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Michael Stuart

smelting again

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I rebuilt and ran my smelter for a third time, still trying to convert it the rest of the way from a smelter-shaped object to the real thing :)

 

Run two last month made some really shiny but nonmagnetic slag, in addition to more of the black oozy-looking magnetic slag I successfully made the first time around. This stuff was all stuck together into one giant bowling-ball sized glowing hot lump when I opened things up. The shiny part looked a bit like silicon metal, shiny with planar crystals (?).

 

For this time, run 3, I moved the air tube higher to about 12" from the previous 8". I also made it run tangentially rather than straight into the middle of the bore. I made the furnace walls higher too, from the previous 36" to about 42-45 inches high.

 

I took all the product from the previous run, hammered it into pieces no wider than a nickel, and kept anything that would stick to a neodymium magnet. I also added a bit more mill scale, which was the original starting material (thanks again Wayne!). After an hour of warming up the furnace with wood and partially charcoaled wood with an air blast through the slag hole, I filled it up with charcoal and moved the air to the higher inlet. I stuffed rocks and gobs of mud into the slag tapping arch to close it off, and added the first charge at the rate of a 1-lb coffee can full of ore and half a can of powdered limestone. I repeated through four more charges, adding probably five pounds of charcoal each time.

 

I upped the limestone because I was trying to make the slag more liquid, but still it was more a blob than a liquid. Any tips here would be appreciated.

 

After adding the last charcoal charge, I let it run down with low air for 20 minutes then another half hour with no forced draft.

 

When I broke it open, there was a large blob of stuff along stuck to the side wall where the draft entered. I broke this up, hosed it down, and took the pieces to the grinder. Lo and behold, some pieces have what appear to be thin ribbons of metallic iron mixed in with all the slag. Unfortunately I didn't have time to get a picture, but maybe I can later. I bet there's at least a couple ounces of iron all together in there. It's not much, but I'm quite excited by even this glimmer of success.

 

I'm not sure if there will be enough to consolidate into a bar, or if my forge welding ability will be up to this task, but that step will have to wait until I get my new shop set up in Florida. Until then, I'll keep thinking about what might work better next time. I'm thinking an even taller smelter, maybe 48" if I can make one that high that will hold together. Incidentally, the top several inches of this one were nothing but yellow clay from my yard, mixed with grass clippings from the lawn. I put a thin wash of satanite inside for insurance, but the top didn't crack any worse than the lower parts that were made mostly of mortar mix, perlite, and cat litter with pine straw binder.

 

Any hints from the more successful smelter-folk out there would be appreciated.

 

Michael

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Sounds like you're getting closer!

 

 

sounds like you have the tuyer at a good height.

 

How much blast did you have?

 

I may have given you some off advice last time on the tuyer. Rehder states that the majority of tuyers on these furnaces was roughly 3/4" daimeter, but I found that in practice, 1" seems to be better, or larger with a squirrel cage blower, as they REALLY don't like back pressure.

 

The last furnace I used was only 3' high, so that probably isn't a factor. I'm guessing that it's either not enough heat, or too much silica. If you're using limestone, that shouldn't be a problem. Probably not enough heat.

 

You definitely want the tuyer going in at a 90 with a 15 degree angle downward.

 

You want lots of heat. We were charging 10 lbs every 10 or so minutes.

 

If your bloom was attached to the furnace wall, you can pretty much guess that you were runnning it too cool.

 

Hope that helps :)

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Thanks Jesse,

You're probably right about it not being hot enough. That said, i did instantly lose half of each eyebrow to a sudden shift in wind direction when I was looking into the top. Hair, I learned, acts like popcorn with that much heat. Fortunately I was wearing glasses so I still have eyelashes. Plus, I cooked some burgers from frozen to medium rare in record time while waiting for it to burn down at the end.

 

I did bump up the ID of the tuyere to about an inch, maybe an inch and a quarter, and I am using a small squirrel cage blower so I bet you're right about not enough air. I have a nice double lung bellows I built that I'm sure would do the trick, but I don't have the help I would want to keep it going. Time to get busy making some more homebrew I suppose, maybe that would draw in the help. Will try it again after the move.

 

Michael

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Thanks Jesse,

You're probably right about it not being hot enough. That said, i did instantly lose half of each eyebrow to a sudden shift in wind direction when I was looking into the top. Hair, I learned, acts like popcorn with that much heat. Fortunately I was wearing glasses so I still have eyelashes. Plus, I cooked some burgers from frozen to medium rare in record time while waiting for it to burn down at the end.

 

I did bump up the ID of the tuyere to about an inch, maybe an inch and a quarter, and I am using a small squirrel cage blower so I bet you're right about not enough air. I have a nice double lung bellows I built that I'm sure would do the trick, but I don't have the help I would want to keep it going. Time to get busy making some more homebrew I suppose, maybe that would draw in the help. Will try it again after the move.

 

Michael

28146[/snapback]

 

Smelters rule! B)

They also stink of singed hair :lol:

Jesse is a great source for smelting. Nows his stuff. Jerry

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If you figure out how much alcohol content divided by how much beer equals how much bellows pumping on the sine wave of sobriety, let me know. I plan on bribing others with beer myself.

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