| 摘要 |
PURPOSE:To prevent environmental pollution due to waste water and facilitate recovery of silver in a bleach-fix bath by using a specified bleach-fix bath contg. iodine ions and a silver halide fixer. CONSTITUTION:A bleach-fix bath is used contg. iodine ions 1.7mol/l or more and a silver halide fixer 0.17mol/l or more and having pH<=7. An iodine compound forming the iodine ions is represented by the formula [where M<n+> is an alkali metal ion (n is 1) such as K<+> or Na<+>, an alkaline earth metal ion (n is 2) such as Mg<2+> or Ca<2+>, or an ammonium ion (n is 1)]. As the fixer thiosulfate or thioureas are used, yet ammonium thiosulfate and thiourea are preferably used in combination. |
