A silicon additive based on crystalline silicon diamond wire cutting waste and its preparation method

Abstract

The invention discloses a silicon additive based on diamond wire cutting wastes of crystalline silicon, and a preparation method thereof, and belongs to the technical field of recycling. The silicon additive comprises, by weight, 5-30 wt% of a solvent, 0-10 wt% of a binder, 0-10 wt% of metallic aluminum powder, and the balance of the diamond wire cutting wastes of crystalline silicon. The preparation method comprises the following steps: weighing the diamond wire cutting wastes of crystalline silicon, the solvent, the metallic aluminum powder and the binder in proportion, adding water, uniformly mixing above materials and the water, carrying out briquetting molding on the above obtained mixture in a briquetting machine, and drying the molded mixture to obtain the silicon additive based ondiamond wire cutting wastes of crystalline silicon. The silicon additive has the advantages of effective utilization of wastes generated in the silicon chip cutting process, realization of changing ofwastes into valuables, great shortening of the process flow for producing silicon-containing aluminum alloy, and reduction of the production cost.

Description

technical field [0001] The invention belongs to the technical field of secondary resource utilization, in particular to a silicon additive based on crystalline silicon diamond wire cutting waste and a preparation method thereof. Background technique [0002] During the production of crystalline silicon wafers, the core material of solar cells, a large amount of cutting waste is generated. Crystalline silicon wafers are obtained by multi-wire cutting of crystalline silicon ingots. The multi-wire cutting process includes mortar silicon carbide cutting and diamond wire cutting. Since the width of the slit is similar to the thickness of the required crystalline silicon wafers, both cutting processes will result in nearly Half of the crystalline silicon loss goes to waste. Among them, the main component of waste generated by diamond wire cutting is high-purity silicon powder with very little impurity content. If this part of waste can be effectively used, it will not only solve ...

AI Technical Summary

Problems solved by technology

Among them, instant silicon contains two types, one is a kind of instant silicon agent with superfine or nanometer aluminum powder added as patent No. CN 1974077A and a new type of environmentally friendly high-content instant silicon and its preparation method with patent No. CN 103484727A As mentioned in , the feature of this kind of instant silicon agent is that a layer of co-solvent is coated on the surface of the silicon block, wherein the particle size of the silicon block is less than 100mm; Additives and their addition methods" (Wang Zhutang, Wang Dianying, Wang Zhenchao. New alloying element additives for aluminum alloys and their addition methods [J]. Light Alloy Processing Technology, 2000, (09): 16-19.), this This kind of silicon agent is a cake made of 150 mesh pure silicon powder, catalyst, special additives and a small amount of aluminum powder. Its use can avoid the disadvantages of directly adding silicon blocks or intermediate alloys. It is a silicon agent commonly used in developed countries. However, the silicon powder used in the production of this additive is obtained by crushing industrial silicon, which not only increases the production cost, but also easily catches fire during the crushing process, which brings safety hazards

Images