METHOD FOR RECOVERING METAL SILVER AND MERCAPTO-S-TRIAZINE

摘要

PROBLEM TO BE SOLVED: To recover metal silver and mercapto-s-triazine by adding a reducing agent such as NaBH4 to a slurry of a silvermercapto-s-triazine precipitate having a specified pH to form a metal silver precipitate and a mercapto-s- triazine soln. by reduction. SOLUTION: Trimercapto-s-triazine is added to a photographic processing soln. to prepare a slurry of a silver-mercapto-striazine precipitate having about >pH 5. About 0.75M NaBH4 as a reducing agent is added to the slurry and the slurry is treated at about 55-60 deg.C to form a relatively high purity metal silver precipitate and a mercapto-s-triazine soln. The solid silver is separated from the soln. and the soln. is reutilized by adjusting the level of mercapto-s- triazine and the pH. The cost of recovery of silver can be reduced.