METHOD FOR RECOVERING SILVER AND PHOTOGRAPHIC PAPER BASE FROM PHOTOGRAPHIC PAPER BY UTILIZING MICROORGANISM

摘要

PURPOSE:To decompose the gelatin films of photographic paper and to separate and recover photographic paper base and silver by exposing the photographic paper in the mists of mixed microorganisms which are aerobic or anaerobic and contain gelatin activating variants. CONSTITUTION:Photographic paper is immersed in the mists or liquid of mixed microorganisms contg. aerobic or anaerobic microbes decomposing org. materials such as protein, starch, fats and oils, more particularly, gelatin activating variants activated with gelatin intake bacteria that intake gelatin as nourishing sources. The gelatin films of the photographic paper are decomposed, whereby silver and photographic paper base are separated. The silver in a black fine powder state is dehydrated with a centrifugal dehydrator and is then melted by heating at 1,100 deg.C, whereby the silver is recovered as silver ingots. The separated photographic paper base is washed and is recovered separately.