阅读说明：本技术 一种锂离子电池正极粉分离锂的方法 (Method for separating lithium from lithium ion battery anode powder ) 是由 彭灿 陈亮 周曜 顾才国 赵海峰 刘志 周鑫柱 胡泽星 张臻 于 2020-07-07 设计创作，主要内容包括：本发明提出了一种锂离子电池正极粉分离锂的方法,属于锂离子电池材料回收技术领域。本发明所述的方法,锂离子电池正极粉在无特殊气氛要求的条件下与硫化物分阶段焙烧,将有价金属转化成为相应氧化物,锂以硫酸锂和单质锂的形态存在。经过水浸后,锂以硫酸锂和氢氧化锂形式进入溶液中,而其它有价金属以氧化物形态留在浸出渣中,达到锂与正极粉其它有价金属的分离。本发明所述的方法操作流程简单,成本低,安全性强。(The invention provides a method for separating lithium from lithium ion battery anode powder, and belongs to the technical field of lithium ion battery material recovery. According to the method, the lithium ion battery anode powder and the sulfide are roasted in stages under the condition of no special atmosphere requirement, valuable metals are converted into corresponding oxides, and lithium exists in the forms of lithium sulfate and simple substance lithium. After water leaching, lithium enters the solution in the form of lithium sulfate and lithium hydroxide, and other valuable metals are left in leached residues in the form of oxides, so that the lithium is separated from other valuable metals of the anode powder. The method has the advantages of simple operation process, low cost and strong safety.)

1. A method for separating lithium from lithium ion battery anode powder comprises the following steps:

step S1, pulping the anode powder obtained after the lithium ion battery is disassembled and sulfide, and performing filter pressing to obtain a premixed wet blank;

step S2, roasting the premixed wet blank;

step S3, mixing the material roasted in the step S2 with auxiliary materials to form a primary roasted premixed blank;

step S4, roasting the primary roasting premixed blank;

step S5, crushing the roasted material obtained in the step S4 and leaching the crushed material with water;

and step S6, filtering after leaching is finished, wherein lithium enters the solution in the form of lithium sulfate and lithium hydroxide, and other valuable metals are left in the leaching residue in the form of oxides.

2. The method for separating lithium from lithium ion battery cathode powder according to claim 1, wherein the sulfide obtained in step S1 is obtained in a wastewater recovery process.

3. The method for separating lithium from the lithium ion battery positive electrode powder according to claim 1 or 2, wherein in step S1, the positive electrode powder obtained by disassembling the lithium ion battery and the sulfide are mixed according to a mass ratio of 1: 0.1-1, adding into a pulping tank, pulping with water, and controlling the liquid-solid ratio to be 1: 1-10, stirring for 0.5-2 hours at the temperature of 30-75 ℃, and performing filter pressing to obtain a premixed wet blank.

4. The method for separating lithium from lithium ion battery anode powder according to claim 1, wherein in step S2, the air inlet amount of the baking furnace is controlled to be 3-20m during the baking process³The material is roasted for 1 to 4 hours at the temperature of 450-600 ℃, then the temperature is raised to 750-850 ℃ for roasting for 1 to 4 hours, and then the temperature is raised to 900-980 ℃ for roasting for 1 to 4 hours.

5. The method for separating lithium from lithium ion battery cathode powder according to claim 1, wherein the auxiliary material in step S3 is one or more of iron oxide, nickel thiosulfate, sodium thiosulfate and industrial sodium sulfide.

6. The method for separating lithium from the lithium ion battery anode powder according to claim 1 or 5, wherein in step S3, the mass ratio of the material roasted in step S2 to the auxiliary material is 1: 0.05-1 of crushing and mixing to form a primary roasting premixing blank.

7. The method for separating lithium from lithium ion battery cathode powder according to claim 1, wherein in step S4, the air inlet amount of the baking furnace is controlled to be 3-20m during the baking process³And/h, roasting at the temperature of 800-950 ℃ for 1-4 hours.

8. The method for separating lithium from the lithium ion battery anode powder according to claim 1, wherein in step S5, the calcined material obtained in step S4 is crushed to be less than-100 meshes.

Technical Field

The invention relates to the technical field of lithium ion battery material recovery, in particular to a method for separating lithium from lithium ion battery anode powder.

Background

The lithium ion battery is popular with manufacturers of various electronic products due to excellent service performance, such as high voltage, large specific capacity, no memory effect and the like, and the output is increased year by year. China is a world-wide country for producing and consuming lithium ion batteries, and the battery consumption is as high as billions each year. In the process of consumption, waste lithium batteries are inevitably produced. The recycling of the waste lithium batteries is beneficial to saving resources and avoiding environmental pollution, and meanwhile, the waste lithium batteries also have great economic value.

In the process of recovering the lithium ion battery, at present, the separation of the anode powder disassembled from the lithium ion battery and valuable metals is mainly two treatment methods. One is to roast with hydrogen or sulfuric acid, sulfate at high temperature, reduce lithium and sulfation transformation, then soak in water, lithium enters into solution, other valuable metal remains in the slag, achieve the purpose of lithium and other valuable metal separation; the other method is to directly perform acid leaching on the decomposed substance, then convert valuable metals into corresponding salts or mixed salts by methods of impurity removal or extraction and the like, and the lithium is left in the solution to exist in forms of lithium sulfate, lithium chloride and the like, so as to achieve the separation of the lithium and other valuable metals.

In the first method, because hydrogen and other reducing gases or other substances are used, the reducing atmosphere needs to be strictly controlled in the reducing roasting process, the operation difficulty is high, the energy consumption is high, certain dangerousness is realized, and the reduction degree and the reduction effect are greatly influenced by materials. The second method has a long whole flow, and the consumption of auxiliary materials is large because lithium and valuable metals are leached together in the early stage. The chemical method for removing impurities is needed in the process, so that the loss of valuable metals and lithium is large, and the production cost is high.

Disclosure of Invention

Aiming at the problems in the prior art, the technical problems to be solved by the invention are as follows: the method for separating lithium from the lithium ion battery anode powder is easy to control the process and low in production cost.

Specifically, the invention provides the method for preparing the anode powder obtained after the disassembly of the lithium ion battery, the anode powder is roasted under the condition of no special atmosphere, valuable metals are converted into corresponding oxides, and lithium exists in the forms of lithium sulfate and simple substance lithium. After water leaching, lithium enters the solution in the form of lithium sulfate and lithium hydroxide, and other valuable metals are left in leached residues in the form of oxides, so that the aim of separating the lithium from other valuable metals of the anode powder is fulfilled.

The solution of the invention is realized by the following steps:

a method for separating lithium from lithium ion battery anode powder comprises the following steps:

step S1, pulping the anode powder obtained after the lithium ion battery is disassembled and sulfide, and performing filter pressing to obtain a premixed wet blank;

step S2, roasting the premixed wet blank;

step S3, mixing the material roasted in the step S2 with auxiliary materials to form a primary roasted premixed blank;

step S4, roasting the primary roasting premixed blank;

step S5, crushing the roasted material obtained in the step S4 and leaching the crushed material with water;

and step S6, filtering after leaching is finished, wherein lithium enters the solution in the form of lithium sulfate and lithium hydroxide, and other valuable metals are left in the leaching residue in the form of oxides.

Further, the sulfide described in step S1 is recovered from the waste water.

Further, in step S1, the anode powder obtained by disassembling the lithium ion battery and the sulfide are mixed in a mass ratio of 1: 0.1-1, adding into a pulping tank, pulping with water, and controlling the liquid-solid ratio to be 1: 1-10, stirring for 0.5-2 hours at the temperature of 30-75 ℃, and performing filter pressing to obtain a premixed wet blank.

Further, step S2, roasting the primary roasting premixed blank in a roasting furnace, wherein the air inlet amount of the roasting furnace is controlled to be 3-20m in the roasting process³The material is roasted for 1 to 4 hours at the temperature of 450-600 ℃, then the temperature is raised to 750-850 ℃ for roasting for 1 to 4 hours, and then the temperature is raised to 900-980 ℃ for roasting for 1 to 4 hours.

The main reactions involved in step S2 are as follows:

（Ni、Co、Mn、Zn）S+O₂→（Ni、Co、Mn、Zn）O+SO₂↑

Li（Ni、Co、Mn）O₂+ SO₂+O₂→Li+Li₂SO₄+（Ni、Co、Mn）SO₄

（Ni、Co、Mn、Zn）O+SO₂+O₂→（Ni、Co、Mn）SO₄

（Ni、Co、Mn）SO₄→（Ni、Co、Mn）O+SO₂↑

further, the auxiliary material in step S3 is one or more of iron oxide, nickel thiosulfate, sodium thiosulfate, and industrial sodium sulfide.

Further, the material roasted in the step S2 and the auxiliary materials are mixed in a mass ratio of 1: 0.05-1 of crushing and mixing to form a primary roasting premixing blank.

Further, in step S4, the air inlet amount of the roasting furnace is controlled to be 3-20m during the roasting process³And/h, roasting at the temperature of 800-950 ℃ for 1-4 hours.

The main reaction process involved in step S4 is as follows:

S+O₂→SO₂↓ (sulphur in industrial sodium sulfide)

Na₂S+O₂→Na₂SO₃

Na₂S₂O₃→Na₂SO₄+SO₂↑

NiS₂O₃→NiSO₄+SO₂↑

Fe₂O₃+SO₂→FeSO₄

FeSO₄→SO₃↑+FeO

Li（Ni、Co、Mn）O₂+SO₃→Li₂SO₄+（Ni、Co、Mn）SO₄

Li（Ni、Co、Mn）O₂+Na₂SO₃→Li+Na₂SO₄+（Ni、Co、Mn）O

Li（Ni、Co、Mn）O₂+SO₂+O₂→Li+Li₂SO₄+（Ni、Co、Mn）O

（Ni、Co、Mn）SO₄→（Ni、Co、Mn）O+SO₂↑

Further, in step S5, the roasted material obtained in step S4 is crushed to be smaller than-100 meshes.

According to the invention, the anode powder obtained after the lithium ion battery is disassembled and the sulfide obtained by wastewater recovery are roasted for multiple times in stages, lithium is converted into water-soluble simple substance lithium and lithium sulfate, the water-soluble simple substance lithium and lithium sulfate enter the leaching solution, and other valuable metals are retained in slag in the form of oxides. The leaching solution has low impurity and high purity. The leached slag contains lithium less than 0.1%, and can realize effective separation of lithium and valuable metals, and the separation degree is high.

The invention also has the following advantages:

1. sulfides obtained by wastewater recovery are fully utilized, resources are effectively utilized, and the cost is saved;

2. the consumption of auxiliary materials is low, the flow is short, and the safety is high;

3. the roasting process does not need atmosphere environment with higher danger or stronger pollution, the operation is simple, and the tail gas generated in the process only needs simple leaching.

Detailed Description

The invention is described in detail below, and the description in this section is merely exemplary and explanatory and should not be construed as limiting the scope of the invention in any way. Furthermore, features from embodiments in this document and from different embodiments may be combined accordingly by a person skilled in the art from the description in this document.