| The pyrometallurgical melting method can effectively improve the platinum recovery rate from spent propane dehydrogenation catalysts, reduce the platinum content in smelting slag, and produce no wastewater. Therefore, it is considered to be an efficient and green process. A study was conducted in this work on the enrichment of platinum through the pyrometallurgical melting of spent propane dehydrogenation catalysts. By optimizing the slag system and components, SiO2-Al2O3-CaO ternary slag with a high Al2O3 content of 40% was chosen for the smelting experiment. The reactions among Al2O3, Fe3O4, CaO, SiO2 and C were analyzed by using thermodynamic calculation methods. When the reaction temperature is relatively high, SiO2 is prone to dissociation, forming a ferrosilicon (Fe-Si) alloy, which will affect the refining and purification of platinum. Hence, the melting temperature should not exceed 1941K. Under the experimental conditions of adding 20% Fe3O4 and excess reducing agent of 20% and CaO/SiO2 mass ratio of 1.6 and when the melting process was carried out at 1823 K for 90 minutes, the recovery rate of platinum reached 98.93%. Therefore, this method can be applied to the recovery of platinum from spent propane dehydrogenation catalysts. |
