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How do you smelt and forge iron sources from & in the wilderness? People must have started somewhere with this sort of thing!

I once saw a video from a primitive technology practitioner on YouTube who smelted iron from a orange bacterial build up in water that served as the ore, using a wildcrafted furnace he made. He noted it was mainly a demonstration of a wildcrafted furnace and that larger furnaces would be built using more charcoal and labor to produce usable quantities of iron. He did not take next steps once he had iron pellets. What would one do with them (or more of them) to make the iron pellets into something useful, such as a nail, a needle, a knife, or an arrowhead?

What are ways to process iron in the wilderness? Since this probably varies geographically, let's focus on common ways that are most widely applicable, and let's assume that we have only wildcrafted tools.

closed as off-topic by fgysin, Martin F, Sue, Phil, Ben Crowell Feb 20 '17 at 19:33

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    I once asked this question of a classmate who was a graduate student in metallurgy at a very good school, and her curriculum had not covered this point. – ab2 Feb 9 '17 at 20:24
  • didn't cover it!? can't forget about the foundations :P – cr0 Feb 9 '17 at 20:38
  • @ab2 I took a single physical geology course in university and part of our curriculum was identifying the mineral ores of many metals. – ShemSeger Feb 9 '17 at 21:39
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    I'm voting to close this question as off-topic because metallurgy is not on topic. – whatsisname Feb 11 '17 at 6:57
  • Have to agree with with @whatsisname here. Metallurgy, even when relying on primitive tools, is a rather elaborate and very very time consuming process. I do not think it really applies to an 'outdoors' SE. – fgysin Feb 13 '17 at 13:49
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The simplest way of smelting iron is a bloomery furnace. This is essentially a beehive shaped structure, covered in clay and containing alternating layers of charcoal and iron ore with openings top and bottom to allow a controlled airflow through the stack.

Iron ore comes in several forms but is essentially various iron oxides mixed with silicates. The chemistry behind a bloomery furnace is that the burning charcoal creates both a high temperature and a carbon rich atmosphere inside the furnace in which oxygen is taken away from the iron to react with the carbon (reduction).

At the end of the burn the furnace is taken apart and if the process is successful there should be a porous mass of metallic iron mixed with silicate slag, called a 'bloom'. Depending on the quality of the ore and the exact conditions in the furnace there may also be a certain amount of steel of varying carbon content.

This bloom must them be re heated in a forge and repeatedly hammered and folded to create a usable material. The end product of this 'fining' process is wrought iorn, a composite of more or less pure metallic iron interspersed with fine fibres of silicates. This can either be used as it is with similar properties to mild steel or further processed by carburisation to make steel.

A development of this process involves a rather more sophisticated furnace fed with forced air which both reduces the ore and diffuses carbon into the metal, creating cast iron which has a significant carbon content (around 3-5%) and consequently a low enough melting point (around 1200C) to be cast. Usually the raw 'pig iron' from a furnace needs to be remelted to produce a usable pure material.

Producing good quality steel requires additional steps as you need to precisely control the carbon content of the resulting alloy.

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Iron ore is called hematite. It's pretty simple to identify, just look for red rocks that appear to be rusting. Iron is the 4th most abundant element on earth, so it's pretty common in most areas.

The most primitive way to smelt ore is to construct a furnace out of mud, create a fiery inferno inside of it and then pour in all of your ore. You can accomplish a similar feat by digging a hole, building a hot fire, tossing your ore in the middle and covering it so the heat doesn't excape. Heat is essential, you have to be able to get your fire hot enough to melt iron, so use hardwood at the very least, (coal if you can find it) and you have to create a bellows to fan the coals or it won't get hot enough, at the very least you need to sit there and blow on your coals (use a reed as a blow pipe then you don't need to get too close). Do this until the fire burns out or you feel you may have sufficiently smelted the ore. You should be able to dig a clump of dirty iron out of the bottom of your pit. How big it is will depend on the quality of your ore, and whether or not you got your fire hot enough.

After you have your chunk of iron, you're ready yo get your 'blacksmith' on.

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    +1 Of interest is the melting point of iron (2,800°F or 1,538°C) and also of copper (1,984°F or 1,085°C) . This is why the bronze age came before the iron age even though iron is much more common than tin. – ab2 Feb 9 '17 at 21:40
  • Great points ab2...inspires another question! And good answer ShemSeger, +1. It would be even more complete if you addressed the blacksmithing part...can the heated chunk of Iron be hit with a rock to blacksmith it, or somehow poured into a clay mold to solidify and take shape? – cr0 Feb 9 '17 at 21:42
  • @cr0 Ya... I've poured metal before, we used a type of tar-sand to create the mold, but you need to make something to hold liquid metal to go that route, which requires some knowledge of firing pottery so you can make a pot for a foundry. Blacksmithing takes less heat, you just need to get it red hot, and then pound it with something hard, on top of something else hard. – ShemSeger Feb 9 '17 at 21:48
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    Here is a page that discusses the shortcut of using "bog iron" but also has pictures and instructions for making and using the furnace: hurstwic.org/history/articles/manufacturing/text/bog_iron.htm – Kate Gregory Feb 10 '17 at 14:08
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    @whatsisname I regularly find the kind of orange-goop iron deposits accumulated by bacteria in water in the foothills of the Canadian Shield. Though that is not very high quality, the link KateGregory shared shows it is sufficient for primitive iron tools Vikings made. – cr0 Feb 13 '17 at 16:15

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