| 摘要 |
PCT No. PCT/EP96/02385 Sec. 371 Date Dec. 12, 1997 Sec. 102(e) Date Dec. 12, 1997 PCT Filed Jun. 3, 1996 PCT Pub. No. WO96/41902 PCT Pub. Date Dec. 27, 1996The invention relates to a process for working up charged aqueous solutions, more especially etching solutions, which contain ammonia, at least one ammonium salt and metal ions in dissolved form and which accumulate in the treatment of substrates containing valuable metals, more especially copper-containing electronic sub-assemblies by contacting the aqueous solution with an organic water-immiscible extractant in one or more extraction stages to form an organic phase containing valuable metals and an aqueous phase, (b) washing the organic phase with a water-containing liquid in one or more successive washing stages wherein the water-containing liquid has a pH above 6.5 in the first washing stage and after said washing stage contacting the washing water before reuse with an organic extraction solution, and (c) conducting one or more stripping stages to transfer the valuable metals from the organic phase to an aqueous phase.
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