阅读说明：本技术 锂云母的提锂方法、含锂母液和填充剂 (Method for extracting lithium from lepidolite, lithium-containing mother liquor and filler ) 是由 魏绪春 魏东东 廖新 于 2019-11-07 设计创作，主要内容包括：本发明公开一种锂云母的提锂方法、含锂母液和填充剂,其中,锂云母的提锂方法包括：将锂云母矿高温焙烧并通入水蒸气脱氟后得到脱氟锂云母；将脱氟锂云母和钠盐、氧化钙分别研磨成细粉,混合后制得混合物并投入高压反应釜中进行压煮后过滤得到第一滤液以及第一滤渣；将纯碱和片碱以及EDTA依次加入到的第一滤液中后过滤,得到第二滤液和第二滤渣；将第二滤液加入纯碱后并进行加热处理后,过滤,从而获得含锂母液,实现锂的提取,与现有技术比较,提锂步骤简单,提取率高。(The invention discloses a method for extracting lithium from lepidolite, lithium-containing mother liquor and a filler, wherein the method for extracting lithium from lepidolite comprises the following steps: roasting the lepidolite ore at high temperature and introducing steam for defluorination to obtain defluorinated lepidolite; grinding defluorinated lepidolite, sodium salt and calcium oxide into fine powder respectively, mixing to obtain a mixture, putting the mixture into a high-pressure reaction kettle, performing pressure boiling, and filtering to obtain a first filtrate and a first filter residue; sequentially adding soda ash, caustic soda flakes and EDTA into the first filtrate, and filtering to obtain a second filtrate and a second filter residue; and adding the second filtrate into soda ash, heating, and filtering to obtain lithium-containing mother liquor, so as to realize extraction of lithium.)

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

step one, roasting lepidolite ore at high temperature, and introducing steam for defluorination to obtain defluorinated lepidolite;

step two, respectively grinding the defluorinated lepidolite, the sodium salt and the calcium oxide obtained in the step one into fine powder, mixing to obtain a mixture, putting the mixture into a high-pressure reaction kettle for pressure boiling, and filtering to obtain a first filtrate and a first filter residue;

step three, sequentially adding soda ash, caustic soda flakes and EDTA into the first filtrate obtained in the step two, and filtering to obtain a second filtrate and a second filter residue;

and step four, adding soda ash into the second filtrate obtained in the step three, heating, filtering, taking filtrate as lithium-containing mother liquor, and taking filter residue as white filler.

2. The method for extracting lithium from lepidolite as set forth in claim 1, wherein the second step includes: respectively grinding 50-80 parts of lepidolite, 30-58 parts of sodium salt and 10-20 parts of calcium oxide into powder with the particle size of 50-250 meshes by mass, and mixing to prepare the mixture.

3. The method for extracting lithium from lepidolite as set forth in claim 1, wherein the sodium salt in the second step is sodium sulfate, sodium chloride, sodium nitrate or the like.

4. The method for extracting lithium from lepidolite as claimed in claim 3, wherein the sodium salt is sodium sulfate.

5. The method for extracting lithium from lepidolite in claim 1, wherein in the second step, the mixture is put into a high-pressure reaction kettle to be cooked at 160-240 ℃ under pressure, and after the mixture reacts for 3-5 hours under continuous stirring, a first filtrate and a first filter residue are obtained by filtration.

6. The method for extracting lithium from lepidolite as set forth in claim 1, wherein the third step comprises:

and (3) taking 10-20 parts of soda ash, 10-20 parts of caustic soda flakes and 5-10 parts of EDTA (ethylene diamine tetraacetic acid) by mass parts, sequentially adding into the first filtrate, and filtering to obtain a second filtrate and a second filter residue.

7. The method for extracting lithium from lepidolite as set forth in claim 1, wherein said step four includes:

taking 10-20 parts by mass of soda ash, adding the second filtrate into the soda ash, heating at a temperature of above 90 ℃ for 2-6 hours, filtering, taking the filtrate as lithium-containing mother liquor, and taking the filter residue as a white filler.

8. A lithium-containing mother liquor prepared by the method for extracting lithium from lepidolite according to any one of claims 1 to 7.

9. A white filler prepared by the method of extracting lithium from lepidolite as described in any one of claims 1 to 7.

Technical Field

The invention relates to the field of chemical industry, in particular to a method for extracting lithium from lepidolite, lithium-containing mother liquor and a filling agent.

Background

Lithium is an important rare metal element, lithium sulfate or lithium carbonate is an important chemical raw material, and with the emergence of the development plan of new national energy, the new lithium battery energy becomes one of the energy industries which are key in national support development; lithium sulfate or lithium carbonate is used as an important basic raw material for the development of new energy of lithium batteries, and the demand of the lithium sulfate or the lithium carbonate is larger and higher, and the price of the lithium sulfate or the lithium carbonate is higher and higher.

The lepidolite explored in China has low taste, and Li₂The content of O is between 0.8 and 1.8 percent, the average content is 1.61 percent, the extraction is difficult, and the lepidolite resource cannot be utilized with high added value. In the prior art, the lepidolite ore is used for extracting lithium, and the lepidolite is extracted from the lepidolite ore by natural dissociation, flotation and purification of the lepidolite ore and then the lithium is extracted from the lepidolite ore. In the process of extracting lepidolite from lepidolite, a large amount of tailings are generated in the process, a large amount of energy and manpower are consumed, and the production cost is increased; on the other hand, the recovery rate of lithium in the process of extracting lepidolite from lepidolite can only reach 70-80%, the recovery rate of lithium in the process of extracting lithium from lepidolite is 80-90%, the recovery rate of comprehensive lithium is only 60-70%, and a large amount of waste of lithium resources is caused. The process is complex, long in flow, low in lithium recovery rate, high in processing cost and poor in effect.

Therefore, it is necessary to provide a novel method for extracting lithium from lepidolite to solve the above technical problems.

Disclosure of Invention

The invention mainly aims to provide a method for extracting lithium from lepidolite, lithium-containing mother liquor and a filling agent, and aims to solve the technical problems of complex lithium extraction process and low recovery efficiency of the existing lithionite.

In order to achieve the purpose, the method for extracting lithium from lepidolite provided by the invention comprises the following steps:

step one, roasting lepidolite ore at high temperature, and introducing steam for defluorination to obtain defluorinated lepidolite;

step two, respectively grinding the defluorinated lepidolite, the sodium salt and the calcium oxide obtained in the step one into fine powder, mixing to obtain a mixture, putting the mixture into a high-pressure reaction kettle for pressure boiling, and filtering to obtain a first filtrate and a first filter residue;

step three, sequentially adding soda ash, caustic soda flakes and EDTA into the first filtrate obtained in the step two, and filtering to obtain a second filtrate and a second filter residue;

and step four, adding soda ash into the second filtrate obtained in the step three, heating, filtering, taking filtrate as lithium-containing mother liquor, and taking filter residue as white filler.

Preferably, the second step includes: respectively grinding 50-80 parts of lepidolite, 30-58 parts of sodium salt and 10-20 parts of calcium oxide into powder with the particle size of 50-250 meshes by mass, and mixing to prepare the mixture.

Preferably, the sodium salt in the second step includes sodium sulfate, sodium chloride or sodium nitrate.

Preferably, the sodium salt is sodium sulfate.

Preferably, in the second step, the mixture is put into a high-pressure reaction kettle to be cooked at 160-240 ℃ under pressure, and after the mixture reacts for 3-5 hours under continuous stirring, a first filtrate and a first filter residue are obtained by filtration.

Preferably, the third step includes:

and (3) taking 10-20 parts of soda ash, 10-20 parts of caustic soda flakes and 5-10 parts of EDTA (ethylene diamine tetraacetic acid) by mass parts, sequentially adding into the first filtrate, and filtering to obtain a second filtrate and a second filter residue.

Preferably, the fourth step includes:

taking 10-20 parts by mass of soda ash, adding the second filtrate into the soda ash, heating at a temperature of above 90 ℃ for 2-6 hours, filtering, taking the filtrate as lithium-containing mother liquor, and taking the filter residue as a white filler.

The invention also provides a lithium-containing mother liquor prepared by the lithium extraction method of the lithium china stone.

The invention also provides a white filler prepared by the lithium extraction method of the lithium china stone.

According to the technical scheme, after sodium sulfate, calcium oxide and lepidolite are used for being pressed and boiled together, sodium hydroxide and sodium carbonate are added firstly for primary precipitation, and in the primary precipitation process, most of impurity metal ions generated in the pressing and boiling process can be generated, so that sodium carbonate is added into the first filtrate and is heated at the temperature of more than 90 ℃, lithium ions in the solution can be separated out to form lithium carbonate, lithium-containing mother liquor can be obtained, lithium extraction is achieved, and compared with the prior art, the lithium extraction step is simple and the extraction rate is high.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic flow chart of a method for extracting lithium from lepidolite according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In addition, the technical solutions in the embodiments of the present invention may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.

The invention provides a method for extracting lithium from lepidolite, which comprises the following steps:

and step S1, roasting the lepidolite ore at high temperature, and introducing steam for defluorination to obtain the defluorinated lepidolite.

Specifically, lepidolite was collected from Jiangxi Yichun Fengxi Xin county, and please refer to Table 1, the main component (wt%)

Li2O

Na2O

K2O

Al

Fe

Rb

Cs

Mn

F

4.33％

3.26％

6.04％

8.25％

0.84％

0.45％

0.14％

0.14％

0.85％

In the step of roasting and defluorinating lepidolite ore at high temperature, the reaction formula is as follows:

MeF·MeOH·Al₂O₃·3SiO₂+xH₂O→MeF·MeOH·Al₂O₃·3SiO₂+xH₂O

2[MeF·MeOH·Al₂O₃·3SiO₂+xH₂O]→K₂O·Al₂O₃·4SiO₂+Me’₂O·Al₂O₃·2SiO₂+2HF↑+2xH₂O

wherein Me is Li, Na, K, Rb or Cs; me' is Li, Na, Rb or Cs

Compared with the existing defluorination method, the defluorinated lepidolite obtained by roasting lepidolite ore at the high temperature of 900 ℃ through the method of the step S1 and defluorinating by water vapor has smaller fluorine content, and the lepidolite with low fluorine content has good transformation and high dissolution rate when roasting the lepidolite ore.

Step S2, grinding the defluorinated lepidolite, the sodium salt and the calcium oxide obtained in the step S1 into fine powder respectively, mixing to obtain a mixture, putting the mixture into a high-pressure reaction kettle, performing pressure boiling at 160-240 ℃, reacting for 3-5 hours under continuous stirring, and filtering to obtain a first filtrate and first filter residue;

in some alternative embodiments, the sodium salt may be sodium sulfate, sodium chloride, or sodium nitrate.

In the embodiment, the sodium salt is sodium sulfate, and 50-80 parts of lepidolite, 30-58 parts of sodium sulfate and 10-20 parts of calcium oxide are respectively ground into powder with the particle size of 50-250 meshes and mixed to prepare the mixture.

When calcium oxide is mixed with lepidolite for roasting at a higher temperature, the calcium oxide can be mixed with SiO in the lepidolite at a high temperature₂、Al₂O₃F reacting to form stable calcium aluminosilicate and CaF₂Thereby effectively improving the melting point of the lepidolite.

Step S3, sequentially adding 10-20 parts of sodium carbonate, 10-20 parts of caustic soda flakes and 5-10 parts of EDTA (ethylene diamine tetraacetic acid) into the first filtrate obtained in the step S2, and filtering to obtain a second filtrate and a second filter residue;

meanwhile, the main component of the lepidolite ore is aluminosilicate, and aluminum and silicon can be corroded by strong alkali, so a certain amount of sodium hydroxide (flake alkali) needs to be added in the roasting and autoclaving process to enhance the alkalinity in the autoclaving system and accelerate the damage to the lepidolite structure so as to achieve the purpose of dissolving out valuable metals such as lithium, potassium and the like. Therefore, in the step, soda ash and caustic soda flakes are added to increase the concentration of carbonate ions in the solution, so that the carbonate ions can react with iron ions, magnesium ions, aluminum ions, silicon ions and calcium ions in the solution to generate impurities which are difficult to dissolve in water, so that the concentration of lithium ions in the solution is increased, and then the second filtrate and the second filter residue are obtained after filtration, wherein the second filtrate comprises iron carbonate, magnesium carbonate, aluminum carbonate, silicon carbonate and calcium carbonate.

Meanwhile, EDTA (ethylene diamine tetraacetic acid) is added into the solution, and the EDTA can be combined with a chelating agent of divalent metal ions such as iron ions, magnesium ions, aluminum ions, silicon ions and calcium ions, so that the precipitation of the iron ions, the magnesium ions, the aluminum ions, the silicon ions and the calcium ions can be accelerated. Meanwhile, EDTA can be dissolved in sodium hydroxide or sodium carbonate solution, so that the addition of EDTA does not influence the precipitation of lithium ions.

And step S4, taking 10-20 parts of soda ash, adding 10-20 parts of soda ash into the second filtrate obtained in the step S3, heating at a temperature of above 90 ℃ for 2-6 hours, filtering, taking the filtrate as lithium-containing mother liquor, and taking the filter residue as white filler.

Since the iron, magnesium, aluminum, silicon, and calcium ions are more easily bonded to the carbonate ions than the lithium ions, the carbonate ions are first bonded to the iron, magnesium, aluminum, silicon, and calcium ions in step S3, so that after the impurity ions are removed in step S3, soda ash is added to the second filtrate, i.e., carbonate is continuously added to the solution, and after the carbonate ions are completely bonded to the iron, magnesium, aluminum, silicon, and calcium ions, the carbonate ions are bonded to the lithium ions to form lithium carbonate, and the lithium carbonate is precipitated from the solution by heating at a temperature of 90 ℃ or higher, and thus the residue is white crystal lithium carbonate having a high purity after refiltering.

In the invention, sodium sulfate, calcium oxide and lepidolite are used for being pressed and boiled together, then sodium hydroxide and sodium carbonate are added firstly for primary precipitation, and in the primary precipitation process, most of impurity metal ions generated in the pressing and boiling process can be generated, so that sodium carbonate is added into the first filtrate and is heated at the temperature of more than 90 ℃, and lithium ions in the solution can be separated out to become lithium carbonate, lithium-containing mother liquor can be obtained, lithium extraction is realized, and compared with the prior art, the lithium extraction step is simple and the extraction rate is high.

The invention also provides a lithium-containing mother liquor prepared by the lithium extraction method of the lithium china stone.

The invention also provides a white filler prepared by the lithium extraction method of the lithium china stone.