CN114350978A - Method for extracting lithium from lithium-containing clay step by step - Google Patents

Abstract

The invention discloses a method for extracting lithium from lithium-containing clay step by step. The product after the reaction is subjected to solid-liquid separation to obtain a filtrate and a filter residue, and the filter residue is washed; S3, the filter residue washed in step S2 is mixed with acid, and then reacted and leached under a pressure of 1.5MPa; S4, the product after the reaction of step S3 is completed Carry out solid-liquid separation to obtain filtrate and filter residue, and then collect the filtrate. The invention optimizes the technological process, saves the high-temperature roasting process, greatly saves the production cost, is more environmentally friendly, can be applied to industrial production, can greatly save the cost and increase the production benefit.

Description

A step-by-step method for extracting lithium from lithium-containing clay

technical field

The invention relates to the field of lithium extraction methods, in particular to a step-by-step method for extracting lithium from lithium-containing clay.

Background technique

Lithium is the lightest metal in nature. It is widely used in emerging application fields such as battery industry, ceramic industry, glass industry, aluminum smelting industry, lubricant, refrigerant, medicine, nuclear industry and optoelectronic industry, and has extremely high strategic value. At present, the production scale of lithium extraction using domestic solid lithium ore is small and cannot meet the needs. Therefore, in recent years, the ore required by lithium production enterprises in my country mainly relies on imports, and Australia has become the main importer of lithium ore in my country.

my country's natural lithium resources are mainly brine resources, but with the depletion of lithium resources, lithium-containing clays have received more and more attention. The main advantages of lithium-containing clay are the large amount of resources, convenient mining and no need for blasting, and the cost advantage in the early stage of mining. Lithium resources in lithium-containing clay have broad development and application prospects in my country.

The "modified roasting-heap leaching" process proposed by the Henan Provincial Rock and Mineral Testing Center uses calcium sulfate, calcium fluoride, and sodium sulfate with a mass ratio of 1:0.7:0.2:0.5 as the roasting auxiliary materials and roasting at 800 ℃ for 2~ 3h, then sulfuric acid spray leaching, and finally sodium carbonate was added to precipitate lithium carbonate. This process uses calcium fluoride for roasting, and the roasting process greatly increases the production cost, and calcium fluoride exists in the roasting auxiliary materials, which brings difficulties to the later defluorination and pollutes the atmosphere.

Song Xiangyu et al. used calcium oxide-calcium fluoride-sodium chloride as additives in the study of a new process for lithium extraction from low-grade lithium-containing clay ore in a certain place in Henan. % sulfuric acid leaching for 1h, the lithium leaching rate was 86.21%. However, the calcium fluoride introduced as an additive in this method will form hydrofluoric acid in the subsequent acid leaching process, resulting in side reactions and an increase in the leaching rate of impurity elements.

Patent CN101736169A discloses a method for extracting lithium from lepidolite by defluorination roasting chlorine salt pressure cooking. First, it is mainly calcined and defluorinated at 900 ° C. After grinding, calcium oxide and sodium chloride are added to pressure cooking in an autoclave. It needs high temperature calcination and defluorination combined with high pressure leaching, the process is long, the equipment investment is large, the energy consumption is high, and the operation is complicated.

The Chinese patent with the application number of 202010472603.7 "a method for efficiently leaching lithium from a lithium-containing clay rock", the disclosed technical scheme also first roasts the raw materials and acid, and then leaches them out to obtain a lithium-containing leachate, which also requires the presence of The problem of long process flow and high energy consumption.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for extracting lithium step by step from lithium-containing clay, so as to solve the problem of high energy consumption that the raw material needs to be roasted or calcined and then leached after the method of extracting lithium in the prior art.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A method for extracting lithium step by step from lithium-containing clay, comprising the following steps:

S1, take the uncalcined lithium-containing clay as a raw material, mix the lithium-containing clay and the acid with a mass concentration of 10% to 80% at a solid-liquid ratio of 1:3 to 1:8, and seal them at a pressure of 1.5MPa. The environment, 60 ~ 200 ℃ temperature reaction 2 ~ 6h for leaching;

S2, carry out solid-liquid separation with the product after the reaction of step S1 finishes to obtain filtrate and filter residue, then collect the filtrate, and wash the filter residue;

S3, after the filter residue washed in step S2 and the acid with a mass concentration of 10% to 80% are mixed at a solid-to-liquid ratio of 1:3 to 1:8, and react 2 in a pressure-sealed environment of 1.5MPa and a temperature of 60 to 200°C. ~6h for leaching;

S4. The product after the reaction in step S3 is subjected to solid-liquid separation to obtain a filtrate and a filter residue, and then the filtrate is collected.

In further step S1, the lithium-containing clay is crushed and screened, and the lithium-containing clay mineral powder below 200 mesh is taken as the raw material in step S1.

The acids in further steps S1 and S3 are both sulfuric acid.

Further steps S1 and S3 are all leaching in an autoclave.

In a further step S2, the filter residue is washed until the washing solution is neutral.

In the present invention, the filtrate collected in step S2 and step S4 is the final extracted lithium-containing liquid.

The principle of the present invention is further elaborated as follows:

The invention uses lithium-containing clay as a raw material, adopts no roasting, directly extracts lithium from lithium-containing clay, adopts a pressure leaching method, and makes certain changes in the structure of the clay lithium ore under the first pressure and acid concentration. Therefore, under the second pressurization and a certain acid concentration, the leaching of lithium can be greatly improved, and the present invention adopts a high-pressure reactor, so that the whole reaction is carried out in a closed environment, and the reaction is more complete. The invention optimizes the technological process, saves the high-temperature roasting process, greatly saves the production cost, and is more environmentally friendly. This makes the process of extracting lithium from lithium-containing mineral resources break through high-energy-consuming processes such as high-temperature roasting, which opens up a new way for the extraction of lithium resources, which can greatly improve the shortage of lithium resources in my country. The method of the invention can be applied to industrial production, which can greatly save costs and increase production benefits.

Description of drawings

Fig. 1 is a process flow diagram of step-by-step lithium extraction from a lithium-containing clay provided by the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, a step-by-step method for extracting lithium from lithium-containing clay comprises the following steps:

S1, take the uncalcined lithium-containing clay as a raw material, mix the lithium-containing clay and the acid with a mass concentration of 10% to 80% at a solid-liquid ratio of 1:3 to 1:8, and seal them at a pressure of 1.5MPa. The environment, 60 ~ 200 ℃ temperature reaction 2 ~ 6h for leaching;

S2, carry out solid-liquid separation with the product after the reaction of step S1 finishes to obtain filtrate and filter residue, then collect the filtrate, and wash the filter residue;

S3, after the filter residue washed in step S2 and the acid with a mass concentration of 10% to 80% are mixed at a solid-to-liquid ratio of 1:3 to 1:8, and react 2 in a pressure-sealed environment of 1.5MPa and a temperature of 60 to 200°C. ~6h for leaching;

S4. The product after the reaction in step S3 is subjected to solid-liquid separation to obtain a filtrate and a filter residue, and then the filtrate is collected.

Example 1

A method for step-by-step extraction of lithium from lithium-containing clay, the process is as follows:

(1) Crushing and screening the uncalcined lithium-containing clay ore, and taking the lithium-containing clay ore powder below 200 mesh as the raw material. The raw materials and sulfuric acid with a mass concentration of 20% were added to the autoclave at a ratio of 1:3, and the reaction was carried out at 1.5MPa and 90 °C for 3 hours for leaching;

(2) After the reaction in step (1) is completed, after the autoclave is cooled, the reaction product is subjected to suction filtration to obtain a filtrate and a filter residue, the filtrate is collected and an atomic absorption test is performed, and the filter residue is washed to neutrality;

(3), adding the filter residue after washing in step (2) and sulfuric acid with a mass concentration of 40% into the autoclave at a ratio of 1:5, and leaching at 1.5MPa and 120°C for 2 hours;

(4) After the reaction in step (3) is completed, after the autoclave is cooled, the reaction product is subjected to suction filtration to obtain filtrate and filter residue, and the filtrate is collected and subjected to atomic absorption test;

In this embodiment, the filtrate obtained in steps (2) and (4) is the final extracted lithium-containing liquid. In steps (2) and (4), atomic absorption tests are performed on the filtrate respectively, and the result of the two atomic absorption tests and is the total leaching rate. Through two leaching, the total leaching rate of lithium in the present invention is 71.34%.

Example 2

A method for step-by-step extraction of lithium from lithium-containing clay, the process is as follows:

(1), crush and sieve the unroasted lithium-containing clay ore, and take the lithium-containing clay ore powder below 200 meshes as the raw material. The raw material and the sulfuric acid with a mass concentration of 10% are added to the In the autoclave, the reaction was carried out at 1.5MPa and 60°C for 2h for leaching;

(2) After the reaction in step (1) is completed, after the autoclave is cooled, the reaction product is subjected to suction filtration to obtain a filtrate and a filter residue, the filtrate is collected and an atomic absorption test is performed, and the filter residue is washed to neutrality;

(3), adding the filter residue after washing in step (2) and sulfuric acid with a mass concentration of 50% into the autoclave at a ratio of 1:6, and leaching at 1.5MPa and 150°C for 4 hours;

(4) After the reaction in step (3), after the autoclave is cooled, the reaction product is subjected to suction filtration to obtain filtrate and filter residue, and the filtrate is collected and tested by atomic absorption.

In this embodiment, the filtrate obtained in steps (2) and (4) is the final extracted lithium-containing liquid. In steps (2) and (4), atomic absorption tests are performed on the filtrate respectively, and the result of the two atomic absorption tests and is the total leaching rate. Through two leachings, the total leaching rate of lithium was 76.34%.

Example 3

A method for step-by-step extraction of lithium from lithium-containing clay, the process is as follows:

(1) Crushing and screening the uncalcined lithium-containing clay ore, and taking the lithium-containing clay ore powder below 200 mesh as the raw material. The raw ore and sulfuric acid with a mass concentration of 20% were added to the autoclave at a ratio of 1:5, and the reaction was carried out at 1.5MPa and 100 °C for 2 hours for leaching;

(2) After the reaction in step (1) is completed, after the autoclave is cooled, the reaction product is subjected to suction filtration to obtain a filtrate and a filter residue, the filtrate is collected and an atomic absorption test is performed, and the filter residue is washed to neutrality;

(3), adding the filter residue after washing in step (2) and sulfuric acid with a mass concentration of 60% into the autoclave at a ratio of 1:6, and reacting at 1.5MPa and 180 ° C for 2 hours to carry out leaching; carry out reaction leaching;

(4) After the reaction in step (3), after the autoclave is cooled, the reaction product is subjected to suction filtration to obtain filtrate and filter residue, and the filtrate is collected and tested by atomic absorption.

In this embodiment, the filtrate obtained in steps (2) and (4) is the final extracted lithium-containing liquid. In steps (2) and (4), atomic absorption tests are performed on the filtrate respectively, and the result of the two atomic absorption tests and is the total leaching rate. Through two leachings, the total leaching rate of lithium was 88.08%.

Example 4

A method for step-by-step extraction of lithium from lithium-containing clay, the process is as follows:

(1) Crushing and screening the uncalcined lithium-containing clay ore, and taking the lithium-containing clay ore powder below 200 mesh as the raw material. The raw ore and sulfuric acid with a mass concentration of 20% were added to the autoclave at a ratio of 1:6, and the reaction was carried out at 1.5MPa and 80°C for 3 hours for leaching;

(2) After the reaction in step (1), after the autoclave is cooled, the reaction product is subjected to suction filtration to obtain a filtrate and a filter residue, the filtrate is collected and subjected to an atomic absorption test, and the filter residue is washed to neutrality;

(3) The filter residue after washing in step (2) and sulfuric acid with a mass concentration of 40% were added to the autoclave at a ratio of 1:6, and the reaction was carried out at 1.5MPa and 140°C for 5h to carry out leaching;

(4) After the reaction in step (3), after the autoclave is cooled, the reaction product is subjected to suction filtration to obtain filtrate and filter residue, and the filtrate is collected and subjected to atomic absorption test.

In this embodiment, the filtrate obtained in steps (2) and (4) is the final extracted lithium-containing liquid. In steps (2) and (4), atomic absorption tests are performed on the filtrate respectively, and the result of the two atomic absorption tests and is the total leaching rate. Through two leachings, the total leaching rate of lithium was 80.37%.

The embodiments of the present invention are only descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. Various modifications and improvements made should fall within the protection scope of the present invention, and the technical content claimed in the present invention has been fully recorded in the claims.

Claims (5)

1. A method for extracting lithium from lithium-containing clay step by step is characterized by comprising the following steps:

s1, taking unfired lithium-containing clay as a raw material, mixing the lithium-containing clay and 10-80% acid in a solid-liquid ratio of 1: 3-1: 8, and then reacting for 2-6 hours at a temperature of 60-200 ℃ in a sealed environment with a pressure of 1.5MPa for leaching;

s2, carrying out solid-liquid separation on the product obtained after the reaction in the step S1 to obtain filtrate and filter residue, collecting the filtrate, and washing the filter residue;

s3, mixing the filter residue washed in the step S2 with 10-80% acid by mass according to a solid-liquid ratio of 1: 3-1: 8, and then reacting for 2-6 h at 60-200 ℃ in a sealed environment with a pressure of 1.5MPa for leaching;

s4, carrying out solid-liquid separation on the product after the reaction in the step S3 is finished to obtain filtrate and filter residue, and then collecting the filtrate.

2. The method of claim 1, wherein in step S1, the lithium-containing clay is crushed and sieved, and the raw material of step S1 is selected from lithium-containing clay ore powder of 200 meshes or less.

3. The method of claim 1, wherein the acid used in steps S1 and S3 is sulfuric acid.

4. The method of claim 1, wherein the steps S1 and S3 are both autoclave leaching.

5. The method of claim 1, wherein in step S2, the filter residue is washed until the washing liquid is neutral.

Images