Method for extracting platinum, palladium, rhodium from automotive catalyst of ore phase reconstruction

Abstract

The invention relates to a method for recovering noble metals from spent automotive exhaust catalysts, comprising the following processes: 1. mixing the spent automotive exhaust catalyst with a reducing agent, an additive and a trapping agent; 2. putting the mixed materials into a clay graphite crucible, and putting the clay graphite crucible into an electric furnace or an electric arc furnace for smelting, thus obtaining a noble metal phase; 3. selectively leaching base metals from the noble metal phase, thus obtaining the enrichment of the noble metal, refining the enrichment of the noble metal to produce platinum, palladium and rhodium products. The method is characterized by simple process flow and high recovery rates of noble metals. The platinum, palladium and rhodium in the waste slag are less than 1g / t and the product purity is 99.95%.

Description

technical field [0001] The invention relates to a method for recovering platinum group metals from automobile exhaust catalysts, in particular to a method for effectively recovering platinum group metals from automobile exhaust catalysts containing precious metals or various low-grade materials. Background technique [0002] After the 1970s, with the increasing emphasis on environmental protection in developed countries, the control of vehicle exhaust pollution has become the focus of improving air quality. Some countries have successively made legislative restrictions on the three harmful components of CH, CO, and NO in automobile exhaust. The best way to control automobile exhaust is to install a three-way catalyst containing platinum, palladium, and rhodium in the exhaust pipe of the automobile. The CH, CO, and NO harmful components in the exhaust gas are converted into harmless CO 2 and N 2 emission. Therefore, the amount of platinum, palladium, and rhodium used in au...

AI Technical Summary

Problems solved by technology

Disadvantages: When the plasma smelting method is used to treat honeycomb cordierite carrier automobile catalysts, there are two shortcomings: one is that the slag generated by cordierite is very viscous, and it is difficult to separate the metal from the slag; the other is that at the melting temperature, if there is Carbon, silicon dioxide in cordierite (at least part of it) is reduced to elemental silicon, and iron added as a platinum group metal collector forms high-silicon ferrosilicon, which forms a new alloy phase with platinum group metals, and this alloy has extremely Strong anti-acid and anti-alkali properties make the follow-up process very difficult

In addition, due to the special equipment, there is no large-scale production of plasma melting equipment in my country at present. The service life of the plasma gun is short, which limits its practical application. It is necessary to further develop a light plasma gun that is easy to replace.

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