METHOD FOR RECOVERING SILVER

摘要

PURPOSE:To separate and recover efficiently metallic silver by precipitation from waste liquor contg. a silver salt by adjusting the waste liquor to a specified pH, adding one or more kinds of compounds selected from alkali metallic hydridoaluminates and alkali metallic hydridoborates, and carrying out reduction treatment. CONSTITUTION:One ore more kinds of compounds selected from alkali metallic hydridoaluminates and alkali metallic hydridoborates and a basic substance are added to the waste liquor contg. the silver salt such as the waste liquor produced by an examination of water or a spent photographic fixing soln. The amount of the alkali metallic compounds added is 0.1-1mol per 1mol silver in the waste liquor. Reduction treatment is then carried out at >=8pH to deposit metallic silver. This metallic silver is recovered by solid-liq. separation.