How to process iron in the wilderness? [closed]

Question

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.

Answer 1

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.

Answer 2

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.