| 摘要 |
<p>PURPOSE:To enable recovery of a noble metal in high purity and a high yield by treating metallic parts having the noble metal with an aq. mixed soln. of iodine and an iodine compd. to dissolve selectively the noble metal, and extracting the same into an org. solvent then extracting reversely the noble metal in an aq. alkali soln. CONSTITUTION:The sepn. and recovery of a noble metal from the state that the noble metal coexists with other metals as a result of plating, cladding, backing, etc. or being coated on ceramics, is accomplished by dipping the parts contg. the noble metal into an aq. soln. contg. iodine and an iodide such as sodium iodide or potassium iodide as a dissolving liquid to dissolve and extract selectively the noble metal alone. An org. solvent such as methyl isobutyl ketone, ethyl ether or the like is added to the solution of such noble metal under stirring to extract the noble metal into the org. solvent. The noble metal is extracted reversely by separating the org. solvent and adding an aq. soln. of KOH, then the noble metal ions in the KOH soln. are reduced by hydrazine or the like, whereby the noble metal having extremely high purity is separated and recovered in a high yield.</p> |
