Process for recovery of silver from hardening photoprocessing solutions

摘要

There is provided a method for removing silver from photoprocessing solutions containing hardening agents which comprises: a) adding a chelating agent to the photoprocessing solution in an amount sufficient to inhibit the precipitation of the high valent cations of the hardening agents; b) adding a base to adjust the pH of the photoprocessing solution to a value above 5.5; and c) adding a chemical precipitant for the silver contained in the photoprocessing solution; and optionally adding as a final component a flocculating agent which causes the precipitate to grow in size.