Thallium Production
Thallium Production
Industrially thallium is obtained as a by-product of iron and non-ferrous metal sulphide ores processing. It is also extracted from copper, lead and zinc production half-products. The processing method depends on feedstock chemical composition. For example, thallium and other valuable metals are extracted from lead production dust by suplhadizing it in boiling bed at 300-350°C, after which the sulphate mass is leached by water. Thallium is extracted by iodine containing 50% kerosene solution of tributyl phosphate, and then the element is reextracted by sulphuric acid (300 g/l) with 3% hydrogen peroxide. The metal is separated from the reextarcting products by cementation on zinc sheets. 99.99% pure thallium is obtained after remelting the products of the processing under caustic soda layer. Electrolytic refining and crystallizing purification is applied for obtaining more high-pure metal.