China Precious Metal Refining Technology And Equipment Leading Brand
Detailed News
impurities during silver electrorefining

     

Answer:During silver electrolysis, the behaviors of impurities are categorized as follows based on differences in the properties and action characteristics of various elements:

(1) Metals with more negative electrode potential than silver: All such impurities may dissolve during electrolysis. Representative metals include lead, antimony, arsenic, bismuth, copper, etc. After entering the electrolyte, these impurities will gradually accumulate, contaminating the electrolyte, consuming nitric acid, and reducing the electrical conductivity of the electrolyte.

(2) Metals with more positive electrode potential than silver: Such impurities do not undergo electrochemical dissolution, but remain in solid state and enter the silver anode slime. Representative metals include gold and platinum group metals (PGMs). When their content is low, they pose no adverse effect on silver electrorefining; however, when their content is excessively high, they will be retained on the anode surface, hindering the dissolution of silver from the anode, and even causing anode passivation, which elevates the electrode potential of silver and disrupts the normal operation of electrolysis.

(3) Metals existing in the form of compounds, such as Ag₂Te (silver telluride), Ag₂Se (silver selenide), Cu₂Te (copper telluride) and Cu₂Se (copper selenide): Due to their extremely low electrochemical activity, they do not undergo electrochemical dissolution during electrolysis. As the anode dissolves, most of these compounds detach as solid particles and settle into the anode slime.

+8613303827570
Related Product
Related Video
Product Center
Related Cases
Contact Us
We'll get in touch with you right away to provide detailed product info and tech insights sincerely.