Fluorine-containing wastewater resource treatment and utilization method

A recycling and waste water technology, applied in the direction of chemical instruments and methods, multi-stage water treatment, water/sewage treatment, etc., can solve the problems of waste of resources, secondary pollution, occupation of land resources, etc., and achieve simple equipment and mild process conditions Effect

Inactive Publication Date: 2020-03-24
中广核环境科技(深圳)有限责任公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method is a harmless disposal method, but a large amount of waste water and waste residues are produced after treatment. The treatment of these waste water and waste residues not only takes up a lot of land resources, but also may cause secondary pollution, which is a waste of resources

Method used

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  • Fluorine-containing wastewater resource treatment and utilization method
  • Fluorine-containing wastewater resource treatment and utilization method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] 1) Adjust the pH value of the system: take 1000mL of fluorine-containing wastewater (main components of fluorosilicic acid, hydrofluoric acid, nitric acid, fluorine content of 160g / L, silicon content of 160g / L, nitrate content of 200g / L), slowly add 1000mL of mass concentration The first precipitation agent is 28% ammonia water, the stirring reaction time is 30min, the reaction temperature is 20°C, and the pH value of the solution after the reaction is controlled to be 8.5.

[0027] 2) Step 1) After the reaction is completed, the solution is filtered to obtain mother liquor A and silica sol.

[0028] 3) The silica sol was washed with water, filtered, and dried to obtain 326.5 g of a precipitated silica product, and the washed wastewater was mixed with mother liquor A for subsequent treatment. After testing, the silicon dioxide content in the silicon dioxide product obtained in this example is 93.6%, which meets the industry standard (HG / T 3061-2009, the silicon dioxide ...

Embodiment 2

[0034] 1) Adjust the pH value of the system: take 1000mL of fluorine-containing wastewater (main components of fluorosilicic acid, hydrofluoric acid, nitric acid, fluorine content 160g / L, silicon content 160g / L, nitrate content 200g / L), slowly add 1600g A precipitant ammonium carbonate, the stirring reaction time is 30min, the reaction temperature is 20°C, and the pH value of the solution after the reaction is controlled to be 8.5.

[0035] 2) Step 1) After the reaction is completed, the solution is filtered to obtain mother liquor A and silica sol.

[0036] 3) The silica sol was washed with water, filtered, and dried to obtain 334.5 g of a precipitated silica product, and the washed wastewater was mixed with mother liquor A for subsequent treatment. After testing, in the silicon dioxide product obtained in this embodiment, the silicon dioxide content is 92.5%, which meets the industry standard (HG / T 3061-2009, the silicon dioxide content (dry product) is greater than 90%), an...

Embodiment 3-4

[0042] In Example 3-4, except that the pH value of the solution after the reaction in step 1) is different, the others are the same as in Example 1. See Table 1 for the specific pH value and the properties of the obtained product.

[0043] Table 1

[0044] pH value Silica yield and purity Calcium Fluoride Yield and Purity Example 3 7.5 67.5%,93.9% 98.2%,99.4% Example 4 13 76%,90.5% 98.2%,99.4%

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Abstract

The invention relates to a fluorine-containing wastewater resource treatment and utilization method. The method includes the steps of: 1, slowly adding a first precipitant into fluorine-containing wastewater, carrying out reaction, controlling the pH value of the wastewater at 7-14, and performing filtering to obtain a first mother solution and silica sol, and conducting washing and drying on thesilica sol to obtain white carbon black; 2, adding a second precipitant into the first mother solution, carrying out reaction, and then performing filtering to obtain a second mother solution and a fluoride, conducting pickling, washing and drying on the fluoride, and then performing recovery; and 3, carrying out wastewater treatment on the second mother solution. The fluorine-containing wastewater resource treatment and utilization method provided by the invention can enable effective recycling of fluorine, silicon, nitrogen and other elements in the wastewater, for example, silicon is converted into a precipitated white carbon black product meeting the industrial standard, and fluorine is converted into a fluoride product meeting the national standard; and the method is mild in process conditions and simple in equipment, thus being easy to realize industrialization.

Description

technical field [0001] The invention relates to a method for resource disposal and utilization of fluorine-containing waste water, in particular to separately extracting and resource utilization of effective resources in waste water through chemical methods, and belongs to the technical field of waste water treatment. Background technique [0002] In the production process of photovoltaic industry, electronics industry and other industries, hydrofluoric acid, hydrochloric acid, nitric acid, etc. are compounded to form fluorine-containing mixed acid for surface treatment. The wastewater after surface treatment is highly toxic and harmful. At present, the process of neutralization and precipitation is used to treat this type of wastewater, that is, lime, carbide slag, and sodium hydroxide are used for neutralization to obtain calcium fluoride, calcium hydroxide, and fluoride. The mixture of sodium chloride and the like precipitates, and is filtered and separated to form waste ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/04C02F101/14
CPCC02F1/001C02F1/5236C02F1/66C02F9/00C02F2101/14C02F2301/08
Inventor 周祯
Owner 中广核环境科技(深圳)有限责任公司
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