UPGRADING OF ARDHUMA SILICA SAND FOR SILICON AND SILICONES INDUSTRIES (PILOT PLANT EXPERIMENTS)

Abstract

To encompass the courageous results achieved by the previous laboratory and bench-scale experiments for up-grading Ardhuma silica sand and to produce sand that can be used as a raw material for Metallurgical-Silicon production. This study was devoted to carry out experiments to confirm the laboratory and bench-scale experiments results. Various physical techniques were applied to beneficiate silica sand of Ardhuma. These techniques include; autogenously grinding, dry vibrating screening, washing by agitation or attrition scrubbing and were applied individually or in combination to upgrade the silica sand that can match the requirements of the raw material for Metallurgical-Silicon, silicones materials and Solar-Grad Silicon production. The results showed that Ardhuma sand can be successfully upgraded via the aforementioned techniques, the applied route include subsequence operations of autogenously girding, dry screening (-850+150) µm and attrition scrubbing at 50% solid for 30 minutes followed by wet screening (150µm). The purified silica sand produced assaying (SiO2 99.5%; Fe2O3 0.03%) which is satisfied to the raw material for MG-Silicon production and optical grade glass. An alternative rout; includes a washing by agitation step instead of washing by agitation. This route produced silica sand with a higher purity (SiO2 ≥ 99.4%; Fe2O3 0.02%) which is compatible for the MG-Silicon raw material and several other industries such as crystal glasses and solar cells as well as semiconductors.