Abstract |
During the selective extraction of Pd(Ⅱ) by LIX 63 from 6 M HCI solutions containing platinum group metals, an oxidation reduction reaction occurs between the LIX 63 and Ir(Ⅳ). Sind the reduced Ir(Ⅲ) cannot be extracted by solvating and amine extractants, the oxidation-reduction reaction has a significant effect on the separation of Pt(Ⅳ), Ir(Ⅳ) and Rh(Ⅲ). Therefore, the effect of HCI concentration on the reduction of Ir(Ⅳ) during the extraction with LIX was investigated at 3 and 6 M HCI solutions. The extraction behavior of Iridium by Aliquat 336 from the Pd(Ⅱ) free raffinate showed that the percentage of iridium extraction rapidly decreased when HCI concentration was increased from 3 to 6 M, indicating that more Ir(Ⅳ) was reduced to Ir(Ⅲ). Extraction schemes for the separation of Pt(Ⅳ), iridium and Rh(Ⅲ) by Alquat 336 from 3 and 6 M HCI solutions were investigated. |
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Key Words |
platinum, iridium, rhodium, LIX 63, separation |
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