Reducing agent used for producing industrial silicon

Abstract

The invention relates to a reducing agent used for producing industrial silicon, which has the advantages of being high in fixed carbon content, less in dosage, low in cost, good in reaction activity and capable of completely replacing wood charcoal to serve as the base or the main reducing agent of the industrial silicon. The reducing agent comprises the following agent by weight: 30 to 50 parts of washed coal, 20 to 30 parts of high-purity carbon powder and 30 to 40 parts of petroleum coke, wherein the washed coal comprises less than 8% of ash and more than 65% of fixed carbon by mass, the high-purity carbon powder comprises less than 8% of ash and more than 80% of fixed carbon by mass, and the petroleum coke comprises less than 5% of ash and more than 90% of fixed carbon by mass. A preparation method of the reducing agent is further disclosed and includes the following steps 1) mixing the washed coal, the high-purity carbon powder and petroleum coke according to the proportion and crushing the mixture to less than 200 meshes; 2) adding adhesive into the mixture evenly in stirring mode and conducting pelleting and drying; and 3) conducting screening to obtain a bonding product with the granularity as 10mm-30mm.

Description

technical field [0001] The invention relates to a reducing agent composition, in particular to a reducing agent composition for producing industrial silicon. Background technique [0002] Industrial silicon is produced in a submerged arc furnace, and the temperature of the reaction zone reaches above 1500°C by using arc heating, so that the SiO in the silica 2 React with C in the reducing agent to form pure Si:SiO 2 +2C=Si+2CO↑, when the silicon liquid in the furnace accumulates enough, the furnace will be released once. The use of submerged arc furnaces to produce industrial silicon has a history of more than 100 years. Although the capacity, equipment and technical level of industrial silicon submerged arc furnaces are constantly improving, the process formula and reducing agent used in them are more than 100 years old. There has been no substantial breakthrough, and charcoal, wood chips, coal, and petroleum coke have been used as reducing agents. Contents of the inven...

AI Technical Summary

Problems solved by technology

The use of submerged arc furnaces to produce industrial silicon has a history of more than 100 years. Although the capacity, equipment and technical level of industrial silicon submerged arc furnaces are constantly improving, the process formula and reducing agent used in them are more than 100 years old. There has been no substantial breakthrough in the past, and charcoal, wood chips, coal, and petroleum coke have been used as reducing agents.