Sb distribution in the phases of SiO2 saturated Sb-Fe-O-SiO2-CaO system in air

Abstract

Sb distribution in the phases of SiO2 saturated Sb-Fe-O-SiO2-CaO system was determined for the first time through hightemperature experiment and quenching techniques, followed by Electron probe X-ray microanalysis (EPMA) in air (Ptot = 1 atm, PO2 = 0.21 atm). The phases were quantified in the temperature range of 900?C-1200?C and the effects of Fe/SiO2 (mass fraction) and CaO/SiO2 (mass fraction) on Sb2O3 content in the Sb-Fe-O-SiO2-CaO system were investigated at 1200?C. The results indicated that the Sb-containing phase primarily existed in the solid solution phase at 1200?C. With the increase of temperature from 1100?C to 1200?C, the Sb2O3 content in the solid solution phase increased drastically from 7.52 wt% to 17.36 wt%. Lowering the values of CaO/SiO2 and Fe/SiO2 in the smelting process effectively reduced Sb2O3 content in the slag. The verification of the experiment results suggested that the antimony content in slag was 0.57 wt%, the crude antimony yield rate was lower than 4%, and the crude antimony grade was beyond 94 wt%, which meant that the reduction of antimony content in the slag could be achieved.