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Rock or stone melting anyone here? Answered

While writing some nonsense in the fun section I started to wonder...
Rock or stone melting is certainly possible but how to do it properly?
In India they went as far as melting stone chains...
But that was ages ago and the know how is lost now.
So how do you do it at home?

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Presumably you need a decent kiln or furnace, which can melt volcanic rocks. Its not THAT hot IIRC 1100C should do it, within the range of an electric kiln, with only kanthal elements. On an larger scale SiC elements would probably be more durable, they're good to 1600C. SiC is tricky to drive though, its rather like a semiconductor

Nichrome will on the limit and I doubt it lasts long under this stress.
SiC is quite costly and I never played around with these elements before :(
Just wondering more anyway how they did it in the old times without fancy electricity.
Not to mention what vessel to use for melting and casting forms.
What was no problem 500 years ago should be very easy today LOL

SiC are nice, just need active control, since they are non-linear.

Could you do it with a large Fresnel lens? this guy does it and claims very high temps 3000F. and at 4:35 he shows a rock he melted (not for long or in great detail) https://www.youtube.com/watch?v=i_8cynWnAw8 I believe you can get the lens out of older large rear projection televisions.

ISTR someone using one of the big 'uns to make a 3d printer - with liquid rock

My 12" Fresnel lens barely melts sand b-bs at noon summer plus I need a welder's eye protection.

Iceng - I'm talking BIG rear projection TV's. You see them pop up every now and again for free (there is a free 46" and 55" in the local classifieds) but there is also a 60" rear projection for $300. So you could estimate 1538 sq inches. which is more than double the area of a 40" TV and more than 10 times that of a 12" lens. I honestly have no 1st hand knowledge of using them (just videos), But I imagine the 60" would put a hurting on whatever it was focused on. I imagine your eyes were very happy they had protection while you were using yours!!

Good thought but tried that last year, just with sand though.
Takes a good frame and steady hands to follow the sun but still the sand did not melt together.
Was only a lens from a 40"" projection TV though.

move to a volcanically active area.

Seems like there was something in the mainstream news about artificial lava; i.e. molten rock, used for culinary purposes. Ah! Here it is:

"The ultimate barbecue? Chef cooks steak using LAVA..."

http://www.dailymail.co.uk/sciencetech/article-271...

Note the word, "lava", is not normally spelled in all caps. It's not an acronym. I think the all caps was done for emphasis, like to suggest molten rock is something remarkable, at least in the culinary arts.

I think a lot depends on the rock.

Iron ore is fairly easy to melt with primative equipment