| 摘要 |
<p>Ag. recovery involves bleaching to convert the Ag into soluble Ag salts, which still adhere to the material, and then absorbing these salts from the material with a commercial fixing soln. The material pref. is cut or torn into small pieces first and washed after both the bleaching and fixing stages while the fixing soln. is passed through a machine in which the Ag is recovered electrolytically. The use of special incinerators is avoided and it is also possible to recover the plastics of the film base. The costs can be reduced by the use of relatively crude chemicals. The 4 stages are carried out at 4 different stations on a track on which the supply bin(s) run. The solns. are pumped into the bin and circulated, whilst the washing water is sprayed into the top of the bin. The solns. and water are drained off, assisted by an air blast.</p> |
