Method for recycling platinum from indissolvable silicon-aluminum-based platinum-containing waste catalyst

Abstract

The invention discloses a method for recycling platinum from an indissolvable silicon-aluminum-based platinum-containing waste catalyst. The precious metal selective oxidation leaching-resin slurry process adsorption technology is adopted for recycling platinum from the high-silicon and high-aluminum platinum-containing waste catalyst. The specific technology sequentially comprises the steps that the medium-temperature roasting is conducted in the platinum-containing waste catalyst for removing coil, deposited carbon and other organic matter; a high-concentration hydrochloric acid medium with the acidity not lower than 5 mol / L is adopted for selective oxidizing leaching of platinum, the platinum leaching rate can reach 99% or above, and the residual platinum in non-dissolved slag is smaller than or equal to 15 g / t; the resin slurry method is adopted for direct adsorption or the slurry method and fixed bed joint adsorption technology is adopted for enriching platinum in a leaching agent, and the platinum content in the tail slurry or the tail liquid is smaller than 1mg / L; the high-concentration platinum solution obtained after resin spraying is subjected to refinement purification, the chloroplatinic acid solution is directly prepared or the ammonium chloride repeated deposition method, the hydrazine hydrate reduction method and other methods are adopted for roasting, a sponge platinum product is obtained, the platinum recovery rate is larger than or equal to 96%, the purity of the sponge platinum is larger than or equal to 99.95%, and the content of other impurities meets the national related standard requirement.

Description

technical field [0001] The invention belongs to the technical field of resource recovery and utilization, and relates to a secondary resource recovery and utilization process of platinum group metals, in particular to a method for recovering platinum from insoluble high-silicon and high-alumina-based spent platinum-containing catalysts. Background technique [0002] Platinum group metal catalysts play an irreplaceable role in petrochemical production. At present, platinum-based catalysts in use in China are mainly alumina-based carrier components. The matrix is ​​easily soluble in acid and alkali. The new platinum catalyst supported by the carrier has become a mainstream product abroad due to its advantages such as low platinum loading, high selectivity in target production and use, long service life and high cost performance. In recent years, while increasing imports, the country has invested a lot of manpower and material resources to speed up the development of new produc...

AI Technical Summary

Problems solved by technology

In the acid-base method, due to the high content of silicon and aluminum in the waste agent matrix, the dissolution of precious metals in acidic or alkaline systems is incomplete, the content of precious metals in the insoluble slag is high, and the high viscosity of the leaching solution makes solid-liquid separation very difficult, resulting in long process flow. , the dispersion loss of precious metals is large, and the recovery rate is not high, only about 80-85%

The fire method includes direct high-temperature smelting method and alkali melting method. The former is seldom used because of large investment in equipment, high energy consumption, serious environmental pollution, and low enrichment of precious metals. Difficult to enrich, the yield is not high, and there are not many applications

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