Miners go after opportunities to extract rare critical metal Metal Tech News – July 21, 2021
Scandium, one of 35 minerals identified as being critical to future production of high-tech and industrial technologies in the West, is seeing a surge in mining and extraction activity in response to increasing demand for the soft, silvery metallic element.
Scandium is not particularly rare – its occurrence in crustal rocks is around 22 parts per million. It is generally more plentiful than lead, mercury, and precious metals. Yet scandium rarely concentrates in nature, so time and geologic forces only rarely form scandium concentrations over 100 ppm. No dedicated single mine source exists, and it is estimated that only 15 metric tons of scandium are produced globally every year.
Furthermore, scandium exists in nature only in its oxide form, as scandia or scandium oxide, making it difficult to reduce to a pure elemental state. In fact, it was not isolated in pure form until 1937, and the first pound of pure elemental scandium metal was not produced until 1960. Processed scandium oxide, a white powder, is stable at ambient temperature and is the standard scandium form for commerce.
Despite scandium's scarcity and high cost, interest in the metal is high and multiple high-value commercial uses have been developed, including an alloy of scandium into aluminum metal products. When used in combination with other common aluminum alloys, scandium can produce stronger, more corrosion resistant, heat tolerant, weldable aluminum products. As a result, aluminum products are being increasingly incorporated into transportation applications (aircraft and automobile) to meet fuel-efficiency requirements.
Aircraft manufacturers are particularly interested in scandium-alloyed aluminum materials. Aircraft designers believe use of these alloys can reduce aircraft weights by 15% to 20%. In addition, the ability to employ weldable structures promises similar cost-reduction potential.
Scandium also exhibits exceptional electrical conductivity and heat stabilization qualities, and the largest volume currently in use is in solid oxide fuel cells. The use of scandium in these fuel cells enables a lower operating temperature resulting in longer-lived equipment and less-costly construction materials. Bloom Energy is the leading manufacturer of SOFCs and currently the single-largest scandium user.
Strong demand, concentrated market
In industrial applications, scandium acts as a grain refiner and hardener of aluminum alloys. Aluminum-scandium alloys combine high strength, ductility, weldability, improved corrosion resistance, and a lower density.
The combination of all these properties makes aluminum-scandium alloys well-suited for the aerospace, automotive and defense industries, which accounted for 82.7% share of the 2017 market. Applications of aluminum-scandium alloys include consumer products such as baseball bats, golf club heads, and high-end bicycle wheel rims. However, the price of aluminum-scandium master alloys is still too high for most commercial applications.
Currently, most of the global scandium market is supplied by China, Kazakhstan, the Philippines, Russia, and Ukraine, according to U.S. Geological Survey estimates. For consumption, it is estimated that North America, Europe, China and Japan are the key markets.
The aluminum-scandium market is concentrated. Of the 2017 global market (the most recent figures available), the top 11 companies, all multinational, accounted for the bulk of sales. RUSAL is by far the leader, with nearly 24.74% of the market. As major suppliers seek to expand their global presence, the market concentration is estimated to increase in the next five years.
A variety of large and small competitors, meanwhile, are making bids to enter this fast-growing market.
Rio Tinto unit opens scandium plant
Rio Tinto Fer et Titane, an iron and titanium division of Anglo-Australian mining giant Rio Tinto, recently reported the opening of a new scandium oxide plant at its metallurgical complex in Sorel-Tracy, Quebec.
The US$6 million project, of which US$650,000 came through Quebec's economic development program for critical and strategic minerals, is projected to reach output of three metric tons of scandium oxide per year. The plant uses a process developed by Rio Tinto that extracts scandium oxide from waste produced from titanium dioxide production, which the company says requires no additional mining.
Rio Tinto intends to supply roughly 20% of the global market for scandium. Already a major aluminum supplier, Rio Tinto plans to produce aluminum-scandium alloys to meet further market demand.
"For the first time, customers will benefit from a North American supply of scandium oxide for applications in solid oxide fuel cells, lasers, lighting products or as an additive to produce high-performance alloys," Stephane Leblanc, managing director at Rio Tinto Fer et Titane, said in a statement.
Guy Gaudreault, another RTFT managing director, cited the importance of having a North American scandium producer.
"[RTFT] is the first producer of scandium in North America. In the past, when people wanted to develop scandium, the problem was with the reliability of the supplier, and we are a reliable supplier," he said during a news conference in Quebec June 17.
New scandium, REE extraction process
Imperial Mining Group Ltd. recently unveiled a new process for extraction of scandium and rare earth elements from the mineralization its Crater Lake project in Quebec. Results from its phase 3 hydrometallurgical development program show high recovery of scandium and rare earths for all mineralization types defined so far on the property, the company said.
The two-stage extraction method that was tested entails a high-pressure caustic leach followed by hydrochloric acid leach of the resultant residue. This new method showed scandium recovery to primary leach solution at 87% for one sample and 84% for a second sample, and recovery of total rare earth elements, including yttrium at 84%, from both samples.
Imperial Mining Group President and CEO Peter Cashin said the company and its partners "are now ready to move to the final stages of their test work to recover a high-purity scandium oxide product."
Imperial said the venture is planning to apply for a patent for the new process after it completes the phase 3 hydrometallurgical flowsheet development program in the third quarter of 2021.
Junior obtains U.S. patents
Scandium International Mining Corp. has been granted two separate patents from the U.S. Patent Office pertaining to the recovery of scandium from copper raffinate solutions via ion exchange technologies, as well as to reserve rights in the manufacture of aluminum-scandium master alloys via these defined techniques. Raffinate is a liquid from which impurities have been removed by solvent extraction.
Both patents are directly applicable to processes and projects in which the company is currently engaged to produce scandium products for use in both aluminum alloys and other technical applications.
Scandium International CEO George Putnam said they add to the company's suite of patent protections designed to give it a competitive advantage in critical metals recovery.
"The scandium ion exchange recovery patent grant meets a technical milestone for recovery of scandium from copper solutions, ...while the unique master alloy production methods grant can be applied to enhance our scandium product offering for any of our potential scandium-source projects," he said.
Another pending final application is more encompassing regarding metal targets identified and covered, including nickel, cobalt, copper, zinc, manganese, beryllium, aluminum, rhenium, scandium, and others, along with various recovery methods based on both ion exchange and solvent extraction methods. This broader patent application specifically covers copper systems where sulfuric acid leachates are present but has also been expanded to cover similar leachate solutions in primary lithium, vanadium, and nickel systems.
Scandium International is focused on developing its Nyngan scandium project in New South Wales, Australia into the world's first scandium-only producing mine. The company said the project has received all key approvals, including a development consent and a mining lease, necessary to proceed with project construction.
Scandium International is also discussing opportunities with various copper industry groups in which it proposes to employ ion-exchange technology to extract unrecovered critical metals from existing mine process streams. This program represents a fast-track concept to make battery-grade nickel and cobalt products, scandium master-alloy products, and other critical metals, from North American sources.