MANUFACTURE OF HIGH PURITY METALLIC THALLIUM FROM THALLIUM-CONTAINING SMELTING INTERMEDIATE

摘要

PURPOSE:To inexpensively recover high purity metallic Tl from a Tl-contg. smelting intermediate by adding a reducing agent to the intermediate, dissolving them in a sulfuric acid soln., separating the residue, adding soda ash to the soln. to remove the resulting precipitate, making the soln. acidic with sulfuric acid, and adding Zn powder. CONSTITUTION:To a smelting intermediate contg. Zn, Pb, Cd, Mn, Fe, etc. as well as Tl is added Na2SO3 or gaseous SO2 as a reducing agent, and they are dissolved in a sulfuric acid soln. so as to adjust the concn. of sulfuric acid to >=1mol/l. After separating and removing the residue, the filtrate is adjusted to >=9pH with soda ash or K2CO3, and the resulting precipitate is separated and removed. The filtrate is then adjusted to <=2.5pH with sulfuric acid, and by adding Zn powder in an amount corresponding to <=90% of the stoichiometric amount of Zn required to substitute for all of Tl in the filtrate, cementation is carried out to recover high purity metallic Tl. Since complex apparatus and operation for electrolysis or other process are unnecessary, Tl is recovered inexpensively.