Method for extracting and enriching rare and precious metals from spent catalyst

Abstract

The invention relates to a method for extracting and enriching rare and precious metals from a spent catalyst, and belongs to the technical field of secondary resources recovery and reuse technology of the rare and precious metals. The method comprises the steps of firstly carrying out low-temperature reduction on the spent catalyst to be treated, a reducing agent and iron oxide or copper oxide, and adding a silicon material and an additive for high-temperature melting so as to collect the rare and precious metals after low-temperature reduction; or directly high-temperature melting the spentcatalyst to be treated, the silicon material, the additive and the iron oxide or the copper oxide so as to collect the rare and precious metals; finally obtaining a silicon-based alloy and a waste residue through residue-gold separation; enriching and separating the obtained silicon-based alloy so as to obtain a rare and precious metal enriched product and high-purity silicon; or solidifying, grinding and hydrometallurgically leaching the obtained silicon-based alloy so as to obtain a leaching agent containing the rare and precious metals and the high-purity silicon; and recycling the obtainedhigh-purity silicon used as a silicon material again, or sending to the photovoltaic or electronic product enterprise so as to be used as a raw material for preparing solar grade silicon or electronic grade silicon. The method for extracting and enriching the rare and precious metals from the spent catalyst provided by the invention has the advantages of low cost and short flow.

Description

technical field [0001] The invention relates to a method for extracting and enriching rare and precious metals from spent catalysts, and belongs to the technical field of recovery and reuse of secondary resources of rare and precious metals. Background technique [0002] At present, the recovery methods of spent catalyst mainly include fire method and wet method. The wet method has the advantages of simple recovery process, low treatment cost and simple equipment, but when dealing with a large number of spent catalysts such as spent automobile exhaust purification catalysts and carrier catalysts for the petrochemical industry, it will face high acid consumption, long treatment time and environmental pollution etc. [0003] Pyrotechnic capture of rare and precious metals in spent catalysts is a mainstream method both at home and abroad. Although the energy consumption of the pyro capture method is high, this method can efficiently process a large number of spent catalysts a...

AI Technical Summary

Problems solved by technology

However, this patent application still has the situation that when the separation effect of silicon and slag is not ideal, the precious metals platinum, palladium and rhodium gather at the boundary between silicon and slag, thereby affecting the recovery rate of precious metals; in addition, the patent application number is 201710363321.1 and The recovery of rare metals such as zirconium, cerium, lanthanum and neodymium in spent catalysts is not described, the present invention has demonstrated and increased recovery of zirconium, cerium, lanthanum and neodymium

Images