Sciencemadness Discussion Board

Isolating elements with an arc furnace

Gooferking Science - 5-2-2014 at 09:46

Hello! I just made a very effective carbon arc furnace. It can easily reach insane temperatures (e.g. I melted a rock into obsidian in under 30 seconds.) Is it possible to isolate elements like silicon from their oxides by placing them with carbon powder and heating them inside the arc? I am concerned that the element might oxidize again because of the heat.

I made an arc furnace before using a conductive water/sodium bicarbonate mix as a ballast. This new design uses a 1500w space heater as a ballast, which creates a hotter arc and is safer than the previous method.

[Edited on 5-2-2014 by Gooferking Science]

bfesser - 5-2-2014 at 10:19

It would be more correct to say that you fused it into a glass, as <a href="https://en.wikipedia.org/wiki/Obsidian" target="_blank">obsidian</a> <img src="../scipics/_wiki.png" /> is a <em>naturally occurring</em> glass of volcanic origin. It's bad practice (a bit unscientific) to call any artificially produced materials rocks or minerals.

Zyklon-A - 5-2-2014 at 10:58

What kind of rock was it?

Gooferking Science - 5-2-2014 at 11:12

It was a lava rock. It "fused" into a glasslike substance similar to obsidian.

bfesser:
If obsidian is of volcanic origin, then can't I have created conditions similar to a volcano? Unless you are meaning that it is artificial obsidian instead of natural obsidian?

Any comments about the original topic of isolating elements and not rocks?

[Edited on 5-2-2014 by Gooferking Science]


[Edited on 5-2-2014 by Gooferking Science]

[Edited on 5-2-2014 by Gooferking Science]

Metacelsus - 5-2-2014 at 11:25

Basically, are you trying to do carbothermal reduction using the arc as a heat source?

According to Wikipedia, "Metallurgical grade silicon is commercially prepared by the reaction of high-purity silica with wood, charcoal, and coal in an electric arc furnace using carbon electrodes."

So isolating silicon has a good chance of success.

From my personal experience with arcs, I recommend using an inductive ballast (you can easily make one from a microwave oven transformer core). They don't heat up as much.

thebean - 5-2-2014 at 11:44

Even if the conditions are similar to that of a volcano, it didn't come from a volcano. It would also be incorrect to call it artificial obsidian because the one of the conditions for something to be called obsidian is that it occurs naturally. You made a glass of some kind.

chemrox - 5-2-2014 at 11:48

Would you like to outline the oven construction? That would be a worthwhile contribution.

Artificial diamonds are still referred to as "diamonds." If you took rhyolite and changed its texture by fusing it with heat you may have made "obsidian." I'd have to see it. On the other hand maybe what you made is more properly referred to as "slag." Got a picture of the resultant?