How I made an Iron Smelter, Iron from Sand

Comments · 1.4K

• JU

  @JulianSovernigo · 1 year ago

  Hey, a few things you should know:<br><br>Your iron bloom you have created IS the desired product of a smelt. Refining it by folding and forge welding it will create wrought iron, which is a very versatile and useful form of iron, and was the end goal of old iron smelting processes. If you take the iron bloom like you did and melt it into a bar, you include all the impurities that working the bloom in a forge can help to remove, like sulphur, phosphorus, manganese, etc., and you also oxidize the crap out of it, which makes it useless. In a forge, you can see the exact problem you had by heating mild steel up beyond its welding temperature: it oxidizes and becomes brittle and useless.<br><br>To answer your question of &quot;why don&apos;t we just pour it into an ingot&quot;, there are two reasons: oxidization from the high temperature, and volatility with oxygen. The process of melting iron and steel (rather than cast iron which has carbon content in excess of 2%) into usable bars at the industrial level began with the Bessemer Process, which was specifically designed to react the impurities with oxygen while purifying the iron before being poured (so that it wouldn&apos;t react and oxidize) into bar molds.<br><br>Cast iron was considered a waste product originally because we had no reliable way of casting it while it was still included in the iron bloom with iron and low carbon steel that will oxidize when brought to melting temperature. Once we figured out that it can be extracted from the bottom of a smelt in a puddle (since it fully melts at a lower temperature than steel and pure iron) and that it was good for thermal conductivity, then it became useful.<br><br>The bloom you created feels like glass, but refining it (you&apos;ll lose a lot of mass) will result in excellent wrought iron. Officina Ferraria has a few great videos on the refining of bloom, and so does Black Bear Forge.<br><br>TL;DR, this is a success, there is just more work to be done to make it iron that we want to work with!

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• KB

  @KBIronworks · 1 year ago

  That is 100% a success. As a blacksmith, I&apos;d love to have that bloom you made and refine it into a billet of wrought iron. You had the right idea of gently hammering on the bloom to get the molten mass to stick together. But with all of the impurities, you have to fold and weld it many times to refine it and make it homogeneous. Think of it like kneading dough. It also purifies it as the pockets of flag that are formed will squeeze out when they are folded close enough to an edge. Collaboration time? 🤔🤔🤔🤔

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• KR

  @Krasus92 · 1 year ago

  Dude made one of the most educational videos ever with learning in every part of it. Well done.

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• RI

  @RichardT2112 · 1 year ago

  The movie references alone made this totally worth watching! 😂

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• PS

  @psycomutt · 1 year ago

  A less scrupulous YouTuber would have made this a long series. Thanks for the resolution

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• TA

  @TareanSmiley · 1 year ago

  I have a couple of observations. <br><br>First, you need mass when you build a smelter. If the walls are too thin, the temperature fluctuates wildly. <br><br>Secondly, it is possible run the smelter so hot that it actually destroys the iron. This is easy to do with forced air. You don&apos;t want massive volumes of air like you found out here. <br><br>Part of the design you didn&apos;t implement was a way to drain off the slag. This is a crucial part of congealing the mass. Essentially, you put a small hole in your slag &quot;bowl&quot; that should fill with slag during the smelt, then you pop the plug and let this drain the slag away while it&apos;s still molten. The slag will run away like water leaving behind the iron mass that&apos;s still not hot enough to flow. <br><br>Great content! Keep it up!

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• AD

  @AdoraciónalAmanecer · 1 year ago

  Who else thinks this is pure talent?

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• JA

  @JaeohnEspheras · 9 months ago

  To keep your minions, pay them in ice creams.

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• EL

  @elitearbor · 1 year ago (edited)

  Oh cool, you made a bloomery.<br>Edit: In the future, if you make another go at this, keep some wet clay handy to patch cracks and such. Works a treat.

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• BL

  @BlunderMunchkin · 1 year ago

  You&apos;ve hit on an interesting point about how unintuitive this is. There is a tendency to think that people in the past were stupid, but this would have been very hard to figure out and they did it.

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• LO

  @LoreTunderin · 1 year ago

  Excellent attempt, I really appreciate how you share both your success and failure. A few things I noticed that perhaps could help, based on watching others attempt it as well:<br><br>Cody&apos;s lab has a video where he made cast iron from black sand thermite, and in it he shows a simple way to purify the sand. He basically let&apos;s it fall like an hour glass through a hole in the bottom of the bucket, and positions a magnet near the stream of falling sand that pulls the magnetite in a different trajectory so he ends up with 2 streams of sand that he catches in different buckets. One bucket has all the silica and the other has all the magnetite. Repeat it a few times to refine it even further and you&apos;ll have some very pure iron sand. <br><br>You don&apos;t necessarily need clay for the smelter, mud can work fine too as long as you &nbsp;pre-fire it and then repair the cracks with more mud. Do it a few times times to build thickness and strength and you should be ready to do your smelt.<br><br>Ideally you want the smelter to be taller and have thicker walls as a larger thermal mass will insulate the bloom better, and a taller chimney gives the ore longer to heat up as it falls through the smelter with the charcoal before reaching the bloom. <br><br>It&apos;s important to fill up the cracks in the walls after pre-firing the smelter as the drafting chimney will draw in cooler outside air and sap heat from walls, and the excess oxygen higher up in the chimney will consume your charcoal too quickly, causing voids in the charcoal stack that allow unheated sand to fall through into bloom, cooling it and starving it of fuel needed to stay hot.<br><br>I remember a documentary on the Ulfbert Sword where their smelter was effectively air tight except for the top of the chimney and tuyere. They pre-heated the smelter using wood before filling it with charcoal and starting their smelt. I know they were making steel in their attempt, but I think the same principle applies here as it&apos;s similar to how the Primitive Technology channel has done it several times, and he was also trying to get iron rather than steel. <br><br>As for getting the bloom out when you&apos;re done, you can add a sacrificial door of sorts to the bottom around the tuyere so you don&apos;t have to knock the whole thing over. When pre-firing the smelter, leave a hole large enough for your shovel at the bottom where the tuyere goes. When adding the tuyere you can then fill the hole in around it using mud without any straw added. This way the dry mud door will be easier to break away to access the bloom without damaging the walls of the smelter.<br><br>Speaking of tuyeres, I think it might be worth making or buying a fired clay nozzle for yours. The steel pipe you&apos;re using melts at roughly the same temperature as your iron sand, so your bloom keeps getting contaminated by outside metal dripping off the tuyere. If you stuck the pipe into a fired clay tuyere, you could keep the pipe outside the smelter away from the heat to keep it from melting. The channel Primitive Technology has several great videos showing how he makes the tuyeres he uses. <br><br>Oh, I noticed you didn&apos;t say whether or not you pre-cooked the magnetite sand before adding it to the smelter. Since you&apos;re getting it from the beach there&apos;s a chance it has trapped moisture inside that&apos;s making it stick to the silica sand and reducing the efficiency of your smelt. Even just heating it up in an oven or bbq for an hour or two to force off moisture might help a bit. If you&apos;re keeping it in a metal bucket you could probably put the bucket in a fire or pile some bbq charcoal around it to let heat it up and steam off any trapped water or volatile organics without getting it hot enough to mess it up. Once it&apos;s super dry it would probably be easier to separate from the silica sand as well.

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• DA

  @darylbrenton4839 · 1 year ago

  I make charcoal for blacksmithing with a 44 gallon drum, but I burn the timber inside a drum with no holes. There isn&apos;t enough air inside the drum to fully burn the wood before it is covered in coals, which stops the air reaching them. When the coals get to the top, I seal off the lid and let it cool down. Bloomery iron is usually full of silicates, iron sand is actually an iron silicate. Silica is the basic ingredient of glass, and in the past, European and Asian iron makers would hammer the bloom many times to force most of the silica out, and push the iron together, which gets rid of the spongy texture. Wrought iron was hammered out of this iron into bars, and had strands of silicates running the length. If you cut a piece half way through, and bend it, you will see a texture that looks like the fibres in wood. Most documentaries of bloomery steel, or Japanese tamagane making, leave the mass to cool inside the smelter, and then process the resulting bloom afterwards. I was surprised that you didn&apos;t get a lump of iron from your melt. Perhaps it might work if you melt it in a sealed crucible and let it cool inside your furnace before opening.

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