METHOD FOR PRECIPITATING SILVER FROM SOLUTION CONTAINING SILVER AND HIGH VALENCY CATION

摘要

PROBLEM TO BE SOLVED: To efficiently precipitate silver from a hardening photography treating solution without accompanying the undesirable precipitation of a hardening agent. SOLUTION: A chelating agent is added to a solution containing silver and a high valency cation in a pH <5.5 to complex the high valency cation. And a base is added to adjust to the pH >5.5. And this method includes adding a chemical precipitating agent for silver.