A method for selectively recovering manganese from failed lithium-ternary materials

Abstract

The application provides a new method for selectively recovering manganese from failed ternary lithium battery materials, and belongs to the technical field of environmental protection and non-ferrous metal recycling. The specific method is as follows: after pretreatment, positive and negative powders of the failed ternary lithium ion battery are obtained, the positive powder is mixed with a reducing agent at a certain ratio, and then reduction roasting is carried out at 650-850 DEG C; the roasting material is subjected to ammonia leaching under the conditions of air isolation and reaction time control, and manganese is selectively and preferentially extracted; and the manganese-containing liquid is subjected to oxidation precipitation to obtain a manganese product. The method realizes selective recovery of manganese in the failed ternary lithium battery material, can greatly simplify the traditional nickel, cobalt and manganese extraction separation process, provides a new idea for the lithium ion battery recycling method, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The application relates to a method for selectively recovering manganese from failed ternary lithium battery materials and belongs to the technical field of environmental protection and non-ferrous metal recycling. BACKGROUND

[0002] Lithium ion batteries have the advantages of high energy density, wide working temperature range, high charging efficiency, small self-discharge, good cycle performance, no memory effect and the like, have been widely used in mobile phones, notebook computers, electric vehicles, medical devices, aerospace and many other fields and have replaced traditional nickel-cadmium batteries and lead-acid batteries on a large scale.

[0003] In recent years, the rapid development of the lithium ion battery industry has led to an explosive growth in the number of failed lithium ion batteries. The failed lithium ion batteries contain valuable metals such as lithium, nickel, cobalt and manganese, organic electrolytes and separators and are important secondary resources. If not effectively recycled, on the one hand, great resource waste will be caused, and on the other hand, if the organic electrolyte and the like are not treated, great environmental pollution and harm to human health will be caused.

[0004] In the traditional wet leaching process, acid leaching basically has no selectivity for valuable metals in the failed ternary lithium battery materials, and impurity elements such as iron, aluminum, calcium and magnesium will all enter the leaching solution, leading to a complex subsequent solution purification process. The manganese extraction process needs a large amount of extractant, and the extraction process takes a long time and has many extraction stages, leading to a high cost of the extraction process. Therefore, it is of great significance to develop a preferential extraction technology for manganese in the failed ternary materials to avoid the manganese extraction process.

[0005] Patent CN 107017443 B performs pre-roasting on the batteries at 300-400 DEG C after simple pretreatment, performs reduction roasting on the batteries at 450-700 DEG C after adding a reducing agent, extracts nickel and cobalt by ammonia oxidation leaching, and manganese is in the form of manganese dioxide into the slag, and the obtained manganese-rich slag is used to prepare manganese sulfate by acid leaching. Although the method realizes the separation of manganese from nickel and cobalt in the leaching process, in the acid leaching extraction process of the manganese-rich slag, manganese will enter the acid leaching solution together with impurities such as iron, aluminum, calcium and magnesium, leading to a complex subsequent solution purification process. SUMMARY

[0006] The application aims to provide a method for selectively recovering manganese from failed ternary lithium battery materials, which has the advantages of low cost, short process, recyclable solution system, no wastewater discharge and the like, provides a new idea for lithium ion battery recycling and has a good application prospect.

[0007] The specific steps of the method are as follows:

[0008] (1) The electrode waste obtained by pretreatment and sorting of the failed ternary lithium ion battery is first reduced and calcined at 650-850 DEG C for 1-4 h, and then the calcined product is directly quenched with water;

[0009] (2) The calcined material after water quenching is leached in an ammonia-ammonium salt mixed solution in an air-tight condition, and after leaching, manganese in the calcined material enters the solution, while nickel and cobalt are hardly leached out;

[0010] (3) After leaching, filtration is performed, manganese-containing leaching solution is obtained, and an oxidizing agent is added to precipitate manganese to obtain a product, the oxidizing agent used includes oxygen and hydrogen peroxide, and the molar amount of the oxidizing agent added is 1.1-2 times the molar amount of manganese in the leaching solution. The solution after manganese precipitation is returned to the leaching process of step (2) for recycling.

[0011] Further, in the reduction and calcination process of step (1), the reducing agent is graphite, conductive agent contained in the battery waste and an additional reducing agent, wherein the additional reducing agent includes one or more of lignite, coke, carbon black, anthracite, methane and biomass, and the carbon content of all reducing agents is 5-35 wt.% of the mass of the battery waste.

[0012] Further, in the ammonia leaching process of step (2), the ammonium salt in the ammonia-ammonium salt mixed solution used is one or more of ammonium chloride, ammonium carbonate, ammonium bicarbonate and ammonium sulfate.

[0013] Further, in the leaching process of step (2), the leaching time is 10-90 min, the concentration of ammonia in the leaching solution is 3-8 mol / L, the concentration of ammonium salt is 1-4 mol / L, the liquid-solid ratio is 2:1-20:1, and the leaching temperature is 20-60 DEG C.

[0014] The principle of the present application is:

[0015] 1. After reduction and calcination of the failed ternary lithium battery material, MnO, Ni and Co are dissociated. Therefore, Ni and Co can be leached under ammonia conditions only in the presence of an oxidizing agent, while MnO can be directly leached without oxidation. Therefore, under an air-tight condition, selective leaching of manganese can be achieved, while nickel and cobalt are not leached at all.

[0016] 2. Under different ammonia and ammonium salt concentrations, the solubility of manganese changes. Therefore, the ammonia concentration, ammonium salt concentration and liquid-solid ratio in the ammonia leaching process need to be controlled to achieve effective leaching of manganese.

[0017] Compared with the prior art, the method for preferentially recovering manganese from the failed ternary lithium battery material has the following advantages:

[0018] (1) The selective and preferential extraction of manganese in the failed ternary lithium battery material is realized, and the manganese extraction process in the traditional process is deleted;

[0019] (2) The high-purity manganese product can be directly obtained by oxidizing and precipitating manganese from the manganese leaching solution, avoiding the complex solution purification process after manganese extraction in the traditional wet process;

[0020] (3) The leaching system has high selectivity and can be recycled, which greatly simplifies the solution purification and separation process, and greatly reduces the wastewater treatment amount. DETAILED DESCRIPTION

[0021] The application will be further described in detail below through some embodiments, which are only used to illustrate the application and do not limit the scope of the application.

[0022] Example 1

[0023] The pretreated failed ternary lithium battery material is mixed with 15wt.% lignite reducing agent, and reduction roasting is carried out at 850℃ for 1h, and the roasted material is obtained after water quenching; the roasted material is added to a mixed solution of 8mol / L ammonia and 1mol / L ammonium bicarbonate, and selective and preferential manganese extraction is carried out under the condition of air isolation, the reaction time is 45min, the liquid-solid ratio is 2:1, and the reaction temperature is 20℃; after the reaction, the manganese-containing leaching solution and the manganese extraction residue are obtained by filtration, the manganese leaching rate is 95.2%, and the nickel and cobalt leaching rates are only 2.3% and 0.8% at this time; oxygen is introduced into the manganese-containing leaching solution to precipitate manganese to obtain a product, the oxygen addition molar amount is 2 times the molar amount of manganese in the leaching solution, and the manganese precipitation rate is 97.3%. The solution after manganese precipitation is returned to the leaching process for recycling.

[0024] Example 2

[0025] The pretreated failed ternary lithium battery material is mixed with 35wt.% anthracite, and reduction roasting is carried out at 650℃ for 4h, and the roasted material is obtained after water quenching; the roasted material is added to a mixed solution of 3mol / L ammonia and 4mol / L ammonium carbonate, and selective and preferential manganese extraction is carried out, the reaction system is sealed, the reaction time is 90min, the liquid-solid ratio is 20:1, and the reaction temperature is 40℃; after the reaction, the manganese-containing liquid and the manganese extraction residue are obtained by filtration, the manganese leaching rate is 95.0%, and the nickel and cobalt leaching rates are only 1.4% and 2.7% at this time; oxygen is introduced into the manganese-containing leaching solution to precipitate manganese to obtain a product, the oxygen addition molar amount is 1.5 times the molar amount of manganese in the leaching solution, and the manganese precipitation rate is 99.8%. The solution after manganese precipitation is returned to the leaching process for recycling.

[0026] Example 3

[0027] The pretreated failed ternary lithium battery material is mixed with 5wt.% negative electrode carbon, reduction roasting is carried out at 800°C, the roasting time is 2h, and after water quenching, the roasted material is obtained; the roasted material is added to a mixed solution of 6mol / L ammonia and 2mol / L ammonium sulfate to selectively preferentially extract manganese, the reaction system is closed, the reaction time is 10min, the liquid-solid ratio is 10:1, and the reaction temperature is 60°C; after the reaction, filtration is performed to obtain a manganese-containing liquid and a manganese extraction residue, the manganese leaching rate is 94.6%, and the nickel and cobalt leaching rates are only 3.4% and 4.8% respectively; hydrogen peroxide is added to the manganese-containing leaching liquid to precipitate manganese to obtain a product, the hydrogen peroxide addition molar amount is 1.1 times the molar amount of manganese in the leaching liquid, and the manganese precipitation rate is 95.6%. The solution after manganese precipitation is returned to the leaching process for recycling.

[0028] Example 4

[0029] The pretreated failed ternary lithium battery material is mixed with 20wt.% negative electrode carbon, reduction roasting is carried out at 750°C, the roasting time is 3h, and after water quenching, the roasted material is obtained; the roasted material is added to a mixed solution of 4mol / L ammonia and 3mol / L ammonium chloride to selectively preferentially extract manganese, the reaction system is closed, the reaction time is 60min, the liquid-solid ratio is 6:1, and the reaction temperature is 30°C; after the reaction, filtration is performed to obtain a manganese-containing liquid and a manganese extraction residue, the manganese leaching rate is 95.4%, and the nickel and cobalt leaching rates are only 5.4% and 6.5% respectively; hydrogen peroxide is passed into the manganese-containing leaching liquid to precipitate manganese to obtain a product, the hydrogen peroxide addition molar amount is 1.2 times the molar amount of manganese in the leaching liquid, and the manganese precipitation rate is 99.8%. The solution after manganese precipitation is returned to the leaching process for recycling.

Claims

1. A method for selectively recovering manganese from a spent ternary lithium battery material, characterized in that The following steps are taken: (1) The electrode scrap obtained by pretreatment and sorting of the failed ternary lithium-ion battery is first reduced and calcined at 650-850°C for 1-4 h, and then the calcined product is directly quenched with water; (2) The calcined material after water quenching is leached in an ammonia-ammonium salt mixed solution in an air-tight manner, wherein the ammonia-ammonium salt mixed solution contains one or more of ammonium chloride, ammonium carbonate, ammonium bicarbonate and ammonium sulfate; after leaching, manganese in the calcined material enters the solution, while nickel and cobalt are hardly leached; (3) After leaching, filtration is performed to obtain a manganese-containing leaching solution, an oxidizing agent is added to the leaching solution to precipitate manganese and obtain a product, the oxidizing agent includes oxygen and hydrogen peroxide, and the molar amount of the oxidizing agent added is 1.1-2 times the molar amount of manganese in the leaching solution; the solution after manganese precipitation is returned to the leaching process in step (2) for recycling.

2. A method of selectively recovering manganese from spent ternary lithium materials as claimed in claim 1, characterized in that In step (1), the reducing agent is graphite, conductive agent contained in the battery scrap and an additional reducing agent, wherein the additional reducing agent includes one or more of lignite, coke, carbon black, anthracite, methane and biomass, and the carbon content of all the reducing agents is 5-35 wt.% of the mass of the battery scrap.

3. A method of selectively recovering manganese from spent ternary lithium materials as claimed in claim 1, characterized in that In step (2), the leaching is performed for 10-90 min, the ammonia water concentration in the leaching solution is 3-8 mol / L, the ammonium salt concentration is 1-4 mol / L, the liquid-solid ratio is 2:1-20:1 g / L, and the leaching temperature is 20-60°C.