[Stoves] Thickness of flame front

[AJH]

On Fri, 18 Jan 2008 21:54:46 +0200, IPC wrote:

>"Some carbon-carbon bonds are so strong the carbon won't burn, diamond
>decomposes to graphite at 1200C but it doesn't burn."
>
>Really?

I think so, as I said the diamond first graphitises and then further
heating will burn the graphite, I think this is how it was proved
diamonds were carbon in the 18th century but a solar concentrator had
to be used to get the temperature high enough.


>  The only diamond I ever found was identified by a mineralogist.
>When I doubted his identification, he said "Watch!", lit a bunsen burner,
>put my stone on the end of a spatula and - Poof! 

I heard a similar story about a researcher at a university that was
"loaned" a diamond to do experiments on the vibrations of the bonds.
To excite the diamond he placed it on a stainless steel ultrasonic
transducer and proceeded to heat it up, being careful to keep below
the transition temperature, it too disappeared and the physics
department had to explain to De Beers how their diamond was now a
small piece of cast iron (or more correctly cementite) in the middle
of a stainless steel platter, search on cast iron eutectic mixture.


>Don't leave your wife's jewels around in a fire.

And this story featured in a novel about a girl casting her diamond
engagement ring into the coal fire, regretting it but only finding a
blob of gold in the ashes next morning, a young lecturer wanted to
test this but De Beers wouldn't co operate!

IIRC diamond auto ignition point in pure oxygen is ~700C and someone I
trust implicitly has told me he has preheated a diamond to ~400C and
burned it by dropping it in liquid oxygen, he, like Tom Miles, has
money to burn ;-).

AJH