I'm pretty sure that's the problem as well....heavy metals. I've ∗heard∗
that when
Western Electric was in business making telco products,
that they were using ferrric chloride to etch their boards. Then
they used a cathodic (electrical) method to extract the copper out of
the etch. Once that was done, the copper "ingot" would be shipped off to
their
own refinery to make wire or whatever.
If that's true...I wonder what exact method they actually used, i.e.,
what
the anodes/cathodes were, how long it took, voltage, etc etc. Anybody
know?
Charlie
On Sun, 10 Mar 2013 18:29:12 +0000 Charlie Taylor <
scubadogct@...>
writes:
> It is the preaence of metals thatbis the problem for sewerage works.
>
> You are correct in that often ferric is used on treatment works as
> a
> floculant.
> On Mar 10, 2013 1:03 PM, "Dave Sage" <davesage12@...> wrote:
>
> > ∗∗
> >
> >
> > Perhaps someone with some knowledge on public works and sewage
> treatment
> > can
> > clarify this for me.
> >
> > I guess it must be the copper in the ferric chloride etchant that
> we
> > dispose
> > of that is the problem - is that correct? Is there actually copper
> per se
> > any more after the reaction of etching?
> >
> > I'm pretty sure somewhere in the sewage treatment process, after
> gross
> > solids are removed, the water in the sewage system is sent to
> settling
> > ponds. While in the ponds ferric chloride is added to act as a
> flocculent
> > i.e. an agent that causes solids to gather together in clumps for
> easy
> > removal. If this is the case, would it make any difference if
> there were
> > some ferric chloride in the system to begin with (from flushing
> etchant
> > down
> > the drain)?
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
>
>
> [Non-text portions of this message have been removed]
>
>
>
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