Method for efficiently separating lithium from multi-element lithium battery electrode waste in one step

Abstract

Disclosed in the present invention is a method for efficiently separating lithium from multi-element lithium battery electrode waste in one step. The multi-element lithium battery electrode waste is at least one of positive electrode waste and negative electrode waste, and the multi-element lithium battery contains at least one of the elements nickel, cobalt, and manganese. The method comprises the following steps: S1. lithium separation in one step: adding an inorganic acid, a leaching auxiliary agent, and a reducing agent to multi-element lithium battery electrode waste powder, stirring for leaching, and subjecting to reaction at a certain temperature for a certain time to obtain a completely reacted slurry; and S2. filtration and washing: subjecting the completely reacted slurry to filtration and washing to obtain a lithium-rich solution with a lithium ion concentration of 10-30 g / L and residues. The present invention achieves one-step efficient separation of lithium from elements such as nickel, cobalt, and manganese, breaks through the production barrier between waste and spent lithium battery recycling and nickel, cobalt, and manganese smelting, reduces the comprehensive unit cost of the recovery of nickel, cobalt, and manganese while improving the lithium recovery rate, and has global popularization significance.

Description

A one-step method for efficiently separating lithium from multi-element lithium battery electrode waste Technical Field

[0001] The present invention relates to the technical field of battery waste resource recycling and reuse, and in particular to a method for efficiently separating lithium from multi-element lithium battery electrode waste in one step. Background Art

[0002] With the development of the new energy vehicle industry, market demand for lithium batteries continues to expand. Demand for lithium carbonate, a primary raw material for power batteries, has also surged in recent years. Analyzing various data from 2022 alone, my country's lithium carbonate consumption reached 505,000 tons, with lithium carbonate's application in lithium-ion battery products primarily focused on cathode materials. Of the downstream lithium carbonate consumption, lithium batteries accounted for 469,700 tons, of which 409,000 tons were cathode materials. However, only 287,000 tons were derived from ore. On the one hand, the booming electric vehicle industry is exacerbating the supply and demand imbalance for the lithium metal raw materials needed for power battery production. On the other hand, power batteries contain high levels of valuable metals such as lithium, cobalt, and nickel, as well as numerous toxic and hazardous compounds. If a large number of retired power batteries are not safely disposed of and reused, they will result in a waste of resources and serious environmental pollution.

[0003] The current conventional method for recycling lithium battery positive (negative) electrode waste containing one or more of the elements nickel, cobalt, and manganese is full leaching. This involves using an inorganic acid such as sulfuric acid, along with hydrogen peroxide or sodium metabisulfite as a reducing agent, to bring all metals, including lithium, nickel, cobalt, manganese, copper, and aluminum, into solution. The leachate is then purified, and the nickel, cobalt, and manganese are extracted and separated to produce sulfate products. The raffinate is then used to recover lithium. However, this process has the disadvantages of a lengthy process, high costs, and a complex nickel, cobalt, and manganese extraction and separation process. The low lithium content in the raffinate results in low lithium recovery rates.

[0004] In contrast, the one-step, highly efficient lithium separation / selective lithium extraction method uses technical means to preferentially separate lithium from nickel, cobalt, and manganese, resulting in a shorter lithium recovery process and simpler procedures. Depending on the technical approach, three different lithium separation processes can be categorized as reduction roasting, acid roasting, and full wet method.

[0005] The original structure is destroyed by reduction roasting to achieve the separation process of lithium from nickel, cobalt and manganese. For example, Chinese patent CN112374511B reports that the graphite and adhesive in the black powder of waste ternary battery are used as reducing agents, and the structure of the ternary material is destroyed by self-reduction phase transformation through roasting. The lithium carbonate is converted into lithium bicarbonate that is easy to be water-leached by carbonated water leaching, thereby achieving one-step efficient lithium separation; Chinese patent CN10872648 reports the use of hydrogen as a reducing agent, through fluidized reduction roasting, to achieve structural transformation, reduce the powder water leaching, obtain lithium hydroxide solution, and achieve the separation of lithium from nickel, cobalt and manganese.

[0006] The original structure is destroyed by acidification roasting, and lithium is separated in one step with high efficiency. For example, Chinese patent CN116516174A provides a process of adding a water-soluble iron salt and an inorganic acid mixture for roasting. The roasted product is soaked in water, and lithium enters the solution to obtain a lithium-rich solution that is separated from nickel, cobalt and manganese.

[0007] A fully wet selective lithium extraction process is used. For example, Chinese patent CN109022793A provides a method of adding an oxidant to oxidize the low-valent nickel, cobalt and manganese ions in the ternary positive electrode material into high-valent compounds, destroying the crystal structure. Lithium enters the solution in the form of ions, and nickel, cobalt and manganese exist in the form of slag, achieving the purpose of efficient lithium separation in one step.

[0008] The above-mentioned methods for efficient one-step lithium separation / selective lithium extraction either use a reduction / acidification roasting treatment-wet process or a fully wet process. By controlling the process conditions, lithium is preferentially leached into the solution, and most of the nickel, cobalt and manganese are leached into the slag, thereby achieving the purpose of separating lithium from most of the nickel, cobalt and manganese. The lithium recovery process is short and the process is simple. However, the roasting treatment-wet process still has problems such as large investment in heat treatment equipment, high operating costs, high safety and environmental protection pressures, and low leaching rate for efficient one-step lithium separation. The fully wet process also has problems such as low lithium enrichment concentration in the leachate, incomplete separation of nickel, cobalt and manganese, and the lithium leaching rate, recovery rate and lithium / nickel, cobalt and manganese separation efficiency all need to be further improved.

[0009] The above one-step efficient lithium separation / selective lithium extraction process has major defects in production line investment, production cost, safety and environmental protection, and production efficiency, so it is not widely used in industrial production.

[0010] Currently, in China, MHP (nickel-cobalt hydroxide intermediate product from mineral production) hydrometallurgical production lines have high production capacity and low comprehensive unit costs for recovering nickel, cobalt, and manganese. However, wet production lines for lithium batteries that recover one or more elements containing nickel, cobalt, and manganese generally have lower production capacity, higher comprehensive costs for recovering nickel and cobalt, and a low comprehensive lithium recovery rate of less than 80%, resulting in poor economic efficiency. By applying the present invention, lithium is preferentially separated, and the (carbon) slag containing one or more elements containing nickel, cobalt, and manganese can be directly incorporated into the existing MHP hydrometallurgical production line to recover nickel, cobalt, and manganese. This reduces the production costs of nickel, cobalt, and manganese, while increasing the lithium recovery rate and improving economic benefits.

[0011] With the rapid development of lithium batteries containing one or more elements of nickel, cobalt, and manganese, particularly new energy vehicles powered by ternary lithium batteries, Europe and the United States are treating end-of-life lithium batteries as high-value waste and have enacted relevant legislation in the hope of establishing a lithium battery recycling industry chain. Umicore, a Belgian company specializing in European battery recycling, uses a pyrometallurgical smelting process to recycle lithium batteries. However, the high construction and operating costs of the production lines, coupled with a lithium recovery rate of less than 50%, make this technology unsuitable for new lithium battery recycling projects. Some projects have simply copied and imported the Chinese nickel, cobalt, manganese, and lithium production process of full dissolution, extraction, and lithium recovery. However, due to the long-standing absence of relevant expertise from industry, academia, and research, the lack of engineers and frontline technicians required for the extraction and purification of wet-process nickel, cobalt, and manganese makes it difficult to achieve continuous production, and such projects have been largely unsuccessful.

[0012] In summary, nickel-cobalt-manganese smelting projects primarily aim to recover nickel and cobalt. The overall cost of nickel-cobalt recovery is relatively low. When lithium- and nickel-cobalt-containing battery waste enters the system as raw material, lithium is recovered as a byproduct, resulting in very low recovery efficiency. Dedicated lithium battery recycling projects focus on the comprehensive recovery of lithium, nickel, cobalt, and manganese. While existing production processes include lithium recovery processes, they still suffer from low lithium recovery rates and high nickel-cobalt recovery costs. Summary of the Invention

[0013] In view of this, it is necessary to develop a new, one-step, efficient lithium separation method for various lithium battery positive (negative) electrode waste materials containing one or more of the elements nickel, cobalt, and manganese on the market, with a short process, low equipment investment, and low production cost, while achieving a fully effective separation of lithium from nickel, cobalt, manganese, and carbon. The present invention thus provides a one-step, efficient lithium separation method from multi-element lithium battery electrode waste.

[0014] The scheme of the present invention is:

[0015] A method for efficiently separating lithium from multi-element lithium battery electrode waste in one step comprises the following steps:

[0016] The multi-element lithium battery electrode waste is at least one of positive electrode waste and negative electrode waste, and the multi-element lithium battery contains at least one of nickel, cobalt and manganese;

[0017] S1, one-step separation of lithium

[0018] Adding inorganic acid, leaching aid and reducing agent to the multi-element lithium battery electrode waste powder, stirring and leaching, reacting at a certain temperature for a certain time to obtain a reaction-completed slurry;

[0019] S2, filtration and washing

[0020] The slurry after the reaction is completed is filtered and washed to obtain a lithium-rich solution with a lithium ion concentration of 10 to 30 g / L and a residue.

[0021] As a preferred technical solution, the waste material in S1 is a mixture of one or more of the electrode waste produced by crushing and sorting batteries and electrode pieces and the positive electrode material production waste;

[0022] The battery is one or more of a nickel cobalt manganese oxide battery, a lithium cobalt oxide battery, a lithium nickel oxide battery, a lithium manganese oxide battery and a nickel cobalt aluminum oxide battery;

[0023] The electrode waste produced by the crushing and sorting of the electrode pieces is one or more of the electrode waste produced by the crushing and sorting of the nickel-cobalt-lithium manganate electrode pieces, the electrode waste produced by the crushing and sorting of the lithium cobaltate electrode pieces, the electrode waste produced by the crushing and sorting of the lithium nickelate electrode pieces, the electrode waste produced by the crushing and sorting of the lithium manganate electrode pieces, and the electrode waste produced by the crushing and sorting of the nickel-cobalt-lithium aluminum oxide electrode pieces; the electrode waste produced by the crushing and sorting of the electrode pieces includes the positive electrode waste produced by the crushing and sorting of the electrode pieces and the negative electrode waste produced by the crushing and sorting of the electrode pieces;

[0024] The positive electrode material production waste is one or more of nickel cobalt lithium manganate positive electrode material production waste, lithium cobaltate positive electrode material production waste, lithium nickelate positive electrode material production waste, lithium manganate positive electrode material production waste and nickel cobalt aluminum oxide positive electrode material production waste.

[0025] As a preferred technical solution, the reducing agent is added after the inorganic acid and the leaching aid are added to the slurry in S2; there is no special requirement for the order of adding the inorganic acid and the leaching aid, but the two cannot be mixed in advance before adding.

[0026] As a preferred technical solution, the inorganic acid in S2 is a mixture of one or more of sulfuric acid, hydrochloric acid, and nitric acid;

[0027] The reducing agent in S2 is one or more of sodium metabisulfite, sodium dithionite, hydrogen peroxide, glucose, soluble starch, ferrous sulfate, sodium sulfite and sodium thiosulfate;

[0028] The leaching aid in S2 is one or more of citric acid, malonic acid, acetylacetone, oxalic acid, ascorbic acid, tartaric acid, salicylic acid, and EDTA.

[0029] As a preferred technical solution, the mass ratio of the multi-component lithium battery electrode waste to the inorganic acid in the slurry of S2 is 1:0.05-0.6.

[0030] As a preferred technical solution, the mass ratio of the multi-component lithium battery electrode waste to the reducing agent in the slurry of S2 is 1:0.1-1.0.

[0031] As a preferred technical solution, the mass ratio of the multi-component lithium battery electrode waste to the leaching aid in the slurry S2 is 1:0.5-3.0.

[0032] As a preferred technical solution, the liquid-to-solid ratio of the leaching reaction in the operating conditions in S2 is 2 to 6:1.

[0033] As a preferred technical solution, the reaction time in the operating conditions of S2 is 1h to 8h; the reaction end point pH value in the operating conditions of S2 is 1.5 to 4.0; and the reaction temperature in the operating conditions of S2 is 40°C to 100°C.

[0034] Due to the adoption of the above technical solution, a method for efficiently separating lithium from multi-element lithium battery electrode waste in one step comprises the following steps: the multi-element lithium battery electrode waste is at least one of positive electrode waste and negative electrode waste, and the multi-element lithium battery contains at least one of nickel, cobalt and manganese elements; S1, one-step separation of lithium, adding inorganic acid, leaching aid and reducing agent to the multi-element lithium battery electrode waste powder, stirring and leaching, reacting at a certain temperature for a certain time, and obtaining a slurry after the reaction is completed; S2, filtering and washing, filtering and washing the slurry after the reaction is completed to obtain a lithium-rich solution and residue with a lithium ion concentration of 10 to 30 g / L. The lithium extraction residue is nickel-cobalt-manganese (carbon) slag, which can be used as a raw material for the production of nickel, cobalt and manganese salts. The simpler approach is to use it as a raw material to enter the existing nickel-cobalt-manganese wet extraction production line.

[0035] Working principle:

[0036] The slurry of the method described in the present invention dissociates the physical phase and structure of the electrode material under acidic conditions under the joint action of a reducing agent and an auxiliary agent, and the dissociated lithium ions react with an inorganic acid to form a water-soluble lithium salt solution; while some high-valent nickel, cobalt and manganese ions in the positive electrode material are converted into low-valent states and form insoluble low-valent compounds that remain in the residue of nickel, cobalt and manganese, thereby achieving the purpose of preferential leaching of lithium and realizing complete separation from nickel, cobalt and manganese.

[0037] Compared with the prior art, the technical solution of the present invention has the following technical advantages or positive effects:

[0038] 1. The raw materials of the method of the present invention are highly adaptable. One or a mixture of positive (negative) electrode waste produced by battery or electrode sheet crushing and sorting, such as lithium nickel cobalt manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium nickel manganese oxide and lithium cobalt aluminum oxide, and positive electrode material production waste can be used as the raw materials in the technical solution of the present invention.

[0039] 2. The method of the present invention achieves the goal of efficient step-by-step separation of lithium and effectively separating nickel, cobalt, and manganese, with lithium leaching rates exceeding 95% and nickel, cobalt, and manganese leaching rates below 3%. The leachate is of high quality, with lithium concentrations reaching 10 to 30 g / L and very low concentrations of other metal impurities. The lithium recovery rate of the lithium carbonate product exceeds 90%, and it is suitable for large-scale industrial application, providing a new approach for the efficient and economical recycling of lithium battery positive and negative electrode waste containing one or more of the elements nickel, cobalt, and manganese.

[0040] 3. The method described in this invention is a new, all-wet process, offering low production line investment, low production costs, significant safety and environmental advantages, and high production efficiency. The lithium recovery process is a self-contained system that can be easily integrated into existing lithium / nickel-cobalt-manganese production systems, allowing the processing of various lithium battery positive (negative) electrode waste containing one or more of the elements nickel, cobalt, and manganese as new production raw materials.

[0041] 4. After applying the present invention, the product lithium-rich solution can be used to produce lithium products (battery-grade lithium carbonate, battery-grade lithium chloride and battery-grade lithium hydroxide, etc.) on site, and the product containing one or more (carbon) slag of nickel, cobalt and manganese elements can be sent to nickel-cobalt smelting enterprises to recover nickel, cobalt and manganese through pyrometallurgy or hydrometallurgy.

[0042] 5. The present invention achieves efficient one-step separation of lithium from nickel, cobalt and manganese, breaking through the production barriers between waste lithium battery recycling and nickel, cobalt and manganese smelting. It improves the recovery rate of lithium while reducing the comprehensive unit cost of nickel, cobalt and manganese recovery, and has global promotion significance.

[0043] 6. The present invention is environmentally friendly, has a short lithium extraction process, is simple to operate, and has a self-contained lithium recovery system that is easy to use. It can selectively and efficiently separate lithium and nickel, cobalt, and manganese from battery waste through a leaching step, allowing them to enter their own production systems separately to obtain their own products, thereby avoiding mutual influence. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG1 is a process flow chart of the present invention. DETAILED DESCRIPTION

[0045] The present invention provides a one-step, highly efficient method for separating lithium from waste multi-element lithium battery electrodes. To facilitate understanding of the technical means, creative features, objectives, and efficacy of the present invention, the present invention is further described below with reference to specific examples.

[0046] Example 1

[0047] Waste nickel-cobalt-manganese oxide lithium batteries were crushed and sorted to obtain positive and negative electrode waste powder (main components and contents were Li 4.32%, Ni 20.0%, Co 8.5%, Mn 9.7%, Cu 1.5%, Al 0.5%, and C 32.5%), and a dilute sulfuric acid solution was added to prepare slurry at a liquid-solid ratio of 2:1. The mass ratio of sulfuric acid to positive and negative electrode waste powder was 37.55%. Leaching aids tartaric acid and ascorbic acid were continuously added at 80°C in a mass ratio of 6:4, and the total amount of leaching aids was 2.0 times the mass of the positive and negative electrode waste powder; then, sodium metabisulfite, a reducing agent, was added in an amount of 0.1 times the mass of the positive and negative electrode waste powder; the reaction was stirred for 8 hours, the pH value at the reaction endpoint was controlled to be 3.0, and solid-liquid separation was performed to obtain a lithium-rich solution and nickel-cobalt-manganese slag.

[0048] The concentrations of the lithium-rich solution were measured to be Li 21.0 g / L, Ni 0.05 g / L, Co 0.01 g / L, Mn 0.4 g / L, Cu 0.3 g / L, and Al 0.05 g / L. Based on the concentrations of each ion in the solution, the lithium leaching rate was 97.22%, the Ni leaching rate was 0.05%, the Co leaching rate was 0.02%, and the Mn leaching rate was 0.08%.

[0049] The lithium-rich solution, i.e., the lithium sulfate leachate, is heated to 90°C, and solid sodium hydroxide is added to adjust the pH value of the solution to greater than 11. The reaction is carried out for 4 hours. The lithium in the leachate remains in an ionic state, while impurities such as nickel, cobalt, manganese, copper, and aluminum form solids and enter the impurity removal slag. Liquid-solid separation is performed to obtain a de-impurity liquid. The prepared 300g / L sodium carbonate solution is heated to 90°C and slowly added to the de-impurity liquid at 90°C. The reaction is carried out for 2 hours, and the impurities are centrifuged to obtain industrial-grade lithium carbonate.

[0050] The lithium extraction residue is slurried with water at a liquid-to-solid ratio of 3:1. Concentrated sulfuric acid is then added and the solution is heated to 90°C for 4 hours. This converts the nickel, cobalt, and manganese sulfate mixture into a nickel, cobalt, and manganese sulfate solution, which is then separated from the negative electrode carbon. This solution can be used to produce various nickel, cobalt, and manganese salt products as needed.

[0051] Example 2

[0052] The waste powder from the production of lithium nickel cobalt manganese oxide (main components and contents are Li 6.54%, Ni 29.63%, Co 12.5%, and Mn 11.7%) was slurried with hydrochloric acid solution at a liquid-solid ratio of 3:1, with a mass ratio of hydrochloric acid to waste powder of 30.0%. Citric acid was added as a leaching aid at 80°C for 2 hours, and the leaching amount was 2.3 times the mass of the waste powder. Hydrogen peroxide was added as a reducing agent, and the amount of the reducing agent was 0.25 times the mass of the waste powder. The mixture was stirred for 6 hours, and the pH value at the reaction endpoint was controlled at 1.5-2.0. Solid-liquid separation was performed to obtain a lithium-rich solution and nickel cobalt manganese slag.

[0053] The concentrations of the lithium-rich solution were determined to be Li 21.36 g / L, Ni 0.08 g / L, Co 0.05 g / L, and Mn 0.8 g / L. Based on the concentrations of each ion in the solution, the lithium leaching rate was 98.00%, the Ni leaching rate was 0.08%, the Co leaching rate was 0.12%, and the Mn leaching rate was 2.05%.

[0054] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel, cobalt, and manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0055] Example 3

[0056] The waste electrode powder of lithium nickel cobalt manganese oxide (main components and contents are Li 6.35%, Ni 25.63%, Co 12.5%, Mn 11.7%, and Al 1.5%) is slurried with sulfuric acid solution at a liquid-solid ratio of 4:1, and the mass ratio of sulfuric acid to waste electrode powder is 60.0%. EDTA is continuously added as a leaching aid at 90°C, and the amount of the leaching aid is 0.6 times the mass of the waste electrode powder; then, sodium dithionite, a reducing agent, is added, and the amount of the reducing agent is 0.15 times the mass of the waste electrode powder; the reaction is stirred for 6 hours, and the pH value of the reaction endpoint is controlled to be 4.0, and solid-liquid separation is performed to obtain a lithium-rich solution and nickel cobalt manganese slag.

[0057] The concentrations of the lithium-rich solution were measured to be Li 15.55 g / L, Ni 0.05 g / L, Co 0.05 g / L, Mn 0.5 g / L, and Al 0.05 g / L. Based on the concentrations of each ion in the solution, the lithium leaching rate was 98.00%, the Ni leaching rate was 0.06%, the Co leaching rate was 0.12%, the Mn leaching rate was 1.28%, and the Al leaching rate was 1.0%.

[0058] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel, cobalt, and manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0059] Example 4

[0060] The waste powder of lithium nickel cobalt aluminum oxide (main components and contents: Li 6.3%, Ni 10.22%, Co 43.05%, Al 1.23%) was mixed evenly with EDTA as a leaching aid, and the amount of the leaching aid was 1.6 times the mass of the waste powder; nitric acid solution was added with a liquid-solid ratio of 6:1 to prepare pulp, and the mass ratio of nitric acid to waste powder was 20.0%. At 75°C, glucose as a reducing agent was added, and the amount of the reducing agent was 0.35 times the mass of the waste powder; the reaction was stirred for 8 hours, and the pH value of the reaction endpoint was controlled to be 4.0, and solid-liquid separation was performed to obtain a lithium-rich solution and nickel-cobalt-manganese slag.

[0061] The concentrations of the lithium-rich solution were measured to be Li 10.34 g / L, Ni 0.05 g / L, Co 0.05 g / L, Mn 0.6 g / L, and Al 0.08 g / L. Based on the concentrations of each ion in the solution, the lithium leaching rate was 98.00%, the Ni leaching rate was 0.08%, the Co leaching rate was 0.02%, the Mn leaching rate was 1.18%, and the Al leaching rate was 1.1%.

[0062] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel, cobalt, and manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0063] Example 5

[0064] Lithium nickelate waste powder (main components and contents: Li 6.8%, Ni 57.8%) was slurried with a hydrochloric acid solution at a liquid-to-solid ratio of 4.5:1, with the hydrochloric acid amount being 50% of the amount of the lithium nickelate waste powder. At 90°C, salicylic acid as a leaching aid was added and stirred for leaching for 2.5 hours, with the amount of the leaching aid added being 1.85 times the mass of the lithium nickelate waste powder. Then, soluble starch as a reducing agent was added, with the amount of the reducing agent being 0.4 times the mass of the lithium nickelate waste powder. The mixture was stirred for 1.5 hours, and the pH value at the reaction endpoint was controlled to be 4.0. Solid-liquid separation was performed to obtain a lithium-rich solution and nickel-cobalt-manganese slag.

[0065] The concentrations of the lithium-rich solution were determined to be 14.84 g / L Li and 0.5 g / L Ni. Based on the concentrations of each ion in the solution, the leaching rate of Li was 98.00% and the leaching rate of Ni was only 0.31%.

[0066] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0067] Example 6

[0068] Lithium manganate waste powder (main components and contents: Li 3.85%, Mn 44.36%) was added to a mixed solution of sulfuric acid and hydrochloric acid at a liquid-to-solid ratio of 3.5:1 to prepare pulp, with the amounts of sulfuric acid and hydrochloric acid being 10% and 15% of the lithium manganate waste powder, respectively. At 60°C, acetylacetone, a leaching aid, was continuously added and stirred for 6 hours, with the amount of the leaching aid being 0.85 times the amount of the lithium manganate waste powder. Then, ferrous sulfate and sodium metabisulfite, reducing agents, were added, with the total amount of the reducing agent being 0.8 times the mass of the lithium manganate waste powder. The leaching reaction was carried out for 2 hours, and the pH value at the reaction endpoint was controlled to be around 1.5. Solid-liquid separation was performed to obtain a lithium-rich solution and nickel-cobalt-manganese slag.

[0069] The concentrations of the lithium-rich solution were measured to be Li 10.78 g / L and Mn 1.5 g / L. Based on the concentrations of each ion in the solution, the leaching rate of Li was 98.02% and the leaching rate of Mn was only 1.18%.

[0070] The lithium-rich solution is purified to remove a small amount of impurity ions such as manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0071] Example 7

[0072] Lithium cobalt oxide waste powder (main components and contents: Li 7.02%, Co 61.4%) is evenly mixed with leaching aid oxalic acid, where the amount of the leaching aid is 2.5 times the mass of the lithium cobalt oxide waste powder; nitric acid solution is added at a liquid-to-solid ratio of 5:1 to prepare pulp, where the amount of nitric acid is 0.4% of the waste mass, and stirred at 80°C for 2 hours. Then, sodium sulfite, a reducing agent, is continuously added in an amount of 0.5 times the mass of the lithium cobalt oxide waste powder, and the reaction is stirred for 3 hours; the pH value at the reaction endpoint is controlled to 2.5, and solid-liquid separation is performed to obtain a lithium-rich solution and nickel-cobalt-manganese slag.

[0073] The concentrations of the lithium-rich solution were determined to be 13.85 g / L for Li and 1.5 g / L for Co. Based on the concentrations of the various ions in the solution, the leaching rates of Li and Co were calculated to be 98.28% and 1.22%.

[0074] The lithium-rich solution is purified to remove a small amount of impurity ions such as cobalt remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0075] Example 8

[0076] Lithium nickel cobalt oxide waste powder (main components and contents: Li 6.25%, Ni 11.22%, Co 44.05%) was slurried with nitric acid solution at a liquid-to-solid ratio of 2.5:1, and the amount of nitric acid was 30% of the mass of the lithium nickel cobalt oxide waste powder; at 90°C, leaching aids salicylic acid and oxalic acid, as well as a reducing agent soluble starch were continuously added, and the amount of salicylic acid and oxalic acid added (1:1) was 1.75 times the mass of the lithium nickel cobalt oxide waste powder, and the amount of soluble starch added was 0.55 times the mass of the lithium nickel cobalt oxide waste powder. The mixture was stirred and leached for 6 hours, and the pH value of the reaction endpoint was controlled to 3.0. Solid-liquid separation was performed to obtain a lithium-rich solution and nickel-cobalt-manganese slag.

[0077] The concentration of the lithium-rich solution was determined to be Li 24.6 g / L, Co 1.5 g / L, and Ni 0.05 g / L. Based on the concentration of each ion in the solution, the leaching rate of Li was 98.40%, the leaching rate of Co was 0.85%, and the leaching rate of Ni was 0.12%.

[0078] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel and cobalt remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0079] Example 9

[0080] Lithium manganate and lithium cobaltate mixed waste powder (main components and contents: Li 5.68%, Co 33.7%, Mn 20.18%) was slurried with water at a liquid-to-solid ratio of 3:1. Sulfuric acid, leaching aids acetylacetone and salicylic acid, and a reducing agent ferrous sulfate were added in sequence. The sulfuric acid dosage was 0.15% of the mass of the lithium manganate and lithium cobaltate mixed waste powder; the salicylic acid and acetylacetone (1:1) leaching aids were 0.85 times the mass of the lithium manganate and lithium cobaltate mixed waste powder; and the reducing agent ferrous sulfate was 0.35 times the mass of the lithium manganate and lithium cobaltate mixed waste powder. The mixture was stirred and leached at 80°C for 5 hours. Solid-liquid separation was performed to obtain a lithium-rich solution and nickel-cobalt-manganese slag.

[0081] The concentrations of the lithium-rich solution were measured to be Li 18.75 g / L, Co 0.8 g / L, and Mn 1.05 g / L. Based on the concentrations of each ion in the solution, the leaching rates of Li, Co, and Mn were calculated to be 99.00%, 0.72%, and 1.56%.

[0082] The lithium-rich solution is purified to remove a small amount of impurity ions such as cobalt and manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0083] Example 10

[0084] Lithium manganate and lithium nickel cobalt manganate mixed waste powder (main components and contents: Li 4.95%, Ni 20.26%, Co4.59%, Mn 20.07%) was added with sulfuric acid solution at a liquid-solid ratio of 2:1 to prepare pulp, and the amount of sulfuric acid was 0.3% of the mass of the mixed waste powder. At 80°C, leaching aid citric acid and reducing agent sodium dithionite were continuously added, and the reaction was stirred for 4 hours. The amount of citric acid added was 1.8 times the mass of the lithium manganate and lithium nickel cobalt manganate mixed waste powder, and the amount of sodium dithionite added was 0.1%. The pH of the reaction endpoint was controlled to 4.0, and solid-liquid separation was performed to obtain lithium-rich solution and nickel cobalt manganese slag.

[0085] The concentrations of the lithium-rich solution were measured to be Li 24.35 g / L, Ni 0.08 g / L, Co 0.04 g / L, and Mn 1.05 g / L. Based on the concentrations of each ion in the solution, the leaching rates of Li, Co, Ni, and Mn were calculated to be 98.37%, 0.17%, 0.1%, and 1.05%.

[0086] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel, cobalt, and manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0087] Example 11

[0088] A mixed waste powder of lithium manganate, lithium cobaltate, and lithium nickel cobaltate (main components and contents: Li 5.96%, Ni 15.77%, Co 20.81%, Mn 12.53%) was first mixed with a leaching aid, malonic acid, at a dosage of 2.8 times the mass of the mixed waste powder. A sulfuric acid and nitric acid solution was added at a liquid-to-solid ratio of 3.5:1 to prepare a slurry, with the dosages of sulfuric acid and nitric acid being 20% ​​and 10% of the mass of the mixed waste powder, respectively. The mixture was reacted at 80°C for 3 hours, and then hydrogen peroxide, a reducing agent, was slowly added for 3 hours, at a dosage of 0.15 times the mass of the mixed waste powder. The pH at the end of the reaction was controlled at 1.5, and solid-liquid separation was performed to obtain a lithium-rich solution and nickel-cobalt-manganese slag.

[0089] The concentrations of the lithium-rich solution were measured to be Li 16.78 g / L, Ni 0.08 g / L, Co 0.1 g / L, and Mn 1.05 g / L. Based on the concentrations of each ion in the solution, the leaching rates of Li, Co, Ni, and Mn were calculated to be 98.54%, 0.18%, 0.18%, and 2.93%.

[0090] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel, cobalt, and manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0091] Example 12

[0092] A mixed waste powder of lithium cobalt oxide and lithium nickel cobalt manganese oxide black powder (main components and contents: Li 4.54%, Ni 10.85%, Co 31.6%, Mn 4.71%) is mixed with ascorbic acid, where the amount of ascorbic acid is 1.5 times the mass of the mixed waste powder of lithium cobalt oxide and lithium nickel cobalt manganese oxide black powder. Water is added to prepare a slurry with a liquid-solid ratio of 3:1. Sulfuric acid is slowly added at 90° C. and stirred for 1.5 hours. The amount of sulfuric acid added is 0.60 times the mass of the mixed waste powder of lithium cobalt oxide and lithium nickel cobalt manganese oxide black powder. Then, sodium thiosulfate, a reducing agent, is added to react for 4.5 hours. The amount of the reducing agent added is 0.35 times the mass of the mixed waste powder of lithium cobalt oxide and lithium nickel cobalt manganese oxide black powder. The pH value at the reaction endpoint is controlled to be 2.5. Solid-liquid separation is performed to obtain a lithium-rich solution and nickel cobalt manganese slag.

[0093] The concentrations of the lithium-rich solution were determined to be Li 15.01 g / L, Ni 0.05 g / L, Co 0.1 g / L, and Mn 0.15 g / L. Based on the concentrations of each ion in the solution, the leaching rates of Li, Co, Ni, and Mn were calculated to be 99.18%, 0.13%, 0.15%, and 0.96%.

[0094] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel, cobalt, and manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0095] Example 13

[0096] Mixed waste powders of lithium manganate, lithium cobaltate, lithium nickelate, lithium nickel cobaltate, lithium nickel cobalt aluminumate and lithium nickel cobalt manganate (main components and contents: Li 5.8%, Ni 10.85%, Co 25.63%, Mn 8.71%, Al 0.5%) were added with water at a liquid-solid ratio of 5:1 to prepare a slurry. A hydrochloric acid solution with a mass concentration of 40% was slowly added at 95°C, and a leaching aid EDTA was added at the same time. The mixture was stirred and leached for 3.5 hours, wherein the amount of EDTA added was 2.2 times the mass of the mixed waste powders of lithium manganate, lithium cobaltate, lithium nickelate, lithium nickel cobaltate, lithium nickel cobalt aluminumate and lithium nickel cobalt manganate, respectively. Then, a reducing agent, glucose, was added and reacted for 3.5 hours, wherein the amount of glucose added was 0.3 times the mass of the mixed waste powder. The pH value at the reaction end point was controlled to be 3.5, and solid-liquid separation was performed to obtain a lithium-rich solution and nickel-cobalt-manganese slag.

[0097] The concentrations of the lithium-rich solution were measured to be Li 11.41 g / L, Ni 0.05 g / L, Co 0.1 g / L, Mn 0.15 g / L, and Al 0.03 g / L. Calculated leaching rates of Li were 98.36%, Co 0.58%, Ni 0.20%, Mn 0.85%, and Al 3.0%.

[0098] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel, cobalt, and manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0099] Example 14

[0100] Waste lithium cobalt oxide and nickel cobalt manganese oxide batteries are crushed and sorted to obtain positive and negative electrode waste powder (main components and contents are: Li 4.24%, Ni 12.85%, Co 35.6%, Mn 5.71%, C 28.7%, Cu 3.0%, Al 0.55%), which is mixed with malonic acid in an amount of 2.0 times the mass of the positive and negative electrode waste powder. Water is added at a liquid-solid ratio of 3:1 to prepare slurry. At 85°C, sulfuric acid is slowly added and stirred for 1.5 hours. The amount of sulfuric acid added is 0.60 times the mass of the positive and negative electrode waste powder. Then, sodium thiosulfate, a reducing agent, is added to react for 4.5 hours. The amount of the reducing agent added is 0.35 times the mass of the positive and negative electrode waste powder. The pH value at the reaction endpoint is controlled at 2.5-3.0. Solid-liquid separation is performed to obtain a lithium-rich solution and nickel cobalt manganese carbon slag.

[0101] The concentrations of the lithium-rich solution were measured to be Li 13.91 g / L, Ni 0.03 g / L, Co 0.1 g / L, Mn 0.15 g / L, Cu 0.3 g / L, and Al 0.05 g / L. Based on the concentrations of each ion in the solution, the leaching rates of Li, Co, Ni, and Mn were 98.42%, 0.08%, 0.07%, and 0.78%, respectively.

[0102] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel, cobalt, and manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0103] Example 15

[0104] Waste lithium manganese oxide and nickel cobalt manganese oxide batteries are crushed and sorted to obtain positive and negative electrode waste powder (main components and contents are: Li 3.54%, Ni 9.85%, Co 5.6%, Mn 20.71%, C 26.7%, Cu 3.5%, Al 1.55%) and mixed with ascorbic acid, with the amount of ascorbic acid being 2.5 times the mass of the positive and negative electrode waste powder; water is added to prepare slurry at a liquid-solid ratio of 3:1, and hydrochloric acid is slowly added at 90°C and stirred for leaching for 3.5 hours, with the amount of hydrochloric acid added being 0.60 times the mass of the positive and negative electrode waste powder; then, a reducing agent, soluble starch, is added to react for 4.5 hours, with the amount of the reducing agent added being 0.35 times the mass of the positive and negative electrode waste powder, and the pH at the reaction endpoint is controlled to be 3.5, and solid-liquid separation is performed to obtain a lithium-rich solution and nickel cobalt manganese carbon slag.

[0105] The concentrations of the lithium-rich solution were measured to be Li 11.65 g / L, Ni 0.01 g / L, Co 0.01 g / L, Mn 0.15 g / L, Cu 0.5 g / L, and Al 0.08 g / L. Based on the concentrations of each ion in the solution, the leaching rates of Li, Co, Ni, and Mn were calculated to be 98.70%, 0.05%, 0.05%, and 0.26%.

[0106] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel, cobalt, and manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0107] Example 16

[0108] Waste lithium cobalt oxide, lithium manganese oxide and nickel cobalt manganese oxide batteries are crushed and sorted to obtain mixed positive and negative electrode waste powder (main components and contents are: Li 3.67%, Ni 19.85%, Co 12.6%, Mn 15.71%, C 30.7%, Cu 2.5%, Al 1.15%). Sulfuric acid solution is added at a liquid-solid ratio of 3:1 to prepare pulp. At 95°C, tartaric acid as a leaching aid is slowly added and stirred for leaching for 3.5 hours. The amount of tartaric acid added is 1.67 times the mass of the mixed waste powder. Then, sodium thiosulfate and soluble starch as reducing agents are added and the reaction is continued for 4.5 hours. The amount of tartaric acid added is 0.35 times the mass of the mixed waste powder. The pH value at the reaction end point is controlled at 1.5-3.5. Solid-liquid separation is performed to obtain a lithium-rich solution and nickel cobalt manganese carbon slag.

[0109] The concentrations of the lithium-rich solution were measured to be Li 12.00 g / L, Ni 0.04 g / L, Co 0.02 g / L, Mn 0.17 g / L, Cu 0.35 g / L, and Al 0.08 g / L. Based on the concentrations of each ion in the solution, the leaching rates of Li, Co, Ni, and Mn were calculated to be 98.10%, 0.05%, 0.06%, and 0.33%.

[0110] The lithium-rich solution is purified to remove a small amount of impurity ions such as nickel, cobalt, and manganese remaining in the solution in preparation for the subsequent preparation of lithium carbonate products.

[0111] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for efficiently separating lithium from multi-element lithium battery electrode waste in one step, characterized in that: The following steps are involved: The multi-element lithium battery electrode waste is at least one of positive electrode waste and negative electrode waste, and the multi-element lithium battery contains at least one of nickel, cobalt and manganese; S1, one-step separation of lithium Adding inorganic acid, leaching aid and reducing agent to the multi-element lithium battery electrode waste powder, stirring and leaching, reacting at a certain temperature for a certain time to obtain a reaction-completed slurry; S2, filtration and washing The slurry after the reaction is completed is filtered and washed to obtain a lithium-rich solution with a lithium ion concentration of 10 to 30 g / L and a residue.

2. The method for efficiently separating lithium from waste multi-element lithium battery electrodes in one step according to claim 1, wherein: The waste material in S1 is one or a mixture of electrode waste produced by crushing and sorting batteries and electrode pieces and positive electrode material production waste; The battery is one or more of a nickel cobalt manganese oxide battery, a lithium cobalt oxide battery, a lithium nickel oxide battery, a lithium manganese oxide battery and a nickel cobalt aluminum oxide battery; The electrode waste produced by the crushing and sorting of the electrode pieces is one or more of the electrode waste produced by the crushing and sorting of the nickel-cobalt-lithium manganate electrode pieces, the electrode waste produced by the crushing and sorting of the lithium cobaltate electrode pieces, the electrode waste produced by the crushing and sorting of the lithium nickelate electrode pieces, the electrode waste produced by the crushing and sorting of the lithium manganate electrode pieces, and the electrode waste produced by the crushing and sorting of the nickel-cobalt-lithium aluminum oxide electrode pieces; the electrode waste produced by the crushing and sorting of the electrode pieces includes the positive electrode waste produced by the crushing and sorting of the electrode pieces and the negative electrode waste produced by the crushing and sorting of the electrode pieces; The positive electrode material production waste is one or more of nickel cobalt lithium manganate positive electrode material production waste, lithium cobaltate positive electrode material production waste, lithium nickelate positive electrode material production waste, lithium manganate positive electrode material production waste and nickel cobalt aluminum oxide positive electrode material production waste.

3. The method for efficiently separating lithium from waste multi-element lithium battery electrodes in one step according to claim 1, wherein: The reducing agent is added after the inorganic acid and the leaching aid are added to the slurry in S2.

4. A method for efficiently separating lithium from multi-element lithium battery electrode waste in one step according to claim 1 or 3, characterized in that: The inorganic acid in S2 is a mixture of one or more of sulfuric acid, hydrochloric acid and nitric acid; The reducing agent in S2 is one or more of sodium metabisulfite, sodium dithionite, hydrogen peroxide, glucose, soluble starch, ferrous sulfate, sodium sulfite and sodium thiosulfate; The leaching aid in S2 is one or more of citric acid, malonic acid, acetylacetone, oxalic acid, ascorbic acid, tartaric acid, salicylic acid, and EDTA.

5. A method for efficiently separating lithium from multi-element lithium battery electrode waste in one step according to claim 1 or 3, characterized in that: The mass ratio of the multi-component lithium battery electrode waste to the inorganic acid in the slurry of S2 is 1:0.05-0.

6.

6. A method for efficiently separating lithium from multi-element lithium battery electrode waste in one step according to claim 1 or 3, characterized in that: The mass ratio of the multi-element lithium battery electrode waste to the reducing agent in the slurry of S2 is 1:0.1-1.

0.

7. A method for efficiently separating lithium from multi-element lithium battery electrode waste in one step according to claim 1 or 3, characterized in that: The mass ratio of the multi-component lithium battery electrode waste to the leaching aid in the slurry S2 is 1:0.5-3.

0.

8. The method for efficiently separating lithium from waste multi-element lithium battery electrodes in one step according to claim 1, wherein: The operating conditions in S2 are such that the liquid-to-solid ratio of the leaching reaction is 2 to 6:

1.

9. The method for efficiently separating lithium from waste multi-element lithium battery electrodes in one step according to claim 1, wherein: The operating conditions of S2 include a reaction time of 1 h to 8 h; a reaction endpoint pH of 1.5 to 4.0; and a reaction temperature of 40° C. to 100° C.

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