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Vol.46, No.4, 233 ~ 241, 2008
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| Title |
| Reductive Precipitation of Platinum and Palladium with Hydrazine in Hydrochloric Acid Solution |
| 김민석 Min Seuk Kim , 김병수 Byung Su Kim , 유재민 Jae Min Yoo , 유경근 Kyoung Keun Yoo , 이재천 Jae Chun Lee , 김원백 Won Baek Kim |
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| Abstract |
| The reductive precipitation of platinum and palladium in hydrochloric acid solution using hydrazine as a reducing agent was investigated. The reductive precipitation ratios of platinum and palladium increased when increasing the stoichiometric ratio for reducing agent, precipitation time, and pH. The precipitation ratio of platinum was much lower than that of palladium. This is the reason the reaction rate of PtCl6 2- → PtCl4 2- at the reduction reaction step of PtCl6 2- → PtCl4 2- → Pt is very slow. The purity of platinum precipitated was very affected by metallic impurities, while it was possible to precipitate the high purity palladium since the precipitation rate of palladium was relatively fast. At the pH of 1.3, the precipitation temperature of 25℃, and the addition amounts of the hydrazine of 10 and 1.75 times the stoichiometric ratio, the reductive precipitation ratios of platinum and palladium from their hydrochloric acid solutions containing 2,000 ppm were 98.5% and 99.9% in 30 min, respectively. |
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| Key Words |
| reductive precipitation, platinum, palladium, hydrochloric acid solution, metallic impurities |
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