An iron crowbar costs about $8; one made of titanium, $80. Solid-titanium scissors start at $700, and don't even ask about the titanium socket wrench. Titanium must be a rare and precious substance, right?
Actually, as raw ore, titanium is 100 times as abundant as copper. Nearly all white paint is white because of the titanium dioxide found in the ore. Something like four million tons a year go into paint, sunscreen, toothpaste, even paper.
The high price of titanium comes not from the raw material but from the difficulty of turning that ore into wrenches and bike frames. At temperatures high enough to melt it, titanium exposed to air catches fire. So it has to be refined, forged, welded, and cast in a vacuum or under inert gas, an expensive process.
Yet I was able to make titanium using equipment I had lying around. I did it with thermite reduction, a process commonly used to weld train tracks. In an iron thermite reaction, iron oxide reacts with aluminum and comes out as liquid iron. I just swapped in titanium dioxide instead. But that reaction, in which titanium dioxide transfers its oxygen atoms to aluminum, doesn't release enough heat to melt the materials.
So I mixed in drywall plaster (calcium sulfate) and more aluminum powder. They react to create huge amounts of extra heat, enough to melt the titanium and allow it to pool at the bottom of the container. Adding ground fluorite powder makes the molten metals more fluid and protects the titanium from air as it cools.
I used clay flowerpots, as suggested by Gert Meyer, who developed this procedure. When nested with sand between them, they last just long enough to let the titanium cool into beads of solid metal.
Sadly, this is not really a practical way to make a lot of titanium, so don't get your hopes up about starting that $700 scissors business.
Do not try this at home. This reaction is extremely energetic. Flaming molten metal can be thrown some distance from the pot and will ignite anything within reach.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.