Chemical upgrading and
aluminothermic reduction of Egyptian sand
Aluminum-silicon (Al-Si) alloys produced by aluminothermic reduction of
Egyptian sand were leached with hydrochloric acid to produce
metallurgical-grade silicon powder and aluminium chloride solution.
Metallurgical-grade silicon containing ~99.3% Si was obtained at the
following conditions: particle size 100% -0.1mm, temperature of the reaction
was 50oC, time of reaction 20.0 minutes, solid/liquid ratio 1:9g/ml and acid
concentration 6.24M. The iron content in aluminium-silicon alloy is almost
dissolved into the solution (besides aluminium) and non-significant iron
content (~0.2%) is detected in the upgraded silicon metal.