Method for separating cutting fluid, silicon carbide and silicon powder from wafer cutting mortar

Abstract

The invention discloses a method for separating cutting fluid, silicon carbide and silicon powder from wafer cutting mortar. The method comprises the steps that: solid-liquid separation is carried out; solid obtained by separation is washed by using ethanol, and is then washed by using pure water; the solid is dried by centrifugation; Particle size composition and distribution state of silicon powder and silicon carbide / metal composition are determined by using a laser particle size analyzer; a mass ratio of the components is precisely determined by X-ray diffraction; the obtained data are converted into horizontal spiral sedimentation centrifuge sorting parameters; with the horizontal spiral sedimentation centrifuge, sand powder is primarily separated into coarse powder with main components of silicon carbide and iron, middle powder with main components of silicon carbide and silicon, and fined powder with a main component of silicon; the middle powder is added into an electrophoresis tank; the electrode in the electrophoresis tank is powered; under the action of an electric field, the silicon carbide powder is precipitated, and the silicon powder floats; the obtained silicon carbide powder and the coarse powder is subjected to alkali washing and iron-removing magnetic separation; and the obtained material is washed by using water, and is dried by centrifugation. The method provided by the invention is innovative than an ultrafine particle separation technology in waste mortar processing in prior arts. With the method, an existing pollution problem can be comprehensively treated and solved.

Description

technical field [0001] The invention relates to the technical field of photovoltaic cutting, in particular to a method for separating cutting liquid, silicon carbide and silicon powder from wafer cutting mortar. Background technique [0002] Solar energy is an internationally recognized clean and renewable energy. The strong development of the solar photovoltaic industry has driven the rapid development of the polysilicon cutting and grinding powder industry, while the consumption of raw materials has also increased significantly. At present, on the one hand, the demand for silicon carbide micropowder in the solar photovoltaic industry continues to increase. On the other hand, manufacturers cannot timely and effectively dispose of the used waste mortar. The direct discharge of polyethylene glycol in the waste mortar will cause a large amount of wastewater COD to exceed the standard. It pollutes the environment. In addition, silicon carbide powder and silicon powder that can ...

AI Technical Summary

Problems solved by technology

[0005] It can be seen that there is no breakthrough ultrafine particle separation technology in the current domestic and foreign status quo. About 15% of silicon powder, about 10% of silicon carbide fine powder and 5% of polyethylene glycol contained in waste mortar have all become waste products. Caused a lot of waste of precious raw materials and pollution to the environment

Silicon carbide micropowder, silicon powder and polyethylene glycol cutting fluid are the main raw materials in the photovoltaic industry, and the production of these raw materials consumes a lot of energy and is easy to cause pollution

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