Unlock instant, AI-driven research and patent intelligence for your innovation.

A method for producing high-purity silicon dioxide using fly ash

A technology of silicon dioxide and fly ash, applied in the direction of silicon dioxide, silicon oxide, etc., can solve the problems of low waste residue discharge, high energy consumption for evaporation concentration, high acid dissolution temperature, high purity, simple process, Uniform particle size effect

Inactive Publication Date: 2018-07-10
SHAANXI NORMAL UNIV
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This process realizes the recycling of raw materials, reduces acid consumption and alkali consumption, and reduces waste residue discharge. However, the roasting and decomposition of aluminum sulfate and the evaporation of sodium hydroxide consume a lot of energy, the acid concentration is high, the corrosion is strong, and the acid dissolution temperature is high. Operation cumbersome, harsh conditions

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A method for producing high-purity silicon dioxide using fly ash
  • A method for producing high-purity silicon dioxide using fly ash
  • A method for producing high-purity silicon dioxide using fly ash

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] 1. Add 10 g of ground and activated fly ash (49.2% silicon dioxide content) into 30 g of glacial acetic acid, mix well, and react with stirring at room temperature for 1 hour to fully remove other impurity components except silicon in the fly ash, Filter to obtain acid leaching residue.

[0019] 2. Add the acid leaching residue obtained in step 1 into the aqueous sodium hydroxide solution with a mass fraction of 15%, and mix evenly, wherein the mass ratio of the acid leaching residue and the aqueous sodium hydroxide solution with a mass fraction of 15% is 1:4.5. Stir and react at 100°C for 2 hours, dissolve silicon in the form of sodium silicate, filter, and wash with distilled water six times the mass of sodium hydroxide aqueous solution to obtain sodium silicate extract.

[0020] 3. Adjust the pH of the sodium silicate extract to neutrality with glacial acetic acid under ultrasonic conditions to form a large amount of silica gel, filter it with suction, wash the silic...

Embodiment 2

[0022] 1. Add 10 g of ground and activated fly ash (with a silicon dioxide content of 47.6%) in 20 g of glacial acetic acid, mix evenly, and react with stirring at room temperature for 1 hour to fully remove other impurity components except silicon in the fly ash, Filter to obtain acid leaching residue.

[0023]2. Add the acid leaching residue obtained in step 1 into 15% aqueous sodium hydroxide solution and mix evenly, wherein the mass ratio of acid leaching residue to 15% aqueous sodium hydroxide solution is 1:4. Stir and react at 100°C for 2 hours, dissolve silicon in the form of sodium silicate, filter, and wash with distilled water 8 times the mass of sodium hydroxide aqueous solution to obtain sodium silicate extract.

[0024] 3. Adjust the pH of the sodium silicate extract to neutrality with glacial acetic acid under ultrasonic conditions to form a large amount of silica gel, filter it with suction, wash the silica gel with distilled water, and freeze-dry to obtain sili...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a method for producing high-purity silicon dioxide by utilizing flyash. The method comprises the following steps: carrying out sour molten activation on the flyash by using organic acid at first to remove other impurities except silicon; then carrying out alkali dissolution with a NaOH aqueous solution; dissolving silicon in the flyash in the form of sodium silicate; and finally, under the ultrasonic or stirring condition, dropwise adding the organic acid until the mixture is neutral and silica gel is produced, filtering and drying to obtain the high-purity silicon dioxide. The traditional thinking of dissolving the flyash by using inorganic acid is broken through, silicon dioxide is extracted by combining the organic acid and inorganic base and using an ultrasonic or stirring method, the silicon in the flyash can be extracted effectively, the aluminum-silicon rate is reduced, and aluminum-silicon separation is realized. An operation process is simple and easy to control, low in investment, low in cost, high in added value of products and high in universality, and is a flyash refining, comprehensive utilizing and industrializing method with good prospect.

Description

technical field [0001] The invention belongs to the technical field of comprehensive resource utilization of fly ash, and in particular relates to a method for extracting high-purity silicon dioxide from fly ash waste. Background technique [0002] With the development of the electric power industry, the amount of fly ash discharged from power plants increases accordingly. Fly ash is piled up in ash and discarded aside, which not only occupies a large amount of land, but also seriously pollutes the environment. The comprehensive utilization of fly ash can not only consume a large amount of fly ash, alleviate its pollution to the environment, reduce land occupation, but also produce light, high-strength, and heat-retaining new building materials for the construction industry, replacing clay bricks. It is used for the production of concrete, road construction, backfilling, etc., serving multiple purposes. Collecting a large amount of fly ash and how to effectively use it has ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C01B33/12
CPCC01B33/12C01P2006/80
Inventor 高梦凡马红竹林青雯李文韵许丹丹武敏
Owner SHAANXI NORMAL UNIV