| 摘要 |
<p>PURPOSE:To manufacture metallic Tl of high purity by adding NaCl to a slurry obtd. by leaching of Tl-contg. substance using SO2, and after filtering, recovering Tl slag containing TlCl, filtering after making the Tl slag basic, and performing cememtation using zinc plate under an acidic condition. CONSTITUTION:Electrolytic solution of lead, and clean slag generally containing 10-20% Tl produced in refining of Cd and impurities such as Zn, Cd etc. is leached with SO2, and Tl contained is reduced from trivalent to monovalent and changed to water soluble. NaCl is then added to the leached slurry. After sufficiently agitating to change Tl to TlCl, it is filtered to separate into a filtrate containing impurities such as Mn etc. and Tl slag. Then, Tl slurry adjusted to above pH 9.0 by adding water and MaOH etc. is leached while agitating at room temperature -80 deg.C, for instance 60 deg.C. Selective leaching is performed restraining leaching of arsenic, zinc and Cd. The leach is filtered, and the filtrate is substituted using a zinc plate keeping the filtrate at pH 2-4. Metallic Tl of high purity is obtained through fine granular spongy Tl.</p> |
