Vanadium is a hard, silvery grey, ductile and malleable speciality metal with a resistance to corrosion, good structural strength and stability against alkalis, acids and salt water. The elemental metal is rarely found in nature.
The main use of vanadium is in the steel industry where it is primarily used in metal alloys such as rebar and structural steel, high speed tools, titanium alloys and aircraft. The addition of a small amount of vanadium can increase steel strength by up to 100% and reduces weight by up to 30%. Vanadium high-carbon steel alloys contain in the order of 0.15 to 0.25% vanadium while high-speed tool steels, used in surgical instruments and speciality tools, contain in the range of 1 to 5% vanadium content. Global increased intensity of use of vanadium in steel in developing countries will drive near term growth in vanadium demand.
The vanadium market is undergoing a structural change driven by China’s enhanced focus on environmental management and enforcement of the new environmental regulations, which is impacting on both vanadium supply and demand, combined with increasing vanadium consumption in the Chinese steel industry as higher vanadium utilisation in rebar is implemented. The supply – demand balance is further exacerbated by the reduction in supply from key sources outside of China, including South Africa.
The very strong focus on enhanced environmental regulations in China is having a dual impact on the vanadium market, with supply being restricted via quotas on production, the ban of import of vanadium slag feedstock plus the closure of highly polluting vanadium operations and demand being boosted due to a clear focus on the deployment of substantial renewable energy sources with the associated requirement for stationary storage solution, of which vanadium redox flow batteries (VRB’s) form a key component. The clear message from Chinese authorities is that the environmental regulations will be enforced, even if that impacts on supply of key commodities, regardless of the demand.
In addition, China recently revised steel product standards in an effort to combat recurring risk from structural damage caused by a series of earthquakes in 2008. China indicated a desire to improve the strength of reinforced steel bar or “rebar” in particular as rebar is a common framework within concrete structures. China aims to remove low strength (335MPa) rebar from production and replace it with higher strength rebar (600MPa). This has a direct impact on the amount of vanadium used in the steel making process and is another source of increasing demand for vanadium.
An emerging and likely very significant use for vanadium is the emerging energy storage (battery) sector with the expanding use and increasing penetration of the vanadium redox batteries (VRB’s). VRB’s are a rechargeable flow battery that uses vanadium in different oxidation states to store energy, using the unique ability of vanadium to exist in solution in four different oxidation states. VRB’s provide an efficient storage and re-supply solution for renewable energy – being able to time-shift large amounts of previously generated energy for later use – ideally suited to micro-grid to large scale energy storage solutions (grid stabilisation). Some of the unique advantages of VRB’s are:
Some of the unique advantages of VRB’s are:
- a lifespan of 20 years with very high cycle life (up to 20,000 cycles) and no capacity loss,
- rapid recharge and discharge,
- easily scalable into large MW applications,
- excellent long term charge retention,
- improved safety (non-flammable) compared to Li-ion batteries, and
- can discharge to 100% with no damage.