Method for extracting silver from silver slag

Abstract

The invention discloses a method for extracting silver from silver separated residue, which relates to a method for recycling silver from the solid residue of copper anode sludge after the metal such as Se, Cu, Te, Au, and Ag is separated and extracted. The invention is characterized in that the invention comprises the steps that firstly, the silver separated residue is pulped, industrial H2SO4 is adopted to adjust the acidity of the solution, the oxidizing agent NaClO3 is added to control oxidation reduction potential of the solution to perform oxidizing pretreatment, Ag2O, Ag2SO4, Ag2S, and simple substance Ag in the silver separated residue which can be hardly leached are changed into AgCl which can be easily leached by Na2SO3, and the AgCl is reduced into coarse Ag powder through CH2O under the alkalinity condition. The method of the invention has the advantages that the equipment is simple, the process flow is simple, the silver recovery ratio is high, the loss of the noble metal such as Pt and Pd, etc. in the silver separated residue can not be caused, and the invention is suitable for large-scale industrial production.

Description

technical field [0001] A method for extracting silver from silver-separating slag relates to a method for recovering silver from the solid residue after separating and extracting Se, Cu, Te, Au, Ag and other metals from copper anode slime. Background technique [0002] Silver separation slag is the solid residue left after extracting main components such as Se, Cu, Te and precious metals Au, Ag, Pt, Pd from copper anode slime. Generally, the output rate of anode slime is 50%-55%, while the output rate of silver-separating slag is 28%-33% of that of copper anode slime. At present, many copper smelting plants in China produce a large amount of silver slag every year. Due to the complex composition of the silver slag, low precious metal content, and difficulty in recycling, some smelters return the silver slag to the fire method for smelting and blowing, resulting in the loss of precious metals and high processing costs; while some smelters return the silver slag Directly ret...

AI Technical Summary

Problems solved by technology

Due to the complex composition of the silver slag, low precious metal content, and difficulty in recycling, some smelters return the silver slag to the fire method for smelting and blowing, resulting in the loss of precious metals and high processing costs; while some smelters return the silver slag Return directly to the anode slime treatment process. This treatment method not only cannot effectively recover the precious metals and valuable metals, but also increases the burden on the anode slime treatment process.