratio of 1:10 (g / mL) to obtain lithium-containing water leaching solution and leaching residue.

[0115] (3) The lithium-containing water leaching solution obtained in step (2) is evaporated and concentrated, and the pH of the water leaching solution is adjusted to 11 with 2 mol / L NaOH solution. After precipitation and impurity removal, impurity-removed residue and impurity-removed solution are obtained.

[0116] (4) The leaching residue obtained in step (2) and the impurity-removed residue obtained in step (3) are directly leached with sulfuric acid solution to dissolve the filter residue and obtain acidic leachate.

[0117] (5) Add the purified liquid obtained in step (3) to a saturated Na2CO3 solution (the molar amount of Na2CO3 is about twice the molar amount of lithium in the raw material) to precipitate Li2CO3. Filter to obtain solid Li2CO3. Wash the solid Li2CO3 with hot water to remove residual sodium ions and obtain lithium carbonate with a purity greater than 99.5%.

[0118] (6) After the nickel, cobalt and manganese leaching solution obtained in step (3) is subjected to deep purification steps such as extraction and back-extraction, battery-grade nickel / cobalt / manganese sulfate is obtained; it can be used for the preparation of ternary precursors.

[0119] Calculations show that the leaching rate of lithium in this comparative example is 63.82%, and the leaching rates of nickel, cobalt, and manganese in the nickel-, cobalt-, and manganese-containing leachates are 99.19%, 98.93%, and 99.67%, respectively.

[0120] In this comparative example, the low roasting temperature during co-roasting weakened the co-roasting effect, resulting in insufficient reaction between the retired lithium-ion battery powder waste and high-grade nickel matte. This led to a significant decrease in the leaching rate of Li during water leaching. The Li that was not leached in water would enter the sulfate solution containing Ni, Co, and Mn during acid leaching, further reducing Li recovery. Therefore, the low roasting temperature prevented the entire process from achieving optimal coupling and made it difficult for nickel in high-grade nickel matte to leach into the solution under normal pressure, thus reducing the recovery rate of all elements.

[0121] Comparative Example 4: The material layer thickness is too large

[0122] (1) 30g of retired lithium-ion battery powder waste (lithium content 3%) and 15.8g of high nickel matte (sulfur content 26%) were mixed at a molar ratio of n(Li):n(S)=1:1. After thorough mixing, the mixture was spread evenly in an alumina crucible with a material layer thickness of 40mm. The alumina crucible was placed in a high-temperature furnace and co-calcined in an air atmosphere. The air flow rate in the furnace was 500 mL / min, the reaction temperature was 600℃, and the reaction time was 180min to obtain a solid product.

[0123] (2) The solid product obtained in step (1) is subjected to water leaching at a temperature of 60°C for 1 hour and a solid-liquid ratio of 1:10 (g / mL) to obtain lithium-containing water leaching solution and leaching residue.

[0124] (3) The lithium-containing water leaching solution obtained in step (2) is evaporated and concentrated, and the pH of the water leaching solution is adjusted to 11 with 2 mol / L NaOH solution. After precipitation and impurity removal, impurity-removed residue and impurity-removed solution are obtained.

[0125] (4) The leaching residue obtained in step (2) and the impurity-removed residue obtained in step (3) are directly leached with sulfuric acid solution to dissolve the filter residue and obtain acidic leachate.

[0126] (5) Add the purified liquid obtained in step (3) to a saturated Na2CO3 solution (the molar amount of Na2CO3 is about twice the molar amount of lithium in the raw material) to precipitate Li2CO3. Filter to obtain solid Li2CO3. Wash the solid Li2CO3 with hot water to remove residual sodium ions and obtain lithium carbonate with a purity greater than 99.5%.

[0127] (6) After the nickel, cobalt and manganese leaching solution obtained in step (3) is subjected to deep purification steps such as extraction and back-extraction, battery-grade nickel / cobalt / manganese sulfate is obtained; it can be used for the preparation of ternary precursors.

[0128] Calculations show that the leaching rate of lithium in this comparative example is 61.00%, and the leaching rates of nickel, cobalt, and manganese in the nickel-, cobalt-, and manganese-containing leachates are 99.99%, 98.81%, and 98.23%, respectively.

[0129] In this comparative co-calcination process, the large material layer thickness weakened the co-calcination effect, resulting in insufficient reaction between the retired lithium-ion battery powder waste and high-grade nickel matte. This led to a significant decrease in the leaching rate of Li during water leaching. The Li that was not leached in water would enter the sulfate solution containing Ni, Co, and Mn during acid leaching, further reducing Li recovery. Therefore, the large material layer thickness prevented the entire process from achieving good coupling and made it difficult for nickel in the high-grade nickel matte to enter the solution under normal pressure, reducing the recovery rate of each element.

[0130] Comparative Example 5: No Co-calcination Process

[0131] (1) Mix 5g of retired lithium-ion battery powder waste (lithium content 3%) with 2.6g of high-grade nickel matte (sulfur content 26%) at a molar ratio of n(Li):n(S)=1:1, and stir thoroughly to obtain a solid mixture;

[0132] (2) The solid mixture obtained in step (1) is subjected to water leaching at a leaching temperature of 50°C for 0.5 h and a solid-liquid ratio of 1:5 (g / mL) to obtain lithium-containing water leaching solution and leaching residue.

[0133] (3) The lithium-containing water leaching solution obtained in step (2) is evaporated and concentrated, and the pH of the water leaching solution is adjusted to 11 with 2 mol / L NaOH solution. After precipitation and impurity removal, impurity-removed residue and impurity-removed solution are obtained.

[0134] (4) The leaching residue obtained in step (2) and the impurity-removed residue obtained in step (3) are directly leached with sulfuric acid solution to dissolve the filter residue and obtain acidic leachate.

[0135] (5) Add the purified liquid obtained in step (3) to a saturated Na2CO3 solution (the molar amount of Na2CO3 is about twice the molar amount of lithium in the raw material) to precipitate Li2CO3. Filter to obtain solid Li2CO3. Wash the solid Li2CO3 with hot water to remove residual sodium ions and obtain lithium carbonate with a purity greater than 99.5%.

[0136] (6) After deep purification steps such as extraction and back-extraction, the leachate obtained in step (3) is purified to obtain battery-grade nickel / cobalt / manganese sulfate, which can be used for the preparation of ternary precursors. However, since there are a large number of lithium ions in the acid leaching solution, it is necessary to add extra steps to recover lithium, which reduces production efficiency and the recovery rate of Li.

[0137] Calculations show that the lithium leaching rate in this embodiment is 0.05%, and the leaching rates of nickel, cobalt, and manganese in the acidic leaching solution are 21.24%, 23.11%, and 33.44%, respectively.

[0138] The lack of a synergistic roasting process in this comparative example resulted in the failure of the retired lithium-ion battery powder waste to react with the high-grade nickel matte. This prevented Li from being leached during water leaching and instead caused it to enter the sulfate solution containing Ni, Co, and Mn during acid leaching, reducing the Li recovery rate. Simultaneously, the lack of a synergistic roasting process also prevented the nickel sulfides in the high-grade nickel matte from reacting, making them difficult to leach under normal pressure acid leaching, resulting in nickel loss. Therefore, the lack of a synergistic roasting process prevented the effective coupling of the entire process flow and affected the acid leaching recovery rate of each element under normal pressure conditions.

Claims

1. A method for the co-recycling of waste lithium-ion battery materials and high-grade nickel matte, characterized in that, Includes the following steps: (1) The waste lithium-ion battery material is mixed with high-grade nickel matte to obtain a mixture; the molar ratio of Li in the waste lithium-ion battery material and S in the high-grade nickel matte is 2:1 to 2:

3. (2) The mixture obtained in step (1) is roasted to obtain a co-roasted solid product; the roasting temperature is 550-750℃ and the roasting time is 0.5-3h; the thickness of the mixture during the roasting process is 3mm-30mm. (3) The solid product obtained in step (2) is leached with deionized water to obtain lithium-containing water leaching solution and water leaching residue; (4) The water leaching residue obtained in step (3) is acid-leached to obtain an acidic leachate; after precipitation to remove impurities and extraction separation, the leachate is used to obtain metal sulfates. (5) The lithium-containing aqueous solution obtained in step (3) is purified to obtain lithium carbonate.

2. The method for co-recycling waste lithium-ion battery materials and high-grade nickel matte as described in claim 1, characterized in that, The lithium content of the waste lithium-ion battery material mentioned in step (1) is 1-7 wt%.

3. The method for co-recycling waste lithium-ion battery materials and high-grade nickel matte as described in claim 1, characterized in that, The waste lithium-ion battery material is a mixture of positive and negative electrode materials from retired lithium-ion batteries. The mixture of positive and negative electrode materials from retired lithium-ion batteries contains lithium and one or more of graphite, manganese, nickel, cobalt, copper, aluminum, phosphorus, or fluorine.

4. The method for co-recycling waste lithium-ion battery materials and high-grade nickel matte as described in claim 1, characterized in that, The high-grade nickel matte mentioned in step (1) is an intermediate product of nickel metallurgy, which contains one or more of the main elements Ni and S, as well as Cu, Fe or Co.

5. The method for co-recycling waste lithium-ion battery materials and high-grade nickel matte as described in claim 1, characterized in that, The high-grade nickel matte in step (1) includes nickel sulfide as the main component and one or more of copper, cobalt or iron, with a nickel content of 40-70 wt% and a sulfur content of 20-35 wt%.

6. The method for co-recycling waste lithium-ion battery materials and high-grade nickel matte as described in claim 1, characterized in that, In step (3), the deionized water and the solid product obtained by roasting are mixed at a solid-liquid ratio of 1:3 to 1:10 g / mL, the water immersion temperature is 20 to 90℃, and the immersion time is 0.5 to 3h.

7. The method for co-recycling waste lithium-ion battery materials and high-grade nickel matte as described in claim 1, characterized in that, The acid leaching in step (4) uses one or more of sulfuric acid, hydrochloric acid, or nitric acid, wherein the acid solution [H + The concentration is greater than 0.1 mol / L. The water-leached residue and acid leaching solution are mixed at a solid-liquid ratio of 1:5 to 1:20 g / mL. The acid leaching temperature is 20 to 90℃ and the leaching time is 0.5 to 3 hours.

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