Chen A.,Kunming University of Science and Technology |
Zhang Z.,Kunming University of Science and Technology |
Wang S.,Yunnan Institute of Supervision and Inspection for Product Quality |
Peng J.,Kunming University of Science and Technology |
And 2 more authors.
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2012
One of difficult problems is the low recovery of rhodium during the recovery of precious metals from spent automobile catalysts, the main problems of the dissolution technique of rhodium are long dissolution period, low dissolution efficiency, high reagent consumption, complex operation, and serious environment pollution. In order to improve the leaching efficiency of rhodium, many researchers focused on clean dissolution and high efficient technique. At the present, the applied dissolution techniques were intermediate temperature chloride-dissolution method and sodium (potassium) bisulfate fusion-dissolution method with some problems. In this work, microwave roasting was used to recovery rhodium from the leached residue of spent automobile catalysts. The impacts of various factors; reaction temperature, reaction time and proportion of solid to reagent on the rhodium leaching efficiency were studied. The result indicates that microwave heating, through accelerating molecular vibration, smashing the particles, and enhancing the contacting area of solid and liquid, increasing heat and mass transfer processes, finally speeds up the reaction, reduces reagent consumption and obviously improves leaching efficiency. Under the best experimental condition, the proportion of material and reagent is 1:10, the reaction temperature is 600°C and the holding time is 60 min. Leaching ratio of rhodium reaches 99.79%. The technique that with less environment pollution, high efficiency of dissolution and high leaching rate has a wide application prospect provides a technical guidance for the recovery of rhodium from spent catalysts of automobile exhaust.