Author: jbtmetals

The technological process of silicon for chemical use includes furnace charge preparation, electric furnace smelting, silicon refining and casting, and crushing for removing slag inclusions. All raw materials must undergo necessary treatment before the charge is prepared. The silica is crushed in the jaw crusher until the size of the pieces is not more than 100mm, and the pieces smaller than 5mm are screened out and washed with water. Because the fragments in the furnace are melted in the upper part of the furnace, the gas permeability of the charge is reduced, making the production process difficult. Petroleum coke has a relatively high electrical conductivity, so it must be broken to a size of no more than 10mm, and the amount of petroleum coke powder must be controlled. Because it burns directly on the furnace mouth, it will cause insufficient reducing agent.

In chemical silicon production, bituminous coal can completely replace charcoal, such as Hunan Zhuzhou refined bituminous coal,

The fixed carbon is 77.19%, the volatile matter is 19.4%, the ash content is 3.41%, the Fe2O3 content is 0.22%, the Al2O3 content is 0.99%, and the CaO content is 0.17%. According to production practice, it is feasible to use this kind of bituminous coal to smelt chemical silicon.

Blocks and chips for the production of silicon for chemical use are processed with timber cutters and wood chippers. The carbonaceous reducing agent in the furnace charge is mainly petroleum coke and bituminous coal, and the amount of wood blocks and wood chips depends on the furnace conditions. Wood is not used in production, but the product quality is more stable. The ratio of the charge is determined according to the grade of the product required to be produced. The proportion of petroleum coke and bituminous coal is determined according to the amount of carbon required for each batch of ore silicon. The ratio of petroleum coke and bituminous coal has a great influence on the working resistance of the charge.

After each component of the furnace charge is weighed, the charge is mixed evenly, and after the furnace is pounded, the uniformly mixed charge is added to the furnace. Keep a certain height of the material surface and feed evenly. Chemical silicon production is continuous. The conditions inside the furnace are not eternal either. Chemical silicon production is a process in which electric energy is converted into heat energy in an electric furnace, and then the heat energy is used to directly heat the material to produce a chemical reaction. Therefore, the electrical characteristics in the furnace are very important. The smelting operation is closed-arc to maintain the high temperature furnace, improve the thermal efficiency, and improve the utilization rate of the electric furnace. In the research, a metal silicon furnace with a capacity of 3200KVA and 6300KVA is used. The smelting is carried out by simmering for a certain period of time and regular concentrated feeding. Under normal circumstances, it is difficult for the charge to sink automatically, and it is generally necessary to force the charge to sink. The furnace condition is easy to fluctuate and difficult to control. Therefore, it is necessary to judge correctly and deal with it in time in production. The furnace is fired every 4 hours for scouring and casting, and the slag is broken and sorted into storage.