Method for recovering silicon carbide

Abstract

The invention discloses a method for recovering silicon carbide. The method is used for recovering silicon carbide from siliceous pulp, wherein the siliceous pulp contains silicon carbide, silicon, impurities and a dispersion solution. The method for recovering silicon carbide from the siliceous pulp comprises the steps: filtering the siliceous pulp to preliminarily filter out the dispersion solution, so as to obtain siliceous mud; heating the siliceous mud until the remaining dispersion solution is volatilized, so as to obtain an impurity-removed silicon carbide/silicon mixture; putting the silicon carbide/silicon mixture in an alkaline solution so as to dissolve silicon in the silicon carbide/silicon mixture by the alkaline solution; and removing the silicon-dissolved alkaline solution, thereby obtaining purified silicon carbide. The method has the advantages that the deterioration of the dispersion solution in the siliceous pulp is avoided; the separation of silicon carbide by an organic solvent is avoided; and the separation of silicon carbide in a high-speed centrifugation manner is avoided.

Description

technical field [0001] The invention belongs to a recycling method, in particular to a silicon carbide recycling method. Background technique [0002] At present, silicon wafers have been widely used in the solar energy industry and the electronic industry, and the production of silicon wafers is usually obtained by cutting silicon crystal rods. Among them, the cutting of silicon crystal rods is usually performed by cutting tools with cutting oil (such as polyethylene glycol, PEG) to cut silicon crystal rods to produce cutting mortar, so that the cutting mortar usually contains silicon carbide, silicon, cutting oil And the cutting loss of cutting tools and other components. If the cutting mortar is directly discarded, it will not only cause environmental pollution, but also cause waste of raw materials. Therefore, relevant units have invested in the research and development of related technologies for the recovery of silicon carbide and silicon in cutting mortar. [0003]...

AI Technical Summary

Problems solved by technology

However, the surfactant has the same toxicity and low flash point as the organic solvent, which will cause this method to have the disadvantages of environmental pollution and danger in the process.