Preparation method of lithium phosphate

Abstract

The invention provides a preparation method of lithium phosphate. The method comprises the following steps: (1) introducing carbon dioxide into water, adding industrial level lithium carbonate, further adding a precipitating agent, continuously introducing the carbon dioxide till the pH value of solution is 8-9, filtering and collecting lithium bicarbonate solution, wherein the raw material lithium carbonate is the industrial level lithium carbonate; (2) adding phosphoric acid into the lithium bicarbonate solution in the step (1) till the pH value of the solution is 6-6.5, heating to 65-70 DEG C, stirring, using ammonia water to regulate the pH value of the solution to 8-8.5, and then carrying out solid-liquid separation at the temperature of 90-95 DEG C, thus obtaining a lithium phosphate wet material; and (3) carrying out vacuum drying on the lithium phosphate wet material, thus obtaining the product. By utilizing the preparation method, the shortcomings of the traditional production process can be solved, the process is simple, the material phase is single, the preparation method ensures not to introduce a large number of other impurity elements, hydrochloric acid is not used during the process, special anti-corrosion treatment does not need to be carried out on reaction equipment, the environment is not influenced basically, and the yield of the process can be more than 97%.

Description

technical field

[0001] The invention relates to a preparation method of lithium phosphate. Background technique

[0002] Lithium phosphate is the basic element that constitutes the lithium iron phosphate required for making lithium-ion batteries, and is also one of the necessary raw materials for the production of colored fluorescent pink powder (hereinafter referred to as red powder).

[0003] Internationally, the application of lithium phosphate in red powder is relatively early and common. Lithium phosphate and lithium carbonate are added as flux in the production of red powder. After mixing, the function is to change the particle size, brightness and chromaticity of red powder to meet the requirements of color picture tube coating. Color picture tube is the core component of color TV, but with the continuous advancement of science and technology, picture tube TV has been marginalized, so that the amount of lithium phosphate in color powder has dropped significantly. Ho...

Examples

Embodiment 1

[0024] (1) 1.8M 3 Add 1400L of pure water into the stainless steel reaction tower, turn on carbon dioxide, control the pressure at 0.2Mpa, add 60Kg of industrial grade lithium carbonate, then add 0.12Kg oxalic acid and 0.29Kg barium hydroxide, continue to feed carbon dioxide until the pH of the solution is 9, and then add The solution obtained is filtered with a polypropylene plate and frame filter press to collect lithium bicarbonate solution;

[0025] (2) at 5M 3 In the stainless steel reaction kettle, add 4000L of lithium bicarbonate solution in step (1), add 186Kg of food-grade phosphoric acid under stirring until the solution pH=6, heat to 70°C and stir for 30 minutes, adjust the solution with ammonia water with a weight concentration of 25% pH = 8, then solid-liquid separation at 95°C, the separation time is not less than 30 minutes, 182.66Kg of lithium phosphate wet material is obtained, and the weight content of water is 5.5%;

[0026] (3) Add the lithium phosphate w...

Embodiment 2

[0029] (1) 1.8M 3 Add 1400L of pure water into the stainless steel reaction tower, turn on carbon dioxide, control the pressure at 0.15Mpa, add 60Kg of industrial grade lithium carbonate, then add 0.16Kg oxalic acid and 0.32Kg barium hydroxide, continue to feed carbon dioxide until the pH of the solution=8, and then add The obtained solution is filtered with a polypropylene plate and frame filter press to collect lithium bicarbonate solution;

[0030] (2) at 5M 3 In the stainless steel reaction kettle, add 4000L of lithium bicarbonate solution in step (1), add food-grade phosphoric acid 188Kg under stirring, until the solution pH=6.0, heat to 70°C and stir for 30 minutes, adjust the solution with ammonia water with a weight concentration of 25% pH = 8.2, then solid-liquid separation at 95°C, the separation time is not less than 30 minutes, 183.95Kg of lithium phosphate wet material is obtained, and the weight content of water is 5.9%;

[0031] (3) Add the lithium phosphate w...

technical field

[0001] The invention relates to a preparation method of lithium phosphate. Background technique

[0002] Lithium phosphate is the basic element that constitutes the lithium iron phosphate required for making lithium-ion batteries, and is also one of the necessary raw materials for the production of colored fluorescent pink powder (hereinafter referred to as red powder).

[0003] Internationally, the application of lithium phosphate in red powder is relatively early and common. Lithium phosphate and lithium carbonate are added as flux in the production of red powder. After mixing, the function is to change the particle size, brightness and chromaticity of red powder to meet the requirements of color picture tube coating. Color picture tube is the core component of color TV, but with the continuous advancement of science and technology, picture tube TV has been marginalized, so that the amount of lithium phosphate in color powder has dropped significantly. Ho...

Examples

Embodiment 1

[0024] (1) 1.8M 3 Add 1400L of pure water into the stainless steel reaction tower, turn on carbon dioxide, control the pressure at 0.2Mpa, add 60Kg of industrial grade lithium carbonate, then add 0.12Kg oxalic acid and 0.29Kg barium hydroxide, continue to feed carbon dioxide until the pH of the solution is 9, and then add The solution obtained is filtered with a polypropylene plate and frame filter press to collect lithium bicarbonate solution;

[0025] (2) at 5M 3 In the stainless steel reaction kettle, add 4000L of lithium bicarbonate solution in step (1), add 186Kg of food-grade phosphoric acid under stirring until the solution pH=6, heat to 70°C and stir for 30 minutes, adjust the solution with ammonia water with a weight concentration of 25% pH = 8, then solid-liquid separation at 95°C, the separation time is not less than 30 minutes, 182.66Kg of lithium phosphate wet material is obtained, and the weight content of water is 5.5%;

[0026] (3) Add the lithium phosphate w...

Embodiment 2

[0029] (1) 1.8M 3 Add 1400L of pure water into the stainless steel reaction tower, turn on carbon dioxide, control the pressure at 0.15Mpa, add 60Kg of industrial grade lithium carbonate, then add 0.16Kg oxalic acid and 0.32Kg barium hydroxide, continue to feed carbon dioxide until the pH of the solution=8, and then add The obtained solution is filtered with a polypropylene plate and frame filter press to collect lithium bicarbonate solution;

[0030] (2) at 5M 3 In the stainless steel reaction kettle, add 4000L of lithium bicarbonate solution in step (1), add food-grade phosphoric acid 188Kg under stirring, until the solution pH=6.0, heat to 70°C and stir for 30 minutes, adjust the solution with ammonia water with a weight concentration of 25% pH = 8.2, then solid-liquid separation at 95°C, the separation time is not less than 30 minutes, 183.95Kg of lithium phosphate wet material is obtained, and the weight content of water is 5.9%;

[0031] (3) Add the lithium phosphate w...

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