Method for producing high-purity silver powder by using silver-containing dead catalyst

Abstract

The invention discloses a method for producing high-purity silver powder by using a silver-containing dead catalyst, and belongs to the technical field of noble metal refining. The method comprises the following steps: the silver-containing dead catalyst is used as a raw material, silver is dissolved and converted to silver nitrate solution by dilute nitric acid; a precipitant is added in the silver nitrate solution after the filtration; a silver-containing compound precipitate is pulped after being filtered and washed; one or two reagents are randomly chosen from hydrazine hydrate, hydrogen peroxide, sodium borohydride, formic acid, ascorbic acid, glucose, fatty aldehyde, fatty amine and formaldehyde as reducing agent; any one reagent is chosen from polyvinylpyrrolidone, cetyl trimethyl ammonium bromide, lauryl sodium sulfate, polyethylene glycol and between as a protective agent; silver ions are reduced to silver particles under the condition of ultrasonic oscillation; and the silver particles are precisely filtered, and are dried in vacuum to obtain the high-purity silver powder product. The method has the benefit that the high-purity silver powder product with high purity, high dispersity and high activity can be obtained, and has the advantages of stable product performance, high recovery rate and environmental friendliness.

Description

technical field [0001] The invention relates to a method for producing high-purity silver powder by using a silver-containing waste catalyst, and belongs to the technical field of precious metal refining. Background technique [0002] At present, the method of recovering silver from silver-containing waste catalysts at home and abroad is that the silver-containing waste catalysts with aluminum oxide and silicon dioxide as the carrier are mostly directly smelted by fire method to obtain crude silver, and then electrolyzed by traditional electrolytic cells. Refining can obtain silver powder; or use nitric acid as leaching agent to obtain silver nitrate solution, and then carry out traditional electrolytic refining to obtain silver powder. Electrolytic refining has some disadvantages, such as high energy consumption, high production cost, and silver is easy to enter the slag phase; electrolysis will produce A large amount of acid mist is easy to corrode equipment and has a grea...

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Problems solved by technology

[0002] At present, the method of recovering silver from silver-containing waste catalysts at home and abroad is that the silver-containing waste catalysts with aluminum oxide and silicon dioxide as the carrier are mostly directly smelted by fire method to obtain crude silver, and then electrolyzed by traditional electrolytic cells. Refining can obtain silver powder; or use nitric acid as leaching agent to obtain silver nitrate solution, and then carry out traditional electrolytic refining to obtain silver powder. Electrolytic refining has some disadvantages, such as high energy consumption, high production cost, and silver is easy to enter the slag phase; electrolysis will produce A large amount of acid mist is easy to corrode equipment and has a great impact on the working environment of the factory: electrolysis will produce anode slime, which needs to be further processed, which increases the process; the waste gas, waste water and waste residue produced are difficult to process, resulting in a decrease in the recovery rate of silver

Moreover, the silver powder prepared by the traditional method has low purity, activity and dispersion, and has single performance.

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