| 摘要 |
<p>PURPOSE:To improve reaction efficiency and to avert the clogging of a piping and the decreased capacity of a pump by using cuprous oxide subjected to surface activation as a seed agent at the time of subjecting the copper dissolved in the form of complex in a waste liquid to reduction deposition in an alkaline reducing atmosphere. CONSTITUTION:The waste chemical copper plating liquid is introduced into a reaction vessel 2 where a prescribed amt. of formaldehyde and NaOH are continuously injected thereto. On the other hand, the cuprous oxide which is the seed agent is thrown at a constant rate in the form of powder into a preliminary reduction vessel 1 and at the same time, a prescribed amt. of the formaldehyde and NaOH are injected thereto to make preliminary reduction of the cuprous oxide and to activate the surface thereof. The pretreated seed agent is continuously added to the vessel 2 and thereafter, the copper in the waste liquid deposits in the reaction vessels 3, 4 and the deposited copper is separated to treated water and copper powder in a settling tank 5. Part of the treated water is returned to the vessel 1. The seed agent has high activity and the performance of the continuous type copper removal is maintained at a high level according to the above-mentioned method.</p> |
