30 May
2007
30 May
'07
10:47 p.m.
On 30 May 2007 at 22:34, woodelf wrote:
Yep! Hydrogen ... but you don't burn it - it
was a plasma arc of some kind. I remember
reading about in Scientific American 1961 I think.
Very hot is the so-called "atomic hydrogen" torch--H2 is passed
through a high-voltage arc and split into monatomic hydrogen which
then recombines and burns. It's the exothermic recombinatin that
really kicks the temperature up--about 3700C; the actual combination
of the hydrogen with oxygen adds very little heat to the reaction.
See:
http://www.lateralscience.co.uk/AtomicH/AHW.html
But for most anything else, oxy-acetylene is fine.
A few years ago, I remember seeing a welding rig for jewelers that
used electrolysis on water to create fuel and oxygen. The thing drew
something like 10 amps at 240VAC and produced a very tiny flame.
There was so little heat produced (although the flame temperature was
pretty high) that you could pass your hand through the flame.
IIRC, gold is usually deplated from other metals (and out of ore)
with sodium or potassium cyanide. At least that's what I recall from
reading about a "heap leach" gold mining operation.
Cheers,
Chuck