Method for removing iron and silicon impurities in silicon carbide micropowder for crystalline silicon wire cutting

Abstract

The invention relates to a method for removing iron and silicon impurities in silicon carbide micropowder for crystalline silicon wire cutting. The iron and silicon impurities in the silicon carbide powder are removed through combination of physical iron removal and chemical silicon removal. The method comprises the specific process as follows: the silicon carbide micropowder ground by a Raymond mill is mixed with deionized water for slurry making; a dispersant is added to obtained silicon carbonate micropowder slurry for stirring dispersion treatment; the dispersed silicon carbonate micropowder slurry is pumped into an electromagnetic separator for iron removal by magnetic separation; then the iron-removed and purified silicon carbonate micropower slurry is washed with water; acid is added to the silicon carbonate micropower slurry for acid leaching; finally, the purified silicon carbonate micropowder slurry is obtained through filtration. The method is simple to operate, high in production efficiency, low in cost and good in environmental benefit, and the use chemicals are reduced. The treated silicon carbonate powder product is stable in quality and suitable for industrial production, and the technical indexes meet the process requirement.

Description

technical field [0001] The invention relates to a method for removing iron and silicon impurities in silicon carbide micropowder, in particular to a method for removing iron and silicon impurities in silicon carbide micropowder for crystalline silicon wire cutting. Background technique [0002] Silicon carbide (SiC), commonly known as corundum, is widely used in grinding fields such as polishing wheels and multi-wire cutting because of its excellent properties such as high strength, high hardness, wear resistance, corrosion resistance, oxidation resistance, high thermal conductivity and good thermal stability. And it is widely used in non-grinding fields such as mechanical electronics, energy and environmental protection, and electronic semiconductors. In recent years, with the intensification of the global greenhouse effect and conventional energy crisis, solar energy, as a renewable energy source, has unlimited and environmental advantages, making the photovoltaic industry...

AI Technical Summary

Problems solved by technology

Although the existing process can remove some elemental iron impurities in silicon carbide micropowder through a single iron removal device, it cannot remove ferric oxide and silicon impurities well, and there are certain limitations.

Although the iron and silicon impurities in the silicon carbide micropowder can be directly removed by the direct mixed acid leaching method or the method of alkali washing first and then acid washing, or pickling first and then alkali washing, it needs to consume a large amount of acid, alkali and water.

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