Patent ID: 7101470

Claim:
A process for preparing highly purified silicon and aluminum and silumin (aluminum silicon alloy) in the same electrolysis furnace, which comprises I. subjecting silicate and/or quartz containing rocks to electrolysis in a salt melt containing fluoride, whereby silicon and aluminum are formed in an electrolysis bath, and the aluminum formed, which may be low alloyed, flows to the bottom and is drawn off, IIa. transferring cathode with deposit to a Si-melting furnace, whereby the deposit with Si on the cathode flows down to the bottom of the melting furnace, and the cathode is removed before melting Si in said furnace, or IIb. during the electrolysis, shuffling the deposit formed on the cathode(s) down into the molten electrolysis bath, and transferring the molten or frozen bath containing Si from the cathode deposit to a Si-melting furnace after Al has flowed down to the bottom of the electrolysis furnace and been drawn off, III. melting the cathode deposit and/or molten or frozen bath, which contain silicon and slag, in the Si-melting furnace, IV. stirring the mixture of silicon and slag intimately, whereafter slag and Si-melt separate directly, V. removing the slag from the Si-melt, and VI. subjecting the silicon to crystal rectification.