Method for recovering and separating silicone and silicon carbide powder through foam flotation in silicon wafer cutting effluent

Abstract

The invention relates to the technology for recovering and recycling solid in silicon wafer cutting effluent in the new energy silicone industry, in particular to a method for recovering and separating silicone and silicon carbide powder through foam flotation in the silicon wafer cutting effluent. The method includes the following steps: performing solid-liquid separation on the cutting effluent by using a separating agent to separate the solid and the liquid; washing the solid into neutral through distilled water, and centrifugally drying the solid for spare; mixing the prepared solid and a flotation agent to form turbid liquid, regulating the pH value to a required value and then stirring; adding the turbid liquid into a flotation machine, stirring with certain rotating speed, and simultaneously feeding gas with the required flow from the lower portion for a flotation test; and filtering to recover foam and precipitate particles, and washing and drying to obtain the silicone and silicon carbide powder. By means of the method, the silicone and silicon carbide powder in the cutting effluent produced by the silicon wafer cutting technology can be effectively recovered and separated, silicone wafer processing cost is remarkably reduced, recycling of resources is achieved, and the method makes contributions for environment protection and is the practical technology in solving the problem of shortage in resources.

Description

technical field [0001] The invention relates to a method for recovering silicon and silicon carbide powder from cutting waste liquid in the new energy silicon industry by foam flotation, in particular to separating silicon and silicon carbide powder by foam flotation. Background technique [0002] As an inexhaustible clean energy source, the development and utilization of solar energy is attracting great attention of human beings. Most solar cells use non-toxic crystalline silicon, which is characterized by high photoelectric conversion efficiency, long life and good stability. At present, the multi-wire saw cutting method is mostly used to produce large and thin silicon wafers for solar cells. A fluid mixed cutting fluid mortar is used in multi-wire cutting, and its components are silicon carbide and polyethylene glycol. During the cutting process, the high-speed reciprocating cutting line drives the mortar to the cutting area, so that the abrasive particles in the mortar...

AI Technical Summary

Problems solved by technology

This method makes full use of the differences in physical properties of substances and achieves the purpose of preliminary separation, but the separation efficiency is low and time-consuming, and it is still difficult to achieve complete separation

[0009] Generally speaking, there are no industrial production application reports on the effective recovery and separation of silicon and silicon carbide powder from the waste liquid of silicon wafer cutting in the new energy silicon industry at home and abroad.