A method for extracting pure calcium fluoride from calcium fluoride sludge

A technology for producing calcium fluoride and calcium fluoride, applied in the field of calcium fluoride sludge treatment, can solve problems such as shortage of fluorine resources, achieve simple process, easy batch continuous production, and solve the effect of secondary fluorine pollution

Active Publication Date: 2021-11-30
盛隆资源再生(无锡)有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The present invention can effectively treat calcium fluoride sludge, avoid causing secondary pollution, and can recycle calcium fluoride in the sludge to solve the problem of shortage of fluorine resources

Method used

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  • A method for extracting pure calcium fluoride from calcium fluoride sludge

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Effect test

Embodiment 1

[0028] In this implementation case, calcium fluoride sludge produced in the photovoltaic industry is used as raw material, and the purity of calcium fluoride in the raw sludge is 37.03%. The treatment is carried out according to the experimental method of the present invention, and the specific steps are as follows.

[0029] Beating and dissolving: Weigh 100g of calcium fluoride sludge into a beaker, add 100ml of water, heat and stir at 50°C for 30min to obtain a uniformly dispersed solid-liquid mixture.

[0030] Caustic soda desiliconization: add 8g sodium hydroxide to the solid-liquid mixture, stir for 2 hours to completely convert the silicon dioxide in the sludge into sodium silicate, filter to obtain filter cake 1 and sodium silicate solution; add in 2 times Add 100ml of water to the filter cake 1 to clean the residual sodium salt in the filter cake.

[0031] Calcium salt conversion: add 100ml of water to the filter cake 1 and stir it evenly, add 2g of sodium carbonate to...

Embodiment 2

[0035] In this implementation case, calcium fluoride sludge produced in the photovoltaic industry is used as raw material, and the purity of calcium fluoride in the raw sludge is 37.03%. The treatment is carried out according to the experimental method of the present invention, and the specific steps are as follows.

[0036] Beating and dissolving: Weigh 100g of calcium fluoride sludge into a beaker, add 150ml of water, heat and stir at 55°C for 30min to obtain a uniformly dispersed solid-liquid mixture.

[0037] Caustic soda desiliconization: add 8g sodium hydroxide to the solid-liquid mixture, stir for 2 hours to completely convert the silicon dioxide in the sludge into sodium silicate, filter to obtain filter cake 1 and sodium silicate solution; add in 2 times Add 150ml of water to the filter cake 1 to clean the residual sodium salt in the filter cake.

[0038] Calcium salt conversion: add 150ml of water to the filter cake 1 and stir it evenly, add 2g of sodium carbonate to...

Embodiment 3

[0042] In this implementation case, calcium fluoride sludge produced in the photovoltaic industry is used as raw material, and the purity of calcium fluoride in the raw sludge is 37.03%. The treatment is carried out according to the experimental method of the present invention, and the specific steps are as follows.

[0043] Beating and dissolving: Weigh 100g of calcium fluoride sludge into a beaker, add 200ml of water, heat and stir at 60°C for 30min to obtain a uniformly dispersed solid-liquid mixture.

[0044]Caustic soda desiliconization: add 8g sodium hydroxide to the solid-liquid mixture, stir for 2 hours to completely convert the silicon dioxide in the sludge into sodium silicate, filter to obtain filter cake 1 and sodium silicate solution; add in 2 times Add 200ml of water to the filter cake 1 to clean the residual sodium salt in the filter cake.

[0045] Calcium salt conversion: add 200ml of water to the filter cake 1 and stir it evenly, add 2g of sodium carbonate to ...

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Abstract

The invention discloses a method for extracting pure calcium fluoride from calcium fluoride sludge. The method comprises the following steps: 1) beating and dissolving; 2) removing silicon with caustic soda to obtain filter cake A and solution A; 3) calcium fluoride Salt conversion; 4) Acidification with hydrochloric acid to obtain calcium fluoride and solution C; 5) Drying and crushing: put the acidified calcium fluoride in an oven at 105°C for drying, and pulverize with a pulverizer to obtain a powder Pure Calcium Fluoride. The invention can effectively treat the calcium fluoride sludge, avoid causing secondary pollution, and can recycle the calcium fluoride in the sludge to solve the problem of shortage of fluorine resources.

Description

technical field [0001] The invention relates to the field of calcium fluoride sludge treatment, in particular to a method for extracting pure calcium fluoride from calcium fluoride sludge. Background technique [0002] Calcium fluoride sludge mainly comes from inorganic and organic fluorine chemical companies, touch screen manufacturers and the photovoltaic industry. These companies discharge a large amount of fluorine-containing wastewater in the process of processing monocrystalline silicon wafers, cells and components. The main method used by enterprises to treat fluorine-containing wastewater is chemical precipitation and coagulation. Generally, calcium chloride, calcium hydroxide or calcium carbonate is added to form calcium fluoride precipitation, followed by flocculation treatment. The amount of sludge produced by the chemical precipitation method is relatively large, and most of the sludge is composed of calcium fluoride, calcium carbonate, silicon dioxide and other ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01F11/22C02F11/00C01D5/00
Inventor 刘秋月陈琪朗超方稳夏鹏辉
Owner 盛隆资源再生(无锡)有限公司
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