SODIUM STANNATE PREPARATION FROM CASSITERITE CONCENTRATE AND SODIUM CARBONATE BY ROASTING UNDER A CO/CO_2 ATMOSPHERE

摘要

Sodium stannate is widely used in. the electroplating and tin alloy industry. But the traditional processes for sodium stannate production are characterized by long flowsheet, high production cost and strict requirement for the equipments, etc. In this study, a novel process for sodium stannate preparation from cassiterite concentrate and sodium carbonate via roasting in CO/CO_2 mixed gas then followed by leaching was developed. The effects of roasting parameters on the Sn leaching efficiency were conducted. A Sn leaching efficiency of 77.2% was obtained under the optimal conditions. Sodium stannate (Na_2SnO_3-3H_2O) with a purity of 95.8% was produced by the new process, which is better than that specified for the industrial first-grade product.