Process for producing silicon ingots by smelting silicon slag

Abstract

The invention discloses a process for producing silicon ingots by smelting silicon slag. The process comprises the following steps: starting a furnace, smelting silicon, removing slag and molding reserved silicon liquid, which accounts for 15 percent to 20 percent of the volume in an intermediate frequency furnace, as initial silicon liquid for the next time of smelting; pouring the residual silicon liquid into a molding system and manufacturing to form the silicon ingots. According to the process disclosed by the invention, the weak electrical conductivity of the silicon liquid is used for carrying out induction heating; the silicon slag is directly used for smelting, silicon is separated after being smelted by utilizing the property that smelting points of the silicon and the waste slag are different and the silicon slag on the silicon liquid is fished by utilizing a slag removing device, so that the silicon and the waste slag are separated and are directly produced into the silicon ingots; compared with a maximum capability of 20KG of a crucible, the smelting amount of a monomer can be improved to be 5 tons in a manner of smelting the silicon by utilizing an induction furnace; compared with crucible smelting in the prior art, the yield and the production efficiency are greatly improved.

Description

technical field [0001] The invention relates to the field of recycling processing of silicon slag, in particular to a process for producing silicon ingots by smelting silicon slag. 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 of silicom...

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.