阅读说明：本技术 一种采取硫酸纳米雾化工艺对锂辉石进行提取的方法 (Method for extracting spodumene by adopting sulfuric acid nano atomization process ) 是由 任燕 邹廷军 于 2020-12-22 设计创作，主要内容包括：本发明公开了一种采取硫酸纳米雾化工艺对锂辉石进行提取的方法。该方法是先将硫酸在空气中雾化成纳米气雾,然后将纳米气雾通入装有锂辉石粉末的流态化煅烧炉中,与锂辉石粉末一起进行气-液-固三相流态化高温焙烧；再将焙烧后的锂辉石粉末与提取液混合制浆,使矿石中的锂溶出,得含硫酸锂的浸提液。本发明通过将硫酸雾化成纳米液滴,并对纳米液滴与锂辉石的混合物进行焙烧,可以将硫酸的利用率提升至最大,进而减少硫酸的用量,锂辉石的提取成本大大降低。另外,提取过程中不会产生污染物,对环境友好,同时提取出的锂盐具有较高的纯度,可用于锂电、核电等领域。(The invention discloses a method for extracting spodumene by adopting a sulfuric acid nano atomization process. Atomizing sulfuric acid in air into nano aerial fog, introducing the nano aerial fog into a fluidized calcining furnace filled with spodumene powder, and carrying out gas-liquid-solid three-phase fluidized high-temperature roasting together with the spodumene powder; and mixing the roasted spodumene powder and the extracting solution for pulping to dissolve out lithium in the ore to obtain the leaching solution containing lithium sulfate. The sulfuric acid is atomized into nano liquid drops, and the mixture of the nano liquid drops and spodumene is roasted, so that the utilization rate of the sulfuric acid can be increased to the maximum, the use amount of the sulfuric acid is reduced, and the extraction cost of the spodumene is greatly reduced. In addition, pollutants are not generated in the extraction process, the method is environment-friendly, and the extracted lithium salt has high purity and can be used in the fields of lithium batteries, nuclear power and the like.)

1. A method for extracting spodumene by adopting a sulfuric acid nano atomization process is characterized by comprising the following steps:

s1: carrying out nano atomization on sulfuric acid and air to form nano aerial fog; then the nano gas fog is introduced into a fluidized calcining furnace filled with spodumene powder, and is subjected to gas-liquid-solid three-phase fluidized high-temperature roasting together with the spodumene powder;

s2: mixing the roasted spodumene powder with the extracting solution for pulping to dissolve out lithium in the ore to obtain the leaching solution containing lithium sulfate.

2. The method for extracting spodumene by adopting the sulfuric acid nano-atomization process as claimed in claim 1, wherein the nano-atomization in S1 comprises the following steps:

SS 1: heating air to 120-160 ℃;

SS 2: spraying the heated air and sulfuric acid outwards through an atomizing nozzle to form nano aerial fog; the atomizing nozzle comprises an inner tube and an outer tube, the axes of the inner tube and the outer tube are superposed, and the outlet of the inner tube is positioned in the outer tube; the heated air is ejected from the outer tube at an ejection speed of 400 to 500m/s, and the sulfuric acid is ejected from the inner tube at an ejection speed of 200 to 300 m/s.

3. The method for extracting spodumene by adopting the sulfuric acid nano-atomization process as claimed in claim 1, which is characterized in that: the vertical distance between the outlet of the inner pipe and the outlet of the outer pipe is 2-5 mm.

4. The method for extracting spodumene by adopting the sulfuric acid nano-atomization process as claimed in claim 1, which is characterized in that: the fluidized calcining furnace comprises a furnace body; the lower part of the furnace body is provided with a high-temperature flue gas inlet, the upper part of the furnace body is provided with a waste gas outlet, a fluidized bed is arranged in the furnace body, and a flue gas channel is formed between the fluidized bed and the furnace body; the bottom and the top of the fluidized bed are respectively provided with a fluidized medium inlet and a fluidized medium outlet, the upper part of the side wall of the fluidized bed is provided with a feed inlet, and the lower part of the side wall is provided with a discharge outlet.

5. The method for extracting spodumene by adopting the sulfuric acid nano-atomization process as claimed in claim 1, which is characterized in that: the particle size of the spodumene powder is 10-50 mu m.

6. The method for extracting spodumene by adopting the sulfuric acid nano-atomization process as claimed in claim 1, which is characterized in that: the ratio of the nano aerial fog and the spodumene powder introduced into the fluidized calcining furnace is 2-4 m³:80～100kg。

7. The method for extracting spodumene by adopting the sulfuric acid nano-atomization process as claimed in claim 1, which is characterized in that: the high-temperature roasting temperature in S1 is 950-1100 ℃.

8. The method for extracting spodumene by adopting the sulfuric acid nano-atomization process as claimed in claim 1, which is characterized in that: the solid-to-liquid ratio of the spodumene powder to the extracting solution in the S2 pulping process is 1: 1-3 g/mL.

9. The method for extracting spodumene by adopting sulfuric acid nano-atomization process as claimed in claim 1 or 8, wherein: the extracting solution is water or sulfuric acid solution with the concentration of 0.5-1 mol/L.

Technical Field

The invention belongs to the technical field of spodumene extraction, and particularly relates to a method for extracting spodumene by adopting a sulfuric acid nano atomization process.

Background

Lithium is a metal material with wide application and is also a very important strategic resource. The method has important application in the fields of traditional industries such as metallurgy, medicine and chemical industry, aviation, new energy, military industry and the like. Among various lithium material products, the lithium battery is one of the most widely used products and products with the greatest development prospect at present, and the support of the lithium battery cannot be provided from electronic equipment such as smart phones and notebook computers to the new energy automobile industry.

China is a big country with abundant lithium resources, the amount of the lithium resources (calculated by metallic lithium) reaches 667 ten thousand tons, and the lithium resources are mainly distributed in the form of ores and brine, wherein the lithium resources in the brine account for about 80 percent of the total amount. Although the ratio is more, the associated elements in the salt lake brine in China are more, particularly the magnesium element is obviously higher than the magnesium content in the foreign brine, so that the difficulty and the cost for extracting lithium from the brine are higher, and therefore, the method has wider application prospect in extracting lithium from ores in China.

Lithium-containing ores mainly comprise spodumene, lepidolite, petalite and the like, wherein lithium is commonly extracted from spodumene. The existing process method for extracting lithium from spodumene comprises the following steps: limestone method, sulfate method, soda method, and the like. The limestone method needs to mix minerals such as lepidolite and limestone according to the mass ratio of about 1:3, lithium in the minerals is converted into a soluble state through high-temperature calcination, the process needs to input a large amount of calcium-containing materials, has high calcination condition requirements, belongs to a process with high reaction energy consumption and is high in cost; sodium-containing filter residue with low value is generated when lithium is extracted by a soda ash method, so that the recycling availability of the filter residue is poor, a large amount of solid waste which is low in recycling value and difficult to treat is generated when lithium is extracted by the whole process, and the process is not environment-friendly.

Disclosure of Invention

Aiming at the prior art, the invention provides a method for extracting spodumene by adopting a sulfuric acid nano-atomization process, so as to solve the problems of high energy consumption, high cost, environmental friendliness and the like of the existing method for extracting lithium from spodumene.

In order to achieve the purpose, the invention adopts the technical scheme that: the method for extracting spodumene by adopting a sulfuric acid nano atomization process comprises the following steps:

s1: carrying out nano atomization on sulfuric acid and air to form nano aerial fog; then the nano gas fog is introduced into a fluidized calcining furnace filled with spodumene powder, and is subjected to gas-liquid-solid three-phase fluidized high-temperature roasting together with the spodumene powder;

s2: mixing the roasted spodumene powder with the extracting solution for pulping to dissolve out lithium in the ore to obtain the leaching solution containing lithium sulfate.

The invention adopts the technical scheme that the beneficial effects are as follows: in the invention, sulfuric acid is atomized into nano aerosol in the air, the size of the sulfuric acid in the aerosol is in a nano level, the sulfuric acid and spodumene can be better combined, and the sulfuric acid can be uniformly attached to the surface of the spodumene and permeates into the spodumene. During the calcination process, the spodumene is subjected to crystal transformation at high temperature, lithium in the spodumene is subjected to crystal transformation and reacts with sulfuric acid to generate lithium sulfate, and the lithium sulfate is easily separated out from the spodumene under the action of the leaching solution, so that the extraction rate of the lithium is improved.

On the basis of the technical scheme, the invention can be further improved as follows.

Further, the nano atomization in S1 includes the following steps:

SS 1: heating air to 120-160 ℃;

SS 2: spraying the heated air and sulfuric acid outwards through an atomizing nozzle to form nano aerial fog; the atomizing nozzle comprises an inner tube and an outer tube, the axes of the inner tube and the outer tube are superposed, and the outlet of the inner tube is positioned in the outer tube; the heated air is ejected from the outer tube at an ejection speed of 400 to 500m/s, and the sulfuric acid is ejected from the inner tube at an ejection speed of 200 to 300 m/s.

Further, the vertical distance between the outlet of the inner pipe and the outlet of the outer pipe is 2-5 mm.

The beneficial effect of adopting the further technical scheme is that: according to the invention, air is heated and acts on sulfuric acid, sulfuric acid and air are sprayed outwards at a higher speed, and high-temperature air can provide a larger impact force to the sulfuric acid while heating the sulfuric acid, so that the sulfuric acid is atomized into small droplets with a nanometer size level under the dual actions of high temperature and the impact force, the combination and reaction of the sulfuric acid and spodumene can be promoted, lithium in the spodumene is completely converted into lithium sulfate, and the extraction rate of lithium is further improved.

Further, the fluidized calcining furnace comprises a furnace body; the lower part of the furnace body is provided with a high-temperature flue gas inlet, the upper part of the furnace body is provided with a waste gas outlet, a fluidized bed is arranged in the furnace body, and a flue gas channel is formed between the fluidized bed and the furnace body; the bottom and the top of the fluidized bed are respectively provided with a fluidized medium inlet and a fluidized medium outlet, the upper part of the side wall of the fluidized bed is provided with a feed inlet, and the lower part of the side wall is provided with a discharge outlet.

Further, the particle diameter of the spodumene powder is 10 to 50 μm.

The beneficial effect of adopting the further technical scheme is that: the spodumene is crushed into 10-50 mu m micro particles, the specific surface area of the spodumene is increased, the spodumene is in contact with sulfuric acid droplets to react, and the precipitation of lithium can be promoted.

Further, the ratio of the nano aerial fog and the spodumene powder introduced into the fluidized calcining furnace is 2-4 m³:80～100kg。

The beneficial effect of adopting the further technical scheme is that: the nano aerial fog and spodumene powder are mixed according to the proportion, and the spodumene can completely absorb the sulfuric acid in the aerial fog, so that the excessive sulfuric acid is avoided, and the environmental pollution caused by the escape of the aerial fog is avoided; and in proportion, the sulfuric acid can basically convert all the lithium in the spodumene into the lithium sulfate, can extract all the lithium in the spodumene, and keeps the extraction rate of the spodumene at a high level.

Further, the high-temperature roasting temperature in S1 is 950-1100 ℃.

Further, the solid-to-liquid ratio of spodumene powder to the leachate in the pulping process in S2 is 1: 1-3 g/mL.

Further, the leaching solution is water or sulfuric acid solution with the concentration of 0.5-1 mol/L.

The beneficial effect of adopting the further technical scheme is that: lithium in the reacted spodumene mainly exists in a form of lithium sulfate, and the lithium sulfate is easy to dissolve in water and can be greatly separated out from the spodumene, so that the purpose of extracting the lithium is realized. The sulfuric acid solution is adopted as the extracting solution, the sulfuric acid can destroy the outer layer structure of spodumene, the internal lithium sulfate is more easily separated out, and the extraction rate of lithium is higher.

The leaching liquor containing lithium sulfate obtained in the invention can be directly jointed with the existing impurity removal process to obtain the leaching liquor containing lithium with higher purity. For example, the pH value of the leaching solution containing lithium sulfate can be adjusted to precipitate impurity metal ions in the leaching solution so as to achieve the purpose of impurity removal. The leaching liquor after impurity removal can also be directly butted with the existing recovery process to obtain the corresponding lithium product. And (3) adding alkali into the leaching liquor to precipitate lithium, filtering and drying to obtain a lithium salt product.

The invention has the beneficial effects that: the sulfuric acid is atomized into nano liquid drops, and the mixture of the nano liquid drops and spodumene is roasted, so that the utilization rate of the sulfuric acid can be increased to the maximum, the use amount of the sulfuric acid is reduced, and the extraction cost of the spodumene is greatly reduced. In addition, pollutants are not generated in the extraction process, the method is environment-friendly, and the extracted lithium salt has high purity and can be used in the fields of lithium batteries, nuclear power and the like.

Drawings

FIG. 1 is a front cross-sectional view of an atomizing nozzle;

FIG. 2 is a main sectional view of a fluidizing calciner;

wherein, 1, an inner tube; 2. an outer tube; 3. heated air; 4. sulfuric acid; 5. nano aerial fog; 6. a furnace body; 7. a fluidized bed; 8. a high temperature flue gas inlet; 9. an exhaust gas outlet; 10. a flue gas channel; 11. a fluidizing medium inlet; 12. a fluidized medium outlet; 13. a feed inlet; 14. and (4) a discharge port.

Detailed Description

The following examples are provided to illustrate specific embodiments of the present invention.

Example 1

A method for extracting spodumene by adopting a sulfuric acid nano atomization process comprises the following steps:

s1: heating air to 150 deg.C; then the heated air and the sulfuric acid are sprayed outwards through an atomizing nozzle to form nano aerial fog 5; as shown in fig. 1, the atomizing nozzle comprises an inner tube 1 and an outer tube 2, the axes of the inner tube 1 and the outer tube 2 are superposed, the outlet of the inner tube 1 is positioned in the outer tube 2, and the vertical distance between the outlet of the inner tube 1 and the outlet of the outer tube 2 is 4 mm; the heated air 3 is sprayed out of the outer pipe 2 at the spraying speed of 450m/s, and the sulfuric acid 4 is sprayed out of the inner pipe 1 at the spraying speed of 250 m/s;

s2: introducing the nano gas fog 5 into a fluidized calcining furnace filled with spodumene powder with the particle size of about 30 mu m, and carrying out gas-liquid-solid three-phase fluidized high-temperature roasting together with the spodumene powder; as shown in fig. 2, the fluidizing calciner comprises a furnace body 6; the lower part of the furnace body 6 is provided with a high-temperature flue gas inlet 8, the upper part is provided with a waste gas outlet 9, a fluidized bed 7 is arranged in the furnace body, and a flue gas channel 10 is formed between the fluidized bed 7 and the furnace body 6; the bottom and the top of the fluidized bed 7 are respectively provided with a fluidized medium inlet 11 and a fluidized medium outlet 12, the upper part of the side wall of the fluidized bed is provided with a feed inlet 13, and the lower part of the side wall is provided with a discharge outlet 14; the nano gas fog 5 is introduced into the fluidized bed 7 from the fluidized medium inlet 11, and the ratio of the nano gas fog 5 to the spodumene powder introduced into the fluidized calcining furnace is 3m³90 kg; high-temperature flue gas enters a flue gas channel 10 from a high-temperature flue gas inlet 8, and materials in a fluidized bed 7 are heated, wherein the temperature of the introduced high-temperature flue gas is 1000 ℃;

s2: mixing the roasted spodumene powder with water according to a material-liquid ratio of 1:2g/mL, and stirring at a stirring speed of 60rpm/min for about 1h to dissolve lithium in the ore to obtain a leaching solution;

s3: evaporating and concentrating the leaching liquor, then gradually adding sodium hydroxide to precipitate lithium ions until no new precipitate is formed, filtering, and drying the filtrate to obtain a lithium salt product.

Example 2

A method for extracting spodumene by adopting a sulfuric acid nano atomization process comprises the following steps:

s1: heating air to 120 deg.C; then the heated air and the sulfuric acid are sprayed outwards through an atomizing nozzle to form nano aerial fog 5; the structure of the atomizing nozzle is shown in figure 1, heated air 3 is sprayed from an outer pipe 2, the spraying speed is 500m/s, sulfuric acid 4 is sprayed from an inner pipe 1, and the spraying speed is 200 m/s;

s2: introducing the nano gas fog 5 into a fluidized calcining furnace filled with spodumene powder with the particle size of about 10 mu m, and carrying out gas-liquid-solid three-phase fluidized high-temperature roasting together with the spodumene powder; the structure of the fluidization calcining furnace is shown in figure 2; the nano gas fog 5 is introduced into the fluidized bed 7 from the fluidized medium inlet 11, and the ratio of the nano gas fog 5 to the spodumene powder introduced into the fluidized calcining furnace is 4m³: 100 kg; high-temperature flue gas enters the flue gas channel 10 from the high-temperature flue gas inlet 8, the materials in the fluidized bed 7 are heated, and the temperature of the introduced high-temperature flue gas is 1100 ℃;

s2: mixing the roasted spodumene powder with a sulfuric acid solution with the concentration of 1mol/L according to the material-liquid ratio of 1:1g/mL, and stirring at the stirring speed of 60rpm/min for about 1h to dissolve out lithium in the ore to obtain a leaching solution;

s3: evaporating and concentrating the leaching liquor, then gradually adding sodium hydroxide to precipitate lithium ions until no new precipitate is formed, filtering, and drying the filtrate to obtain a lithium salt product.

Example 3

A method for extracting spodumene by adopting a sulfuric acid nano atomization process comprises the following steps:

s1: heating air to 160 ℃; then the heated air and the sulfuric acid are sprayed outwards through an atomizing nozzle to form nano aerial fog 5; the structure of the atomizing nozzle is shown in figure 1, heated air 3 is sprayed out of an outer pipe 2, the spraying speed is 400m/s, sulfuric acid 4 is sprayed out of an inner pipe 1, and the spraying speed is 300 m/s;

s2: introducing the nano gas fog 5 into a fluidized calcining furnace filled with spodumene powder with the particle size of about 50 mu m, and carrying out gas-liquid-solid three-phase fluidized high-temperature roasting together with the spodumene powder; the structure of the fluidization calcining furnace is shown in figure 2; the nano gas fog 5 is introduced into the fluidized bed 7 from the fluidized medium inlet 11, and the ratio of the nano gas fog 5 to the spodumene powder introduced into the fluidized calcining furnace is 2m³: 80 kg; high-temperature flue gas enters the flue gas channel 10 from the high-temperature flue gas inlet 8 to heat the materials in the fluidized bed 7, and the temperature of the introduced high-temperature flue gasThe temperature is 900 ℃;

s2: mixing the roasted spodumene powder with a sulfuric acid solution with the concentration of 0.5mol/L according to the material-liquid ratio of 1:3g/mL, and stirring at the stirring speed of 60rpm/min for about 1h to dissolve out lithium in the ore to obtain a leaching solution;

s3: evaporating and concentrating the leaching liquor, then gradually adding sodium hydroxide to precipitate lithium ions until no new precipitate is formed, filtering, and drying the filtrate to obtain a lithium salt product.

While the embodiments of the invention have been described in detail in connection with the drawings and examples, the invention should not be construed as limited to the scope of the claims. Various modifications and changes may be made by those skilled in the art without inventive step within the scope of the appended claims.