Large Scale Central

Iron Blast Furnance Operations

As I am working on the Featherkyile Furnance and Foundry Co. it got me wondering how these things work. Basing this loosely on the Carrick Furnance I am wondering a couple things. Are these small operations considered “blast furnaces”? I assume Iron ore is fed into the top of the furnace into some sort of crucible that sits in a bed of coke? That bed of coke is “blasted” with air injected from bellows or a blower? I do know that on the small operations like these the molten iron is, or can be, poured right into molds at the base of the furnace. As such I am going to build a mold shed next to the furnace for prepping molds. Then those molds will be poured, allowed to cool and de-molded at the shed. Finished product will be moved to the warehouse for shipping. Does all of that seem reasonable so far? Another considerations is an unloading facility and storage for the coke coal.

Now what has me really in the dark is the ore itself. In these older small operations how was ore extracted and refined so that it was ready to be melted down in the furnace? In my neck of the woods silver mining is a gigantic operation. Huge operations with massive mines and massive ball or stamp mils to crush and separate ore from its parent rock and then shipped to giant smelters for refining. I don’t think we are talking the same thing here. But no matter what the principle is the same. We need to get iron ore from the parent rock and into a for that then can be dumped into the furnace for smelting.

Another small question I have is what about slag? If they are continuously feeding ore in from the top and pouring it out the bottom how are they eliminating the slag building up on the top of the molten ore? Do they periodically drain it all the way down and let it run out the bottom? Do they skim it?

I’ll google it as well but I was curious if anyone could walk me through the basics so that I can set up a plausible small foundry operation.

DCNR signage from Pine Grove Furnace PA (images should be full size if you open them)

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Thanks Rooster. That pretty well says all I really need to know. At least for me to make a plausible model. I like that they used charcoal instead of coke as that would be way more relevant to my RR. I also see that there was no metal chimney it was lined with what loos to be refractory brick. None of that matters since you won’t see it. I also see that the charcoal, ore, and limestone flux was all just dumped in from the top.

I like the covered loading track something to consider modeling. And I see they have a shed at the base much like I envisioned for prepping and pouring the molds straight from the furnace. At any rate I now know enough to make a decent model of one.

I think you meant to add a comma after limestone so I’m gonna pretend to add one and you are,your,you’re,UR correct!~

Flux yes it was all dumped in from the top !

Don’t make me add my “Napkin Drawings” to this thread of Carrick Furnace that you asked for!

No comma in the write-up you posted. I think Limestone acts as the flux.

Regarding slag. Large operations, like the Rockhill Furnace created huge slag piles. At Rockhill, these piles still exist today. I dion’t think I have any photos as it’s not that interesting, but they are whitish gray piles that nothing grows on even after 100 years!

I read a small write up and it sounds like they basically do as I figured. The slag floats and the iron sinks. They draw off the very bottom of the crucible. So they extract the pure iron and then when they drain all that off they run the slag out the same pipe. Really rather crude but effective.

But I am glad you chimed in because modeling a slag pile was not on my radar. But may want to add one.

When I work with lead (and pewter) casting I get slag obviously and yes it’s a dull metallic gray. Just looks like a metallic booger.

The way I understood it they also mixed it into the track ballast. It’s all along the old South Mountain RR which is now a rail trail in certain places but you have to look for it these days.

That would have been waste from Pine Grove Furnace ^^^^^

{Photo and slag from roosters private collection}

Why not. As good a use as any.

Actually, it made for pretty poor ballast since it would hold water in the voids, but it was free, so it got used. The East Broad Top used furnace slag as well as Boney (rock waste from coal cleaning) as ballast. The current EBT Foundation has excavated several inches of the stuff when re-laying the track and replaced it with rock ballast on top.

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Devawn, I have been for the last 14 years before I retired hauling sand blasting abrasives from this old copper slag pile in Cottonwood Arizona ,they bag it and when they moved from the previous slag pile to this one they said a 30 year pile of slag to blast, crush, sort to size.

Tomorrow I will add a picture of some chunks I brought home

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We had a Slag Street in Broken Hill, and I always smiled when thought about trying to sell your house if it was on that street. But then, it was Broken Hill where most of the streets came off the periodic table.

I hope there’s room on your layout for a slag street to service the blast furnace though.

Broken Hill as in Broken Hill Properties the mine company? I knew they were world wide but didn’t know they had their own town!

Yeah Pete, founded in 1883 with an ever declining population due to the drop in lead prices. BHP now runs it shop out of Melbourne, but there are bronze statues depicting the syndicate of seven who created BHP in 1885 in the CBD.

The Hill Is still broken but it’s been filled in with slag, so it doesn’t look broken anymore. In fact there’s a restaurant on the top of the heap.

The town has an interesting history.

  • Broken Hill is the scene of the only enemy attack on Australian soil in WWI.
  • It has a strong musical heritage and when the story about the bandsmen playing on the TITANIC as it sank, hit hard. So in the middle of the arid zone is a statue dedicated to those musicians.
  • Mad Max and Pricilla Queen of the Dessert were filmed in town and the surrounding area.
  • It proudly serves the freshest thawed seafood in Australia and is known for its traditional cheese slaw (substituting the cabbage with shredded cheese].


The Indian Pacific runs through the middle of town and connects the Indian Ocean to the Pacific (Perth to Sydney). The rail line interestingly has the longest straight section in the world (478km with out a single bend)

Oh, and if you’re going to ride the Indian Pacific and you have a car, keep an eye open for the $99 take-your-car-with-you special.