A method for producing pure silver and co-producing metallic aluminum from a waste silver catalyst whose carrier is alumina

Abstract

The invention discloses a method for producing pure silver from a waste silver catalyst whose carrier is alumina to co-produce metallic aluminum. In the method, the waste silver catalyst whose carrier is alumina is mixed with a flux, placed in an aluminum electrolytic cell for electrolysis, and respectively Obtain crude aluminum, crude silver and residual electrolyte, break the residual electrolyte and return to the electrolysis process; heat the crude aluminum above the melting point by melting method and stir, and precipitate as silver-aluminum intermetallic compound in solid state to form infusible residue, and the rest is liquid metal Aluminum, remove the residue and send it to the condensate process; use the condensate method to raise the temperature of the crude silver above the melting point, and then slowly cool it down to 960 ° C, the silver solidifies into a solid, and the aluminum floats on the surface of the solid silver in liquid form, then remove Liquid aluminum is returned to the smelting process; adopting this method to produce pure silver and metal aluminum, the recovery rates of silver and aluminum are greater than 98.0% and 95% respectively, and the purity of pure silver and aluminum products are respectively 98.5% and 98.0%, with high silver recovery rate , short process, green environmental protection, high resource utilization, low cost, and mature equipment.

Description

technical field [0001] The invention belongs to the field of metallurgy of rare and precious metals, and relates to a method for producing pure silver and co-producing metallic aluminum from a waste silver catalyst whose carrier is alumina. Background technique [0002] At present, the main methods for recovering silver from spent silver catalysts of alumina are as follows: [0003] Zhang Shengen and others disclosed a method for recycling waste catalysts containing silver (application publication number: 201910032809.5), the steps are as follows: (1) Use dilute nitric acid to selectively leach silver from waste catalysts containing silver, and filter to obtain silver nitrate solution and filter residue (2) Use sodium chloride solution to precipitate silver nitrate filtrate, and filter to obtain silver chloride and sodium nitrate filtrate; (3) Use hydrogen to reduce silver chloride to obtain silver powder, and reduce tail gas to obtain HCl after absorbing it with water The ...

AI Technical Summary

Problems solved by technology

[0009] To sum up, the recovery of silver from waste silver catalysts whose carrier is alumina is mainly based on wet method, and the leaching agent is nitric acid, and hydrochloric acid is also used for leaching. During the extraction process, a large amount of waste residue, waste liquid, and waste gas are produced. Aluminum oxide becomes waste residue containing acid and alkali, which increases recycling costs

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