Stone Soup anyone?

sunshadow

sunshadow

Joined
Oct 2, 2006
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Just thought Id do an update on my Thanksgiving rock cooking.
My plan for doing a Thanksgiving smelt was pretty much doomed from the point last week when I found out my magnetite is backordered, but I decided I was psyched up for it, I'd get some sort of ore and try to run it anyway. I built a little tylecote smelter with a chimney flue tile, some satanite, chicken wire, clay, straw, (mix the clay and straw together for lute) a forge blower and a piece of high temperature ceramic tube for a tuyre. I had about 50 pounds of homemade charcoal, 70 pounds of Wegmans charcoal, and 25 kilos of very fine ground "spanish red oxide" (supposedly 85% fe2o3). Aside from my ore getting backordered, the first indication of trouble was during the pre-heat when my refractory ceramic tuyre started to alternate between breaking off in small sections until it was flush with the wall of the smelter and getting blocked by slag from the melting chimney tile. I started charging with ore, and when I wasn't getting any slag to speak of, I added a little powdered clay to give it some silica to chew on, I ran it for a while, never really getting the kind of liquid slag at the tapping arch that would indicate a happy bloom, and realising that I was loosing a good portion of my "ore" to the wind (everything around for about a 15 foot radius was stained red at this point) I decided to let it burn down hoping against hope that I would have at least magnetic slag. When I finally broke up everything at the bottom of the furnace I had a lot of not really good slag, a couple of pounds of magnetic slag AND A COUPLE POUNDS OF REALLY POORLY CONSOLIDATED IRON!

Hopefully my next smelt in a couple of weeks when my magnetite arrives will work better.

Hope everyone had a great thanksgiving and safe travels

-Page
 
Dang that sucks. What ratio were you using for charges(charcoal to ore)? How long did you pre-heat for? How far above your slag hole was your tuyre and what was the angle?
 
ekibyougami said:
Dang that sucks. What ratio were you using for charges(charcoal to ore)? How long did you pre-heat for? How far above your slag hole was your tuyre and what was the angle?
Click to expand...

My charcoal to ore was about 2-1 by weight, my preheat was in stages, when I set up the base and chimney tile 2 weeks ago I coated them in refractory cement reinforced with chicken wire to try to create enough structure that I would be able to get more than one use out of the smelter, the weather was turning to freezing/snow so I started a naturally aspirated wood fire in the flue tile to keep things warm enough that the refractory cement wouldn't freeze before it hardened. The night before thanksgiving I put my tuyre in place, (about 25 degree angle) made a "lute" mixture (also called clay cobb by some) of clay and straw which I coated my original construction with, reinforced with another wrap of chicken wire, and covered with another layer. This was followed by introducing a wood fire with the tap arch open to begin the preheat/drying (fire started 10 PM stopped feeding it at 2 am to get sleep) at this point the high temperature high tech ceramic tuyre tube started to show evidence of cracking
8:30am thanksgiving I restart the preheat with wood over the still glowing coals 9 am switch to charcoal, start the blower, 9:20 tuyre tube breaks off flush with sidewall, 9:30 sidewall slag drips across tuyre opening blocking it, roger the tuyre opening
10:00 first charge, as the red oxide I am using (since my magnetite is backordered) has almost no silica content to contribute to the slag, I added some powdered clay to facilitate slag
for the next couple hours I was fighting with the chimney tile slag plugging up what was left of the tuyre, the slag I had was not liquid enough to tap off, and was forming too high up due to the tuyre having broken off, and the ore was so finely ground that a fair amount of it was being carried out of the stack in a plume that coated everything for about a 15 foot radius in a thin layer of red. When I realised that I decided that I would quit fighting with it, see what I had, and try to learn from it.

When the stack burned down to the top of the slag I tried to get the contents out through the tap arch, and it wouldn't budge, I tried driving it out with a steel rod and a ten pound sledge and it still wouldn't budge. after about an hour of beating on it to no avail I applied the sledgehammer directly to the furnace, what I found was a 4 1/2 inch thick deposit of slag, mostly foamy, unmagnetic and glasslike with some of the nice greyish fluid metallic looking slag like Michael McCarthy got at the Ashokan smelt, some of which was magnetic, and probably 3 or 4 pounds of what appears to be really poorly consolidated bloom iron. I haven't tried to consolidate any of it into anything yet, I may keep it as a souvenir for documentation of what not to do :D

I will try to get some pics up soon

-Page
 
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