CN117326577A - Micro-powder-grade lithium oxide and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of oxide preparation, and discloses a micro-powder-level lithium oxide and a preparation method thereof, wherein the preparation method comprises the following steps: heating and melting metallic lithium, and then blowing oxygen to perform oxidation reaction to obtain lithium oxide liquid drops; and cooling the lithium oxide liquid drops, and sequentially separating and sieving to obtain the micro-powder lithium oxide. The micro-powder grade lithium oxide obtained by the invention has the characteristics of small granularity, high purity and high yield.

Description

A kind of micronized lithium oxide and preparation method thereof

Technical field

The present invention relates to the technical field of oxide preparation, and in particular to a micron powder grade lithium oxide and a preparation method thereof.

Background technique

Lithium oxide is a non-aqueous electrolyte with excellent performance. In addition to the characteristics of general lithium batteries, batteries made with it also have the advantages of low cost and no pollution. In addition to its important applications in lithium batteries, lithium oxide can also be used as an additive in the glass industry to improve the properties of glass. In addition, lithium oxide is also used in the preparation of special glass and lithium compounds and nuclear fusion reactors.

The current industrial production of battery-grade lithium oxide mainly uses metallic lithium as raw material, using the fire method, and then oxidizing, calcining, screening, ball milling, and screening to obtain battery-grade lithium oxide. However, in the ball milling and screening process, semi-mechanized operations are mainly used. There are problems such as poor sealing of equipment, large amount of dust, easy moisture absorption of products, low yield and non-environmental protection, and heavy workload of operators in the production site.

Therefore, it is of great significance to study a preparation method that can improve the yield and purity of lithium oxide products.

Contents of the invention

In view of this, the present invention provides a micro-powder grade lithium oxide and a preparation method thereof, which aims to solve the problems of low efficiency and low purity of lithium oxide prepared by existing processes.

In order to achieve the above objects, the present invention adopts the following technical solutions:

The invention provides a method for preparing micron-grade lithium oxide, which includes the following steps:

1) Heat and melt metallic lithium, then blow it with oxygen and perform an oxidation reaction to obtain lithium oxide droplets;

2) Cool the lithium oxide droplets and then separate and screen them sequentially to obtain micro-powder grade lithium oxide.

Preferably, the purity of the metallic lithium is ≥99.9%.

Preferably, the heating and melting is performed in a vacuum state, and the degree of vacuum in the vacuum state is ≤1×10 ^-1 Pa.

Preferably, the heating and melting temperature is 390-410°C, and the heating and melting time is 50-70 minutes.

Preferably, the oxygen purity is ≥99.99%.

Preferably, the blown gas pressure is ≥4MPa.

Preferably, the cooling temperature is ≤25°C, and the cooling medium is white oil.

Preferably, the separation is multi-stage cyclone separation.

The present invention also provides micro-powder-grade lithium oxide prepared by the preparation method of micro-powder-grade lithium oxide.

Preferably, the D90 of the fine powder grade lithium oxide is 60-80 μm.

It can be seen from the above technical solutions that compared with the prior art, the beneficial effects of the present invention are as follows:

1) The heating and melting in the present invention is carried out in a vacuum environment, which avoids the introduction of impurities, and the obtained lithium oxide has higher purity. At the same time, only the reaction between metallic lithium and oxygen occurs, no other by-products are produced, and the yield is higher.

2) The present invention uses a gas atomization method to prepare lithium oxide powder without ball milling operation, which simplifies the preparation process, saves labor, avoids the problem of introducing impurities during the ball milling process, and improves the purity and yield of lithium oxide.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without exerting creative efforts.

Figure 1 is a process flow chart of the preparation method of micro-powder grade lithium oxide of the present invention;

Figure 2 is a particle size distribution diagram of the fine powder grade lithium oxide obtained in Example 3.

Detailed ways

The invention provides a method for preparing micron-grade lithium oxide, which includes the following steps:

1) Heat and melt metallic lithium, then blow it with oxygen and perform an oxidation reaction to obtain lithium oxide droplets;

2) Cool the lithium oxide droplets and then separate and screen them sequentially to obtain micro-powder grade lithium oxide.

In the present invention, the purity of the metallic lithium is preferably ≥99.9%, and further preferably is ≥99.99%.

In the present invention, the heating and melting is performed in a vacuum state, and the degree of vacuum in the vacuum state is preferably ≤1×10 ^-1 Pa, more preferably ≤5×10 ^-2 Pa, and more preferably ≤3×10 ^-2 Pa.

In the present invention, the heating and melting temperature is preferably 390 to 410°C, more preferably 395 to 405°C, and more preferably 398 to 402°C, and the heating and melting time is preferably 50 to 70 min, further preferably 55 to 55 min. 65min, more preferably 58-62min.

In the present invention, the blowing is preferably performed in a spray plate, which contains an angle-adjustable nozzle. The angle of the nozzle is preferably 0 to 80°, more preferably 30 to 60°, and more preferably 40 to 40°. 50°.

In the present invention, the heated and melted metallic lithium flows to the spray plate through the guide nozzle, and the temperature of the guide nozzle is preferably ≥250°C, more preferably ≥300°C, and more preferably ≥320°C.

In the present invention, the purity of the oxygen is preferably ≥99.99%, and further preferably ≥99.999%.

In the present invention, the blown gas pressure is preferably ≥4MPa, more preferably 4-6MPa, and more preferably 4.5-5.5MPa.

In the present invention, the cooling temperature is preferably ≤25°C, more preferably ≤23°C, and more preferably ≤20°C, and the cooling medium is preferably white oil.

In the present invention, the white oil is preferably cosmetic grade white oil.

In the present invention, the separation is preferably multi-stage cyclone separation.

In the present invention, the separated product is preferably screened after the separation, and a vibrating screen is preferably used for the screening.

The present invention also provides micro-powder-grade lithium oxide prepared by the preparation method of micro-powder-grade lithium oxide.

In the present invention, the D90 of the fine powder grade lithium oxide is preferably 60 to 80 μm, more preferably 63 to 78 μm, and even more preferably 65 to 70 μm.

The technical solutions provided by the present invention will be described in detail below with reference to the examples, but they should not be understood as limiting the protection scope of the present invention.

Example 1

Add 5kg of metallic lithium with a purity of 99.99% into a stainless steel crucible, evacuate to 5×10 ^-2 Pa, and heat at 400°C for 60 minutes to obtain completely melted metallic lithium;

Adjust the nozzle angle of the spray plate to 45°, introduce oxygen with a purity of 99.99% at an air pressure of 4MPa, open the guide valve, lift the metal blocking rod at the bottom of the stainless steel crucible, and allow the metallic lithium liquid to flow through the 300°C guide nozzle. To the spray plate, it is broken and atomized by oxygen injection, and the broken lithium metal liquid undergoes an oxidation reaction with oxygen to obtain lithium oxide droplets;

The lithium oxide droplets are passed into a cooling chamber in which the cooling medium is cosmetic-grade white oil and are cooled to 25°C to obtain lithium oxide powder. The lithium oxide powder undergoes multi-stage cyclone separation in an induced draft fan and then enters the collection tank, where the oxidized water in the collection tank is removed. The lithium powder is sieved through a vibrating sieve to obtain micro-powder grade lithium oxide.

The mass of the micronized lithium oxide obtained in this example is 10.809kg, the purity of the micronized lithium oxide is 99.281%, and the particle size is D10=5.323μm, D50=30.210μm, and D90=78.862μm.

Example 2

Add 5kg of metallic lithium with a purity of 99.99% into a stainless steel crucible, evacuate to 3×10 ^-2 Pa, and heat at 410°C for 55 minutes to obtain completely melted metallic lithium;

Adjust the nozzle angle of the spray plate to 45°, introduce oxygen with a purity of 99.99% at an air pressure of 5MPa, open the diversion nozzle valve, lift the metal blocking rod at the bottom of the stainless steel crucible, and allow the metallic lithium liquid to flow through the diversion nozzle at 250°C. To the spray plate, it is broken and atomized by oxygen injection, and the broken lithium metal liquid undergoes an oxidation reaction with oxygen to obtain lithium oxide droplets;

The lithium oxide droplets are passed into a cooling chamber in which the cooling medium is cosmetic-grade white oil and are cooled to 23°C to obtain lithium oxide powder. The lithium oxide powder undergoes multi-stage cyclone separation in the induced draft fan and then enters the collection tank. The lithium powder is sieved through a vibrating sieve to obtain micro-powder grade lithium oxide.

The mass of the micronized lithium oxide obtained in this example is 10.803kg, the purity of the micronized lithium oxide is 99.374%, and the particle size is D10=4.805μm, D50=25.201μm, and D90=64.745μm.

Example 3

Add 8kg of metallic lithium with a purity of 99.99% into the titanium crucible, evacuate to 8×10 ^-3 Pa, and heat at 395°C for 65 minutes to obtain completely melted metallic lithium;

Adjust the nozzle angle of the spray plate to 45°, introduce oxygen with a purity of 99.99% at an air pressure of 5MPa, open the diversion nozzle valve, lift the metal blocking rod at the bottom of the titanium crucible, and allow the metallic lithium liquid to flow through the diversion nozzle at 350°C. To the spray plate, it is broken and atomized by oxygen injection, and the broken lithium metal liquid undergoes an oxidation reaction with oxygen to obtain lithium oxide droplets;

The lithium oxide droplets are passed into a cooling chamber in which the cooling medium is cosmetic-grade white oil and are cooled to 25°C to obtain lithium oxide powder. The lithium oxide powder undergoes multi-stage cyclone separation in an induced draft fan and then enters the collection tank, where the oxidized water in the collection tank is removed. The lithium powder is sieved through a vibrating sieve to obtain micro-powder grade lithium oxide.

The mass of the micronized lithium oxide obtained in this example is 17.289kg, the purity of the micronized lithium oxide is 99.332%, and the particle size is D10=5.731μm, D50=30.390μm, and D90=78.716μm.

Example 4

Add 5kg of metallic lithium with a purity of 99.99% into the titanium crucible, evacuate to 5×10 ^-3 Pa, and heat at 400°C for 60 minutes to obtain completely melted metallic lithium;

Adjust the nozzle angle of the spray plate to 60°, introduce oxygen with a purity of 99.99% at an air pressure of 4MPa, open the diversion nozzle valve, lift the metal blocking rod at the bottom of the titanium crucible, and allow the metallic lithium liquid to flow through the diversion nozzle at 250°C. To the spray plate, it is broken and atomized by oxygen injection, and the broken lithium metal liquid undergoes an oxidation reaction with oxygen to obtain lithium oxide droplets;

The lithium oxide droplets are passed into a cooling chamber in which the cooling medium is cosmetic-grade white oil and are cooled to 20°C to obtain lithium oxide powder. The lithium oxide powder undergoes multi-stage cyclone separation in an induced draft fan and then enters the collection tank. The oxidation in the collection tank is The lithium powder is sieved through a vibrating sieve to obtain micro-powder grade lithium oxide.

The mass of the micro-powder grade lithium oxide obtained in this example is 10.804kg, the purity of the micro-powder grade lithium oxide is 99.351%, and the particle size is D10=4.168 μm, D50=27.022 μm, and D90=69.069 μm.

The above are only preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications can also be made. should be regarded as the protection scope of the present invention.

Claims (10)

1. The preparation method of the micro-powder lithium oxide is characterized by comprising the following steps of:

1) Heating and melting metallic lithium, and then blowing oxygen to perform oxidation reaction to obtain lithium oxide liquid drops;

2) And cooling the lithium oxide liquid drops, and sequentially separating and sieving to obtain the micro-powder lithium oxide.

2. The method for preparing micro-powder lithium oxide according to claim 1, wherein the purity of the metal lithium is not less than 99.9%.

3. The method for preparing micro-powder lithium oxide according to claim 1, wherein the heating and melting are performed in a vacuum state, and the vacuum degree in the vacuum state is not more than 1 x 10 ^-1 Pa。

4. The method for preparing micro-powder lithium oxide according to claim 3, wherein the temperature of the heating and melting is 390-410 ℃, and the time of the heating and melting is 50-70 min.

5. A method for preparing a micro-powder grade lithium oxide according to claim 2 or 3, wherein the purity of the oxygen is not less than 99.99%.

6. The method for preparing micro-powder lithium oxide according to claim 5, wherein the gas pressure of the blowing is not less than 4MPa.

7. The method for preparing micro-powder lithium oxide according to claim 6, wherein the cooling temperature is less than or equal to 25 ℃, and the cooling medium is white oil.

8. The method of claim 7, wherein the separation is a multi-cyclone separation.

9. The fine powder lithium oxide produced by the process for producing fine powder lithium oxide according to any one of claims 1 to 8.

10. The micro-powder lithium oxide according to claim 9, wherein the D90 of the micro-powder lithium oxide is 60 to 80 μm.