Method for recycling noble metal from automobile exhaust catalyst

The invention provides a method for recycling noble metal from an automobile exhaust catalyst, and belongs to the technical field of resource recycling. The method comprises the following steps: deoiling and decarbonizing the automobile exhaust catalyst, finely pulverizing, and carrying out acid leaching; carrying out primary chlorination on acid leaching residues in a solution of sodium chloride, sodium chlorate and sulfuric acid; mixing primary chlorination residues with sodium peroxide, carrying out water leaching on an alkaline transfer residue, carrying out secondary chlorination on a water leaching residue; mixing primary chlorination liquid with secondary chlorination liquid, and replacing with Fe powder, so as to obtain a displacement liquid and precious metal ore concentrate; mixing an acid leaching liquid, the water leaching liquid and the replacement liquid, and carrying out neutralization-oxidization; and adding calcium chloride to a neutralization liquid, carrying out desulphuration treatment, and returning a desulphuration liquid to primary chlorination and secondary chlorination procedures by adjusting the amount of sodium chloride, sodium chlorate and sulfuric acid. According to the method disclosed by the invention, noble metal is smoothly leached and recovered; the problems of noble metal recovery and environment protection of the automobile exhaust catalyst are solved; and the method has the characterizes of high adaptability and simple equipment, and is suitable for industrialized production and environmental friendly.