TWI741603B - Method for recovering valuable metals from waste lithium batteries - Google Patents

Abstract

The present invention relates to a method for recovering valuable metals from waste lithium batteries, and mainly proposes a hydrometallurgical process of extraction, purification and separation of lithium, cobalt, nickel and manganese powders contained in waste lithium batteries.

Description

Method for recovering valuable metals from waste lithium batteries

The present invention relates to a method of resource acquisition, in particular to a method of recovering valuable metals from waste lithium batteries.

After the successful introduction of lithium-ion batteries into the market, due to their relatively light weight, small size and long life, they are widely used in various 3C products, energy storage equipment and even electric vehicles around the world. However, lithium-ion batteries contain valuable metals such as lithium, cobalt, nickel, and manganese. If they are discarded arbitrarily after use, the environment will easily be polluted by heavy metals and even change the environment. And because of the rising awareness of environmental protection and the importance of environmental protection issues worldwide, industry or academia also develops technology for resource recovery. For example: Taiwan Invention Patent No. I286850 "Method for Recycling Waste Lithium Battery Resources", according to its patent specification, discloses that the positive electrode part where lithium and cobalt are located is immersed in hydrochloric acid for two hours and then adjusted with sodium hydroxide (NaOH). The pH value of the dipping solution reaches eight, then the gelled substance containing cobalt (Co), aluminum (Al), and nickel (Ni) can be separated by filtration at this time, and finally sodium carbonate saturated solution is added to the dipping solution. Lithium carbonate powder can be obtained; in addition, the gelled substance containing cobalt (Co), aluminum (Al), and nickel (Ni) obtained by filtration is first pickled with sulfuric acid and adjusted to a pH of two to dissolve the contained metals. Add ammonia water to adjust the pH to 8 to filter and remove the gelatinous material containing aluminum ions. Finally, the filtered pickling solution is adjusted to pH 4.3 with sulfuric acid and then poured into the electrolytic cell for electrolysis and recovery, and electrolysis is carried out with a constant temperature water bath. The temperature of the liquid is maintained at 55°C, and after a fixed current is applied, the cobalt and nickel metal will be deposited on the cathode stainless steel sheet, and the cobalt and nickel metal can be recovered after drying, so as to achieve the purpose of waste resource regeneration.

Taiwan Invention Announcement No. 501294 "Method for Recovering Metals from Waste Lithium Ion Batteries Using Sulfuric Acid", its patent specification discloses the process of roasting and decomposing used waste lithium ion batteries in a high-temperature furnace to remove organic electricity. After digestion, it is crushed and sieved. The material on the sieve can be processed by magnetic separation and eddy current separation to separate the broken iron shell, copper foil and aluminum foil. The material under the sieve is a mixture of sulfuric acid and hydrogen peroxide. Dissolution is carried out, the solution obtained by the dissolution is filtered out, and the iron and aluminum ions are precipitated by adjusting the acid-base value. In the meantime, the metal copper and the metal cobalt are electrolytically separated by electrolysis, and the electrolysis is rich in lithium ions In the solution, carbonate is added to form lithium carbonate precipitation and the lithium is effectively recovered.

And Taiwan Invention Announcement No. 399347 "A method for recycling waste batteries", in which the metal compound to be recycled is fully contacted with reducing gas (mainly carbon monoxide) at high temperature and undergoes a reduction reaction, effectively reducing it to metal elements. And by series-staged condensation, the metal substances contained in the waste battery can be recycled into a variety of single enriched metal substances, such as lithium, zinc, cadmium, mercury and other recycled products, and the residual substances after treatment It also no longer has heavy metal pollution.

Taiwan's new M341943 "Waste Battery Treatment and Recycling Device" manual reveals that a dry metallurgical thermal plasma melting process replaces the induction high-temperature furnace to process waste dry batteries such as alkaline manganese, carbon zinc, zinc air and nickel cadmium, which not only can get better The recovery rate.

Taiwan Invention Patent No. I535479 "Method for Recovering Valuable Metals", the specification discloses the use of sulfuric acid and hydrogen peroxide acid solution and ultrasonic device, and existing recovery procedures for metal recovery.

The patent specification of Taiwan Invention Bulletin No. 511306 "Method for Purifying and Recycling Metal in Waste Lithium-ion Batteries" discloses that waste lithium-ion batteries are roasted in a high-temperature furnace to decompose and remove organic electrolytes, crushed, sieved, and the sieved material is then magnetically separated. The eddy current sorting process separates the broken iron shell, copper foil and aluminum foil, etc.; and the under-sieve is eroded and filtered, and the pH value and electrolysis conditions are controlled to electrolytically separate the metal by the diaphragm electrolysis method. Copper and cobalt, the acid generated on the cathode side during the electrolysis process can be recovered by diffusion dialysis and recycled to the dissolution step for use, forming a closed process. The solution rich in lithium ions after electrolysis, after adjusting the pH value to precipitate metal impurities, can add carbonate to form a high-purity lithium carbonate to recover the lithium.

Taiwan Invention Patent No. I392745 "Method for Recovering Valuable Metals from Lithium Battery Residues Containing Co, Ni, and Mn" discloses that a hydrochloric acid solution with a concentration of 250g/l or more is used for the treatment of lithium metal salt (containing approximately the same amount of Co). , Ni and Mn) lithium battery residues are stirred and dipped, or a sulfuric acid solution with a concentration of more than 200g/l, while heating to 65~80℃, while stirring and dipping, or mixed with a concentration of more than 200g/l After stirring and immersing the sulphuric acid solution and the hydrogen peroxide solution above 20g/l, the leaching solution is solvent-extracted with an acidic extractant to extract more than 98% of Mn, Co and Ni three metals, resulting in Recover valuable metals such as Mn, Co, Ni, and Li from the solution containing each metal and the remaining liquid containing Li after extraction.

Taiwan Invention Patent No. I625882 "Method for Recycling Cathode Materials in Waste Lithium-Iron Battery" patent specification discloses that it includes the following steps: an impregnation step is to immerse the cathode material in the waste lithium-iron battery in an impregnation with a concentration of about 1N. The solid-to-liquid ratio of the two is about 3g/50ml, and the immersion temperature is about 27°C. After about 0.75hr, the filter residue containing aluminum is filtered out to obtain a lithium, aluminum, and iron impregnation liquid; The pH adjustment step is to adjust a pH adjuster to the aforementioned lithium, aluminum, and iron immersion liquid to a pH of about 7, and then filter out the filter residue containing lithium, aluminum, and iron to obtain a lithium-containing filtrate; and In the analysis step, the lithium-containing filtrate is heated to about 70° C. and maintained for at least 5 hours to obtain a white crystallized product.

From the various methods mentioned above, it can be found that individual inventors have solved and improved individual problems to be solved, such as emphasizing the importance of the valuable metals to be removed, or some of them are basic physical and chemical methods. However, for the entire treatment process, it has not been found to combine the ion exchange method in the hydrometallurgical technology with the chemical precipitation method to separate valuable metals such as Ni, Co, Li, and Mn. Therefore, there is still room for improvement in the purity of individual valuable metals. .

In view of the problems of the prior art, the inventor believes that there should be a need to solve the previous problems. To this end, the inventor designs a method for recovering valuable metals from waste lithium batteries. Separation of the hydrometallurgical process. The recovery rate of manganese, lithium, nickel and cobalt is 99.9%, and the purity of each element of manganese, lithium, nickel and cobalt reaches 98%, 99%, 98.5%, and 99.9% respectively. The method steps of the present invention include: pre-treatment step: pre-treating the waste lithium battery and pulverizing to form a pulverized product; dipping and dissolving step: impregnating the pulverized product containing Ni, Co, Li, and Mn metal with hydrochloric acid immersion solution; precipitation; Separation of manganese step: adding potassium permanganate to the hydrochloric acid leaching solution; precipitating manganese into manganese oxide, which is separated from the other three elements after filtration to obtain a filtrate; step of adsorbing cobalt and nickel: adjusting the pH of the filtrate to above 4; Then use the Na ⁺ type IRC748 anion exchange resin to adsorb cobalt and nickel on the Na ⁺ type IRC748 anion exchange resin, and the lithium is left in the liquid phase in an ionic state and separated from it; the first resin desorption step: the cobalt remaining in the resin The nickel is desorbed by HCl; the nickel is separated in the liquid phase by adsorption of cobalt: adding HCl to a Cl ^- concentration of 8N, within the error range of 5%, so that Co is complexed to form [CoCl ₄ ] ^2- , using a strong base anion resin Co is adsorbed on the resin, and Ni is separated from it in the liquid phase; the second resin desorption step: adding sulfuric acid to wash the cobalt adsorbed on the resin into the water phase.

S1: Pre-processing steps

S2: Dipping and dissolution step

S3: Separation of manganese by precipitation

S4: Adsorption of cobalt and nickel step

S5: The first resin desorption step

S6: Adsorption of cobalt to separate nickel in the liquid phase

S7: Second resin desorption step

The first figure is the flow chart of the method of the present invention

In the following, the structure, features and embodiments of the present invention will be explained by the coordination of the drawings, so as to make your reviewer Have a further understanding of the present invention.

Generally speaking, if you want to take out valuable metals, the process of resource recycling can be roughly divided into pyrometallurgy and hydrometallurgy. Pyrometallurgy is to heat and melt materials, reducing agents and fluxes to make Metal components are reduced or alloys are formed to achieve resource utilization; the hydrometallurgy method is to dissolve the metal components in the material in a solvent to form a solution, and then recover the metal through processing procedures such as ion exchange, solvent extraction, and chemical precipitation. The present invention The department adopts the wet method.

Please refer to the first figure. The present invention relates to a method for recovering valuable metals from waste lithium batteries. The steps at least include:

Pre-treatment step (S1): pre-treat the waste lithium batteries and crush them to form pulverized products; before using hydrometallurgical technology to recover valuable metals in waste lithium batteries, it must first go through crushing, sorting, screening and other procedures (Mineral Processing) The pretreatment of waste lithium-ion batteries is mainly to separate most non-metallic substances from target metals.

Leaching dissolution step (S2): immerse the crushed material containing Ni, Co, Li, and Mn metals with hydrochloric acid immersion solution; in specific implementation, the concentration of hydrochloric acid is 6N, and the immersion dissolution step is performed at a temperature of 60±5°C, The stirring speed is 350±50rpm. So that the four elements can reach 99% dissolution, when the PH reaches 0, NaOH can be added to adjust the pH to reach 2. This impregnation method is mainly to dissolve valuable metals into the liquid phase under optimal reaction conditions, and the liquid phase after solid-liquid separation becomes the feed for the subsequent recovery process.

Separation of manganese by precipitation (S3): adding potassium permanganate to the hydrochloric acid leaching solution; precipitating manganese into manganese oxide, which is separated from the other three elements after filtration to obtain a filtrate; in other words, using KMnO ₄ and Mn ²⁺ ions An oxidative precipitation reaction occurs, and manganese is separated from the solution. The pH of the precipitation and separation step of manganese is 2, and the environment should be at 45° C., Mn2+/KMnO4 molar ratio of 2.3, and a numerical error of 5%.

Adsorption of cobalt and nickel step (S4): adjust the pH of the filtrate to above 4; then use the Na ⁺ type IRC748 anion exchange resin to adsorb cobalt and nickel on the Na ⁺ type IRC748 anion exchange resin, and the lithium remains in the liquid phase in an ionic state. The separation; according to, the ion exchange process (Ion-exchange Process) is a reversible chemical reaction that occurs between the solid phase and the liquid phase. The reaction process needs to be maintained under electrically neutral conditions. After the ions are adsorbed by the ion exchange solid, they will release equivalent ions in the liquid phase. This process also needs to comply with thermodynamics and mass balance. Its advantages are: (1) Resins with different exchange groups can be used in different fields ( 2) High selectivity, which is beneficial to use in solutions containing a variety of valuable metal ions. (3) The operation method is easier.

The first resin desorption step (S5): The cobalt and nickel remaining in the resin are desorbed with HCl; the HCl is preferably 2N. Desorption is mainly to enrich and concentrate the target metal adsorbed on the resin, and then use the regeneration solution to restore the resin functional groups to the original ions. Common desorption agents and regenerating agents are HCl, H ₂ SO ₄ , NaCl, For solutions such as NaOH, the desorption effect is judged by the target gold enrichment effect and desorption rate. Choose the desorption agent with high desorption rate and good enrichment effect as the desorption agent, and the desorption rate is calculated as the total desorption amount of the target metal The ratio of adsorption to resin.

Adsorption of cobalt to nickel in the liquid phase separation step (S6): add HCl to a Cl ^- concentration of 8±1N to make Co complex to form [CoCl ₄ ] ^2- , use strong base anion resin to adsorb Co on the resin, and Ni in the resin The liquid phase is separated from it; the strong base anion resin is IRA900C1. Since Co ²⁺ and Cl ^- form an anion complex [CoCl ₄ ] ^2- but Ni ²⁺ does not, the adsorption reaction can be carried out through an anion exchange resin to separate Co from Ni in the desorption solution.

The second resin desorption step (S7): adding sulfuric acid to wash the cobalt adsorbed on the resin into the water phase. After the resin reaches saturation adsorption, ^{the residual feed is flushed out with a solution of the same Cl-} ion concentration, and then a desorbent is introduced to desorb and enrich the metal ions loaded on the resin.

In summary, the present invention is indeed in line with industrial applicability, and has not been seen in publications or publicly used before the application, and has not been known to the public, and it is non-obvious and easy to know, and meets the requirements of patentability. Therefore, a patent application is filed in accordance with the law. . However, what has been described above is a preferred embodiment in the industry of the invention, and all the equivalent changes made in accordance with the scope of the patent application of the invention belong to the scope of the claims of this case.

S1: Pre-processing steps

S2: Dipping and dissolution step

S3: Separation of manganese by precipitation

S4: Adsorption of cobalt and nickel step

S5: The first resin desorption step

S6: Adsorption of cobalt to separate nickel in the liquid phase

S7: Second resin desorption step

Claims (5)

A method for recovering valuable metals from waste lithium batteries, the steps at least include: pre-processing steps: pre-treating the waste lithium batteries and pulverizing them to form pulverized products; dipping and dissolving steps: pulverizing metals containing Ni, Co, Li, and Mn The material is immersed in hydrochloric acid leaching solution; the precipitation separation step of manganese: adding potassium permanganate to the hydrochloric acid leaching solution; the manganese is precipitated as manganese oxide, which is separated from the other three elements after filtration to obtain the filtrate; the cobalt and nickel adsorption step: Adjust the pH of the filtrate to above 4; then use the Na ⁺ type IRC748 anion exchange resin to adsorb cobalt and nickel on the Na ⁺ type IRC748 anion exchange resin, and the lithium is left in the liquid phase in an ionic state and separated from it; the first resin desorption step : The cobalt and nickel remaining in the resin are desorbed by HCl; cobalt is adsorbed to separate the nickel in the liquid phase. Step: add HCl to a Cl ^- concentration of 8N, within the error range of 5%, so that the Co complex forms [CoCl ₄ ] ^{2 -} using a strong base anion resin in the resin adsorbed Co, Ni in the liquid phase separated therefrom; a second resin desorption steps of: adding sulfuric acid adsorbed to the resin rinsed cobalt in the aqueous phase. The method for recovering valuable metals from waste lithium batteries as described in item 1 of the scope of patent application, wherein the immersion and dissolution step adopts 6N hydrochloric acid, and the immersion and dissolution step is performed at a temperature of 60±5°C and a stirring speed of 350±50 rpm, making four The elements can reach 99% dissolution. When the PH reaches 0, NaOH can be added to adjust the pH to reach 2, and the error of the above values is within the range of 5%. The method for recovering valuable metals from waste lithium batteries as described in item 1 of the scope of patent application, in which the precipitation and separation of manganese step, pH=2, and at 45℃, Mn ²⁺ /KMnO4 molar ratio is 2.3 environment, and above The numerical error is within 5%. For the method for recovering valuable metals from waste lithium batteries as described in the first item of the scope of patent application, in the first resin desorption step, the HCl is in the range of 2N, 5%. The method for recovering valuable metals from waste lithium batteries as described in item 1 of the scope of patent application, wherein the adsorption of cobalt separates nickel in the liquid phase separation step; the strong base anion resin is IRA900C1.

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