Recuperation of silver from photosensitive material waste ­ consists of washing with sodium hydroxide soln., sludge separation, and alkaline fluxing after drying

The process comprises washing with minimum 1 per cent concn. sodium hydroxide soln., to solubilise the photosensitive layer on its support. Settling, flotation and/or filtration then separates the silver sludge, for drying and melting using alkaline fluxes. The sepd. silver, the washed and dried support and the spent soln. are all able to be reused.