Actually both are used as  source for reclaimed copper. It is strictly a
matter of at which facility the recliming takes place. The process for
reclaiming ammoniacal etchants is a bit more complicated and generally takes
place at the chemical manufacturer's facility (although there is a company
now that will provide Liquid Ion Exchange equipment to perform this in-house
and will provide necessary additives for the recycled etchant, the name
escapes me). In most cases the PWB manfacturer is not charged for this
service as the sale of reclaimed copper is already a significant source of
revenue to the chemical manufacturer. Shipping charges may be another
matter, and some states still do regulate transport of this material as a
hazrdous waste.

Reclaiming Cupric Etchant is less likely to be handled on a "round robin"
type arrangement with the chemistry manufacturer (at least when I was
dealing with it 8 years ago). However in-house copper reclaim is a less
complicated endeavour, and there are several chemical cos. that would be
willing to take spent etchant to reclaim the copper at a nominal fee (again
copper being a nice source of revenue for them).

Bob Dube

-----Original Message-----
From: <Rudy Sedlak> <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Thursday, January 06, 2000 1:40 PM
Subject: Re: [TN] Comparison data for cupric chloride and alkaline
copperetching


>Great answer Mr. Stern.
>
>May I add that what is done with the spent etchant can also dramatically
>effect cost of stripping.
>
>With Ammoniacal, the spent is always returned, usually at the cost to the
>generator, to the supplier of etchant.   Cupric, regenerated with either
>Chorine, or Hydrogen Peroxide has the POSSIBILITY of becoming a commercial
>source of Cupric Chloride, (at least of spent etchant from the PCB
industry),
>and thus can become a source of revenue.
>
>I qualify this heavily, as the EPA has trouble dealing with treating
>(hazarous) wastes as raw materials for other processes.
>
>Rudy Sedlak
>RD Chemical Company
>
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