A method for enriching platinum from the oxidative leaching precipitate of silicon-alumina-based platinum-containing spent catalyst

Abstract

The invention discloses a method for enriching platinum from a precipitate obtained by oxidation leaching of a silicon-aluminum based platinum-containing spent catalyst. The method particularly comprises the following steps: (1) slowly adding a flocculant solution to the precipitate under a stirring condition, allowing to stand for 10-15 min, filtering, washing the obtained filter cake with waterfor multiple times, measuring the platinum concentration in the washed water after each time of washing until the platinum content in the washed water is less than 0.5 mg / L, and stopping water washing; (2) merging a filtrate A with the washed water, adjusting the pH of the solution to 0.5-1, measuring the platinum concentration in the solution, adding copper powder according to the excess coefficient of 1-2 according to the platinum metal amount in the solution, replacing, and filtering, to obtain copper-containing platinum powder and a filtrate B; and (3) adding activated carbon into the filtrate B, adsorbing and filtering, to obtain platinum-loaded activated carbon and a tail liquid which is directly used as wastewater for treatment. The problem of solid-liquid separation is solved by adding the flocculant, then 70-80% of platinum is recovered by metal replacement, and then activated carbon is used for adsorbing low-concentration platinum in the solution, so the cost is saved and therecovery rate of platinum is high.

Description

technical field [0001] The invention belongs to the technical field of resource recovery, and relates to a secondary resource recovery process for platinum group metals, in particular to a method for enriching platinum from oxidative leaching precipitates of silicon-aluminum-based spent platinum-containing catalysts. Background technique [0002] High-silicon and high-alumina-based platinum-based waste catalysts, due to their special carrier components, high silicon-aluminum content, low platinum content, and the carrier components are insoluble in acid and alkali, currently there is little research on the recovery technology of such catalysts. Chinese patent application CN106480313A discloses a method for recovering platinum from insoluble silicon-aluminum-based platinum-containing waste catalysts. First, carbon, oil and other organic matter are removed by roasting, and then hydrochloric acid and oxidizing agents are added to selectively oxidize and leaching platinum. A sma...

AI Technical Summary

Problems solved by technology

Chinese patent application CN106480313A discloses a method for recovering platinum from insoluble silicon-aluminum-based platinum-containing waste catalysts. First, carbon, oil and other organic matter are removed by roasting, and then hydrochloric acid and oxidants are added for selective oxidation and leaching of platinum. A small amount of impurities such as aluminum and silicon are also leached, and most of the carrier is insoluble

However, the precipitate is a solid-liquid mixture, and the solid is mainly leached silicate polymer and small carrier particles (Al 2 o 3 ·SiO2 2 ), due to the high solid content, the resin is prone to clogging during the process of adsorbing platinum with the resin, and the resin damage rate is high, and the recovery cost is high

Images