Anyone tried to work slag?

[jcherrellglass]

I'm having conversations with a swordsmith buddy of mine about slag and I'm wondering if anyone's ever tried to work with stuff? We figure if we collect the slag, throw it in a crucible kiln and let the junk settle that I might have something I can play with. We were thinking that would be a kicking demo at his shows! Input badly need, if you have any!! Thanks!!!

[jcherrellglass]

In case you are curious slag is the left over stuff of an iron smelt. Here's how my buddy explained it to me: "The ore in a smelt is basically rocks with a lot of iron oxide in some form or other, embedded in a matrix of stuff that
amounts to silica... most things out of the ground, even things like quartz, have a chemical heritage that goes back to carbon and silica, and the application of heat can break things back to these root materials. So when the ore goes down the furnace, the silica gets heated and has a fairly low melting point compared to the iron, and it liquifies. In that state its a very simple liquid silica glass, with iron oxide in it so it usually has a dark green colour."

Here's a shot of slag from about 5 hours into his burn a couple weekends ago:

[Infinity glass]

slag is also the protective coating u get when you are welding to keep the weld form over oxidizing. myself dont think u can do anything with it. its pretty nasty and breathing it is very very bad for u.

[jcherrellglass]

I think you're thinking of the slag from welding which is supplied by the dry chemicals on the electrodes, or in the wire in the case of gasless mig welding.... in any case, in welding, the FLUX is synthetic and made to emulate the slag in natural materials, but only barely in character, not in composition - according to my friend. I don't wanna play with that at all... icky.

The slag from an charcoal or biomass fueled smelter/furnace is primarily silica, with traces usually of many things, but usually, in the case of iron smelting, it has a lot of iron oxide and the colour of this glass is a dark green when cooled.
It is glass (totally liquified silica).

[RHGraham]

It's mainly liquid silica, iron oxide, then other "stuff", and hardens ( on the ground in our case) to just plain old super-brittle glass.
In any case, I'll save some next time and we'll find out.
Every thing I've studied in this field (smelting) indicates that this substance is the original primal glass, or at least raw material.
Be fun to find out in any case.

[jcherrellglass]

Hey! That's my friend!! Welcome!

[RHGraham]

Hi JC.... thanks...

[The Goat]

sounds like a cool idear!

[harpentuan]

One more definition. Isn't slag also clay scraps from a potter's wheel or such,that is thrown in a watery bin to be recycled?

[RHGraham]

Yes, the term shows up in a number of crafts describing things that are different, but have the same flavor, if you know what I'm sayin.
In welding it's the chemical glass flux that has to be chipped-off the welds after they are made. In smelting it's the liquid flux inside the furnace as a melted by-product of the ore, also a number of by-products from coal-fired operations can be called "slag" sometimes, or "clinker" by blacksmiths...

Aren't words wonderfull?
:0)

I can phonetically at least say slag in three languages at this point.... it's multicultural too.

[jcherrellglass]

I looked it up on wikipedia and was further educated. It appears that slag is a slang term in the UK that mean slut. I know some you have worked that slag!!! ;) http://en.wikipedia.org/wiki/Slag_%28slang%29

[RHGraham]

shouldn't you be workin or somethin?

:0)

[jcherrellglass]

shouldn't you be workin or somethin?

:0)


Dude. I hear that a lot. Don't tell Adam how much I slack. He thinks I'm a hard worker. ;)

[RHGraham]

hehehe, ditto...

:0)

[Din]

Are you referring to the slag from forge welding, or that which flakes off during regular working of steel?
Your welds may be cleaner than mine, but I've often managed to clean it up with magnets, which would indicate a pretty significant amount of iron present. Iron is used in boro to make greens (if I remember correctly, feel free to ice me if I'm wrong Henry), but so much as to respond to a magnet is undoubtably excessive. Greens are notorious for cracking a piece, as they are.
However, you never know untill you try. I'd say give it a shot, but make sure your ventilation is on point.

[Brian Newman]

I think iron is what makes soft glass green. With boro it is chrome oxide (the green that has reducing problems) or copper dioxide for a transparent green that reduces to copper oxide red on the surface.

[raynsandy]

I regret not knowing about glass back in the day I worked in the cast iron foundry. Every morning we would skim hundreds of pounds of slag off of 2900 F, four 55 ton furnaces. All that good hot glass is now cold and laying at the bottom of the land fill................ if I only knew then what I know now. Oh and btw the lid of the furnace was a cool 1000 F coincidently.


Ray