metalresearcher
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Is this silicon ?
I heated a little bit of SiO2 sand with powdered charcoal in a stoiciometrcal 5:1 mass ratio (actually 6:1 to get a bit overdose of carbon) in an
electric arc. The arc is made by a 80A welder with carbon rods and heats the stuff easily to over 2000oC. This results in:
SiO2 + C => Si (l) + CO2 (g)
In the picture (center where the arc occurred) very small globular particles can that be metallic Si ?
The SiO2 "melts" @ 1710oC but then it actually gets a sticky mass in which the Si droplets precipitate, but is this Si ??
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blogfast25
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Could be: heavily contaminated with SiC of course...
Try and chisel one out of there: Si reacts well with strong alkali, giving hydrogen and silicate... It does look like it.
Oversized photo alert! Try cropping to the part that's most interesting: 75 % of this pic is junk.
[Edited on 19-11-2011 by blogfast25]
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metalresearcher
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I put some particles into hot NaOH solution, but no gas escaped. So it is probably SiC. According to http://en.wikipedia.org/wiki/SiC this will form SiC and this substance is produced this way.
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Adas
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So next time try to use less carbon.
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blogfast25
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Not really: the combination of silica and carbon at these temperatures tends to form SiC (which looks rather much like Si)
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