LAUSR

Abstract Flotation separation of smithsonite from quartz is difficult due to the dissolved zinc species activated the quartz flotation. To solve this problem, calcium lignosulphonate (CLS) was introduced as a depressant for quartz in smithsonite flotation when using sodium oleate (NaOL) as a collector. Micro-flotation results showed that NaOL exhibited excellent collecting performance to smithsonite and zinc ions activated quartz in the pH range of 10–11. In the presence of CLS, the flotation separation of smithsonite from quartz can be achieved by selective depression of quartz. The zeta potential measurements showed that the addition of CLS prevented the adsorption of NaOL on zinc ions activated quartz surface while did not prevent the adsorption of NaOL on smithsonite surface at pH 10–11. XPS analysis revealed that CLS selectively adsorbed on zinc ions activated quartz surface primarily through chemical interaction.