Method for producing precipitate silicon dioxide by using sodium bicarbonate to control supersaturation degree

A technology for precipitating silica and sodium bicarbonate, which is applied in the direction of silica, etc., can solve problems such as corrosion of equipment, harm to human health, and low precipitation reaction efficiency, and achieve convenient operation, uniform particle size distribution, and strong controllability Effect

Inactive Publication Date: 2013-12-25
INST OF PROCESS ENG CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, ammonium bicarbonate solution is unstable and easily decomposes above 36°C to release CO 2 and NH 3 , the precipitation process is not easy to control, which makes the precipitation reaction less efficient and the particle size distribution of the product is uneven
On the other hand, both ammonium bicarbonate and ammonia water have pungent smell and corrosiveness, endanger human health and corrode equipment

Method used

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  • Method for producing precipitate silicon dioxide by using sodium bicarbonate to control supersaturation degree
  • Method for producing precipitate silicon dioxide by using sodium bicarbonate to control supersaturation degree
  • Method for producing precipitate silicon dioxide by using sodium bicarbonate to control supersaturation degree

Examples

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Effect test

Embodiment 1

[0047] Mix 600g of quartz sand with 1270g of soda ash, and calcinate at 1300°C for 60 minutes to obtain 1205g of solid sodium silicate, while recovering CO 2 . Solid sodium silicate was dissolved in sodium carbonate solution to obtain 1.2mol / L sodium silicate solution.

[0048] Put 500mL of sodium silicate solution in a 10L crystallization reactor, control the temperature at 40°C, turn on the stirrer, and add a sodium bicarbonate solution with a concentration of 2.7mol / L dropwise with a peristaltic pump. By adjusting the drop rate of the solution and To control the degree of supersaturation, a total of 700 mL of sodium bicarbonate solution was added dropwise to precipitate hydrated silica.

[0049] The suspension in the crystallization reactor was filtered. Filter to obtain 1160mL sodium carbonate solution, wherein 500mL sodium carbonate solution absorbs CO 2 Gas, get 2.7mol / L sodium bicarbonate solution, return to the peristaltic pump for recycling; 300mL sodium carbonate ...

Embodiment 2

[0051] Mix 1,000g of quartz sand with 2,650g of soda ash, and calcinate at 1,350°C for 60 minutes to obtain 1,880g of solid sodium silicate, while recovering CO 2 . Solid sodium silicate was dissolved in sodium carbonate solution to obtain 1.2mol / L sodium silicate solution.

[0052] Put 800mL of sodium silicate solution in a 10L crystallization reactor, control the temperature at 45°C, turn on the stirrer, and use a peristaltic pump to add dropwise a sodium bicarbonate solution with a concentration of 2.7mol / L. By adjusting the drop rate of the solution and To control the degree of supersaturation, a total of 1120 mL of sodium bicarbonate solution was added dropwise to precipitate hydrated silica.

[0053] The suspension in the crystallization reactor was filtered. Filter to obtain 1870mL sodium carbonate solution, wherein 800mL sodium carbonate solution absorbs CO 2 Gas, get 2.7mol / L sodium bicarbonate solution, return to the peristaltic pump for recycling; 500mL sodium ca...

Embodiment 3

[0055] Mix 1,000g of quartz sand with 3,000g of soda ash, and calcinate at 1,400°C for 60 minutes to obtain 1,975g of solid sodium silicate, while recovering CO 2 . Solid sodium silicate was dissolved in sodium carbonate solution to obtain 1.2mol / L sodium silicate solution.

[0056] Put 1000mL of sodium silicate solution in a 10L crystallization reactor, control the temperature at 50°C, turn on the stirrer, and use a peristaltic pump to add dropwise a sodium bicarbonate solution with a concentration of 2.7mol / L. By adjusting the drop rate of the solution and To control the degree of supersaturation, a total of 1400 mL of sodium bicarbonate solution was added dropwise to precipitate hydrated silica.

[0057] The suspension in the crystallization reactor was filtered. Filter to obtain 2275mL sodium carbonate solution, wherein 1000mL sodium carbonate solution absorbs CO 2 Gas, get 2.7mol / L sodium bicarbonate solution, return to the peristaltic pump for recycling; 600mL sodium ...

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Abstract

A method for producing precipitate silicon dioxide by using sodium bicarbonate to control a supersaturation degree comprises the steps of taking quartz sand and soda as raw materials, roasting, dissolving a sodium carbonate solution to prepare a sodium silicate solution, allowing the sodium silicate solution to react with a sodium bicarbonate solution, separating out a hydrated silicon dioxide precipitate by a method for controlling the reaction crystallization supersaturation degree, washing and drying the filtered precipitate, and finally obtaining precipitate silicon dioxide, namely white carbon black. Filtered filtrate is the sodium carbonate solution which is recycled for absorbing carbon dioxide from a roasting working section to prepare a concentrated sodium bicarbonate solution required for crystallization reaction, dissolving solid sodium silicate, and returning to the quartz sand roasting working section after evaporation and concentration. Precipitate silicon dioxide prepared by the method is high in purity and uniform in particle size distribution; materials are recycled during the whole production flow; and the problem of sodium sulfate sewage discharge in conventional production is solved.

Description

technical field [0001] The invention belongs to the field of precipitated silica production, and in particular relates to a method for preparing precipitated silica by crystallization through the reaction of sodium silicate solution and sodium bicarbonate solution to control supersaturation through the sodium bicarbonate solution. Background technique [0002] Precipitated silica is commonly known as white carbon black, also known as hydrated silica, and its molecular formula is SiO 2 ·nH 2 O, is a white, non-toxic, amorphous ultrafine powder with excellent properties such as porosity, high dispersibility, light weight, good chemical stability, high temperature resistance, non-combustion and good electrical insulation. Silica is an important inorganic chemical raw material, which is widely used in the fields of rubber, plastics, coatings, papermaking, medicine, pesticides and daily chemicals. At present, 70% of the world's silica is used in the rubber industry, and it is a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/113
Inventor 李志宝曾艳
Owner INST OF PROCESS ENG CHINESE ACAD OF SCI
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