Method for producing pure silicon by using by-product silica gel in phosphate fertilizer industry

A silica gel and by-product technology, applied in chemical instruments and methods, silicon compounds, inorganic chemistry, etc., can solve the problems of increasing the burden of refining and purification, unrealized industrial production, and insignificant economic benefits, and achieve good social and economic benefits. , Conducive to protection and effective utilization, and the effect of environmental pollution control

Active Publication Date: 2014-04-23
云南云天化国际化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the metallothermic reduction method is mostly used in laboratories, and its cost mainly depends on the cost of raw materials, while the price of aluminum metal powder is relatively high, and the energy efficiency of resources is low, and the Si-Al alloy is prepared first and then refined and purified, which increases the burden of refining and purification , the economic benefits are not obvious, and it is difficult to realize industrialization
In addition, there are no other studies and related reports
[0016] Due to the huge output of phosphate fertilizer by-product silica gel, and the molten salt electrolysis method is still in the laboratory exploration stage, the production capacity is limited, and industrial production has not been realized. Therefore, the carbothermal reduction method with relatively mature industrial production technology was selected in the test.

Method used

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  • Method for producing pure silicon by using by-product silica gel in phosphate fertilizer industry
  • Method for producing pure silicon by using by-product silica gel in phosphate fertilizer industry
  • Method for producing pure silicon by using by-product silica gel in phosphate fertilizer industry

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] After the raw materials are pretreated, according to the material ratio (C-Si ratio) as , material ratio (charcoal-petroleum coke ratio) is Perform batching; send the mixture into a high-temperature carbon tube furnace, and the preheating condition is to vacuumize to 5.0×10 -3 mbar (1mbar=100Pa), the temperature rises to 600°C, and the heating rate is 50°C·min -1 , keep warm for 20min; the protective atmosphere condition is to evacuate to 5.0×10 -2 Below mbar, argon is used as the protective gas, the protective gas pressure is 0.02MPa, and the protective gas flow rate is 7.5CFH (1CFH=472 cm 3 min -1 ), the pressure is 25mbar, the temperature rises to 1825°C, and the heating rate is 50°C·min -1 , keep warm for 25min; cool to room temperature, the product can be obtained.

Embodiment 2

[0049] After the raw materials are pretreated, according to the material ratio (C-Si ratio) as , material ratio (charcoal-petroleum coke ratio) is Perform batching; send the mixture into a high-temperature carbon tube furnace, and the preheating condition is to vacuumize to 5.0×10 -3 mbar (1mbar=100Pa), heating up to 600℃, the heating rate is 50℃·min -1 , keep warm for 20min; the protective atmosphere condition is to evacuate to 5.0×10 -2 Below mbar, argon is used as the protective gas, the protective gas pressure is 0.02MPa, and the protective gas flow rate is 7.5CFH (1CFH=472 cm 3 min -1 ), the pressure is 25mbar, the temperature rises to 1825°C, and the heating rate is 50°C·min -1 , keep warm for 25min; after the reaction product is cooled and crushed, when the silicon powder particle size is D=150~75μm, the wet purification stage is two stages, the leaching agent is 8.00% HCl, 5.15% HF, and the liquid-solid ratio is 5:1, the stirring rate is 140 rad min -1 Under ...

Embodiment 3

[0051] After the raw materials are pretreated, according to the material ratio (C-Si ratio) as , material ratio (charcoal-petroleum coke ratio) is Perform batching; send the mixture into a high-temperature carbon tube furnace, and the preheating condition is to vacuumize to 5.0×10 -3 mbar (1mbar=100Pa), heating up to 500~700℃, the heating rate is 25~50℃·min -1 , keep warm for 10-30 minutes; the protective atmosphere condition is to vacuumize to 5.0×10 -2 Below mbar, argon is used as the protective gas, the protective gas pressure is 0.02MPa, and the protective gas flow rate is 7.5CFH (1CFH=472 cm 3 min -1 ), the pressure is 50mbar, the temperature rises to 1775°C, and the heating rate is 50°C·min -1 , keep warm for 30min; after the reaction product is cooled and crushed, when the particle size of silicon powder is D=150~75μm, the number of wet purification stages is two, the leaching agent is 8.00% HCl, 5.15% HF, and the liquid-solid ratio is 5:1, the stirring rate is...

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Abstract

The invention relates to a method for producing pure silicon by using by-product silica gel in a phosphate fertilizer industry, which belongs to the fields of inorganic chemical industry, resource comprehensive utilization of the by-product silica gel in the phosphate fertilizer industry and the production technology of pure silicon. In the method, pure silicon is produced from the by-product silica gel in the phosphate fertilizer industry, which is used as a silicon source, by a carbon thermal reduction method. The method comprises the following steps of: a. pretreatment of raw materials; b. material mixing; c. reaction; d. cooling; e. crushing; f. wet purification; g. washing with water to be neutral after the wet purification, and then drying; h. vacuum refining; and i. finally cooling. The invention takes the by-product silica gel in the phosphate fertilizer industry as the silicon source, develops a new product and a new technology of the resource comprehensive utilization of the by-product silica gel in the phosphate fertilizer industry; the method has the advantages of simple process, low cost, high purity and the like, not only is favorable for the environmental pollution control in the phosphate fertilizer industry, but also is favorable for the protection and effective utilization of silicon resource associated with phosphate ores. Meanwhile, the method also brings good social and economic benefits.

Description

technical field [0001] The invention belongs to the field of inorganic chemical industry, relates to a method for producing pure silicon by using silica gel by-product of phosphate fertilizer, and relates to the technical field of resource utilization and comprehensive utilization of silica gel by-product of phosphorous fertilizer and production of pure silicon. Background technique [0002] Phosphate fertilizer by-product silica gel mainly comes from the absorption process of fluorine-containing waste gas and the process of producing fluoride (sodium fluoride, ammonium fluoride, aluminum fluoride, cryolite, hydrogen fluoride, etc.) using fluorosilicate solution. With the improvement of fluorine recovery technology in my country's phosphate fertilizer industry, the discharge of phosphate fertilizer by-product silica gel will increase, which will inevitably cause waste of resources and environmental pollution. [0003] Silicon ( ) material is the basic material of the micro...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B33/025C01B33/037
Inventor 明大增李英翔李志祥李崇贵李勇辉
Owner 云南云天化国际化工有限公司
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