Before revision: The only metals it has been used to purify on an industrial scale are titanium, zirconium and hafnium, and in fact is still in use today on a much smaller scale for special purity needs.
After revision: itThe only metals it has been used to purify on an industrial scale are titanium, zirconium and hafnium, and in fact is still in use today on a much smaller scale for special purity needs.