In this experiment I smelt iron ore using a modern aluminothermic reduction reaction (also known as thermite). Although this is the same kind of reaction as thermite, thermite uses man-made (or at least heavily processed) iron oxide while this reaction uses the natural impure ore as its iron oxide source. Performing this reaction both validates the smelting technique and also indicates that I am using high quality ore. The quality of the ore was something I was interested in because I can eliminate ore quality as one of the variables in the poor operation of my large smelting furnace. From a starting ore mass of about 36.5 grams, I recovered 11 grams of iron metal after breaking apart the slag bowl that had formed.
I performed this reaction by first gathering a few small pieces of iron ore that looked like they would be easy to crush. I then roasted them in a campfire twice where they were held at a nice cherry red heat for many hours. This step is important because it converts the iron sulfides, hydroxides, and other complex oxides into the simple iron oxides which are needed for the smelting reaction. Once roasted, the ore was then crushed to a powder and then mixed with aluminum powder and filings. This was then placed inside a small paper cup and an ignition charge was placed on top to kick-start the reaction.
The reaction is extremely exothermic and melts the resultant aluminum oxide and iron metal that formed in the reaction. In a future experiment, I will increase the the amount of reagents used as well as add some additional alloying metal oxides and carbon to give me a workable piece of steel from which I can make tools!
