Preparation method for recycling nickel cobalt lithium manganate from waste lithium batteries

Abstract

The invention relates to the technical field of lithium battery positive electrode materials, in particular to a preparation method for recycling nickel cobalt lithium manganate from waste lithium batteries. The method comprises the following steps: 1, crushing the waste lithium battery to obtain a positive electrode material and other wastes; 2, carrying out water washing and alkali washing on the crushed positive electrode material to remove organic matters and metal impurities in the positive electrode material; 3, roasting the positive electrode material subjected to alkali washing at high temperature; 4, cooling the roasted positive electrode material, and then carrying out mechanical grinding; 5, adding a proper amount of acid into the ground positive electrode material for acid leaching, and adding a proper amount of oxidant into an acid leaching solution; 6, carrying out solid-liquid separation on the solution subjected to acid leaching; 7, adding a proper amount of precipitant into the solution containing the metal ions; and 8, carrying out solid-liquid separation on the precipitated solid and liquid to obtain a nickel cobalt lithium manganate product. The method has the advantages of high recovery rate, high purity, better environmental protection property, lower cost and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery positive electrode materials, and in particular to a preparation method for recycling lithium nickel cobalt manganese oxide through waste lithium batteries. Background Art

[0002] With the continuous development of science and technology and the improvement of people's living standards, the number of electronic devices using lithium batteries is also increasing year by year. Due to the limited service life of lithium batteries, the number of waste lithium batteries is also increasing. The positive electrode materials in waste lithium batteries, such as lithium nickel cobalt manganese oxide (LiNiCoMnO2, referred to as NCM), have a high recycling value. If the lithium nickel cobalt manganese oxide in waste lithium batteries can be recycled efficiently and environmentally friendly, it can not only reduce the pollution of waste to the environment, but also reduce production costs and improve resource utilization. Therefore, it is of great practical significance and application value to develop a highly efficient and environmentally friendly preparation method for recycling lithium nickel cobalt manganese oxide through waste lithium batteries. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a preparation method for recycling nickel cobalt manganese oxide from waste lithium batteries.

[0004] The technical solution of the present invention is:

[0005] A preparation method for recycling lithium nickel cobalt manganese oxide from waste lithium batteries comprises the following steps:

[0006] Step 1: crush the waste lithium batteries to obtain positive electrode materials and other waste;

[0007] Step 2: Wash the crushed positive electrode material with water and alkali to remove organic matter and metal impurities;

[0008] Step 3: calcining the positive electrode material after alkali washing at a high temperature of 600-800°C for 1-3 hours;

[0009] Step 4: The calcined positive electrode material is cooled and then mechanically ground to a particle size of less than 100 mesh;

[0010] Step 5: Add an appropriate amount of acid to the ground positive electrode material for acid leaching, add an appropriate amount of oxidant to the acid leaching solution, control the reaction temperature to 50-100°C, and the acid leaching time to 1-3 hours;

[0011] Step 6: performing solid-liquid separation on the solution after acid leaching to obtain a solution containing metal ions;

[0012] Step 7: Add an appropriate amount of precipitant to the solution containing metal ions, the precipitation temperature is 40-80°C, and the precipitation time is 1-3 hours;

[0013] Step 8: The solid-liquid separation after precipitation is carried out to obtain a lithium nickel cobalt manganese oxide product.

[0014] Preferably, in step one, the waste lithium battery is directly contacted with a sacrificial anode to obtain a pretreatment system; the pretreatment system is then immersed in a conductive salt solution to discharge; and finally, the positive and negative electrodes of the battery are drawn out.

[0015] Preferably, in the step 1, the discharge is terminated when the voltage of the battery tends to be stable.

[0016] Preferably, in the step 1, an inlet is fixedly installed on the top of the crusher, and a relatively arranged crushing shaft is rotatably installed above the inner wall of the crusher.

[0017] Preferably, in the step one, the waste lithium battery discharge device is provided with an opening on the top surface of the salt water pool and an openable and closable cover, the top side wall of the salt water pool is provided with an air intake port, and the air intake port is connected to the negative pressure device through an exhaust gas pipe, so that the exhaust gas generated during the salt water discharge of the waste lithium batteries can be collected and processed.

[0018] Preferably, in the step 2, a waste lithium battery storage device containing waste batteries is installed on a reaction tank of an incinerator, and the air in the incinerator is evacuated by a vacuum treatment device to place the waste lithium battery storage device and the reaction tank in the incinerator in a vacuum state.

[0019] Preferably, in step three, the crushing device is used to crush the discharged waste lithium batteries; and the filtering device is used to filter the crushed waste lithium batteries.

[0020] Preferably, in step 4, the spiral sedimentation centrifuge is connected to the output port of the magnetic separator through a conduit; the cone-bottom reaction tank adopts a steel-lined brick structure, and an agitator is arranged inside the cone-bottom reaction tank.

[0021] Compared with the prior art, the present invention has the following beneficial effects: by crushing, washing with water and washing with alkali, the organic matter and metal impurities in the waste lithium batteries are removed; and by high temperature roasting, mechanical grinding and acid leaching, the recovery and preparation of lithium nickel cobalt manganese oxide is realized. The method has the advantages of high recovery rate and high purity, good environmental protection and low cost. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0023] Example 1

[0024] This embodiment provides a preparation method for recycling lithium nickel cobalt manganese oxide from waste lithium batteries, comprising the following steps:

[0025] Step 1: crush the waste lithium batteries to obtain positive electrode materials and other waste;

[0026] Step 2: Wash the crushed positive electrode material with water and alkali to remove organic matter and metal impurities;

[0027] Step 3: calcining the positive electrode material after alkali washing at a high temperature of 600-800°C for 1-3 hours;

[0028] Step 4: The calcined positive electrode material is cooled and then mechanically ground to a particle size of less than 100 mesh;

[0029] Step 5: Add an appropriate amount of acid to the ground positive electrode material for acid leaching, add an appropriate amount of oxidant to the acid leaching solution, control the reaction temperature to 50-100°C, and the acid leaching time to 1-3 hours;

[0030] Step 6: performing solid-liquid separation on the solution after acid leaching to obtain a solution containing metal ions;

[0031] Step 7: Add an appropriate amount of precipitant to the solution containing metal ions, the precipitation temperature is 40-80°C, and the precipitation time is 1-3 hours;

[0032] Step 8: The solid-liquid separation after precipitation is carried out to obtain a lithium nickel cobalt manganese oxide product.

[0033] Preferably, in step one, the waste lithium battery is directly contacted with a sacrificial anode to obtain a pretreatment system; the pretreatment system is then immersed in a conductive salt solution to discharge; and finally, the positive and negative electrodes of the battery are drawn out.

[0034] Preferably, in the step 1, the discharge is terminated when the voltage of the battery tends to be stable.

[0035] Preferably, in the step 1, an inlet is fixedly installed on the top of the crusher, and a relatively arranged crushing shaft is rotatably installed above the inner wall of the crusher.

[0036] Preferably, in the step one, the waste lithium battery discharge device is provided with an opening on the top surface of the salt water pool and an openable and closable cover, the top side wall of the salt water pool is provided with an air intake port, and the air intake port is connected to the negative pressure device through an exhaust gas pipe, so that the exhaust gas generated during the salt water discharge of the waste lithium batteries can be collected and processed.

[0037] Preferably, in the step 2, a waste lithium battery storage device containing waste batteries is installed on a reaction tank of an incinerator, and the air in the incinerator is evacuated by a vacuum treatment device to place the waste lithium battery storage device and the reaction tank in the incinerator in a vacuum state.

[0038] Preferably, in step three, the crushing device is used to crush the discharged waste lithium batteries; and the filtering device is used to filter the crushed waste lithium batteries.

[0039] Preferably, in step 4, the spiral sedimentation centrifuge is connected to the output port of the magnetic separator through a conduit; the cone-bottom reaction tank adopts a steel-lined brick structure, and an agitator is arranged inside the cone-bottom reaction tank.

[0040] Embodiment 1:

[0041] The waste lithium battery is crushed to obtain positive electrode materials and other wastes. The crushed positive electrode materials are washed with water and alkali to remove organic matter and metal impurities therein. The positive electrode materials after alkali washing are placed in a high-temperature furnace for high-temperature roasting at a temperature of 700°C for 2 hours. The roasted positive electrode materials are cooled and then mechanically ground to a particle size of less than 100 meshes. A preparation method for recovering lithium nickel cobalt manganese oxide from waste lithium batteries by adding an appropriate amount of hydrochloric acid to the ground positive electrode materials.

Claims

1. A method for recovering lithium nickel cobalt manganese oxide from waste lithium batteries, characterized in that: The steps include: Step 1: crush the waste lithium batteries to obtain positive electrode materials and other waste; Step 2: Wash the crushed positive electrode material with water and alkali to remove organic matter and metal impurities; Step 3: calcining the positive electrode material after alkali washing at a high temperature of 600-800°C for 1-3 hours; Step 4: The calcined positive electrode material is cooled and then mechanically ground to a particle size of less than 100 mesh; Step 5: Add an appropriate amount of acid to the ground positive electrode material for acid leaching, add an appropriate amount of oxidant to the acid leaching solution, control the reaction temperature to 50-100°C, and the acid leaching time to 1-3 hours; Step 6: performing solid-liquid separation on the solution after acid leaching to obtain a solution containing metal ions; Step 7: Add an appropriate amount of precipitant to the solution containing metal ions, the precipitation temperature is 40-80°C, and the precipitation time is 1-3 hours; Step 8: The solid-liquid separation after precipitation is carried out to obtain a lithium nickel cobalt manganese oxide product.

2. The method for recovering lithium nickel cobalt manganese oxide from waste lithium batteries according to claim 1, characterized in that: In the step 1, the waste lithium battery is directly contacted with a sacrificial anode to obtain a pretreatment system; then the pretreatment system is immersed in a conductive salt solution to discharge; and finally the positive and negative electrodes of the battery are led out.

3. The method for recovering lithium nickel cobalt manganese oxide from waste lithium batteries according to claim 1, characterized in that: In the step 1, the discharge is terminated when the voltage of the battery becomes stable.

4. The method for recovering lithium nickel cobalt manganese oxide from waste lithium batteries according to claim 1, characterized in that: In the step 1, an inlet is fixedly installed on the top of the crusher, and a relatively arranged crushing shaft is rotatably installed on the inner wall of the crusher.

5. The method for recovering lithium nickel cobalt manganese oxide from waste lithium batteries according to claim 1, characterized in that: In the step 1, the waste lithium battery discharge device is provided with an opening on the top surface of the salt water pool and a cover that can be opened and closed. The top side wall of the salt water pool is provided with an air intake port, and the air intake port is connected to the negative pressure device through an exhaust gas pipe. The exhaust gas generated during the salt water discharge of the waste lithium battery can be collected and processed.

6. The method for recovering lithium nickel cobalt manganese oxide from waste lithium batteries according to claim 1, characterized in that: In the step 2, the waste lithium battery storage device containing waste batteries is installed on the reaction tank of the incinerator, and the air in the incinerator is evacuated by a vacuum treatment device to make the waste lithium battery storage device and the reaction tank in the incinerator in a vacuum state.

7. The method for recovering lithium nickel cobalt manganese oxide from waste lithium batteries according to claim 1, characterized in that: In the step three, the crushing device is used to crush the discharged waste lithium batteries; and the filtering device is used to filter the crushed waste lithium batteries.

8. The method for recovering lithium nickel cobalt manganese oxide from waste lithium batteries according to claim 1, characterized in that: In the step 4, the spiral sedimentation centrifuge is connected to the output port of the magnetic separator through a conduit; the cone-bottom reaction tank adopts a steel-lined brick structure, and an agitator is arranged inside the cone-bottom reaction tank.