New titanium making technique may lead to cost savings

A new titanium making process being developed by research organisation SRI International could allow titanium to be used in cars.

A new titanium making process being developed by research organisation SRI International could cut the cost of making the metal and even allow it to be used in cars.

As MIT Technology Review reports, the standard method used to make titanium is expensive, labour intensive and uses a lot of energy. Called the Kroll process, it has been used for over 80 years.

Kroll involves creating TiCl4 by heating titanium dioxide to about 1,000 degrees Celsius and reacting it with chlorine. The “tickle” is then covered with argon and reacted with magnesium at about 850 degrees Celsius.

This takes place in batches in stainless steel retorts, which react with titanium (about 20 per cent of the sponge produced becomes ferro titanium and has to be removed manually).

The sponge is then removed and melted into ingots.

However, the new technique from SRI requires less energy than Kroll. According to Barbara Heydorn, senior director of the Energy Center at SRI, it involves plasma arcs which facilitate reactions between molecules of hydrogen and titanium chloride, a chemical produced from titanium ore.

“Arcs, like lightning bolts, crack the hydrogen, producing atomic hydrogen that can readily react,” said Heydorn.

That reaction produces a titanium vapour that then solidifies, forming titanium powder.

As Gizmodo reports, titanium is currently used only in applications where its high costs can be justified, such as making fighter jets. The new technique could cut costs and make it a viable option for other applications like car making.

A further advantage of the new technique is that it produces titanium that can be made into shapes that more closely resemble the final products. In comparison, the Kroll method only produces solid lumps of titanium which need significant extra shaping to achieve finished products.

Image: CSIRO