Process for the recovery of silver values from silver-containing material which also contains iron and arsenic

Claim 1

A process for the recovery of silver values from silver-containing material which also contains bismuth, iron and arsenic, said process comprising leaching the material under oxidizing conditions at elevated temperature and pressure in aqueous nitric acid solution to dissolve a substantial amount of silver together with substantial amounts of bismuth, arsenic, and iron, the amount of nitric acid used in said leaching being sufficient to provice nitrate ions at least stoichiometrically equivalent to the dissolved metal ions in the leach solution, separating resultant leach solution from undissolved leach residue, treating the leach solution with a solution containing chloride ions to selectively precipitate substantially all dissolved silver as silver chloride without significant coprecipitation of other dissolved metals, separating the silver chloride precipitate from the remaining solution, raising the pH of the solution to a value in the range of from about 0.4 to about 0.8 to precipitate a bismuth compound, and separating the bismuth compound from the remaining solution.