A method for the production of silicon by electrolysis and crystallization and production of low-alloy and high-alloy aluminum - silicon - alloys

摘要

Process for preparing highly purified silicon and optionally aluminum and silumin (aluminum silicon alloy) in the same cell, wherein silicate and/or quartz containing rocks are subjected to electrolysis in a salt melt containing fluoride, whereby silicon and aluminum are formed in the same bath, and aluminum formed, which may be low alloyed, flows to the bottom and is optionally drawn off, cathode with deposit is transferred to a Si-furnace, the deposit with Si on the cathode flows down to the bottom of the furnace, and the cathode is removed before melting Si in the furnace, orthe deposit on the cathode(s) is shuffled down into the bath, molten bath or frozen bath containing Si from the cathode deposit istransferred to a Si-furnace after AI has flowed down to the bottom of the electrolysis furnace and been drawn off, the silicon in the cathode deposit and/or from molten or frozen bath, is melted and separated from slag by allowing molten silicon to flow to thebottom in the Si-furnace, slag is stirred intimately into the silicon melt, whereafter slag and Si-melt separate directly, the slag is removed from the Si-melt, and the silicon is subjected to crystal rectification.