Silicon Metal 97 is also a kind of silicon metal that also have other names like crystalline silicon or industrial silicon. Metal silicon is a product from production of materials of quartz and coke in an electric furnace. In recent years, as the market has become increasingly demanding on the quality and variety of metal silicon products, the demand for Silicon Metal and The smelting method of 97 is also puts forward new requirements.
In the traditional smelting process of Silicon Metal 97, there are mainly hydrometallurgy methods (pickling, solution corrosion). Such as: slag treatment methods, powder metallurgy methods, gas blowing methods, energy beam (electron beam, plasma beam) methods. There are also directional Solidification method, silicon alloy method. Moreover, high-purity raw material method, sodium reduction method, aluminothermic reduction method and electrolysis method. The above-mentioning smelting methods of Silicon Metal 97 cannot remove multiple impurities at the same time. And those methods are only effective for certain impurities among them. It cannot meet the requirements of metallurgical grade high-purity silicon, which affects the quality of Silicon Metal 97 products.
The steps for smelting Si 97 grade are: A. turn on the power of the submerge arc furnace, heat up the furnace body of the submerged arc furnace, increase the temperature of the submerge arc furnace to 500℃-700℃, crush and screen the silicon ore raw materials, after cleaning and drying, add it to the submerge arc furnace;
B. Add the mixed materials to the submerged arc furnace, and raise the temperature of the submerg arc furnace to 1600℃-1900℃ for calcining and melting to cause a reduction reaction;
C After the reduction reaction is completed, put the slagging agent to the feed end, wait till the submerg arc furnace heat around 1200℃-1400℃. A chemical reaction occurs for slagging refining. After the slagging refining is completed, the mixed liquid is allowed to stand, and the silicon liquid floats and stratifies with the slag phase;
D . The silicon liquid after slagging and refining flows out from the outlet of the submerg arc furnace. During this process, turn on the water cooling device in order to perform directional solidification;
E. Using the property that the equilibrium segregation coefficient of impurities. In the crystallization process of silicon liquid is much less. The directional solidification method is for continuously segregate impurities. Impurities are from the solid-liquid interface into the silicon liquid. After all the silicon liquid is crystallized, the parts with high impurity concentration are mechanically removed. Then we can obtain Silicon Metal 97.
The production process of Silicon Metal 97 is simple and easy to implement. It uses a mixture of charcoal, petroleum coke and bituminous coal to reduce silicon ore. Silicon metal manufacturers combines it with slagging refining, and adopts directional solidification method. Various impurities will remove at the same time. It meets the requirements of metallurgical grade high-purity silicon. This further improves the quality of Off-Grade Silicon products and makes them suitable for industrial production. Silicon Metal 97 has become an entry-level product in many emerging energy markets.