| 摘要 |
<p>PURPOSE:To recover a Tl concentrate from a Tl-contg. substance in a high yield by leaching the substance with SO2 followed by chlorination and filtration. CONSTITUTION:Cleaning sludge discharged from a Cd refining process contains a small amt. of Cd, Zn and As besides 5-20% Tl. This sludge is adjusted to pH2-4 with sulfuric acid or the like and leached by blowing SO2 gas or adding sulfite. The contained Tl is reduced from trivalent Tl to monovalent Tl and chlorinated by adding hydrochloric acid or NaCl or blowing chlorine gas. Thus, the monovalent Tl is converted into TlCl, and the TlCl-contg. liquor is separated into a filtrate and a cake by filtration. This cake contains more than 80% Tl and a little As, Cd and Zn, so it is used as a Tl source to recover the Tl.</p> |
