Method for extracting and refining platinum group metal in automobile tail gas three-way catalyst

Abstract

The invention relates to a method for extracting and refining platinum group metal in an automobile tail gas three-way catalyst. The method comprises the procedures of conducting extraction through apyrogenic method recycling process and conducting refining through a platinum group metal refining process. The extraction procedure comprises the steps of 1, pulverizing the waste catalyst, and conducting material compounding; 2, conducting smelting; 3, conducting blowing; 4, conducting atomization; and 5, obtaining a mixture of copper, platinum, palladium and rhodium through leaching. The refining procedure comprises the steps that 1, pretreatment is conducted; 2, a platinum refining process comprises the sub-steps of solution production, oxidation, repeated precipitation and calcination; 3,a palladium refining process comprises the sub-steps of conducting dissolution through ammonium hydroxide and precipitation, conducting acidification to precipitate the palladium, and conducting reduction through hydrazine hydrate; and 4, a rhodium refining process comprises the steps of conducting matching through sodium nitrite, conducting precipitation through ammonium chloride, conducting dissolution, and conduction reduction. According to the method for extracting and refining the platinum group metal in the automobile tail gas three-way catalyst, the platinum group metal is gathered through copper obtained through the pyrogenic method process; and the platinum group metal in the waste catalyst can be gathered through the copper at the low temperature and in weak reducing atmosphere.The method is high in treatment capacity; a small amount of waste water and a small amount of waste gas are generated; and in addition, the recycling rate of the platinum group metal is high.

Description

technical field [0001] The invention relates to a method for extracting and refining platinum group metals, in particular to a method for extracting and refining platinum group metals in an automobile exhaust three-way catalyst for simultaneously purifying multiple components in the automobile exhaust three-way catalyst. Background technique [0002] The three-way catalyst for automobile exhaust gas contains platinum group metals platinum (Pt), palladium (Pd), and rhodium (Rh). Autocatalysts are generally granular or monolithic, the granular shape includes spherical or cylindrical, and the monolithic shape is a continuous honeycomb structure with a circular or elliptical cross-section. The granular catalyst carrier is γ-Al 2 o 3 , the honeycomb structure is iron cordierite 2FeO 2Al 2 o 3 ·5SiO2 2 , or magnesian cordierite 2MgO·2Al 2 o 3 ·5SiO2 2 95% of the currently used automotive catalyst supports are honeycomb cordierite ceramic supports. In order to increase the ...

AI Technical Summary

Problems solved by technology

[0003] The current common purification usually only purifies platinum metal, while there is no specific purification method for metal palladium (Pd) and rhodium (Rh)