Scandium — a Rare Earth Revolution in the Waiting

In this constant barrage of rare earth production and supply issues, scandium (Sc) appears to be an outlier. Distributed worldwide up to a few hundred parts per million (ppm) wherever it occurs, it is revolutionizing the aluminium industry, having deep and lasting effect on all aluminium uses from airplanes to automobiles, sports and mobility devices for the disabled. Alloying 0.01% to 0.4% of scandium in aluminium changes the beneficial properties of the latter and opens up methods of fabrication that were difficult or not possible earlier.

The other major application of scandium is the manufacture of solid oxide fuel cells (SOFCs). Addition of Scandium to existing yttria‑stabilized zirconia (YSZ) (often the 8% form, 8YSZ) – termed scandia stabilized zirconia (ScSZ) – improves ion conductivity and durability and reduces operating temperature drastically.

Sources

There are five identified sources for scandium production:

1. Tailings of uranium (U) mines;
2. Tailings from rare earth element (REE) production;
3. Nickel production;
4. Alumina red mud; and
5. Waste acid from titanium dioxide (TiO₂) production.

The waste acids generated during TiO₂ production – both by chloride and sulphate routes – is a more easily extractable source of scandium. The waste acid from sulphate route contain 10‑25 mg/l of scandium, while the waste acid from the chloride route contains 60‑140 mg/l as also significant quantities of other critical raw materials, viz. vanadium and niobium. Recovery from TiO₂ waste acid is extensively practiced in China. In the last few years R&D in recovery of scandium from TiO₂ waste has progressed rapidly in Europe.

Tailing from uranium mines were the main source in Russia and Kazakhstan, while tailings from REE are one of the sources in China. Philippines (and possibly China) are the main producers from nickel production.

Red mud from alumina production can be an important source and indeed research consortia have been formed in Europe and India to develop the technologies to do so.

Applications

Al‑Sc alloys

Small quantities of scandium when added to aluminium alloys significantly improves the tensile strength and physical properties of the finished product. The addition of 0.025‑0.25% scandium to Al‑Mg alloy enhances its strength by 150%. When aluminium is alloyed with similar percentage of scandium the strength increases by 1500%.

Fig. 1: [Image placeholder: Conceptual flowchart for the recovery of scandium from TiO₂ waste acids]

The first use that comes to mind for these alloys is aerospace, as it makes for lighter and stronger structures. The MIG‑29 aircraft, made in Russia, supposedly uses Al‑scandium alloy structures. In the passenger aircraft segment, Airbus introduced Al‑Mg‑Sc alloys. The 45% weight reduction for its A320 planes reduces its fuel consumption and lowers its carbon footprint.

There is also very large potential use for Al‑Sc alloys in the automotive industry if the cost can be brought down.

Scandium is also used in manufacture of premium tennis rackets, baseball bats, sports cycles, tent poles and mountain climbing gear. Smith & Wesson revolvers are a faster draw as they have become lighter with use of Al‑Sc alloys. Some of the other uses of Al‑Sc alloys are high‑performance, lightweight mobility devices – such as wheelchairs, walkers, scooters, crutches, canes, and prosthetic and orthotic device – that can enable people with physical disabilities participate in sports and other physical activities are also made from Al‑Sc alloys.

An unintended consequence of these traits is that it could reduce basic aluminium consumption.

Table 1: Properties and the benefits of Al‑Sc alloys

Property	Benefit
Increased strength to weight ratio	Overall weight may reduce by 10‑15%.
Increased fuel efficiency	Reduction in fuel consumption and consequently emissions.
Enhanced weldability and durability	Typically, high‑strength aluminium alloys suffer from poor weldability, limiting its use. Components made from Al‑Sc alloys can be welded without losing strength at the weld joints, maintaining durability and longevity in structural applications.
Improved high‑temperature performance	Al‑Sc alloys remain stronger and more stable at higher temperatures than conventional aluminium alloys, making it ideal for use in aerospace and automotive components, where materials are subjected to extreme heat. This makes them especially useful in engines, exhaust systems, and other high‑heat applications.
Increased corrosion resistance	Al‑Sc alloys offer excellent resistance to corrosion, including pitting and stress corrosion cracking, particularly in harsh environments such as marine with exposure to salt water.
Enhanced formability	Can be easily shaped into complex structures without compromising mechanical properties. There is improved toughness and enhanced fatigue resistance.

Solid Oxide Fuel Cells (SOFCs)

SOFCs are high efficiency stationary fuels cells with 80‑85% (even 90%) efficiency with a modular capacity up to 250‑kW. They can operate with natural gas or biogas; however the quality requirements for inputs are stringent. SOFCs operate at high temperatures up to 900°C.

When Scandia‑Stabilized‑Zirconia (SSZ) is used as the solid electrolyte layer of the SOFC, it allows longer life and higher power density compared to the traditional electrode of yttria‑stabilized zirconia (YSZ). Other advantages of SSZ use are:

• Improved ionic conductivity: Adding scandium oxide (Sc₂O₃) helps boost conductivity, improving the fuel cell's performance.
• Increased durability: Sc₂O₃ helps stabilize parts of the fuel cell, making them more resistant to heat and mechanical stress.
• Lower operating temperature: Scandium provides the highest known rate of transport of oxygen, and this permits the SOFC to operate at temperatures around 700°C, much lower than the roughly 1000°C of conventional yttrium‑doped SOFCs. This lower operating temperature makes the system much more mechanically robust with less wear on the materials, a longer lifespan, and reduced cost of insulation and cooling.

The future of Sc₂O₃ in SOFCs is promising. As the need for clean energy grows, so will the demand for efficient and reliable fuel cells. Ongoing research aims to enhance Sc₂O₃'s properties, making it even more effective in fuel cells. Advances in production methods may also help reduce costs, making Sc₂O₃ more accessible.

Bloom Energy (USA) has commercialised use of Sc₂O₃ in SOFCs and appears to be the biggest scandium consumer globally.

Table 2: Applications of Sc₂O₃ in SOFCs

Application	Benefits
Stationary power generation	Sc₂O₃‑enhanced SOFCs are perfect for stationary power generation, such as power plants, backup systems, and distributed energy. Their high efficiency and durability make them a reliable source of clean energy, especially in remote areas or where a steady power supply is critical.
Transportation	Sc₂O₃‑enhanced SOFCs can power vehicles where long‑range and low emissions are essential (e.g., trucks, ships, and even planes). Their ability to use different fuels makes them flexible for various transport needs.
Combined heat and power (CHP) systems	SOFCs generate electricity and use leftover heat for heating, boosting overall efficiency to about 85%. Sc₂O₃ improves the performance and durability of these systems, making them more attractive for homes, businesses, and factories.

Other applications

Scandium‑based lasers have unique properties:

• Erbium‑chromium: yttrium‑scandium‑gallium‑garnet (Er, Cr: YSGG) lasers are used in dentistry. Gadolinium‑scandium‑gallium garnet (GSGG) lasers have been extensively studied in strategic defence applications (laser defence systems).

Regional trends

China

China is the world's largest producer of scandium, but exact statistics are difficult to get as under HS classification rare earth metals and scandium are clubbed together and scandium may be a very small percentage of the total.

The vast majority of Sc₂O₃ produced in China comes from the waste acid discharged during the production of TiO₂ by the sulphuric acid process. For every tonne of TiO₂ produced, about 8‑10 tonnes of waste acid containing 10‑25 mg/l Sc₂O₃ is released during the hydrolysis process.

With the wide application of TiO₂ increasing amount of waste acid containing scandium will be discharged during the production of TiO₂. Therefore, TiO₂ waste acid is a significant raw material for recovering Sc₂O₃.

China has TiO₂ capacity of 7‑mtpa, of which about 12‑13% is via the chloride route, and the rest by the sulphate route.

China is known to have a dozen Sc₂O₃ producers, and most of the production is from acid wastes of TiO₂ industry.

Bayan Obo is the world's largest known REE deposit. The fluorspar content of the ores also makes it the world's largest fluorspar deposit. Reserves are estimated at more than 40‑mt of REE minerals grading at 3‑5.4% REE (70% of world's known REE reserves); 1 million tons of neodymium oxide (Nd₂O₃) and 470‑mt of iron. The quantity of REE deposits mined is not clear, but there are two large mines. Various ores in the Bayan Obo deposit have Sc₂O₃ contents between 40‑169 ppm. In the REE ore tailing, the Sc₂O₃ content reaches 250‑ppm, therefore it is expected it should be a major producer.

Hunan Oriental Scandium extracts scandium from waste acid of TiO₂ plants. The company's products include Sc₂O₃ and scandium metal. It has a Sc₂O₃ production line with a capacity of more than 10‑tpa. The oxide is used in the preparation of Al‑Sc master alloy and the development and production of Al‑Sc alloys for civilian use. It has a few subsidiaries with annual capacity about 20‑tpa of oxides.

Taojiang Ruilong Metals New Materials is a joint venture of Hunan Metal Material Institute and Bloom Energy of USA (the largest producer of SOFCs). Capacity of Sc₂O₃ is 5‑tpa and of Al‑Sc alloys 50‑tpa.

Guangxi Maoxin Technology Co. produces Sc₂O₃ from TiO₂ waste acid. It processes 450‑ktpa of waste acid with an annual capacity of 3‑tpa of high purity Sc₂O₃.

Jiaozuo Rongjia Scandium Industry is connected with Hunan Oriental Scandium Co., and produces about 30‑tpa of Sc₂O₃.

MCC Ramu New Energy Technology Co. is a producer of nickel and cobalt. Scandium is recovered from the solid waste of the process. These ores contain about 300‑ppm of scandium. The capacity is 20‑tpa of Sc₂O₃.

Hunan Kunwell Advanced Material Co. Ltd. has a capacity of 2‑tpa of crude oxides.

The total Chinese capacity of Sc₂O₃ may of the order of 90‑100 tpa, excluding production from Bayan Obo tailings as scandium recovery is part of REE plants for which details are not available.

In October 2024, China commenced construction of a Scandium‑Vanadium New Materials Industrial Park, with a total investment of CNY 1.08‑bn, in three phases.

The first phase targets production of 2,500‑tpa of vanadium pentoxide, 60,000 cubic meters of vanadium electrolyte (needed for flow batteries for bulk electricity storage), and 50‑tpa of scandium fluoride by 2027. The second phase will expand production by: 50‑tpa of scandium fluoride, 1,200‑tpa of aluminium‑based intermediate alloys; and 40,000 cubic meters of vanadium electrolyte annually.

The third phase will include the production of 20,000‑tpa of new high‑performance aluminium alloy billets containing scandium and 20,000‑tpa of aluminium alloy profiles.

Table 3: Sc₂O₃ producers in China

Company	Scandium source
Bayan Obo Deposit (REE plant and recovery of Sc₂O₃)	REE
Hunan Oriental Scandium Co. Ltd. (TiO₂ route)	TiO₂ waste acid
Taojiang Ruilong Metals New Materials Ltd.	TiO₂ waste acid
Guangxi Maoxin Technology Co., Ltd.	TiO₂ waste acid
Jiaozuo Rongjia Scandium Industry Science & Technology Co., Ltd.	TiO₂ waste acid
MCC Ramu New Energy Technology Co., Ltd.	Nickel recovery
Huizhou Top Metal Material Co., Ltd.	TiO₂ waste acid
Hunan Jinkun New Material Co., Ltd.	REE
Ganzhou Wanfeng Advanced Material Technology Co., Ltd.	REE
Hunan Kunwell Advanced Material Co. Ltd.	TiO₂ waste acid
Henan Rongjia Scandium Vanadium Technology Co., Ltd.	TiO₂ waste acid
Hunan Oriental Scandium New Material Co., Ltd.	TiO₂ waste acid

Russia

Scandium production in the former Soviet Union began in the Cold War, specifically at the Nova Mine, near the town of Zhovti Vody, in Ukraine. The Nova mine was a deep (1,000 meters) underground polymetallic resource, primarily iron ore, but also containing scandium, uranium and other radioactive minerals. The scandium resource was estimated to be 7.9‑mt grading 105 ppm scandium, and the mine was believed to be the only primary scandium mine in operation in the world. The Sc₂O₃ from this source was used to make lightweight, high performance Al‑Mg‑Li‑Sc materials for MIG fighter jets. During this time, the knowhow on scandium was tightly held as a proprietary military secret.

Today, except for Rusal, an aluminium producer, in Russia the recovery of scandium is from uranium residues. The Dalmatovskoye uranium deposit is probably the only operating scandium recovery plant. But there are three other deposits – Tomtor, Koydor and Kurmi – that are being actively pursued.

The Tomtor Sc‑REE‑Ta‑Nb deposit is estimated to have 1.18‑mt of ore resources, with Sc₂O₃ content of 0.048 wt.%; The Kumir Sc‑U‑REE deposit with Sc₂O₃ content of up to 0.1 wt.% has possible Sc resources exceeding 100 tonnes; The Kovdor deposit, considered a large source of Sc in Russia, is estimated at 420 tonnes at 0.078 wt.% of Sc₂O₃, which would secure annual Sc₂O₃ production of up to 8‑tpa.

Rusal has announced a pilot facility for the production of 1,550 kg of Sc₂O₃ per year, at its Bogoslovsky Aluminium Smelter. The facility is scheduled to be commissioned by the end of 2025. The investment in the project is approximately 500‑mn roubles. Production will be eventually scaled up to 19‑tpa of Sc₂O₃.

Table 4: Russian exports of scandium & certain scandium compounds to US

Year	Scandium metal			Scandium compounds
	Qty. (kg)	Value (US$)	Exports to US, share	Qty. (kg)	Value (US$)
2017	14	199,820	100%	5	14,420
2018	54	757,800	100%	3	17,131
2019	60	819,000	97%	5	32,725
2020	130	1,746,780	100%	2	52,840
2021	420	5,557,980	95%	7	179,870

Source: Official export statistics from Russia under Russian export classification numbers 2805.30.4000 and 2846.90.3000

Australia

About 19 Australian companies have announced plan for scandium production based on nickel‑bearing ores, but production is at least 5‑10 years away.

This is illustrated by the Nyngan scandium project owned by Scandium International Mining Corp in New South Wales, which could be the first project to on stream. The separation and refining plant flow sheet was validated by considerable bench scale/small pilot scale tests. The process uses high pressure acid leach (HPAL) and solvent extraction (SX) techniques. It will produce 37‑tpa of oxides. The project is awaiting agreements for offtake.

There are two other projects at preliminary stage by this company. Similarly there are many others where only the reserves of ores have been confirmed.

Rio Tinto has reached a binding deal to buy the Platina Scandium Project, a high‑grade scandium resource in New South Wales, Australia, from Platina Resources Ltd., for US$14‑mn. The project has a long life, high‑grade scalable resource that could yield up to 40‑tpa of Sc₂O₃ for an estimated period of three decades. At present, Rio Tinto generates Sc₂O₃ from TiO₂ processing waste streams at Sorel‑Tracy in Quebec, Canada, with a nameplate capacity of 3‑tpa.

Europe

Europe has two sources of Scandium – from TiO₂ waste acids and from alumina red mud. EU has funded two projects totalling ~€ 9‑mn, which have reached a stage where within 3‑4 years the flowsheet can be commercialized. The two consortium‑based projects, named Scavenger and Scaleup, are based on TiO₂ and red mud respectively. The goal of the EU is to reach strategic independence with competitive prices.

European TiO₂ pigment plants have a total capacity of about 1.50‑mtpa. Of this, approximately 0.5‑mtpa is produced via the chloride process. Scavenger will use iron chloride rich solutions from TiO₂ production mainly from high grade TiO₂ feedstock as the scandium content of waste acid would be 60‑140 mg/l. The first Scavenger plant will be operated at Tronox, a TiO₂ producer. It can be adapted to other chlorine TiO₂ production sites later on. This plant will be able to supply about 21‑tpa of Sc₂O₃ which represents about two‑third of the expected EU consumption in 2028.

Table 5: Red mud generation in Indian bauxite refineries (mtpa)

Company	Location	Red mud generation
Nalco	Damanjodi, Odisha	3.10
Hindalco	Utkal, Odisha	2.05
Hindalco	Belgavi, Karnataka	0.44
Hindalco	Muri, Jharkhand	0.61
Hindalco	Renukoot, Uttar Pradesh	0.97
Vedanta	Langigarh, Odisha	2.00
Total		9.17

Scale‑Up is developing a process for Sc‑products from red mud. The first plant will come up in Greece within the Mytilineos alumina plant, processing 850‑ktpa of residue, to produce 67‑tpa of crude Sc concentrate. The concentrate will be refined at Scavanger into 22‑tpa of pure Sc₂O₃ which will then be returned to Mytilineos' Al smelter for production of 733‑tpa of Al‑Sc 2% master alloy.

Other alumina producers in EU are AOS Stade (Germany), LARCO (Greece), ALUM (Romania) and MAL (Hungary).

The EU scandium market is forecast to increase from 25‑tonnes Sc₂O₃ in 2020 to 350‑tonnes in 2026 and 1,100‑tonnes in 2031. Today, the EU imports 100% of its requirement, mainly from China (~67% share of total imports).

India

India has possible two sources of scandium: waste acid from TiO₂ production; and red mud from alumina production.

As per the Jawaharlal Nehru Aluminium Research Development and Design Centre (JNARDDC), India produces about 9.17‑mt of red mud. The REE content ranges (in ppm) between: Sc 30‑65, La 20‑65, Ce 45‑105, Pr 4.9‑6.6, Nd 15‑30, Y 4‑10, and Gd 4‑8 ppm.

Assuming average of 45 ppm of Sc and extraction efficiency of 75% the maximum potential as Sc₂O₃ is 474‑tpa. Probably half, i.e., 237‑tpa may be reachable, which as 2% master alloy, is 11,850‑tpa. There is an added advantage that it would be possible to recover vanadium and neodymium, as well.

There is an inter‑institutional R&D project with aluminium industry participation at CSIR‑Institute of Minerals and Materials Technology (IMMT) (Bhubaneswar), which is at pilot plant stage. In contrast, the EU Scale‑Up project, which is very similar, has reached a stage where a commercial lot may be delivered by 2027.

The author believes that enough R&D has been done and a semi‑commercial scale plant to produce 1‑tpa of Sc₂O₃ should be a priority in India.

In March 2025, MTM Critical Metals signed a non‑binding MoU with Vedanta Ltd., a global giant in aluminium production, to explore use of their proprietary, patented Flash Joule Heating (FJH) Technology to recycle Vedanta's red mud and recover valuable metals, including iron, alumina, titanium, gallium, scandium, rare earths that are locked up by the iron.

As already mentioned EU has paid attention to the availability of scandium in waste acids of TiO₂ production. India's TiO₂ production capacity is about 83,000‑tpa. Some new projects are also underway. KMML is the only producer using the chloride route (all others use the sulphate route). Assuming that 8‑10 tonnes of acid is generated per tonne of TiO₂ by sulphate route, containing 10‑25 mg/litre Sc₂O₃ the potential is 580‑600 kg/year. With KMML's capacity at 40,000‑tpa and the waste acid containing 60‑140 mg/litre of oxides, the Sc₂O₃ potential is about 1,200 kg/yr. The technology to recover Sc from acid wastes is based on solvent extraction and ion exchange.

Others

Ukraine has U‑Fe deposits in its Nova mines. The scandium resource was estimated to be 7.9‑mt, grading 105 ppm scandium. Scandium recovery dates since Soviet era and the mines closed in 2002 for various reasons. Apparently many tons of oxides were produced over a period of time under Russian control.

In Kazakhstan most information was classified, and declassification has been done partially. Scandium is produced from uranium tailings, and a pilot project was started in 2013‑14 and was slated to produce 5‑tpa of oxides.

Sumitomo Philippines produces Sc₂O₃ from nickel‑cobalt operations. Production capacity is ~7.5‑tpa and is mostly exported to USA.

Rio Tinto Canada has started trial production capacity of 3‑tpa of Sc₂O₃ to be ramped up gradually. Scandium Canada Ltd. is another mine development project in Crater Lake area in Quebec.

In USA, Niocorp Developments Ltd.'s Elk Creek project is awaiting further funding. The estimated potential is 11,337‑tonnes of Sc₂O₃ besides other rare earths over a 30‑year period.

PT Vale Indonesia, a large nickel producer, has indicated plans to recover scandium.

Pricing

Scandium is an expensive material. The price is mostly quoted on basis of the oxide and its purity. Scandium metal as such has very small uses. Recent prices (per kg) in China (as of April/May 2025) are as follows:

• Sc₂O₃ 99.99% – $568
• Sc₂O₃ 99.99% – $5746 (likely a typo; keeping as given)
• Scandium metal 99.99% – $313,879
• Scandium metal 99.999% – $522,223
• Scandium alum alloy 2% – $30.70

At these prices it appears viable to produce Sc₂O₃ from TiO₂ waste acid (as in China); from Nickel production sources (as in Philippines) and alumina red mud (as planned by EU). A project in Australia based on nickel ores indicates an estimated cost of $557/kg Sc₂O₃.

Demand‑supply trends

Current capacity for Sc₂O₃ is about 122‑tpa, but in the next five years, the expected additional capacity is 356‑tpa. Thus it may be expected that worldwide total could rise to between 480‑tpa to 520‑tpa – a very big leap and that will shake up the world of aluminium metal products. The prediction of future production however is fraught with many caveats.

Table 6: Production capacity of Sc₂O₃ [tpa]

Region	Current capacity	Expected addition
China	100	100
Philippines	7.5	—
Russia	1.5	19
Canada	3	—
Kazakhstan	5	—
Others	5	—
Europe	—	43
Australia	—	77
USA	—	100
Indonesia	—	17
Total	122	356

The EU Sc market is forecast to increase from 25‑tpa Sc₂O₃ in 2020 to 350‑tpa in 2026 and 1,100‑tpa in 2031. This equals to 55,000‑tonnes of 2% Sc‑Al master alloy. But the feasibility of such volumes needs to be verified.

Bloom Energy, the largest producer of SOFCs, has a stated capacity of 1 GW per year or 10,000 modules of 100‑kW each. A 2020 report indicated that each module may have 13‑15 kg of Sc₂O₃. Thus the demand for oxide would be around 130‑150 tpa by Bloom Energy alone. But this does not reconcile with numbers put out by the USGS (10‑15 tonnes production).

Reconciliation of demand‑supply is rendered difficult given the fragmented nature of information from diverse sources; information not uniformly dated; and the fact that import‑export statistics are of no help (as Sc is combined with other REE). Sc₂O₃ may be produced, say, in Philippines, refined another country and the product produced in third country and shipped to the final user in fourth.

CONCLUSION

Scandium appears to be a rare earth that is available from many sources worldwide. Although the concentration are low in the resources, it is still viable to extract it.

Major resources like TiO₂ waste acids and red mud from alumina production are available in many countries, including Europe, USA, India, Russia, China, etc. Technology for recovery from TiO₂ waste acid is well established in China. Technology developments from red mud are at take‑off stage in Europe. The extraction of ores and tailings is at level which requires large investments at the stage of mining and production. The conversion of oxide to Al‑Sc master alloy is commercial in China. Other countries need surge in R&D efforts.

For further reading: Rare earths: Applications and market scenario, Chemical Weekly, October 19, 2021.