Process for producing silicon ingot by smelting silicon powder

Abstract

The present invention discloses a process for producing a silicon ingot by smelting silicon powder. The process comprises: (a) starting a furnace: preparing a silicon liquid in a medium frequency furnace, wherein the purity of the silicon liquid achieves the standard; (2) silicon smelting: pouring silicon powder into the silicon liquid, and smelting to prepare a silicon solution; and c) molding: reserving the silicon solution accounting for 15-20% of the volume of the medium frequency furnace as the initial silicon water for the next smelting, pouring the remaining silicon solution into a molding system, and manufacturing to form the silicon ingot. According to the present invention, the weak conductivity of the silicon liquid is used to perform induction heat generation so as to achieve the silicon block smelting; and the smelting capacity of the monomer can be increased to 5 ton through the smelting with the induction furnace relative to the maximum capacity 20 KG of the crucible so as to substantially improve the yield and the production efficiency compared to the smelting with the crucible in the prior art.

Description

technical field [0001] The invention relates to the field of reutilization and processing of silicon slag, in particular to a process for producing silicon ingots by smelting silicon powder. Background technique [0002] Silicon slag generally refers to the remaining part after the ore is refined, and it also contains a certain amount of silicon. There are many kinds of silicon slag, industrial silicon slag, solar silicon slag, semiconductor silicon slag and so on. Silicon slag can be used to return to the furnace for recrystallization and purification. Now silicon materials are in short supply and expensive. Silico-manganese slag, also called silicomanganese smelting slag, is a kind of industrial waste slag discharged when smelting silicon-manganese alloys. Its structure is loose, and its appearance is often light green particles, which are composed of some porous amorphous particles with irregular shapes. The silicomanganese slag is brittle and fragile. The large pieces ...

AI Technical Summary

Problems solved by technology

[0004] The current main equipment for silicon smelting is the crucible, and the technology of using the crucible for silicon smelting is relatively mature, but the biggest disadvantage of the crucible is that the capacity is too small, the amount of single smelting is small, and the bottleneck of difficult mass production has always restricted the development of silicon.