New Metal Manufacturing Process is a Game-changer
From The Economist
ALUMINIUM was once more costly than gold. Napoleon III, emperor of France, reserved cutlery made from it for his most favoured guests, and the Washington monument, in America’s capital, was capped with it not because the builders were cheapskates but because they wanted to show off. How times change. And in aluminium’s case they changed because, in the late 1880s, Charles Hall and Paul Héroult worked out how to separate the stuff from its oxide using electricity rather than chemical reducing agents. Now, the founders of Metalysis, a small British firm, hope to do much the same with tantalum, titanium and a host of other recherché and expensive metallic elements including neodymium, tungsten and vanadium.
The difference between its process and that of Hall and Héroult (and why electrolysis has not previously been used to make metals such as tantalum and titanium) is that the Hall-Héroult method requires both input oxide and output metal to be in liquid form. That demands heat. But aluminium has a fairly low melting point and its oxide can be dissolved in a substance called cryolite that also has a low melting point, so the amount of heat needed is manageable. Titanium and tantalum are not so obliging. The Metalysis trick is to do the electrolysis on powdered oxides directly, without melting them.
Elements will still be expensive if the ores are expensive, but the process described here seems to be orders of magnitude cheaper than the current method. Aluminum went from being Napoleon’s “silverware” to littering our roadways with discarded soft drink cans, so can we expect a similar transformation for titanium? Its ore is extremely common, as is that of tantalum, neodymium, tungsten and vanadium, though the latter two are more regionally localized (ie, China). I am not seeing too much hype in this article. This is likely to be the single largest change in metallurgy until we start mining asteroids.