enhance pigment colour and increase drying of paints
help rubber adhere to steel bracing in tyres
improve anti-corrosion properties of alloys and augment surface treatment
enhance digital storage and increase digital processing
provide hardmetals for cutting, drilling, and grinding
There are also many other uses and applications of cobalt and its compounds. As a result, cobalt is widely considered the technology enabling metal.
It is difficult to find a sector that doesn’t include cobalt, though it is only used in relatively small quantities in each application.
Indeed, without cobalt we would not have many of the innovative products and processes that we often take for granted. Aircraft are considerably more efficient thanks to the addition of cobalt in superalloys for gas turbines for example. It is a co-constituent of catalysts in the oil sector that help make cleaner fuel by removing large quantities of sulphur and nitrous oxide for a fractional input of catalyst material.
Such is the importance of cobalt to industry, that the EU defines the metal as a Critical Raw Material (CRM). The USA also considers cobalt to be ‘strategically important’.
For industry to remain competitive, improvement and evolution of various products and processes is integral. One way is to investigate how substitute materials would perform in order to seek greater efficiencies, effectiveness and lower cost.
For cobalt, substitution has proved complicated as in many applications it is absolutely essential, such as for medical diagnostics and in the pharmaceutical industry. However, that is not to say industry stops looking to the future. Rechargeable batteries is the largest end-use sector and cobalt is a key constituent of Li-ion systems (NMC and NCA). Despite cobalt containing Li-ion still being the preferred system, other chemical systems are being developed such as LMO and LIP that don’t contain cobalt. For the future, there is work being carried out to investigate Zn-air, Li-sulphur or Li-air systems which could be the next generation of rechargeable batteries.
There is also considerable pressure to make gas turbines more efficient and great strides have been made over the years. The key here is to reduce weight whilst increasing operating temperatures and pressures, so considerable research is undertaken in the area of superalloys. Here we see the emergence of metal matrix composites (MMCs), reinforced carbon-carbon composites, titanium aluminides, nickel-based single crystal alloys, iron-based superalloys and ceramic matrix composites (CMCs). However, the lead time to replace already certified aerospace material is long and cobalt is not currently under pressure in this sector. In other less critical applications such as high speed steel for cutting, some substitution is possible, however performance of these materials is adversely affected without cobalt.
In pigments, paint/varnish driers, adhesives and catalysts there are numerous alternatives to cobalt, however few are able to match the performance and so cobalt remains important in these applications. Cobalt is particularly important in catalysts as some 50-years of research have gone into identifying cobalt as the metal of choice in numerous applications.