Abstract

Upgrading of Metallurgical Grade Silicon (MG-Si) Using Wet Milling Process as a Pretreatment Step before Acid Leaching

Author(s): Ali HHM, El-Sadek MH, Morsi MB, El-Barawy KA and Abou-Shahba RM

Locally produced metallurgical grade silicon (MG-Si ~ 97%) was upgraded by using wet-milling process. This is including milling of MG-Si in presence of 2 M HCl solution for different time periods up to 60 min. The effect of milling time in HCl solution was studied. Soaking of the milled products (at optimum milling time 15 min) with continuous stirring in the same solution of 2 M HCl for interval time up to 240 min also were investigated. Finally, the effect of addition of 2 M HF to the milled product was discussed. The leached samples were investigated by X-ray fluorescence (XRF) and scanning electron microscope (SEM). It was found that, 99.92% purity of MG-Si was achieved after 15 min milling time with 2 M HCl followed by addition 2 M HF for 240 min with continuous stirring. About 97% removal efficiency of the impurities was obtained.