Precious metal extraction from waste three-way catalysts Trapping agent selection

When selecting and adding the proper trapping agent, the melting atmosphere is controlled to achieve high trapping efficiency. The base metals iron, copper, lead and their sulphides in the spent Ternary catalyst can trap the dispersed platinum group metal particles in the melt. The choice of trapping agent for refining precious metals from spent three-way catalysts depends mainly on the following factors.
1, waste three-way catalyst refining precious metals subsequent precious base metal separation process does not lead to the secondary dispersion of precious metals. Compared with various trapping agents, lead trapping has serious environmental pollution and should be avoided as far as possible. Iron trap requires a higher temperature and greater energy consumption, but when the melting conditions are well controlled, it is easy to use simple acid dissolution methods to separate iron from iron alloys to obtain platinum group metal concentrates, and the separation process of precious base metals is simple. The melting temperature of copper trapping is lower, but the separation of copper from copper alloys requires electrolysis or high temperature oxidation method, the electrolysis method has a long cycle time, and the operating environment of high temperature temperature oxidation is poor. Iron sulfide, copper sulfide, nickel sulfide than the corresponding metals with low melting point and good fluidity smelting trapping efficiency is higher, available pressure oxidation acid leaching method of separation of base metals, extraction of platinum group metal ore, the disadvantage is that the melting process inevitably produces low concentrations of sulfur dioxide, the need to increase the flue gas smelting measures.

2, processing scale and has the corresponding on art and equipment supporting conditions.
3, waste three-way catalytic converter refining precious metal separation base metals: there should be mature from the capture concentration of base metal separation technology to extract a good dissolution activity of platinum group metals crude concentrate.
4, the whole process of refining precious metals from waste three-way catalysts should meet the requirements of the green metallurgical process, the reagents used do not pollute the environment, and try to recycle and comprehensive use.