Refining Iron Ore

[AlexanderBlacksmith]

Hello this is my first post on this forum so thank you for your time and patience.

I would like to know how i can refine some iron ore i found.

I am a bit of an explorer and while I was out bushwhacking in southern Queensland, Australia i picked up a bunch of iron ore using a magnet, approximately 3-5kg, out of a river bottom and on the side of a mountain. I built my own forge using some very thick concrete tiles, a metal pole, some duct tape and a hair dryer and i have been using charcoal as a fuel source. However i live right next to some bushland and getting wood would not be an issue for me [let me know if this is a viable source of fuel as charcoal can be semi expensive]. I tried to use a terracotta bowl as a crucible but it melted though the bottom :blink: so i simply heaped it straight onto the fire. I know that it is hot enough to melt steel because i melted the end off some scrap steel i had lying around. After cooling down the forge i picked up the metal pieces using a magnet but i found that it was very very crumbly, after looking around the website i heard someone say that because of the sulphur i might have wrecked my iron ore [i only used 14 of the ore i have so its not much of an issue]. I need some advice on how i can refine my iron ore, any advice is greatly appreciated :)


Just an update, I've had a look at some bloom forges and am wondering if my conventional pit forge [with airflow through a hole underneath] is still a viable way to refine my ore. I am really in the dark about whether its possible just to heat it up in a crucible and remove the slag from the top.

Edit: I am painfully aware of how newbie i sound.

[GNJC]

No problem with questions. There is a lot of stuff on the net about this and quite a bit here on IFI, check youtube for videos of successful furnaces.

 

Make sure your ore is smashed small - it gets hotter & there is more surface for necessary reactions to take place over, therefore it's more efficient.

 

I was introduced to smelting by Mick Maxen and Owen Bush - 'Basher' here on IFI. They've done it many times and may be able to suggest specific remedies to problems. Both busy chaps, but I'm sure they'll find time to help out with some advice

[AlexanderBlacksmith]

thank you for the suggestions :] yes i had already broken my ore up into pea size or smaller pieces when i added them to the fire, what im mystified about is whether or not i can change my forge [which is quite easy to do] into a side air-fed style bloomery or whether i can keep it as a forge and use a crucible to melt down the iron and scrape the slag off the top. Also I am wondering whether or not the crumbly ore i have now, as a result of simply placing the iron ore onto the top of the charcoal, is worth keeping and can it be refined more.


Ive decided to have a go at changing my forge into a rough furnacebloomery and try to use an improvised tuyere for any slag, can someone please explain the process of what happens in the furnace and why a tuyere is needed. I have a had a good look at the rockbridge bloomery website that a number of memebers have recommended.

[Nobody Special]

Mmmm....Little fuzzy on what's going on with your furnace.....A tuyere is used to introduce gas to a furnace (in this case air). It slows the entry of the gases (if it's conical), and can affect how much oxygen is going into the blast, which in turn affects how much carbon is in the iron.

 

Also, without a tuyere the entry of oxygen can create cool or hot spots. Also also.....You want something between whatever you're blowing from and your fire that doesn't melt.

 

You should roast your ore prior to smelting, break it up, and pick out any obvious impurities. Alternate charges of charcoal and ore. (and it takes a LOT of charcoal). Basically, the slag melts and runs off, and the iron that's left falls down to the bottom and sinters (think of it like mini-spot welding from heat and pressure) sticking together into a big spongy mass.

 

You let it sit in the slag for a bit, then tap the slag out of a drain hole and let it run out the side. Then pull apart the furnace and beat the bloom so that it welds into a nice solid piece, and so the remaining bits of slag and what not are beaten out of it. Get help, this part is doable alone, almost, but much more user friendly with.....well, friends.

 

If you end up actually melting the iron, by getting it too hot, say especially by using something like coal, then the carbon in whatever you're burning will act as a flux, and when the ore melts, you'll have lots of carbon in the metal, ending up with good old cast iron. Hard, but very very brittle....basically not forgable

[Frosty]

Welcome aboard, glad to have you. Please put your general location in your header so folk within visiting distance will know you're close.

 

Get rid of the concrete, getting it much over 230f, say 115c and it'll start popping and shoot spalled pieces of concrete around. This is BAD.

 

There are a number of well proven bloomery melters and there are guys here on IFI who are experienced with them, hopefully one or more will chime in soon.

 

Asking questions is the way to avoid having to make more mistakes than necessary to master thigs. Learning fro other folks mistakes is preferable in my book.

 

Frosty The Lucky.

[GNJC]

Crush the ore to a coarse sand size, lots of charcoal in for a roaring fire then the ore bit by bit with more charcoal; keep it roaring. I think you'll just have to experiment to see what works. Good luck.

[AlexanderBlacksmith]

thank you everyone for your kind and helpful advice, i am going to make a mini bloomery about 3O-4Ocm high considering im only going to be making around 3-4kg of iron instead of, say, 25kg that some people have been making. I have about 2Okg of charcoal for this and only around 5kg of partially refined ore [ore that i crushed up and used a magnet to pick up the iron pieces]. I work for a hardware warehouse so picking up charcoal is quite easy if i need more. I guess im just going to have to do some experimentation, but ill take some photos and upload for you guys if youd like. The only problem i can forsee is trying to tap out the slag... but I'll figure something out.

Thanks again

[Dale M.]

Some time back there was a show on US television of a sword maker that  actually took black sand (iron ore found in river bottoms) and through repeated heating in forge and working at anvil the clumps/limps created in the forge eventually turned into a steel bar.... His process, as he claimed dated back to early Chinese techniques that produced some of the earliest swords (kitanas), dating back to around 1600 ( I believe - may be wrong date here)....I'm sure he added many other ingredients  (carbon) to increase the strength of the metals, but the first pieces he was working with looked like the rusty metal piles one finds under grinding wheels or brake turning equipment  is automotive repair shop..... The end result was a kitana that was probable pretty close or better than the early Chinese ones.... He claimed his processes  were the same as the early Chinese from  forming the first clumps of iron to the finished  sword....

 

I think if you can once get the iron base materials separated from the waste, you may be on to something.... Early metal smiths pretty much only had heat to work with and probably were not into crucibles and such at first so maybe getting iron extracted  from the impurities maybe a challenge, once you have a workable, malleable piece of metal you can do most anything from there....  Essentially you will be just forge welding iron dust/pebbles into a metal bar....

 

Dale

[ThomasPowers]

First of all you are NOT trying to melt it you are trying to reduce it!  So a "crucible" is not necessarily what you need.

Second a charcoal fueled forge doesn't have any sulfur so that is a no-op  (and yes all iron was smelted using charcoal up until the 1700's when Abraham Darby worked out a commercial method of using coke)

 

Next to smelt using a forge like system look up "Catalan Forge"  (and of course "The Mastery and Uses of Fire in Antiquity", Rehder, has plans for a modernish "foolproof" bloomery in the appendicies.)

[AlexanderBlacksmith]

thanks again everyone for your help, ive got some pictures that ill upload later but firstly, the results.

burned for 6 hours in my mini bloomery, i dont know what i did wrong, it came out in a bloom but as soon as i hit it with a hammer it crumbled instantly, im not sure whether its just that it hasnt been reduced enough or whether my fire wasnt hot enough, i was only using a hairdryer, or whether or not my iron ore just isnt pure enough. Its crumbly almost like cooled magma and looks very similar to the top half of this: http://www.indiana.edu/~margi/photos/zp.jpg only more charcoal colored. Can anyone give me an idea of what im doing wrong, or why its so crumbly and not forming any steeliron hotspots in the bloom.


 

[Frosty]

Iron isn't likely to come out of a bloomery is a nice single piece, it'll probably come out in little chunks and pieces you'll have to learn to judge. Do a search for the samari swordsmith's and review their techniques. What you're doing more resembles a Tatara and will probably produce a version of Tamahagane. Like so many things, simple in principle can be very VERY difficult in practice.

 

Don't get me wrong, I'm not saying you can't do IT, it's just a long complicated path and will take time. Lots of time, especially if you're doing this by yourself.

 

Frosty The Lucky.

[AlexanderBlacksmith]

im going to try again with a bigger 'stack' or chimney and replacing the hair dryer with a leaf blower on idle, which, when i tested it, melted and pooled the iron ore i used. I also collected around another 5kg of iron ore, so i have about 1O-13kg total. I was wondering if using heat beads would work, they are 7O% fixed carbon, 17% ash, 6% water and some other mixed chemicals which they dont state, does anybody know if these will work as well as lump charcoal, they are much cheaper.

[AlexanderBlacksmith]

SUCCESS! created lots of little pieces of iron, not a 'bloom' the iron pieces were scattered throughout the slag so i had to crush the slag up, but from about 8-1Okg of iron ore i got around 5-8OOg of ironsteel so roughly a pound and a half. Which, when i looked at the creation and use of the tatara in the making of samurai swords, is about right when they say they use 18 tonnes of iron ore sand to create 1 tonne of ironsteel. Thank you all for your help, now ive just got to fuse the little pieces together.

[Frosty]

Cool, improvements are improvements. Making and using our own iron/steel has a powerful allure for most of us. I'll be watching for the results.

 

Frosty The Lucky.