Homebrew PCBs

On Tue, 2009-07-14 at 17:14 +1000, Adam Seychell wrote:
> I've heard platinum anodes are no good either in chloride, they slowly
> corrode. I remember reading an article on the web on how to make your
> own lead(II) oxide anodes on a titanium substrate.


Adam, Thanks for the high value and expert suggestions. 
But this all ideia don't worth your time, the time off the thousands of
people that subscribe this list, or mine. 

I wish this to give a right 'disposal' to the etchant, not so much for
the regeneration, air works good for me. I thought that will need to
split the hydrogen from the oxygen or chlorine, otherwise i will be
moving water or HCl at high energy expense. The ideia will work nice in
that field, could be used a water bottle, a inverted syringe (easy to
fit a tube) or a glue tube or a silicone sealant package, to grab the
gas. But there is no oxygen/chlorine bubbles at all!

The machines used in copper electrowinning from CuCl use 1000A or more
currents with just little kg/hour of copper. A CuCl bath has very high
conductivity. But worst CuCl electrolysis is said to be one off the most
efficient for hydrogen production (at high temperature). This is a
energy waste.

I tested the most powerful psu i have: a 24V 14A switched mode one. Ok i
also have a 12v 60A  (it says 300A peak in the package and i have
already modified it for better) as huge battery charger, and various
mono/bi/three-fase welding machines. But used the cnc stepper motor psu,
it has current limit. For electrodes was just copper wire because its
copper and i wont damage the etcher. The psu went down to 8V so it was
at 14A. I got some small bubbles ONLY in the CATHODE and judging by the
color I got a non solid deposit of copper oxide (red).

>From a CuCl electrolisys paper i got this equation and I added the water
and copper oxide.

2CuCl(aq) + 2HCl(aq) + H20(aq) + ?e- -> 2CuCl2(aq) + CuO (aq) + 2H2(g)

So this could be a process off getting copper from there since copper
oxide and sulfuric acid give copper sulphate. Or a way to inicialize the
CuCl etchant from HCl and copper scrap with a psu (without any H2O2). 
Or just to spend the etchant without etching anything :>
And with high energy cost.
But NOT for making chlorine gas! 

Sorry for wasting your time. It seems the original thread author already
has a much efficient ideia for regeneration :)




PS
> There are platinum coated titanium anodes, the smaller ones are so
> > expensive.

I wanted to say here: 'the smaller ones are NOT so expensive.'