Silicon wafer-cutting waste slurry recovery method

Abstract

The invention discloses a silicon wafer-cutting waste slurry recovery method, which adopts a physical treatment process. The silicon wafer-cutting waste slurry recovery method includes the following steps of: (step 1) pretreatment: solid-liquid separation is carried out; (step 2) recovery of polyethylene glycol on a liquid line: the filtrate obtained by separation in the first step undergoes particle-removing pressing, decoloration, ion exchange, four-effect distillation and cooling, so that the finished polyethylene glycol product is obtained; and (step 3) recovery of silicon carbide on a solid line: the filter cake obtained in the first step undergoes primary filter pressing, secondary filter pressing, drying and impurity separation by a separator, so that the finished silicon carbide product is obtained. The silicon wafer-cutting waste slurry recovery method not only has the advantages of large separation capacity, high recovery rate and good quality of recovered polyethylene glycol and silicon carbide, but also realizes environment-friendliness and zero-pollution treatment, and also reduces the production cost.

Description

technical field [0001] The invention relates to a method for recovering waste mortar from silicon chip cutting, which is mainly used for processing the waste mortar produced after silicon chip cutting, and recovering polyethylene glycol and silicon carbide therein. Background technique [0002] The process of human modernization continues to accelerate, and non-renewable resources such as coal and oil are also becoming increasingly exhausted. As a new energy source, solar energy has been strongly supported by governments of various countries. The solar photovoltaic industry has developed rapidly, and its related industries have also risen rapidly. The used silicon carbide waste mortar can be recycled and reused, which can save costs and protect the environment. At present, although some manufacturers have started to recycle and treat, but mostly adopt the method of acid-base washing, the amount of waste water generated is very large, and about 100 tons of alkali washing wast...

AI Technical Summary

Problems solved by technology

At present, although some manufacturers have started to recycle, but mostly adopt the method of acid-base washing, the amount of wastewater generated is very large, and about 100 tons of alkali washing wastewater and pickling wastewater can be produced per ton of sand, forming a secondary high Pollution, high investment cost of environmental protection treatment in the later stage, at the same time, a large amount of caustic soda and fluoride ions are consumed in the acid-base washing process, and the cost investment is high

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