Home Grown Titanium

Although my current lack of posting might not indicate it, I've actually come across quite a few interesting articles lately. Unfortunately, they all involve nanochemistry, and since I've already talked too much about nanochemistry recently, I'm imposing a moratorium on that subject for awhile. Fortunately, I do have something else to talk about.

The Goldschmidt reaction.

Not familiar with the Goldschmidt reaction? Perhaps you have heard of it referred to as "the thermite reaction."

Surely everyone who has ever taken a freshman chemistry course has read or heard about the thermite reaction. Most of you have probably seen it in action. The pyrotechnics are impressive and most freshman chemistry lecturers simply cannot resist demonstrating it in front of a class. In its most common incarnation, aluminum and Fe2O3 (or Fe3O4) powders are mixed and ignited. The aluminum is converted to Al2O3 while the iron oxide is reduced to the metallic state. Significant quantities of heat are released, and if the experiment is set up correctly, molten iron will drip out of the bottom of the reaction vessel. Although iron oxide is the material most associated with the thermite reaction, copper and manganese oxides can also be used.

In a continuation of "the type of experiments I'd like to try at home when my wife is away" category, I recently came across a method for generating titanium metal in your garage using TiO2 and the thermite reaction. A full description of the technique as well as a video of the pyrotechnics are included. Metallic titanium was actually recovered, which is amazing since titanium tends to oxidize in air at temperatures near its melting point. In order to generate the temperatures necessary to melt the titanium, CaSO4 was added to generate additional heat. CaSO4 reacts with aluminum in its own version of the thermite reaction to form CaS. A more detailed description of the process involved can be found here.

This would have been an awesome experiment for alchemists to have performed back in the day. Simple, yet impressive. Perhaps the substitution of iron oxide with some form of gold oxide (or other suitable gold compound) might have resulted in the appearance of molten gold, always a good way to impress the wealthy patrons upon whom the alchemists depended. Unfortunately, although aluminum salts were known to the alchemists as far back as ancient Greece, aluminum metal was not produced until the 1800's. And it's the chemical energy stored in the metal which drives the whole reaction.