| 摘要 |
<p>PURPOSE:To selectively and effectively extract and recover Pd without deteriorating extracting agent by adjusting Pd-containing water solution to the specific oxidation-reduction potential and bringing this into contact with organic solvent for extraction containing dialkyl sulfide. CONSTITUTION:Ore, waste catalyst, etc., is treated with aqua resia, hydrochloric acid, etc., to obtain oxidized acidic water solution containing Pd as essential component and further, Pt, Ph and non-metal, etc. To this water solution, reducing agent of hydrazine, etc., is added to adjust the oxidation-reduction potential to 725-830mV (normal hydrogen electrode standard). Successively, this water solution is brought into contact with the organic solvent for extraction containing dialkyl sulfide as the extracting agent. As the above organic solvent, kelocine, etc., is used, and if necessary, phase separating reforming agent of higher alcohol, etc., is added. Further, the above dialkyl sulfide is suitable to use the one having 4-10 number of C in the alkyl group. By this method, the deterioration caused by oxidation of the dialkyl sulfide for the extracting agent is suppressed, and Pd is selectively extracted from the water solution and recorded at high yield.</p> |
