Recycle treatment method for wafer rinse waste liquor

Abstract

The invention relates to a treatment method for rinse waste water of silicon wafer cutting, which not only can fully recover and utilize polyethylene glycol and water in waste water, but also can reduce the treatment amount of the waste water to realize resource recovery. The method comprises the following steps: preliminarily filtering the rinse waste water of the silicon wafer cutting, carrying out softening process, filtering to remove mechanical impurities and sticky materials by one or the combination of a microfiltration membrane and a superfiltration membrane, entering a multi-level membrane separation device to obtain pure water and polyethylene glycol solution, and refining the polyethylene glycol solution to obtain polyethylene glycol the mass percent of which is larger than 95%. The invention has the advantages that the obtained pure water can be used for the rinse waste water of the silicon wafer cutting and the obtained polyethylene glycol is used for the preparation of cutting fluid of the silicon wafer; by the implementation of the invention, water can be recycled, and the polyethylene glycol in the waste water also can be recycled, thus realizing the source treatment of the waste water, greatly saving the cost, reducing the environmental pollution for silicon wafer manufacturing enterprises, and having considerable economic benefit and social benefit.

Description

technical field [0001] The invention relates to a treatment method for silicon wafer cutting and cleaning wastewater, which can fully recycle and utilize polyethylene glycol and water in wastewater, reduce the amount of wastewater treatment, and realize resource recovery, and belongs to the field of silicon wafer cutting wastewater treatment technology. Background technique [0002] Monocrystalline silicon wafers and polycrystalline silicon wafers are indispensable raw materials for solar cells and semiconductors. As the most potential energy source in the 21st century, the solar energy industry has great potential for development. As an emerging sunrise industry, coupled with a good policy environment and the characteristics of the industry itself, the solar cell industry has high investment value and development potential. In recent years, my country's silicon industry has developed rapidly, especially the silicon wafer industry. The environmental problems brought about b...

AI Technical Summary

Problems solved by technology

However, there is no report on the recycling of cutting and cleaning wastewater. Currently, sedimentation, air flotation, and biochemical methods are generally used for treatment, which has the disadvantages of high cost and waste of resources.