After washing, screening and drying, the raw silica is dosed in different proportions depending on the type of reducing agent used. The different proportions of materials are controlled by computer programmes and collected on a conveyor belt from the plant warehouse. Then, it's all mixed together and fed into the electric furnace. The whole process is highly automated and on a large scale, which makes sure everything runs smoothly and efficiently. An electric current is connected to the electrode to heat the material inside, reaching a high temperature of over 1800 degrees Celsius. The silicon shrinks in the intracranial region, resulting in a liquid state. The material comes out through an exhaust port and is cast into silicon ingots, which are then crushed and packaged into industrial silicon powder for sale.
The bottom blowing process mixes oxygen and air. The packaging is fitted with breathable oxygen bottom blowing bricks that have lots of thin copper tubes in them. Oxygen and air are blown from the thin copper tubes into the silicon melt to refine it. At the end of the oxygen purge, the air also creates a positive pressure in the silicon melt through the air permeable bricks. The refining process needs more agitation, which is done using compressed air. This creates the right conditions for the reaction of metallic elements in the material, accelerates slag formation, removes impurities as quickly as possible and reduces heat loss and silicon liquid buildup.
