Cobalt is a hard, shiny and greyish metal, appearing in the Periodic Table between iron and nickel. Today, cobalt has many strategic and irreplaceable industrial uses as a result of its unique properties.
In conjunction with other metals cobalt is often used as an alloying agent in a diverse range of metallurgical uses. The element also has a wide range of chemical uses where the exceptional properties of cobalt compounds help to promote specific chemical reactions.
To learn more about cobalt, its uses, sources and the supply / demand dynamics of the cobalt market we refer to our annual Market Review.
The oldest uses for cobalt are chemical. Cobalt colouring of ceramics has been known for well over 2,000 years and the use of cobalt in pigments is still an important use today. While cobalt is currently used in numerous industrial chemical processes, close to half of the world’s cobalt supplied today is used in lithium-ion batteries. This puts cobalt at the heart of the drive for alternative and renewable energy systems.
- Cobalt is a critical component in the cathode of rechargeable lithium-ion batteries.
- Today, over half of the worlds’ cobalt supply is consumed in rechargeable batteries which are used in portable electronics, energy storage systems, electric vehicles and numerous other applications.
- Vehicle electrification is recognised as being the biggest growth area for cobalt use in the years to come.
- Cobalt has major catalytic uses in both the petrochemical and plastic industries. It is used to remove sulphur during the refining of oil and gas, produce resins for plastic bottles (PET) and polyester, and to convert natural gas into liquid fuels.
- Catalysts represent the third largest cobalt consuming market, after the battery chemical and superalloy markets.
- The ability of cobalt to impart colour has been of importance for thousands of years. This property is still being used today in porcelain, ceramics, paints, inks and enamelware.
- Pigments are often prepared by mixing ingredients as cobalt oxides or sulphates and then calcining them.
- Cobalt is also added to colour glass or as a decolouriser, suppressing the yellow tint glass would otherwise have due to iron contamination.
- Cobalt salts of the higher carboxylic acids (cobalt soaps) are used to accelerate the drying of oil-based paints, inks and varnishes.
- Cobalt compounds are also used to promote the adhesion between rubber and the brass plated steel cable used in radial tyres.
Cobalt’s high temperature resistance, hardness and wear characteristics make it a critical ingredient in alloy systems that need to endure severe mechanical and temperature stress. Cobalt containing alloys have higher melting points, superior hot corrosion, thermal fatigue as well as greater wear resistance.
- Cobalt is added to alloys containing balanced additions of other metallic elements which combined create compositions that have superior creep resistance at high temperatures, excellent surface stability as well as a high corrosion and oxidation resistance.
- It is these characteristics that make cobalt bearing superalloys essential in the hottest parts of gas turbines, both for power generation and aircraft.
- Superalloys are also widely used in various industrial, medical, automotive and defence related applications.
Hard metals and diamond tools
- Fine cobalt powders act as binding material in cemented carbide and diamond tool applications.
- Tools made from cemented carbides are often used in steel cutting applications, as well as in mining, oil and gas drilling and construction.
- Diamond saw blades are produced by blending fine cobalt powder with diamonds, whereby the cobalt bond holds the diamonds tight and erodes at a rate compatible with the diamond loss. These are mainly used for the cutting of concrete, bricks and natural stone.
Special Steels and Alloys
- Special cobalt alloys (stellites) are used to coat other metals to provide them high temperature properties and erosion resistance. These alloys are often deposited by welding or plasma/flame spraying; but can be cast and used as complete parts or as inserts.
- Cobalt is added to certain high speed steels, commonly used in high end drilling and cutting, to improve strength and temperature resistance.
- Due to its biocompatibility, cobalt is also used in produce prosthetic and dental alloys.
- Due to its ferro-magnetic properties, cobalt is alloyed with nickel and aluminium to produce a permanent magnetic alloy called AlNiCo.
- Cobalt is also combined with the rare-earth Samarium to make SmCo magnets, one of the most advance, high temperature and high strength magnetic material available today.
- SmCo magnets are used in applications where high temperature performance is critical, such as: automotive, aerospace, military and industrial automation.