As part of his attempt at manufacturing a toaster from scratch(!), Thomas Thwaites had to figure a way to smelt his own iron (for the grill piece) –

Finding ways to process the raw materials on a domestic scale is also an issue. For example, my first attempt to extract metal involved a chimney pot, some hair-dryers, a leaf blower, and a methodology from the 15th century – this is about the level of technology we can manage when we’re acting alone. I failed to get pure enough iron in this way, though if I’d tried a few more times and refined my technique and knowledge of the process I probably would’ve managed in the end. Instead I found a 2001 patent about industrial smelting of Iron ores using microwave energy.

Microwaves, as we all know, are just so much more convenient – and so I tried to replicate the industrial process outlined in the patent using a domestic microwave. After some not-so-careful experimentation which necessitated another microwave, followed by some careful experimentation, I got the timing and ingredients right and made a blob of iron about as big as a 10p coin.

It’ll be very interesting to see how this project turns out – see more of the process & progress on the Toaster Project site. [via Kottke]


  • Anonymous

    I would love to see someone try the same method to melt aluminum for casting.

  • Anonymous

    I cast my wife’s engagement ring by melting silver in a microwave. Took me seven tries but I did it.

  • Ushanka

    Can someone *please* leave more details about how to do this? How to prep the ore and the microwave, what what the post-microwaved ore looks like, how to get the iron away from the slag, &c.

    As for the people who’ve melted other metals in microwaves, I’d like to hear details of your exploits as well.

  • tiedyedpie

    Tom actually finished the toaster. Great work, pictures here:
    http://www.di09.rca.ac.uk/thomas-thwaites/the-toaster-project

  • pip

    Overview of Basic Hazards are as follows:

    1. Infrared radiation can cook the colour vision out of your eyes without protective eyewear (Orton Kiln glasses).

    2. The process begins to couple at over 800’C and can emit poisonous gas like Carbon Monoxide.

    3. The 1000grit SiC (Silicon Carbide) is known to contribute to the development of tumors (wear HEPA grade respirators.)

    4. The high temperature Refractive Brick and Ceramic Blanket should be handled with precautions such as eye protection, respirators, and nylon gloves (prolonged exposure can cause serious respiratory problems.) Make sure to completely destroy the oven after experimenting to prevent accidental reuse for food.

  • http://www.facebook.com/people/Eddie-Hyle/100002917392419 Eddie Hyle

    What an incredibly informative article!