SBIR Phase I: Closed-Loop Lithium Reduction of Pure Scandium Metal

The broader impact/commercial potential of this Small Business Innovation Research Phase I project is to reduce the cost, and improve commercialization prospects, for new light-weight scandium-containing alloys with extraordinary strength, weldability, fitness for 3-D printing, and new shape memory and other properties. At $3500-4000/kg (6-7 times the price of silver), the price of scandium metal is more than twice the metals-basis price of its oxide, which is about $1800/kg. This has deterred commercial deployment of new alloys beyond small-scale laboratory demonstrations. As new scandium oxide mines and production facilities around the world boost production from just 10-15 tonnes per year (TPY) to several hundred tons per annum in the next 5-10 years, this will reduce the cost of the oxide. The new high-yield technology supported by this award aims to dramatically reduce the cost of converting oxide to metal, bridging the gap to make alloys with scandium more viable for high-performance applications. This in turn will enable new light-weight high-performance alloys to replace steel and titanium, dramatically reducing the weight of aerospace parts while improving strength. The technical objectives in this Phase I research project are to demonstrate feasibility at laboratory scale of key unit operations of a brand new production process for pure scandium metal production from its oxide. Because Scandium oxide is the most stable oxide in the periodic table, reduction to the metal first requires reaction with hydrofluoric acid (HF) at 700C to produce scandium fluoride, then metallothermic reduction using calcium metal at 1600C in a welded refractory metal retort (usually tantalum). Calcium metal is a contaminant which must be removed by distillation. These operations result in a price of scandium metal at $3500-4000/kg, which is more than twice the metals-basis cost of its oxide ($1200/kg Scandium oxide leads to $1840/kg Sc). The new process funded by this award will avoid any use of HF, making it safer and less costly. It will retain very close to 100% of the scandium and other reagents in a tight closed-loop system, reducing emissions and costs. If successful with scandium, this method will readily apply to heavy rare earth and metals such as gadolinium, dysprosium and yttrium.