The role of sodium phytate in the flotation separation of smithsonite from calcite

The effective flotation separation of smithsonite and calcite has always been a thorny problem due to their relatively similar physicochemical property. Developing efficient and selective depressant is the key to address this obstacle. In this study, sodium phytate (SP) was introduced as a novel depressor for high-efficient flotation separation of smithsonite and calcite. Influences in flotation performances induced by SP and its possible underlying mechanism were thoroughly studied by various advanced detection techniques. Flotation tests indicated that calcite flotation was significantly depressed, whereas the smithsonite flotation was barely affected. Zeta potential analysis showed that SP adsorbed stronger on calcite than smithsonite. Furthermore, the SP adsorption exhibited little influence on the subsequent sodium oleate (NaOl) adsorption onto smithsonite, whereas it strongly hindered the NaOl adsorption on the calcite surface. Fourier transform infrared (FTIR) measurement and X-ray photoelectron spectroscopy (XPS) analysis further unveiled that SP weakly adsorbed on the smithsonite surface through electrostatic attraction that did not interfered the subsequent NaOl adsorption, whereas SP chemically adsorbed on the calcite surface strongly which greatly blocked the following adsorption of NaOl on the calcite surface. As a result, the calcite flotation was selectively depressed and the flotation separation of smithsonite from calcite was eventually achieved.

Automated summary

This study introduced sodium phytate (SP) as a novel depressant for the high-efficient flotation separation of smithsonite and calcite. The influences on flotation performances induced by SP and its possible underlying mechanism were thoroughly studied. The results showed that SP could significantly depress calcite flotation while barely affecting smithsonite flotation. The adsorption behaviors of SP on calcite and smithsonite surfaces explained the selective depression of calcite flotation.