A novel strategy for the efficient purification of quartz ore: Experiments, DFT calculations, and life cycle assessment

Abstract

Quartz ore is a useful raw material for producing high-purity quartz. In this study, high-purity quartz is prepared by superconducting high-gradient magnetic separation (S-HGMS) coupled with fluorine-free acid leaching process. The results indicate that the main impurities in quartz ore are monticellite (Ca (Mg, Fe) SiO4), grossular ((Ca, Fe) (Al, Zr, Fe) Si3O12), thadeuite (Mg (Ca, Mn) (Mg, Fe, Mn)2(PO4)2(OH)2), and berlinite (AlPO4). The weak magnetic impurities are removed by the S-HGMS process, while the fluorine-free acid leaching technology removes berlinite and inclusion impurities from the quartz ore. The final high-purity quartz sand grade is 99.971 %. In addition, experimental analysis as well as first-principles density functional theory (DFT) calculations are utilized to examine the magnetic properties of mineral components in quartz ore. Life cycle assessment (LCA) is conducted to determine the environmental impact of the high-purity quartz sand preparation process, and the contribution of each raw material to high-purity quartz sand production is analyzed. Overall, this study not only establishes an advanced purification process for efficiently removing impurities from quartz ore, which can serve as a theoretical basis for boosting the industrial applications of quartz ore.