A medicament for separating silicon carbide in mortar

Abstract

A medicament for separating silicon carbide from mortar is prepared from raw materials in parts by weight as follows: 4-7 parts of oleic acid, 1-2 parts of styrene phosphonic acid, 3-4 parts of hydroxybutyl vinyl ether, 4-6 parts of triethyl citrate, 2-3 parts of oleic acid polyoxyethylene ester, 1-2 parts of polypropylene glycol diglycidyl ether, 50-55 parts of methanol, 30-35 parts of diesel, 4-5 parts of an assistant and 40-45 parts of water. According to the invention, multiple solvents and water are used for forming a steady emulsification system, silicon and the silicon carbide are separated by utilizing tiny difference between interfacial tensions of the silicon and the silicon carbide, and delamination is steady; with the adoption of the assistant, the silicon and the silicon carbide are separated more thoroughly, the obtained silicon carbide powder is higher in purity. The medicament for separating the silicon carbide from the mortar is relatively low in cost, not only efficiently avoids resource waste and environment pollution caused by direct discharge of cutting liquid waste, but also reduces production cost of silicon wafer cutting, and is a technique for making waste profitable.

Description

technical field [0001] The invention relates to a powder separation technology for silicon and silicon carbide in mortar produced by a silicon wafer wire sawing process, in particular to a medicament for separating silicon carbide in mortar and a preparation method thereof. Background technique [0002] Various silicon wafers, including monocrystalline silicon and polycrystalline silicon solar cells, and silicon wafers for the microelectronics industry, are generally produced by cutting with wire saws and silicon carbide abrasive slurry, referred to as mortar. The thickness of the silicon wafer is generally 0.22mm, and there is no development trend of thinning at present. The width of the wire saw kerf is generally 0.18-0.30mm, which means that 20-60% of the high-purity silicon material will enter the mortar as sawdust, and its extraction Recycling is equivalent to opening up a new and sizable source of high-purity silicon raw materials. [0003] Although the benefits of re...

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Problems solved by technology

[0003] Although the benefits of recovering high-purity silicon are considerable, the physical and chemical properties of silicon and silicon carbide are relatively close. So far, there are few research results on this project, and there are no successful cases of actual production. Further research is needed on feasible methods for actual production. Separation agents and methods