Recovery of Hazardous Metals from Spent Refinery Processing Solid Catalyst

The extraction properties of metallic elements from the spent refinery processing catalyst were examined under citric acid leaching conditions. Different temperatures were tested for the extraction experiments and 80 °C was found to be most effective for metal extraction from the spent refinery processing catalyst. Compared to room condition, citric acid leaching treatment with 80 °C accelerated the dissolution of the catalyst waste solid, thus promoted the reaction of acid with hazardous metals such as Al, Ni, Mo. Furthermore, the optimum hydrothermal treatment temperature, time and liquid/solid ratio were 80 °C, 10 h and 8:1 (ml: g), respectively.