Production of high purity silicon metal, aluminium, their alloys, silicon carbide and aluminium oxide from alkali alkaline earth alumino silicates

摘要

The present invention concerns a procedure for production of high purity metals, their alloys and other species from feldspars and feldspar containing rocks. Silicon "metal" (Si) and aluminium oxide (Al2O3) are produced by electrolysis. High purity Si produced from electrolysis is leached and refined by water which forms sodium hydroxide (NaOH), aluminium hydroxide (Al(OH)3) and hydrogen (H2). Si is then refined by using acids, and melted above 1410 DEG C. High purity silumin (AlSi alloys) is produced by alloying high purity Al and high purity Si from residual Si and Si(IV) in cryolite (Na3AlF6)/Al2O3 mixtures at about 970 DEG C. High purity silicon carbide (SiC) is produced by melting Si and adding cathodic and leached purified graphite (C) above 1410 DEG C.