Method for recycling noble metal from automobile exhaust catalyst

Abstract

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.

Description

technical field [0001] The invention relates to the technical field of resource recycling, in particular to a method for recycling precious metals of automobile exhaust catalysts. Background technique [0002] Since the 1970s, with the emphasis on environmental protection in developed countries, the control of automobile exhaust pollution has become the focus of improving air quality. Many countries have successively legislated to limit CH in automobile exhaust n , CO, NO and other harmful components. Since the 1990s, the United States, Europe and Japan have continuously increased the requirements for exhaust emission purification. In order to ensure the purification effect, the manufacturers have successively increased the content of platinum group metals in the catalyst. Since my country's reform and opening up, production has developed rapidly, living standards have improved significantly, and automobiles have begun to enter households in large numbers; the demand for r...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a method for recovering precious metals from automobile exhaust catalysts to solve the problems of oil pollution and residual carbon on the recovery of precious metals from automobile exhaust catalysts, low recovery rate of precious metals, and inability to circulate tail liquid. The carbon pretreatment method eliminates the adsorption of waste oil and residual carbon on precious metals; a combination of one-stage acid leaching, two chlorination and alkali conversion processes is proposed to strengthen the leaching of precious metals; the idea of ​​tail liquid regeneration and utilization is proposed to eliminate tail liquid Disposal and secondary pollution; a complete solution to the recovery of precious metals and environmental protection of automobile exhaust catalysts

Images