Method for recovering high-purity silicon powder from crystal silicon cutting waste material slurry

Abstract

The invention relates to a method for recovering high-purity silicon powder from crystal silicon cutting waste material slurry, and belongs to the technical field of secondary resource utilization. According to the method, firstly, electric plating diamond wire or resin diamond wire cutting can be used for crystal silicon cutting; then, during the cutting, a plate which does not contain aluminum oxide or calcium oxide is used for a holding material for replacing a conventional resin plate containing 20 to 60 percent of aluminum oxide; next, the waste material slurry obtained after the crystal silicon cutting is subjected to solid-liquid separation to obtain solid materials; next, the solid materials are subjected to magnetic separation and acid soaking impurity removal to obtain purified materials; finally, the purified materials are dried and sieved to obtain the high-purity silicon powder with the purity higher than 98 percent. The method has the advantages that the flow process is short; the energy consumption is low; the pollution is low; the recovery rate is high; simplicity is realized; the implementation is easy, and the like. In addition, the industrialized production can be easily realized. The method realizes the efficient ecologicalization recovery; waste materials are changed into valuable materials; in addition, the environment pollution is reduced.

Description

technical field [0001] The invention relates to the technical field of secondary resource utilization, in particular to a method for recovering high-purity silicon powder from crystalline silicon cutting waste slurry. Background technique [0002] In the 21st century, in order to cope with increasingly serious energy and environmental problems, countries around the world are vigorously developing renewable energy, among which solar energy is considered to be one of the most promising renewable energy sources. There are three main forms of solar energy utilization: photochemical conversion, photothermal and photovoltaic power generation. Among them, the huge potential of solar photovoltaic power generation and its social, economic and environmental benefits are very attractive. Solar photovoltaic power generation devices are mainly solar cells, and solar cells made of crystalline silicon as the main raw material account for more than 95% of all solar cell raw materials. , an...

AI Technical Summary

Problems solved by technology

Among them, the preparation of silicon wafers is the process of cutting silicon ingots by using multi-wire cutting machines. Multi-wire cutting includes mortar cutting and fixed abrasive cutting. Among them, mortar cutting is more widely used, but mortar cutting has obvious disadvantages: such as waste slurry Difficulty in recycling, harsh operating environment, etc.

[0009] In addition, the patent No. ZL201210127930.4 invented the "Method for Recycling Polysilicon from Diamond Wire Saw Wafer Waste Slurry" and the patent No. ZL201610086247.9 invented "A Method for Recycling and Reusing Crystalline Silicon Diamond Wire Saw Waste Slurry" The recycling of diamond wire cutting waste slurry is realized, but the silicon ingot holding material in this invention is a resin plate containing 20% ​​to 60% alumina, and part of the alumina will enter the cutting process in the form of powder during the cutting process. In the waste slurry, the cost of subsequent purification and removal of silicon powder is increased

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