| The process of alkali roasting-leaching was used to remove silicon and aluminum matrix in the spent automobile exhaust catalyst refining residue which was difficult to dissolve, so that platinum, palladium and rhodium were enriched. The effects of alkali dosage, roasting temperature, roasting time, material layer thickness and leaching temperature on the dissolution rate of refining residue were investigated. The results showed that the dissolution rate of the refining residue was more than 90% with a 1:1 ratio of alkali to material, a roasting temperature of 650℃, 3 h roasting time, 4 cm of roasting thickness, and 70℃ of water leaching temperature, and that the content of platinum group metals in refining residue was increased by 10 times at the optimum conditions. |
