Method and device for extracting lithium from waste battery positive electrode material

Abstract

The invention provides a method and device for extracting lithium from a waste battery positive electrode material, and relates to the technical field of waste battery recovery. The method for extracting lithium from the waste battery positive electrode material comprises the following steps: mixing the waste battery positive electrode material, industrial acid, a sulfur-containing catalyst and water to obtain a to-be-reacted system; according to the method, the recovery rate of lithium is increased, leaching of other metal elements is reduced, and follow-up purification of lithium is facilitated.

Description

Technical Field

[0001] This application belongs to the technical field of waste battery recycling. Specifically, it relates to a method and device for extracting lithium from waste battery cathode materials. Background Art

[0002] With the development of 3C devices and electric vehicles, the number of waste ternary batteries has been increasing year by year. It is urgent to recycle waste ternary batteries to achieve resource recycling and reuse. Waste ternary batteries need to be discharged first to ensure safety, and then disassembled to separate the coating on the positive electrode in the battery (i.e., waste battery cathode material). The waste battery cathode material contains various valuable metal elements, such as lithium (Li), nickel (Ni), cobalt (Co), manganese (Mn), etc., and valuable metal elements need to be extracted from it in the subsequent recycling process. At present, most of them use acid and reducing agents for full-component reduction leaching, chemical impurity removal, and sequential extraction of nickel, cobalt, and manganese metals. Lithium metal can only be recovered at the end. Part of the lithium is lost during chemical impurity removal and extraction, and at the same time, the consumption of auxiliary materials is large, resulting in increased costs. Summary of the Invention

[0003] The main purpose of this application is to provide a method and device for extracting lithium from waste battery cathode materials to solve the problems of low lithium recovery rate and high cost in existing waste battery cathode materials.

[0004] To achieve the above object, in the first aspect of this application, a method for extracting lithium from waste battery cathode materials is provided, including the following steps: mixing waste battery cathode materials, industrial acid, sulfur-containing catalyst, and water to obtain a reaction system to be reacted; making the water in the reaction system to be reacted in a subcritical state and performing leaching treatment to obtain a lithium-containing leaching solution.

[0005] Further, the industrial acid includes sulfuric acid.

[0006] Preferably, the sulfur-containing catalyst includes sulfur and / or sulfide.

[0007] Preferably, the sulfide includes at least one of nickel sulfide, cobalt sulfide, and manganese sulfide.

[0008] Preferably, the sulfur-containing catalyst is nickel matte, and the mass content of nickel in the nickel matte is 60% - 80%, and the mass content of sulfur is 15% - 30%.

[0009] Further, the mass ratio of the sulfur-containing catalyst to the waste battery cathode material is (0.5 - 2):100.

[0010] Further, the molar ratio of lithium ions in the waste battery cathode material to hydrogen ions in the industrial acid is (0.95 - 1.0):1.

[0011] Further, first mix the waste battery cathode material with water to obtain a slurry; add industrial acid and a sulfur-containing catalyst to the slurry to obtain a reaction system to be treated; control the temperature of the reaction system to be treated at 200°C to 250°C and the saturated vapor pressure at 1.55 MPa to 3.97 MPa so that the water therein is in a subcritical state.

[0012] Further, the concentration of the waste battery cathode material in the slurry is 150 g / L to 350 g / L; preferably, the leaching treatment time is 4 h to 12 h.

[0013] Further, the waste battery cathode material is obtained by disassembling, crushing, and sorting waste ternary batteries;

[0014] Preferably, the chemical formula of the waste battery cathode material is Li(Ni x Co y Mn z )O2, where x + y + z = 1, 0 < x < 1, 0 < y < 1, 0 < z < 1.

[0015] Preferably, by mass content, the waste battery cathode material includes: 6% to 7.5% of Li element, 30% to 55% of Ni element, 0.5% to 14% of Co element, and 0.5% to 20% of Mn element.

[0016] Further, the mass concentration of lithium ions in the lithium-containing leachate > 17 g / L, and the leaching rate of lithium element ≥ 95%.

[0017] In the second aspect of the present application, there is provided a device for extracting lithium from a waste battery cathode material, which is used to execute the method provided in the first aspect. The device includes:

[0018] A reaction vessel for providing an environment for leaching treatment;

[0019] A water storage tank for storing water;

[0020] An acid storage tank for storing industrial acid;

[0021] A raw material bin for storing waste battery cathode material;

[0022] An auxiliary material bin for storing a sulfur-containing catalyst;

[0023] Among them, the outlet of the water storage tank, the outlet of the acid storage tank, the outlet of the raw material bin, and the outlet of the auxiliary material bin are each independently connected to the inlet of the reaction vessel.

[0024] Further, the device further includes an acid addition coil for adding industrial acid into the reaction vessel.

[0025] Preferably, the acid-adding coil pipe is embedded in the top of the reaction vessel. The outlet of the acid storage tank is connected to the inlet of the acid-adding coil pipe, and the outlet of the acid-adding coil pipe is connected to the inlet of the reaction vessel.

[0026] Preferably, a plurality of holes are provided at the outlet of the acid-adding coil pipe.

[0027] Preferably, a temperature and pressure jacket is provided on the outer periphery of the reaction vessel for real-time monitoring of the temperature and pressure inside the reaction vessel.

[0028] Applying the technical solution of the present application, by utilizing the special properties of subcritical water and combining with the use of a sulfur-containing catalyst, under the combined action of subcritical water and the sulfur-containing catalyst, the leaching efficiency of lithium is significantly improved, not only the recovery rate of lithium is increased, but also the leaching of other metal elements is reduced, which is beneficial to the subsequent purification of lithium. At the same time, this method reduces energy consumption and environmental pollution, is easy to operate, and is easy to realize industrial production, which is conducive to the resource utilization of waste batteries. Description of the Drawings

[0029] The specification drawings forming a part of the present application are used to provide a further understanding of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0030] Figure 1 It is a schematic diagram of a device for extracting lithium from a waste battery cathode material in an embodiment of the present application.

[0031] Description of the Reference Numerals:

[0032] 1 - water storage tank; 2 - acid storage tank; 3 - raw material bin; 4 - auxiliary material bin; 5 - reaction vessel; 6 - acid-adding coil pipe; 7 - temperature and pressure jacket. Detailed Embodiments

[0033] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the embodiments.

[0034] As described in the background art, the existing waste battery cathode materials have the problems of low lithium recovery rate and high cost. To solve the above technical problems, the present application provides a method for extracting lithium from waste battery cathode materials, including the following steps: mixing waste battery cathode materials, industrial acid, sulfur-containing catalyst and water to obtain a reaction system to be reacted; making the water in the reaction system to be reacted in a subcritical state and performing leaching treatment to obtain a lithium-containing leaching solution.

[0035] During the leaching process, all the lithium elements in the spent battery cathode material are converted into lithium salts that are easily soluble in water, while the transition metal elements are all retained in the form of oxides insoluble in water. After the leaching process, the lithium-containing leachate can be separated from the reaction solution by physical separation methods such as filtration. The obtained lithium-containing leachate may still need to undergo a series of chemical and physical treatment steps, such as precipitation, extraction, evaporation crystallization, etc., to further purify lithium and convert it into a high-concentration lithium-containing solution or solid lithium compound, which is convenient for subsequent metal recovery and utilization.

[0036] Among them, the role of the industrial acid is to provide H + , promote the dissolution of lithium, and the properties of subcritical water change, its dissolution ability is enhanced, and it can promote the extraction of lithium under the combined action of a sulfur-containing catalyst, while controlling the leaching amount of other metals and improving the selectivity of leaching. Specifically, under the action of subcritical water, lithium ions are more likely to dissociate from the cathode material and enter the solution. At the same time, the addition of the catalyst promotes the H + and Li + exchange reaction, as well as redox reactions, further improving the recovery rate and purity of lithium.

[0037] In the method provided by this application, lithium in the spent battery cathode material can be efficiently and selectively recovered, while controlling and reducing the leaching of other metals, so as to obtain a high-purity and high-concentration lithium-containing solution, providing a scientific and effective way for the recycling of lithium resources. In addition, the method provided by this application is simple to operate and has low energy consumption, which is beneficial to cost reduction.

[0038] In some embodiments, the industrial acid includes sulfuric acid. By using sulfuric acid, the leaching rate of lithium can be further improved. Specifically, the sulfuric acid in this application refers to industrial sulfuric acid with a mass concentration of 98%.

[0039] In some embodiments, the sulfur-containing catalyst includes sulfur and / or sulfide, where the sulfide includes at least one of nickel sulfide, cobalt sulfide, and manganese sulfide. For example, the sulfur-containing catalyst is matte nickel, and the mass content of nickel in matte nickel is 60% - 80%, and the mass content of sulfur is 15% - 30%. By using matte nickel as the catalyst, the leaching of other metal elements except lithium can be further controlled, which is beneficial to the subsequent lithium purification process.

[0040] Specifically, matte nickel refers to a sulfide intermediate product containing a high concentration of nickel. It is usually a product in the pyrometallurgical process of nickel sulfide ore. Specifically, it is a nickel-containing sulfide mixture obtained by smelting and converting nickel sulfide ore and removing some impurities (such as iron, copper, etc.).

[0041] This application uses nickel matte as a catalyst to help improve the leaching rate and selectivity of lithium. At the same time, by utilizing its own characteristics in redox reactions, it reacts with oxygen in the hydrothermal process to generate sulfate or sulfur dioxide. These products help to further promote the leaching of lithium, while having relatively low corrosivity to equipment and less environmental impact.

[0042] In some embodiments, the mass ratio of the sulfur-containing catalyst to the cathode material of waste batteries is (0.5 - 2):100, which also means that the sulfur-containing catalyst is 0.5% - 2% of the mass of the cathode material of waste batteries, such as 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2% or the range composed of any two of them. By limiting the addition amount of the sulfur-containing catalyst, it is possible to ensure efficient leaching of lithium while avoiding additional costs and environmental problems caused by excessive catalyst.

[0043] In some embodiments, the molar ratio of lithium ions in the cathode material of waste batteries to hydrogen ions in industrial acid is (0.95 - 1.0):1, such as 0.95:1, 0.96:1, 0.97:1, 0.98:1, 0.99:1, 1.0:1 or the range composed of any two of them. By limiting the molar ratio of lithium ions in the cathode material of waste batteries to hydrogen ions in industrial acid, essentially the addition amount of industrial acid is limited. By controlling the molar ratio within the above range, the leaching efficiency of lithium can be maximized while reducing the consumption of acid, which helps to further reduce costs.

[0044] This application can make water reach the subcritical state by heating and pressurizing. In some embodiments, first mix the cathode material of waste batteries with water to obtain a slurry; add industrial acid and a catalyst to the slurry to obtain a reaction system to be processed; control the temperature of the reaction system to be processed at 200°C - 250°C and the saturated vapor pressure at 1.55 MPa - 3.97 MPa, so that the water therein is in the subcritical state. By limiting the above temperature and pressure conditions, the water therein can be maintained in the subcritical state, making it have good solvent properties, capable of effectively leaching lithium while reducing the leaching of other metals.

[0045] In some embodiments, the concentration of the cathode material of waste batteries in the slurry is 150 g / L - 350 g / L, and the leaching treatment time is 4 h - 12 h. By controlling the mass concentration of the cathode material of waste batteries and the leaching time within the above range, it is possible to ensure sufficient leaching of lithium while improving the treatment efficiency.

[0046] The cathode material of waste batteries can be obtained by pretreating waste batteries, such as discharging, disassembling, crushing, sorting, etc., to ensure safety and improve the recycling efficiency. In some embodiments, the cathode material of waste batteries is obtained by disassembling, crushing, and sorting waste ternary batteries. The chemical formula of the cathode material of waste batteries is Li(Nix Co y Mn z )O₂, where x + y + z = 1, 0 < x < 1, 0 < y < 1, 0 < z < 1.

[0047] In some embodiments, by mass content, the cathode material of waste batteries includes: 6% - 7.5% of Li element, 30% - 55% of Ni element, 0.5% - 14% of Co element, and 0.5% - 20% of Mn element. During the leaching process, under the combined action of subcritical water and a catalyst, it promotes H + to exchange Li in the cathode material of waste batteries + , and the slag transforms from lithium nickel cobalt manganese to nickel cobalt manganese hydroxide, and the solution transforms into a lithium-containing leaching solution with high concentration and low impurities.

[0048] Specifically, when the cathode material of waste batteries is the cathode material of waste ternary batteries, during the leaching process, a sulfur-containing catalyst (MeS and / or S) is used as a catalyst, which helps to promote H + to exchange Li in the cathode material of waste batteries + , so that the cathode material of waste batteries transforms into nickel cobalt manganese hydroxide without destroying its lattice form during the process.

[0049] In some embodiments, the mass concentration of lithium ions in the lithium-containing leaching solution > 17 g / L, the leaching rate of lithium element ≥ 95%, and the leaching rate of other elements < 4%. It shows that the method provided by the present application can efficiently recover lithium while controlling the leaching of other metal elements, providing favorable conditions for subsequent lithium purification.

[0050] In the second aspect of the present application, a device for extracting lithium from the cathode material of waste batteries is provided, which is used to implement the method provided in the first aspect. The device includes: a reaction vessel for providing an environment for leaching treatment; a water storage tank for storing water; an acid storage tank for storing industrial acid; a raw material bin for storing the cathode material of waste batteries; an auxiliary material bin for storing a sulfur-containing catalyst; wherein, the outlets of the water storage tank, the acid storage tank, the raw material bin, and the auxiliary material bin are independently connected to the inlet of the reaction vessel. The device provided by the present application has a reasonable design and is easy to operate, can efficiently recover lithium in the cathode material of waste batteries, is suitable for waste battery recycling, and has obvious advantages especially in realizing automated and continuous production.

[0051] In some embodiments, the device further includes an acid addition coil for adding industrial acid into the reaction vessel. By introducing the acid addition coil, it can ensure the uniform distribution of acid, can achieve precise control and uniform distribution of acid, avoid equipment corrosion and resource waste caused by local over-acidity, and improve the uniformity and efficiency of the reaction at the same time.

[0052] In the specific implementation process of this application, open the water storage tank to let water flow into the reaction vessel, and then turn on the stirring of the reaction vessel; open the raw material bin and the auxiliary material bin to let the waste battery cathode material and the sulfur-containing catalyst fall into the reaction vessel through a high potential difference; open the acid storage tank to add industrial acid and let it flow into the acid addition coil, and then enter the reaction vessel.

[0053] In some embodiments, the acid addition coil is embedded in the top of the reaction vessel. The outlet of the acid storage tank is connected to the inlet of the acid addition coil, and the outlet of the acid addition coil is connected to the inlet of the reaction vessel; wherein, the outlet of the acid addition coil is provided with a plurality of holes. When the industrial acid is evenly sprayed into the reaction vessel through the plurality of holes of the acid addition coil, it can ensure that every part of the slurry contacts enough acid, promote the uniform leaching of lithium elements, and improve the leaching efficiency and selectivity.

[0054] In some embodiments, a temperature and pressure jacket is provided on the outer periphery of the reaction vessel for real-time monitoring of the temperature and pressure inside the reaction vessel, so as to ensure that the temperature of the reaction system to be reacted is 200°C to 250°C and the saturated vapor pressure is 1.55 MPa to 3.97 MPa.

[0055] The following further describes this application in detail with specific embodiments, and these embodiments should not be construed as limiting the scope claimed in this application.

[0056] In the following embodiments, a device for extracting lithium from waste battery cathode materials is used to extract lithium, as Figure 1 shown. The device includes: a reaction vessel 5 for providing an environment for leaching treatment; a water storage tank 1 for storing water; an acid storage tank 2 for storing industrial acid; a raw material bin 3 for storing waste battery cathode materials; an auxiliary material bin 4 for storing sulfur-containing catalysts; wherein, the outlet 1-5 of the water storage tank, the outlet 2-6 of the acid storage tank, the outlet 3-5 of the raw material bin, and the outlet 4-5 of the auxiliary material bin are each independently connected to the inlet of the reaction vessel; an acid addition coil 6 for adding industrial acid into the reaction vessel, the acid addition coil is embedded in the top of the reaction vessel, the outlet 2-6 of the acid storage tank is connected to the inlet of the acid addition coil 6, and the outlet of the acid addition coil is connected to the inlet of the reaction vessel; a temperature and pressure jacket 7 is provided on the outer periphery of the reaction vessel 5 for real-time monitoring of the temperature and pressure inside the reaction vessel; wherein, the outlet of the acid addition coil is provided with a plurality of holes, and when the industrial acid is evenly sprayed into the reaction vessel through the plurality of holes of the acid addition coil.

[0057] Example 1

[0058] In this example, the waste battery cathode material from a certain chemical plant is selected. By mass fraction, it includes: Li: 7.33%, Ni: 36.6%, Co: 12.5%, Mn: 11.6%.

[0059] The method for extracting lithium from the cathode material of waste batteries in this embodiment includes the following steps: Mix 250 g of the cathode material of waste batteries with 1000 mL of water for pulping, then add 129.4 g of sulfuric acid (mass concentration of 98%) and 2.5 g of sulfur and mix evenly. Put it into a 2 L high-pressure reactor, and make the water in a subcritical state at a leaching temperature of 220 °C and a saturated steam pressure of 2.2 MPa. Under this condition, after leaching for 4 h, filter and separate to obtain a lithium-containing leaching solution.

[0060] Example 2

[0061] The cathode material of waste batteries selected in this embodiment is from a certain chemical plant. By mass fraction, it includes Li: 7.33%, Ni: 36.6%, Co: 12.5%, and Mn: 11.6%.

[0062] The method for extracting lithium from the cathode material of waste batteries in this embodiment includes the following steps: Mix 250 g of the cathode material of waste batteries with 1000 mL of water for pulping, then add 129.4 g of sulfuric acid and 5 g of nickel matte and mix evenly. Put it into a 2 L high-pressure reactor, and make the water in a subcritical state at a leaching temperature of 220 °C and a saturated steam pressure of 2.2 MPa. Under this condition, after leaching for 4 h, filter and separate to obtain a lithium-containing leaching solution; among them, the mass content of nickel in the nickel matte is 75.1%, and the mass content of sulfur is 21.5%.

[0063] Example 3

[0064] The difference from Example 1 is that the leaching temperature in this embodiment is 200 °C and the saturated steam pressure is 1.55 MPa.

[0065] Example 4

[0066] The difference from Example 1 is that the leaching temperature in this embodiment is 240 °C and the saturated steam pressure is 3.35 MPa.

[0067] Example 5

[0068] The difference from Example 1 is that the leaching temperature in this embodiment is 250 °C and the saturated steam pressure is 3.97 MPa.

[0069] Comparative Example 1

[0070] The difference from Example 1 is that sulfur is not added in this comparative example.

[0071] Comparative Example 2

[0072] The difference from Example 1 is that the leaching temperature in this comparative example is 80 °C, the saturated vapor pressure is 0.1 MPa, and the water is not in a subcritical state.

[0073] Comparative Example 3

[0074] The difference from Example 1 is that in this comparative example, the leaching temperature is 170 °C, the saturated steam pressure is 0.79 MPa, and water is not in the subcritical state.

[0075] Li leaching rate (%) = mass of lithium element in lithium-containing leaching solution / mass of lithium element in waste battery cathode material × 100%;

[0076] Ni leaching rate (%) = mass of nickel element in lithium-containing leaching solution / mass of nickel element in waste battery cathode material × 100%;

[0077] Co leaching rate (%) = mass of cobalt element in lithium-containing leaching solution / mass of cobalt element in waste battery cathode material × 100%;

[0078] Mn leaching rate (%) = mass of manganese element in lithium-containing leaching solution / mass of manganese element in waste battery cathode material × 100%.

[0079] The test results are shown in Table 1.

[0080] Table 1

[0081]

[0082] According to Table 1, under the combined action of the sulfur-containing catalyst and the subcritical water system in this application, H + is more likely to exchange Li in the waste battery cathode material + , lithium is more easily leached, effectively solving the problem of selective leaching of lithium in ternary cathode powder, and a lithium leaching rate of ≥ 95% can be achieved, while the leaching rates of impurity elements such as Ni, Co, and Mn are < 3%; the example directly selectively leaches lithium by a one-step method, avoiding the disadvantages of traditional lithium recovery at the end of leaching. Compared with the existing lithium extraction technology, the leaching time and steps are shortened, and the amount of catalyst added is reduced at the same time.

[0083] It should be noted that the terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of this application described here can be implemented in an order other than those described here.

[0084] The above are only the preferred embodiments of this application and are not used to limit this application. For those skilled in the art, this application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the protection scope of this application.

Claims

1. A method for extracting lithium from the cathode material of waste batteries, characterized in that, It includes the following steps: Mix the waste battery cathode material, industrial acid, sulfur-containing catalyst and water to obtain a reaction system to be treated; make the water in the reaction system to be treated in a subcritical state and perform leaching treatment to obtain a lithium-containing leachate.

2. The method according to claim 1, wherein The industrial acid includes sulfuric acid; Preferably, the sulfur-containing catalyst includes sulfur and / or sulfide, and the sulfide includes at least one of nickel sulfide, cobalt sulfide, and manganese sulfide; Preferably, the sulfur-containing catalyst is nickel matte, and the nickel matte contains 60% - 80% by mass of nickel and 15% - 30% by mass of sulfur.

3. The method according to claim 1 or 2, characterized in that, The mass ratio of the sulfur-containing catalyst to the waste battery cathode material is (0.5 - 2):

100.

4. The method according to claim 1 or 2, characterized in that, The molar ratio of lithium ions in the waste battery cathode material to hydrogen ions in the industrial acid is (0.95 - 1.0):

1.

5. The method according to claim 1 or 2, characterized in that, First, mix the waste battery cathode material with the water to obtain a slurry; add the industrial acid and the sulfur-containing catalyst to the slurry to obtain the reaction system to be treated; control the temperature of the reaction system to be treated at 200°C - 250°C and the saturated vapor pressure at 1.55 MPa - 3.97 MPa so that the water therein is in a subcritical state.

6. The method according to claim 5, characterized in that, The concentration of the waste battery cathode material in the slurry is 150 g / L - 350 g / L; preferably, the leaching treatment time is 4 h - 12 h.

7. The method according to claim 1 or 2, characterized in that The waste battery cathode material is obtained by disassembling, crushing, and sorting waste ternary batteries; Preferably, the chemical formula of the waste battery cathode material is Li(Ni x Co y Mn z )O2, where x + y + z = 1, 0 < x < 1, 0 < y < 1, 0 ＜z＜1； Preferably, by mass content, the waste battery cathode material includes: 6% - 7.5% of Li element, 30% - 55% of Ni element, 0.5% - 14% of Co element, and 0.5% - 20% of Mn element.

8. The method according to claim 1 or 2, characterized in that The mass concentration of lithium ions in the lithium-containing leachate > 17 g / L, and the leaching rate of lithium element ≥ 95%.

9. An apparatus for extracting lithium from the cathode material of waste batteries, characterized in that, For implementing the method according to any one of claims 1 to 8, the device includes: A reaction vessel for providing an environment for leaching treatment; A water storage tank for storing water; An acid storage tank for storing industrial acid; A raw material bin for storing waste battery cathode material; An auxiliary material bin for storing sulfur-containing catalyst; Wherein, the outlets of the water storage tank, the acid storage tank, the raw material bin, and the auxiliary material bin are independently connected to the inlet of the reaction vessel.

10. The device according to claim 9, characterized in that, The device further includes an acid addition coil for adding the industrial acid into the reaction vessel; Preferably, the acid addition coil is embedded in the top of the reaction vessel, the outlet of the acid storage tank is connected to the inlet of the acid addition coil, and the outlet of the acid addition coil is connected to the inlet of the reaction vessel; Preferably, the outlet of the acid addition coil is provided with a plurality of holes; Preferably, a temperature and pressure jacket is provided on the outer periphery of the reaction vessel for real-time monitoring of the temperature and pressure inside the reaction vessel.

Images