Most of our readers will probably have at least passing familiarity with thermite, and many, if asked, would probably be able to identify the most common thermite reaction: a mixture of powdered aluminum and iron oxide which, properly ignited, produces extremely high temperatures and a stream of molten iron that can be used, for example, to weld steel.
In fact, this well-known process is only one of a very large number of possible reactions between metal powders and metal oxides, all of which are rightly called “thermite.” Because aluminum is cheap, readily available, and has a very high oxidation potential, it is commonly used as the reducing agent in these processes, and any thermite process using aluminum as the metal reactant can be described as an aluminothermic reaction.
UCLA physicist Jeffrey Schwartz, whose traditional thermite demonstrations I very much enjoyed at BAMF last week, has compiled what, he quite plausibly claims, is the world’s largest online gallery of thermite reaction videos at his fascinating site Amazing Rust.com. By my count, Jeffrey has there documented, with pictures or video or both, more than 40 different aluminothermic thermite events, smelting eleven different metal oxides including vanadium, cobalt, and titanium. [Thanks, Jeffrey!]