The whole point of HCl/H2O2 solution is that you *dont* have to discard it. Over time, it grows into a CuCl etchant which is air regenerated and shelf stable.
Otherwise, mix NaOH slowly until the solution turns from clear green to opaque white. Let the water evaporate, bring the remaining copper salt cake to hazardous waste disposal. _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user

