SYNTHESIS OF SODIUM STANNATE USING ALKALINE PRESSURE LEACHING PROCESS

Sodium stannate has numerous applications, including electroplating, tin alloy, catalysts, precursor to flame retardants, and also can be used as solid electrolytes and electrode materials in emerging battery systems. The primary method for producing sodium stannate typically involves the reaction between tin metal and sodium hydroxide solution. However, the procedure exhibited several limitations, such as high energy consumption, a long process flow for the production of metallic tin, as well as the release of potentially hazardous gases. Therefore, the present study focused on synthesizing sodium stannate from cassiterite minerals through alkaline pressure leaching, followed by crystallization. The main aim of this study was to examine the effect of various leaching process parameters, such as sodium hydroxide concentration, leaching temperature, and leaching time on the improvement of tin dissolution. The results showed that the alkaline pressure leaching process can successfully produce sodium stannate from the cassiterite mineral. The optimum parameters for alkaline pressure leaching to produce sodium stannate from cassiterite have been determined: temperature of 150°C, sodium hydroxide concentration of 4 mol/L, and duration of 240 minutes.