UPGRADING OF ARDHUMA SILICA SAND FOR SILICON AND SILICONES INDUSTRIES (Bench-Scale Experiments)

Abstract

In this research, bench-scale experiments were conducted to increase the confidence of the laboratory experiments results. Various physical techniques and processes consisted of dry vibrating screening, strong agitation, and attrition scrubbing and dry magnetic separation. These techniques were applied individually or in combination to upgrade the silica sand for the Metallurgical-Silicon production, which is in turn used as a raw material for silicones materials and Solar-Grad Silicon. The results indicated that Ardhuma sand can be up-graded using the aforementioned techniques, via two routes: The first one includes subsequent operations of autogenously girding, dry screening (-850+150) µm, attrition scrubbing and wet screening (150µm). The purified silica sand produced assaying (SiO2 99%; Fe2O3 0.03%) which is satisfied for the raw material of MG-Silicon production. The second route; includes in addition to the first route, a dry high intensity magnetic separation process. This route produced silica sand with a high purity (SiO2 ≥ 99.5%; Fe2O3 < 0.02%) which is compatible to the MG-Silicon raw material and to several other industries that require a high purity silica sand such as optical glasses, crystal glasses as well as semiconductors.