A kind of recovery method of silicon carbide micropowder

Abstract

The invention discloses a method for recovering carbonized silica powder, which belongs to the technical field of silicon carbide production. The method solves the problems of large pollution, little production power, low product content and high refinement content in the prior art can be solved. The method comprises the following steps: calcining a recovered material, mixing the calcined raw material and water as well as mixing slurry, introducing the material into a cyclone for rotational flowing; fully stirring the slurry after rotational flowing, beating the material into an acid bubble barrel, adding sulfuric acid for immersion and using a vacuum filtration filter for depickling; fully stirring the depickled slurry, adding sodium hydroxide for alkali washing and impurity removal, then using the vacuum filtration filter for dealkalization to obtain the dealkalized slurry; using a pump for beating the slurry after alkali washing into a moisture feeding barrel, stirring fully the material and beating the material to a taper grading overflow barrel for waterpower grading to obtain a product; respectively dehydrating and drying the product according to the models; placing the dried product into a feed mixer for batch mixing, uniformly granulating the material, and respectively sieving the product. The method can be used for recovering the carbonized silica powder.

Description

technical field [0001] The invention relates to a method for recovering silicon carbide micropowder, which belongs to the technical field of silicon carbide production. Background technique [0002] Silicon carbide micropowder is widely used in the field of solar cell crystalline silicon wafer cutting as a cutting edge material for crystalline silicon wafers. In the actual production process, it is necessary to purify the silicon carbide micropowder to make its purity meet the production requirements. Existing methods are generally solid-liquid separation, solid waste as reclaimed raw materials containing silicon carbide micropowder, and then the solid waste is subjected to steps such as pulping, alkali washing, pickling, rinsing, and drying to obtain silicon carbide micropowder. The content of silicon carbide micropowder in the finished product generally requires multiple pickling and alkali washing, which will not only cause waste of water resources but also generate a la...

AI Technical Summary

Problems solved by technology

Existing methods are generally solid-liquid separation, solid waste as reclaimed raw materials containing silicon carbide micropowder, and then the solid waste is subjected to steps such as pulping, alkali washing, pickling, rinsing, and drying to obtain silicon carbide micropowder. The content of silicon carbide micropowder in the finished product generally requires multiple pickling and alkali washing, which will not only cause waste of water resources but also generate a large amount of sewage. This method has high recovery costs and low output, and the COD in sewage can reach hundreds of thousands. The cost of sewage treatment is high, and often due to insufficient purity or high content of fine powder, it is difficult for the recovered silicon carbide powder to meet the technical standards for cutting edge materials for solar silicon wafers. When silicon carbide powder is used for cutting solar silicon wafers, 0- The fine powder of 2μm can not achieve the cutting effect. When the fine powder content is too high, the cutting efficiency will be reduced. At the same time, there will be line marks on the silicon wafer, which will reduce the qualified rate of the silicon wafer. Therefore, the fine powder content should be strictly controlled during the purification process.