Impurity removing process for enhancing quality of silicon carbide fine micro powder

Abstract

The invention discloses an impurity removing process for enhancing quality of silicon carbide fine micro powder and relates to an impurity removing method of silicon carbide micro powder. The process comprises the following steps: firstly, adding the silicon carbide fine micro powder into deionized water to prepare 30% slurry, and adding a foaming agent and polyoxyethylene which account for 0.01% of the total weight of the slurry; then, feeding the slurry to a flotation column to float and decarbonize; then, feeding the floated slurry to a wet magnetic separator for magnetic separation to remove iron; repeating the above operations till foam in the floatation column changes from being deep to being light and is off-white and stopping flotation and magnetic separation process; then, diluting the concentration of the slurry discharged from the wet magnetic separator, and adding a surfactant; then, feeding to a cyclone grading system to remove particles which are less than 5.5 microns; and then dehydrating and drying to obtain high quality silicon carbide fine micro powder with Fe2O3 less than or equal to 0.4%, free carbon less than or equal to 0.3% and particle content less than or equal to 3.5%. The silicon carbide fine micro powder disclosed by the invention is stable in quality, high in cleanliness and simple in production process, and the treatment time is greatly shortened.

Description

technical field [0001] The invention relates to a process method for removing impurities of silicon carbide fine powder, in particular to a process for removing impurities by pretreating the silicon carbide fine powder and improving physical and chemical indicators before the silicon carbide fine powder is classified. Background technique [0002] As an important auxiliary material for crystalline silicon wire cutting in the photovoltaic industry and semiconductor industry, silicon carbide fine powder products have high requirements for physical and chemical indicators. At present, the improvement of its physical and chemical indicators is mainly to control the free carbon, ferric oxide, and fine powder contained in the raw material of silicon carbide fine powder. Fish out to achieve the purpose of removing free carbon, use magnetic rods to absorb iron, achieve the purpose of removing ferric oxide in raw materials, and use natural precipitation to remove fine particles and f...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is that the content of fine powder in the silicon carbide fine powder processed by the existing silicon carbide fine powder impurity removal process is easy to exceed the standard, and the content of free carbon and ferric oxide is relatively high, and the silicon carbide fine powder unstable quality