Abstract:A new preparation method (reduction-decomposition process) for high purity SrCO₃was investigated, which mainly includes four processes: reduction, leaching, purification and precipitation. The affecting factors about S₂-behaviors in leaching process and the effects of variables on purity and particle sizes distribution of SrCO₃were analyzed theoretically and practically. It is concluded that with the increase of temperature or decrease of pH value in leaching process, the strontium recovery increases, but SrS decomposes and hydrogen sulphide (H₂S) gas discharges. The purity of SrCO₃is dependent on dissolution-recrystallization times, for example, the purity of SrCO₃is as high as 99.97% when it is recrys tallized three times. Besides, the solution concentration of Sr(OH)₂and flow rate of CO₂have important effects on particle size distribution of SrCO₃particles, especially, the particle sizes of SrCO₃meanly distribute in 0.1 1.0μm when the flow rate of CO₂is about 2 000 mL/min and other parameters are invariable.

Key words: strontium carbonate; high purity; reduction-decomposition process;
behavior analysis