A kind of purification method of ammonium metavanadate deep silicon removal

Abstract

The invention discloses a purification method for deep desiliconization of ammonium metavanadate. 7-9, (5) filtration to obtain ammonium metavanadate. The method of the invention does not use flake caustic soda, does not generate waste water, and the obtained products are high-purity ammonium metavanadate and ammonium sulfate solutions, which can be recycled.

Description

technical field

[0001] The invention relates to a purification method for deeply removing silicon by ammonium metavanadate, which belongs to the field of metallurgical chemistry of vanadium and also belongs to the field of high-purity vanadium. Background technique

[0002] High-purity ammonium metavanadate refers to ammonium metavanadate with extremely low impurity content and high purity. It is a high-end product in the market and is mainly used in the production of catalysts and vanadium battery electrolytes. It has extremely high requirements for various impurity elements.

[0003] Usually, the production method of high-purity ammonium metavanadate is to add crude ammonium metavanadate to alkali solution water to form sodium metavanadate solution, and then add ammonium salt to precipitate it to obtain ammonium metavanadate. However, this remelting method is only effective for removing impurities of some metal ions, and is ineffective for removing silicon, that is, the si...

Examples

Embodiment 1

[0028] The crude ammonium metavanadate has a silicon content of 150ppm and other impurities not exceeding 150ppm. Granularity report see figure 1 .

[0029] Take 300g of the above-mentioned ammonium metavanadate, put it into 800ml water, stir and heat to 70°C, add 92.5% sulfuric acid, adjust the pH to 2.5, add acid for 10min, continue stirring for 30min, filter, the filtrate is ammonium sulfate solution, and the solid is polyvanadate Ammonium filter cake, containing 15% moisture;

[0030] Stir, add the ammonium polyvanadate filter cake to ammonia water, control the end point pH to 8, continue to stir for 30min, filter, the filtrate contains V 2 o 5 3g / L, used as a solution for converting crude ammonium metavanadate into ammonium polyvanadate; the filter cake was dried to obtain ammonium metavanadate A296g, the extraction rate of vanadium was 98.7%, and the silicon content was 35ppm.

Embodiment 2

[0037] Crude product ammonium metavanadate, with embodiment 1, silicon content is 150ppm, and other impurity is no more than 150ppm.

[0038] Take 300g of the above-mentioned ammonium metavanadate, put it into 800ml of water, stir and heat to 80°C, add 92.5% sulfuric acid, adjust the pH to 2.5, add acid for 120min, continue stirring for 5h, filter, the filtrate is ammonium sulfate solution, and the solid is polyvanadate Ammonium filter cake, containing 60% moisture;

[0039] Stir, add the ammonium polyvanadate filter cake to ammonia water, control the end point pH to 8, continue to stir for 30min, filter, the filtrate contains V 2 o 5 3.1g / L, the filter cake was dried to obtain ammonium metavanadate B with a silicon content of 20ppm.

[0040] The difference between embodiment 2 and embodiment 1 is the time of adding acid and the stirring time after adding acid, here will contrast the influence of adding time of acid on ammonium metavanadate. Moisture analysis shows that th...

Embodiment 3

[0042] Crude product ammonium metavanadate, with embodiment 1, silicon content is 150ppm, and other impurity is no more than 150ppm.

[0043] Take 500g of the above-mentioned ammonium metavanadate, put it into 800ml of water, stir and heat to 90°C, add 60% sulfuric acid, adjust the pH to 2.5, add acid for 120min, continue stirring for 5h, filter, the filtrate is ammonium sulfate solution, and the solid is polyvanadate Ammonium filter cake;

[0044] Stir, add the ammonium polyvanadate filter cake to ammonia water, control the end point pH to 8, continue to stir for 30min, filter, the filtrate contains V 2 o 5 1.7g / L, the filter cake was dried to obtain ammonium metavanadate C with a silicon content of 47ppm.

[0045] The difference between embodiment 3 and embodiment 2 is that the feeding amount of ammonium metavanadate is increased from 300g to 500g, and the silicon content of the product is higher than that of embodiment 2. This shows that the amount of feed will affect t...

technical field

[0001] The invention relates to a purification method for deeply removing silicon by ammonium metavanadate, which belongs to the field of metallurgical chemistry of vanadium and also belongs to the field of high-purity vanadium. Background technique

[0002] High-purity ammonium metavanadate refers to ammonium metavanadate with extremely low impurity content and high purity. It is a high-end product in the market and is mainly used in the production of catalysts and vanadium battery electrolytes. It has extremely high requirements for various impurity elements.

[0003] Usually, the production method of high-purity ammonium metavanadate is to add crude ammonium metavanadate to alkali solution water to form sodium metavanadate solution, and then add ammonium salt to precipitate it to obtain ammonium metavanadate. However, this remelting method is only effective for removing impurities of some metal ions, and is ineffective for removing silicon, that is, the si...

Examples

Embodiment 1

[0028] The crude ammonium metavanadate has a silicon content of 150ppm and other impurities not exceeding 150ppm. Granularity report see figure 1 .

[0029] Take 300g of the above-mentioned ammonium metavanadate, put it into 800ml water, stir and heat to 70°C, add 92.5% sulfuric acid, adjust the pH to 2.5, add acid for 10min, continue stirring for 30min, filter, the filtrate is ammonium sulfate solution, and the solid is polyvanadate Ammonium filter cake, containing 15% moisture;

[0030] Stir, add the ammonium polyvanadate filter cake to ammonia water, control the end point pH to 8, continue to stir for 30min, filter, the filtrate contains V 2 o 5 3g / L, used as a solution for converting crude ammonium metavanadate into ammonium polyvanadate; the filter cake was dried to obtain ammonium metavanadate A296g, the extraction rate of vanadium was 98.7%, and the silicon content was 35ppm.

Embodiment 2

[0037] Crude product ammonium metavanadate, with embodiment 1, silicon content is 150ppm, and other impurity is no more than 150ppm.

[0038] Take 300g of the above-mentioned ammonium metavanadate, put it into 800ml of water, stir and heat to 80°C, add 92.5% sulfuric acid, adjust the pH to 2.5, add acid for 120min, continue stirring for 5h, filter, the filtrate is ammonium sulfate solution, and the solid is polyvanadate Ammonium filter cake, containing 60% moisture;

[0039] Stir, add the ammonium polyvanadate filter cake to ammonia water, control the end point pH to 8, continue to stir for 30min, filter, the filtrate contains V 2 o 5 3.1g / L, the filter cake was dried to obtain ammonium metavanadate B with a silicon content of 20ppm.

[0040] The difference between embodiment 2 and embodiment 1 is the time of adding acid and the stirring time after adding acid, here will contrast the influence of adding time of acid on ammonium metavanadate. Moisture analysis shows that th...

Embodiment 3

[0042] Crude product ammonium metavanadate, with embodiment 1, silicon content is 150ppm, and other impurity is no more than 150ppm.

[0043] Take 500g of the above-mentioned ammonium metavanadate, put it into 800ml of water, stir and heat to 90°C, add 60% sulfuric acid, adjust the pH to 2.5, add acid for 120min, continue stirring for 5h, filter, the filtrate is ammonium sulfate solution, and the solid is polyvanadate Ammonium filter cake;

[0044] Stir, add the ammonium polyvanadate filter cake to ammonia water, control the end point pH to 8, continue to stir for 30min, filter, the filtrate contains V 2 o 5 1.7g / L, the filter cake was dried to obtain ammonium metavanadate C with a silicon content of 47ppm.

[0045] The difference between embodiment 3 and embodiment 2 is that the feeding amount of ammonium metavanadate is increased from 300g to 500g, and the silicon content of the product is higher than that of embodiment 2. This shows that the amount of feed will affect t...

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