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Smelting iron


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Hi, guys it's been a long while since I made a topic, but here it comes.

I got 3kg of Fe2O3 from school to use. My plan is to use it to smelt iron for a school project. But I don't know how to do this.
I do know I need charcoal and a furnace, which I know how to make. Ratio charcoal to "ore" is 1 pound of charcoal to 1 pound "ore"

I hope one or more of you guys could give me advice about this, because I'd really like to smelt iron for a school project.

Joe

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Joe,

You don’t have enough ore to make the process work. With only 3kg (about 6.5lbs) of ore it would be a very tiny bloomery. You would need about ten times that amount or between 36 and 27 kg. It takes more than 4 hours of charging ore and charcoal (about every 10 minutes) to develop the bloom.

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You could do a crucible smelt of that amount of ore *iff* you had a crucible large enough and rated for the temps. You basically mix the ore and carbon monoxide producer in a crucible with a cap to keep O2 out and heat to reducing temps producing your "bloom".

I can't speak to the exact details as we have always done bloomeries; but I know a couple of guys who did it that way a decade or so ago.

Do you know Jeroen Zuiderwijk, also in the Netherlands? As I recall he has been involved in some bloomery smeltings as part of an Iron Age re-enactment as well as his bronze age work.

I know of him through www.swordforum.com/forums/forumdisplay.php?12-Ancient-Weapons-Forum

You may want to join SFI and PM him for information on local iron smeltings

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Over here in the UK we have run quite a few smelts for steel and iron. With a good smelt for iron we would expect to get about 18 kilos of bloom from 50 kilos of ore. Building the stack, drying it out, pre heating and charging with ore and charcoal is a good days work for two people.

Here is a link to one we did recently http://forums.dfoggknives.com/index.php?showtopic=19636
For a huge resource of smelting have a look on the above site under Buttons and Bloomers.

Mick.

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Thanks for the info. guys.

That video is from Thijs van de Manakker (Dutch). I know him and have talked to him. And for what I can see now. It looks like it's going to be a tiny bloomery, I never had intentions to do a live sized bloomery. Since I can't get the right amount of ore and actually isn't ore, it's pure Fe2O3. Also the amount of charcoal will be a problem for a live sized bloomery.

So, I will try and see what happends. Maybe some succes maybe not. All experiences help.

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Thanks Frosty; I'm sure I needed that.

Got the winters wood in yet? I may need to contract with a great white birch...

Smelting is one of those things where having someone show you can save months and multiple tries at it.

Of course if you are willing to go a bit modern....The Mastery and Uses of Fire in Antiquity by Rehder, ISBN: 0773530746 / 0-7735-3074-6, has plans for a "fool proof" bloomery in the appendix. Built from 2 metal classroom wastebaskets and modern refractory and air handling equip.

Find a local smith that is willing to save their scale for you and your "ore" will grow!

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Joe that the same book Thomas recommended it to me its a good read. I would consider making a mini one and bring it to school to show what the steps are what the heck make the charcoal you may even get mini bloom. if shipping was not so much I would offer to send you some more. Maybe you can find some bog iron in your country then you can have a bigger bloom

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As I recall it can't be scaled down too far as the heat balance gets out of whack---the ratio of the surface area to the volume goes up and so the heat loss becomes greater and you can't get enough fuel down the smaller pipe to burn at a faster rate to provide more heat.

If you go high tech you could probably use insulating refractories and slide the cutoff point for usability a lot further down but then the cost of refractories gets higher.

I suggest you read the book I suggested as it will provide a wealth of information to wow your teacher---like how the mean fuel size controls where the reduction point is in the furnace, etc.

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  • 5 months later...

Hey guys, im going to try to make a bloom sometime this summer and i was wondering if i can use scrap iron if i cut it small enough, and also if anyone had some VERY simple plans for a Tatara furnace, im working on a budget of under 200, probally under 100 LOL, and i have a near ENDLESS supply of clay i can use, i was wondering if i made a square base of clyinder blocks and coated it witht the clay if it would be good enough to withstand the temperatures? also to make the tower can i use blocks and coat it with the clay also?? im trying to make one as simple as i can, and i have a shop vac i use to blow air, can that be used for this also?

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Funny I have never spent more that zero on my furnaces and perhaps $20 on other peoples. I do adobe (our traditional mix was 3:2:1---3 shovels of sandy silty soil, 2 head sized bunches of chopped straw and 1 shovel full of powdered clay---bought from the feed store where the money comes in. Me I have adobe soil here in New Mexico and scavenged clay plates from when the arroyos flood and dry out---I'm *cheap*)

No! scrap iron cut up small is NOT iron ore! If you want to smelt you need to get iron ore! Scale from smithing and magnetite sand make easily sourced iron ore---and is much closer to the japanese materials than the bog ores of northern Europe and eastern North America.
'
I strongly recommend you participate in someone else's smelting run before trying your own!

Also for plans for a small "fool proof" bloomery Rehder's "The Mastery and Uses of Fire in Antiquity" has one in the appendix.

As for your proposed air source: Yes, No, Maybe: depending on information you didn't supply and don't even have yet.

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wow we smelted a lot of ore that came from eastern Canada with the glaciers and was recovered from the creeks and lake banks by dragging a magnet to get magnetite sand the "iron sand" of Japanese smelting.

Magnetite is found in most igneous rocks and in many metamorphic and should well be found in Eastern Canada---have you done a proper search? An old speaker magnet double bagged was our harvester of choice. If you can find an area where currents have pre-sorted the sediments you can sometimes hit a bonanza of iron sand!

I recycle the scale from my smithy which adds 10 to 20 pounds of ore right there and I don't bother with the floor sweepings which is where most of the scale ends up anywhere.

Try to avoid grinding residue though cutting residue is most likely OK.

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There is always google. I found about 91,100 results in. 10 seconds by just typing in "Backyard smelting".

http://www.backyardmetalcasting.com/

And then there is our own smelting section.

http://www.iforgeiron.com/topic/24977-overview-of-metal-casting-for-beginners/

I love reading these. I havn't gotten into it yet but it is one of the things on my to do list. Some day I'll get there.

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And there is the danger of the net as well---I took a glance at backyardmetalcasting.com and didn't see ANYTHING on smelting just stuff on melting and casting metal which is very different than smelting metal from ore and might be why someone would end up asking if they could use small chunks of metal instead of ore.

And the IFI section you reference again refers to melting NOT smelting.

MELTING != SMELTING

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Jargon is important allowing people in a craft to make fine distinctions that may seem invisible to "outsiders". I know my wife the Spinster can reel off stuff on crimp, fineness, staple length, luster, etc, to specify a particular wool where to me it's just "wool"---and in reverse when I speak about alloys and carbon contents and heat treats for steel.

Making things even more fun is that jargon has dialects so what someone teaming crucible steel may call a tool or process might very well be different on this side of the pond.

So please folks be careful with your jargon lest we mislead the newcomers amongst us.


Yes there is good info out there---some of it I wrote about 20 years ago---but there is a lot of bad or misleading information to---haven't we all seen the "I've never done this before; but this is how it's done" posts or people putting up training films that are working on their first go at something.

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hi fellows i do a few smelts a year i have a tube catalan furnace i made from a 16 steel pipe 1200 mm tall lined with refractory and a opening near the bottom on the side to extract the bloom i have 2 air inlets about 250mm up from bottom an i run it for about 6 -8 hour and get about 4kg off bloom from about 12kg of iron ore i use coke as the fuel , and line stone powder as flux , then after i extract the bloom i forge it softly at first till it gett solider then harder hit till it solid i the forge an over lay on to itself reweld till perfect bar
have fun its not hard to do its is just time consuming
as dont run the furnace to hot or u get nothing except slag as traces or iron
happt smelting

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