Method for producing silicon dioxide by using gas phase process

Abstract

The invention relates to a method for producing silicon dioxide by using a gas phase process, which radically solves the problem of high cost of the traditional method for producing the silicon dioxide. The method comprises the steps of: enabling a silicon tetrachloride raw material as a by-product obtained during the production of trichlorosilane, hydrogen and air to enter a combustion reactor respectively by adopting an indirect path and a direct path for reacting to generate silicon dioxide primary particles, wherein the total mol ratio of the silicon tetrachloride raw material to the hydrogen to the air is 1:2.05-7:5.1-198; aggregating the silicon dioxide primary particles through an aggregating device into aggregative state particles, carrying out two stages of cyclone separation of two cyclone separators and spraying and deacidifying through a two-stage air injection deacidifying furnace and entering a bin after deacidifying, and packaging by using vacuum compression; and pre-decontaminating the silicon tetrachloride raw material by using a decontaminating gasifier, wherein the decontaminating gasifier comprises three functional sections of a pre-deslagging section, a gasification section and a high boiling point matter separating section. The invention lowers the production cost on the basis of ensuring the high quality of the silicon dioxide.

Description

technical field [0001] The invention relates to the related technical field of silicon dioxide in inorganic fine chemical industry, in particular to a method for producing silicon dioxide by fumed phase method. Background technique [0002] The important raw materials in the production of silicon dioxide by the gas phase method are inseparable from the raw materials of silicon tetrachloride. Due to the relatively high purity requirements for the raw materials of silicon tetrachloride, generally more than 99.5% can meet the production requirements, so the production process conditions are quite harsh. As a result, the cost of fumed silica is high. In order to reduce the production cost of fumed silica, some manufacturers choose silicon tetrachloride as the main raw material by-product of trichlorosilane, because the purity of silicon tetrachloride by-product in the production of trichlorosilane is generally between More than 80%, which contains mechanical impurities such as ...

AI Technical Summary

Problems solved by technology

Fundamentally solve the problem of high cost of existing silicon dioxide production methods, the silicon dioxide produced by the method of the present invention can be used for the same purposes as commercially available silicon dioxide, and on the basis of ensuring high quality silicon dioxide , reducing production costs

Images