"Titanium could become part of everyday life"
new extraction process
Titanium may become an everyday metal thanks to a new low cost extraction process.
Stronger and more corrosion resistant than SS and just over half as dense, mixable with other metals to provide tough yet flexible alloys , titanium is the dream material of countless designers.
What has always held it back is its price - but a new extraction process, reported yesterday in the journal NATURE, may change this.
Althought titanium ore is plentiful, the pure metal carries an exotic price tag of about US$7,500 per tonne , while complex titanium alloys for planes or spacecraft sell for
around US $40,000 per tonne.
About a third of this cost is derived from the extraction process, a slow and dangerous business in which titanium dioxide ore is mixed with chlorine to produce a volatile corrrosive liquid, which is then reduced to pure metal by exposure to magnesium or sodium at high temperature in sealed vats.
Engineers trying to get around this by using electrolysis, the method used to smelt aluminum, have also hit problems. It still requires conversion of the oxide to a volatile chloride and only be used at ultra-high temperatures that prevent continuous production of liquid metal.
The solution , say scientists at the University of Cambridge, is a new electrolysis technique whose prime advantage is to cut out the need to convert the ore.
It uses a molten salt to take the oxygen out of the core,leaving a pure titanium at the cathode,the negative terminal of the electrolytic bath. In laboratory conditions, amounts of up to one kilogram of titanium have been produced.
If this can be made the basis of an industrial process, said Harvy Flower, a professor of metals at London's Imperial College of Scince, Tech, and Medicine,titanium production could up by a factor of 10. The automobile industry would love to use the ultra-light, heat resistant metal in areas of cars that are exposed to high temperatures, such as the engine and exhaust system, he added.
Other metals that could benefit from the new technique include zirconium, uranium, plutonium, niobium and chromium.
Taken from the National Post today in a report from France Presse. |
