Reclaiming of aq. electroplating solns. contg. noble metals - by immersing electroplated workpieces in water displacement bath contg. petroleum spirit fraction

摘要

After workpieces have been coated by immersion in an aq. electroplating bath (I), they are immersed in a bath (II) contg. a water-displacement agent and a surfactant, so the soln. (I) carried over by the workpieces is removed from the latter and can be reclaimed and re-used. Bath (II) pref. contains a petroleum spirit fraction with b.pt. 130-180 deg.C as the water-displacement agent; and also 0.5-5 wt.% surfactant. The surfactant is pref. a polyethylene-glycol of an aliphatic acid or its derivs., or a fluorinated alkyl ester. Used esp. with baths employed for the electrodeposition of Au, Ag, Pt and alloys of these metals, and possibly also Cu. Conventional reclaiming methods use a row of rinsing tanks contg. water; but a lot of costly energy is needed to concentrate the rinsing water if the plating soln. is to be reclaimed. The invention is much simpler and is inexpensive.