Rio Tinto develops method of extracting scandium from waste

Rio Tinto says that scientists at the company’s technology centre in Sorel-Tracy, Quebec, Canada, have found a way to extract and purify scandium — a rare and useful metallic element — from titanium dioxide production waste.

The United States, Canada, Australia and the European Union have listed scandium as a critical mineral, but it is difficult to acquire. Scandium can be used in industries like aerospace, sporting goods and clean technology. It is one of the main ingredients used to make solid oxide fuel cells — a new clean energy technology used in hospitals, data centres and factories, where a steady and reliable power back-up is vital.

And even though scandium is found all over the world, it is usually in very small amounts and mixed up with other minerals and metals. So it can be hard to find, and even harder — and more expensive — to process. Now Rio Tinto says it is able to create a scalable, high-quality, reliable and sustainable scandium source.

After becoming the first North American producer of scandium when the first batch of high purity scandium oxide was produced at a commercial-scale demonstration plant, the company is now planning to quadruple production capacity to reach up to 12 tonnes of scandium oxide per year, from the current nameplate capacity of three tonnes.

New modules will be added to the existing plant, which uses an innovative process to extract high-purity scandium oxide from the waste streams of titanium dioxide production, without the need for any additional mining.

Using scandium oxide, Rio Tinto has developed high-performance aluminium-scandium alloys for use in a range of industries — from aerospace and shipping to sporting goods and 3D printing.

Scandium and aluminium go well together. By mixing scandium with aluminium, some aluminium alloys can be made stronger, more flexible and more resistant to heat and corrosion, creating a perfect metal for everyday objects that need to be light, strong and manoeuvrable — from sporting equipment like bikes, golf clubs and baseball bats to aircraft.

Rio Tinto currently produces scandium oxide from titanium dioxide production waste streams at Sorel-Tracy in Quebec. Once operational, the Platina Scandium Project would enable Rio Tinto to more than double its annual scandium production, according to the company.

Scandium is a rare, versatile and useful mineral for the green economy and energy transition. It is one of the most effective elements able to strengthen aluminium, while also offering improved flexibility and resistance to heat and corrosion. As a result, it is used to produce high-performance aluminium alloys for applications that need to be light, strong and heat resistant, including in aerospace, automotive, heat exchangers, sporting goods, 3D printing and energy transmission applications.

Scandium oxide is also used to improve the performance of solid oxide fuel cells used as a green power source for buildings, medical facilities and data processing centres, as well as in niche products such as lasers and lighting.

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