摘要 |
FIELD: chemistry. ^ SUBSTANCE: thallium metal, containing other elements, is dissolved in sulphuric acid with concentration of 90 to 100 g/l. The solution is evaporated, cooled and the residue is filtered. The obtained solution, which contains thallium sulphate, is filtered and evaporated. Hydrogen sulphide gas is passed through the solution and sulphides of heavy metals are precipitated. Thallium metal is separated by electrolysis. The obtained metal is dissolved in nitric acid and diluted with water to thallium concentration of 60 to 80 g/l. Potassium hydroxide is added until pH equals 10. Using electrolysis, thallium (III) oxide is deposited on the anode and thallium metal is deposited on the cathode. Current density at the anode ranges from 0.25 to 1.00 A/cm2, and from 0.05 to 3.00 A/cm2 at the cathode. ^ EFFECT: obtaining thallium oxide and thallium metal with low content of impurities maximum 0,0048%, high output of the desired product of minimum 84,2-99,6%, reduced formation of filtrates and pollution of the environment. ^ 2 cl, 1 dwg, 10 ex |