A method to recover silver from waste X-ray films with spent fixing bath

This article discusses a method to recover silver from waste X-ray films with the spent fixing bath. At first, the silver in the waste fixing bath was reduced by KBH4 at pH 8 ~ 9. Then the silver-free fixing bath was oxidized by air and some main components were replenished. As a leaching solution, the silver-free spent fixing bath was used to recover silver on the waste X-ray films. The total silver recovery from the spent fixing bath and waste X-ray films was 98.0% and 95.8%, respectively. The purity of recovered silver was more than 99.5%. The spent fixing bath can be reused again in the present method. The discharging of wastewater can be reduced and the polymer substrate of waste X-ray films can also be recycled.