阅读说明：本技术 一种从废旧锂电池中提取锂的方法 (Method for extracting lithium from waste lithium batteries ) 是由 余海军 谢英豪 李爱霞 张学梅 李长东 于 2021-09-06 设计创作，主要内容包括：本发明公开了一种从废旧锂电池中提取锂的方法,将废旧锂电池的正极粉置于盐酸中进行浸出,过滤得浸出液,浸出液除去铜和铁,再通入硫化氢气体进行反应,固液分离得到第一滤渣和第一滤液,向第一滤液中加入高锰酸钾,固液分离得到第二滤渣和第二滤液,对第二滤液进行喷雾热解,得到固体颗粒,对固体颗粒进行水洗得到洗液,喷雾热解产生的尾气经水淋收集后与洗液混合得到锂盐溶液。本发明通过盐酸浸出正极粉,获得盐酸浸出液,再依次去除浸出液中的铜、铁杂质后,采用硫化氢沉淀镍钴,加入高锰酸钾,使锰离子沉淀,生成二氧化锰,最后经喷雾热解使溶液中的铝镁转化为氧化物,并分离出锂盐,整个反应过程,无需有机溶剂萃取,降低了锂的损失。(The invention discloses a method for extracting lithium from waste lithium batteries, which comprises the steps of placing anode powder of the waste lithium batteries in hydrochloric acid for leaching, filtering to obtain a leaching solution, removing copper and iron from the leaching solution, introducing hydrogen sulfide gas for reaction, carrying out solid-liquid separation to obtain first filter residue and first filtrate, adding potassium permanganate into the first filtrate, carrying out solid-liquid separation to obtain second filter residue and second filtrate, carrying out spray pyrolysis on the second filtrate to obtain solid particles, washing the solid particles to obtain washing liquid, and mixing tail gas generated by the spray pyrolysis with the washing liquid to obtain a lithium salt solution after water spraying and collecting. According to the invention, the anode powder is leached by hydrochloric acid to obtain a hydrochloric acid leaching solution, copper and iron impurities in the leaching solution are sequentially removed, then, nickel and cobalt are precipitated by hydrogen sulfide, potassium permanganate is added to precipitate manganese ions to generate manganese dioxide, finally, aluminum and magnesium in the solution are converted into oxides by spray pyrolysis, and lithium salts are separated out.)

1. A method for extracting lithium from waste lithium batteries is characterized by comprising the following steps:

s1: placing the anode powder of the waste lithium battery in hydrochloric acid for leaching, and filtering to obtain a leaching solution;

s2: removing copper and iron from the leachate, introducing hydrogen sulfide gas for reaction, and performing solid-liquid separation to obtain first filter residue and first filtrate;

s3: adding potassium permanganate into the first filtrate, and carrying out solid-liquid separation to obtain a second filter residue and a second filtrate;

s4: and carrying out spray pyrolysis on the second filtrate to obtain solid particles, washing the solid particles to obtain washing liquor, and mixing the tail gas generated by the spray pyrolysis with the washing liquor to obtain a lithium salt solution after water leaching and collection.

2. The method as claimed in claim 1, wherein in step S1, the concentration of hydrochloric acid is 1.0-6.0mol/L, and the solid-to-liquid ratio of positive electrode powder to hydrochloric acid is 100-250 g/L.

3. The method as claimed in claim 1, wherein in step S2, the process of removing copper and iron is: adding iron powder into the leachate for replacement reaction, adding an oxidant after the reaction is finished, adjusting the pH value to 3.5-4.0, and carrying out solid-liquid separation to remove copper and iron residues.

4. The method according to claim 3, wherein in step S2, the molar ratio of the amount of the iron powder added to the content of the copper ions in the leachate is (1.0-1.1): 1.

5. the method of claim 3, wherein in step S2, the pH is adjusted by using calcium carbonate.

6. The method as claimed in claim 1, wherein the pressure of the hydrogen sulfide in step S2 is 200kPa to 300 kPa; preferably, the temperature for introducing hydrogen sulfide gas to carry out the reaction is 65-125 ℃.

7. The method of claim 1, wherein in step S2, the first filter residue is nickel cobalt sulfide precipitate, and the nickel cobalt sulfide precipitate is dissolved by sulfuric acid to obtain nickel sulfate and cobalt sulfate solution.

8. The method of claim 1, wherein in step S3, the potassium permanganate is added titratively until no more precipitate is formed.

9. The method as claimed in claim 1, wherein the temperature of the spray pyrolysis is 600 ℃ and 1350 ℃ and the pressure of the carrier gas is 0.1-0.3MPa in step S4.

10. The method of claim 1, wherein in step S4, carbonate is added to the lithium salt solution to perform a reaction, and lithium carbonate is precipitated; preferably, the temperature of the reaction is 80-95 ℃.

Technical Field

The invention belongs to the technical field of lithium battery recovery, and particularly relates to a method for extracting lithium from waste lithium batteries.

Background

The ternary lithium ion battery has the characteristics of good safety, high energy density, environmental protection, good electrochemical performance and the like, and is widely applied to the fields of electronic products, mobile power supplies and new energy automobiles. However, after the battery is charged and discharged for many times, the active material in the battery loses activity, so that the capacity of the battery is reduced and the battery is scrapped. With the widespread use of lithium ion batteries, a large amount of waste batteries must be brought, if the waste batteries are discarded at will, the environment is seriously polluted, and meanwhile, the anode material contains various precious and rare metals such as nickel, cobalt, lithium and the like. Wherein, Ni and Co are non-ferrous metals with higher value, the highest price of the Ni element can reach 40 ten thousand yuan/ton, the highest price of the cobalt can also reach 37 ten thousand yuan/ton, so that the recovery of the waste lithium ion battery is not only green and environment-friendly, but also has rich return. Therefore, it is important to select an appropriate method for treating the waste batteries from the viewpoint of environmental protection and resource recycling.

At present, much research is carried out on the recovery of valuable metals in waste lithium ion batteries, and the more traditional recovery method is to adopt an acid leaching process, firstly, the waste lithium ion batteries need to be disassembled to obtain anode powder, then, the valuable metals are leached by strong acid, and oxidants such as H are utilized to recover the valuable metals₂O₂Reducing agent Na₂SO₃Treating, purifying, and extracting with solutionThe process of (a) obtains pure solutions of Ni, Co and Mn salts. And finally, recovering metals through element separation or adding a certain amount of nickel sulfate, cobalt sulfate and manganese sulfate solution in proportion to form the mother solution of the precursor of the regenerated anode material. Although the method has simple process, the efficiency is very low, a large amount of waste water is generated, the environment is polluted, and the problem of low Li recovery rate exists. On the other hand, the battery material has high requirements on the content of impurities, the waste lithium ion battery contains elements such as iron, aluminum, copper, magnesium and the like, and leachate needs to be purified in the process of recovering valuable metals in the battery. At present, a method for separating and recovering metals one by one is adopted, the process is longer, the cost is high, and the extracting agent has the extraction capacity on lithium, so that the recovery rate of the lithium is reduced. If the leachate is directly used as a precursor of the cathode material, the recovery of lithium cannot be considered. Therefore, on the premise of ensuring complete recovery of nickel, cobalt and manganese, the recovery rate of lithium needs to be improved at the same time.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art described above. Therefore, the invention provides a method for extracting lithium from waste lithium batteries.

According to one aspect of the present invention, a method for extracting lithium from waste lithium batteries is provided, which comprises the following steps:

s1: placing the anode powder of the waste lithium battery in hydrochloric acid for leaching, and filtering to obtain a leaching solution;

s2: removing copper and iron from the leachate, introducing hydrogen sulfide gas for reaction, and performing solid-liquid separation to obtain first filter residue and first filtrate;

s3: adding potassium permanganate into the first filtrate, and carrying out solid-liquid separation to obtain a second filter residue and a second filtrate;

s4: and carrying out spray pyrolysis on the second filtrate to obtain solid particles, washing the solid particles to obtain washing liquor, and mixing the tail gas generated by the spray pyrolysis with the washing liquor to obtain a lithium salt solution after water leaching and collection.

In some embodiments of the invention, in step S1, the concentration of hydrochloric acid is 1.0-6.0mol/L, and the solid-to-liquid ratio of the positive electrode powder to the hydrochloric acid is 100-250 g/L.

In some embodiments of the invention, hydrogen peroxide is also added to participate in the leaching in step S1. The leaching rate can be improved.

In some embodiments of the invention, in step S2, the process of removing copper and iron is: adding iron powder into the leachate for replacement reaction, adding an oxidant after the reaction is finished, adjusting the pH value to 3.5-4.0, and carrying out solid-liquid separation to remove copper and iron residues.

In some preferred embodiments of the present invention, in step S2, the molar ratio of the addition amount of the iron powder to the content of the copper ions in the leachate is (1.0-1.1): 1.

in some preferred embodiments of the present invention, in step S2, the pH adjustment is performed using calcium carbonate. The calcium carbonate is cheap, and can remove fluoride ions and phosphate radicals while adjusting the pH.

In some preferred embodiments of the present invention, in step S2, the oxidizing agent is one or more of chlorine, hydrogen peroxide, or nitric acid.

In some embodiments of the present invention, the pressure of the hydrogen sulfide in step S2 is 200kPa to 300 kPa; preferably, the temperature for introducing hydrogen sulfide gas to carry out the reaction is 65-125 ℃.

In some embodiments of the invention, in step S2, the first filter residue is nickel cobalt sulfide precipitate, and the nickel cobalt sulfide precipitate is dissolved in sulfuric acid to obtain a nickel sulfate solution and a cobalt sulfate solution, which can be used as a precursor solution.

In some embodiments of the invention, in step S3, the potassium permanganate is added titratively until no more precipitate is formed.

In some embodiments of the present invention, in step S4, the temperature of the spray pyrolysis is 600-1350 ℃, and the pressure of the carrier gas is 0.1-0.3 MPa.

In some embodiments of the present invention, in step S4, carbonate is added to the lithium salt solution to perform a reaction, so as to obtain a lithium carbonate precipitate; preferably, the temperature of the reaction is 80-95 ℃. Lithium carbonate is used as a lithium source for the positive electrode material. Further, the lithium carbonate precipitate is further refined and purified.

According to a preferred embodiment of the present invention, at least the following advantages are provided:

1. according to the invention, the waste battery anode powder is leached by hydrochloric acid to obtain hydrochloric acid leachate, copper and iron impurities in the leachate are sequentially removed, then, nickel and cobalt are precipitated by hydrogen sulfide, potassium permanganate is added to precipitate manganese ions to generate manganese dioxide, and finally, aluminum and magnesium in the solution are converted into oxides by spray pyrolysis, and lithium salts are separated out. In order to ensure the smooth proceeding of the subsequent spray pyrolysis, the invention adopts hydrochloric acid to leach the anode powder, because the leachate contains magnesium and aluminum, and a common organic extractant cannot be separated, hydrogen sulfide is selected to precipitate nickel and cobalt, potassium permanganate is selected to oxidize manganese ions to prepare manganese dioxide, finally spray pyrolysis is adopted, and the aluminum chloride and the magnesium chloride are thermally decomposed into oxides by utilizing the characteristic that hydrogen chloride and lithium chloride are volatile.

2. The method has the advantages of short process flow and low production cost, omits the extraction process of an organic solvent, avoids the loss of lithium and improves the yield of the lithium in the leaching solution.

Drawings

The invention is further described with reference to the following figures and examples, in which:

FIG. 1 is a schematic process flow diagram of example 1 of the present invention.

Detailed Description

The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.

Example 1

A method for extracting lithium from waste lithium batteries is disclosed, referring to FIG. 1, and the specific process is as follows:

(1) leaching: putting 100g of waste lithium battery anode powder into 1L of hydrochloric acid with the concentration of 6.0mol/L, adding 100mL of hydrogen peroxide for leaching for 5 hours, and filtering to obtain leachate and carbon black residue after the reaction is finished;

detecting the leaching solution:

(2) reduction and replacement: adding iron powder into the leachate obtained in the step (1), wherein the molar ratio of the addition amount of the iron powder to the content of copper ions in the leachate is 1.1: 1;

(3) oxidizing hydrolysis: after the reaction in the step (2) is finished, adding chlorine and calcium carbonate to adjust the pH to 3.5-4.0, and performing solid-liquid separation to obtain copper-iron slag and filtrate;

(4) nickel cobalt sedimentation: introducing hydrogen sulfide gas with the pressure of 200kPa into the filtrate obtained in the step (3) at the temperature of 65-70 ℃ until nickel and cobalt are completely precipitated, and after solid-liquid separation, respectively preparing nickel and cobalt sulfide precipitate and lithium-enriched filtrate;

(5) oxidation titration: titrating and adding potassium permanganate into the lithium-rich filtrate obtained in the step (4) until no precipitate is generated (namely the solution is not colorless after stirring), and separating out manganese dioxide precipitate;

(6) spray pyrolysis: carrying out spray pyrolysis on the filtrate remained in the step (5), controlling the spray pyrolysis temperature to be 600-700 ℃ and the carrier gas pressure to be 0.1MPa, and preparing oxide solid particles;

(7) precipitating with water to collect lithium: washing the oxide generated by spray pyrolysis in the step (6) with water to obtain washing liquor, collecting tail gas generated by spray pyrolysis by water spraying, and mixing the tail gas with the washing liquor to obtain a lithium salt solution;

(8) and adding carbonate into the lithium salt solution at the temperature of 80-95 ℃, and separating to obtain precipitate, namely lithium carbonate. The lithium carbonate is refined and purified to obtain pure lithium carbonate.

The mass of lithium carbonate after purification was weighed to 31.50g, and the lithium yield was calculated to be 98.47%.

Example 2

A method for extracting lithium from waste lithium batteries comprises the following specific processes:

(1) leaching: putting 100g of waste lithium battery anode powder into 0.5L of hydrochloric acid with the concentration of 3.0mol/L, adding 800mL of hydrogen peroxide for leaching for 6h, and filtering to obtain a leaching solution and carbon black residues after the reaction is finished;

detecting the leaching solution:

(2) reduction and replacement: adding iron powder into the leachate obtained in the step (1), wherein the molar ratio of the addition amount of the iron powder to the content of copper ions in the leachate is 1.05: 1;

(3) oxidizing hydrolysis: after the reaction in the step (2) is finished, adding hydrogen peroxide and calcium carbonate to adjust the pH to 3.5-4.0, and performing solid-liquid separation to obtain copper-iron slag and filtrate;

(4) nickel cobalt sedimentation: introducing hydrogen sulfide gas with the pressure of 300kPa into the filtrate obtained in the step (3) at the temperature of 80-90 ℃ until nickel and cobalt are completely precipitated, and after solid-liquid separation, respectively preparing nickel and cobalt sulfide precipitate and lithium-enriched filtrate;

(5) oxidation titration: titrating and adding potassium permanganate into the lithium-rich filtrate obtained in the step (4) until no precipitate is generated (namely the solution is not colorless after stirring), and separating out manganese dioxide precipitate;

(6) spray pyrolysis: carrying out spray pyrolysis on the filtrate remained in the step (5), controlling the spray pyrolysis temperature to be 800-900 ℃ and the carrier gas pressure to be 0.2MPa, and preparing oxide solid particles;

(7) precipitating with water to collect lithium: washing the oxide generated by spray pyrolysis in the step (6) with water to obtain washing liquor, collecting tail gas generated by spray pyrolysis by water spraying, and mixing the tail gas with the washing liquor to obtain a lithium salt solution;

(8) and adding carbonate into the lithium salt solution at the temperature of 80-95 ℃, and separating to obtain precipitate, namely lithium carbonate. The lithium carbonate is refined and purified to obtain pure lithium carbonate.

The mass of lithium carbonate weighed 31.93g, and the lithium yield calculated was 98.18%.

Example 3

A method for extracting lithium from waste lithium batteries comprises the following specific processes:

(1) leaching: putting 100g of waste lithium battery anode powder into 0.8L of hydrochloric acid with the concentration of 1.0mol/L, adding 120mL of hydrogen peroxide for leaching for 5h, and filtering to obtain a leaching solution and carbon black residues after the reaction is finished;

detecting the leaching solution:

(2) reduction and replacement: adding iron powder into the leachate obtained in the step (1), wherein the molar ratio of the addition amount of the iron powder to the content of copper ions in the leachate is 1.1: 1;

(3) oxidizing hydrolysis: after the reaction in the step (2) is finished, adding nitric acid and calcium carbonate to adjust the pH to 3.5-4.0, and performing solid-liquid separation to obtain copper-iron slag and filtrate;

(4) nickel cobalt sedimentation: introducing hydrogen sulfide gas with the pressure of 250kPa into the filtrate obtained in the step (3) at the temperature of 85-95 ℃ until nickel and cobalt are completely precipitated, and after solid-liquid separation, respectively preparing nickel and cobalt sulfide precipitate and lithium-enriched filtrate;

(5) oxidation titration: titrating and adding potassium permanganate into the lithium-rich filtrate obtained in the step (4) until no precipitate is generated (namely the solution is not colorless after stirring), and separating out manganese dioxide precipitate;

(6) spray pyrolysis: carrying out spray pyrolysis on the filtrate remained in the step (5), controlling the spray pyrolysis temperature to be 950-;

(7) precipitating with water to collect lithium: washing the oxide generated by spray pyrolysis in the step (6) with water to obtain washing liquor, collecting tail gas generated by spray pyrolysis by water spraying, and mixing the tail gas with the washing liquor to obtain a lithium salt solution;

(8) and adding carbonate into the lithium salt solution at the temperature of 80-95 ℃, and separating to obtain precipitate, namely lithium carbonate. The lithium carbonate is refined and purified to obtain pure lithium carbonate.

The mass of lithium carbonate weighed 31.61g, and the lithium yield calculated was 97.52%.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.