Not all acids can be boiled to concentrate it mainly due to fume
concerns... HCl releases HCl fumes esp when its concentrated and its
harmful (must be used in fume cupboard). Nitric acid releases NO2 fumes
(nasty stuff, eats almost everything)..

So I think before you heat the acid you better make sure nothing nasty
is gonna come out.

------------------------------------------------------------------------
Daniel Chia

"Genius is one percent inspiration and ninety-nine percent
perspiration."

     - Thomas Edison

E-mail: danielcjh@yahoo.com.sg
MSN: danstryder01@yahoo.com.sg
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> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On
Behalf Of
> Peter L. Peres
> Sent: 26 September 2004 05:34
> To: Microcontroller discussion list - Public.
> Subject: Re: [EE:] Etchant chemistry- WAS- Ferric chloride etchant
disposal
> 
> 
> On Sat, 25 Sep 2004, Philip Stortz wrote:
> 
> > i definitely would not boil it!  at best, you'll get Cl2 fumes, more
> > likely HCl fumes, which are far worse.  most acids will
evaporate/boil
> > faster than water, acids can be distilled to get stronger, drier
acids
> > so you'd actually be lowering the CuCl concentration.
> 
> I'm pretty sure most acids can be concentrated by boiling, but maybe
not
> HCl. Also boiling would likely decompose any H2O2 present. So, boiling
HCl
> to concentrate it is probably a bad idea.
> 
> Peter
> 
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