Origins of the Word "Cobalt"
The word ‘cobalt’ is generally accepted as having been derived from Greek via medieval German. The earliest recorded use of the archaic form “kobelt” appeared in Agricola’s Bermannus in 1530. Mellor’s Inorganic Chemistry in 1935 quoted Ducange (1842) as saying that, in the Chronicles of Leoben in 1335, kobelt was applied to legendary gnomes living in the mines in the Schneeberg Mountains of Germany. However, cobalt colouring of ceramics has been known for 2600 years with evidence in Persia and Egypt, though we are not aware of what it could have been referred to at that time.
Cobalt occurred in the Schneeberg Mountains with silver and nickel and it was the silver that was of principal interest at that time. When problems in separation and smelting arose, they were blamed on the “Kobolds” – later it was found to be the cobalt in the ore that complicated the refining process – hence the name transference.
History of Cobalt Uses
Colourings from oxides and silicates were the main use of cobalt up to the 20th Century; even in 1916, total cobalt output was only 554 tonnes of which 400 tonnes were produced as oxides for colourings.
Cobalt has been used to colour pottery and glass for at least 2600 years evidenced by cobalt-containing glazes having been found in Ancient Egyptian tombs. Chinese pottery from Tang (600-900 AD) and Ming dynasties (1350-1650 AD) also contained blue colours made from cobalt-containing minerals. The metal itself seems to have only been isolated in 1735 by G. Brandt, a Swedish scientist, and its metallic uses stem from Elwood Haynes’ studies and patents in the early 1900s. The Co-Cr alloys, and superalloys in general, which caused the great leap in cobalt use, are of course still in use as are the Alnico series of magnets invented in the 1930s.
Cobalt has increasingly been used in specialist applications where it is difficult to substitute with alternative materials. In some applications cobalt is essential, such as in medical diagnostics, pharmaceuticals and fermentation processes (e.g. bio-mass). Demand has moved towards chemical applications as a result of the large increase in demand for rechargeable batteries. Such is the importance of cobalt to industrial and technological development, that in 2011 it was recognised as ‘critical’ in the EU and strategically important in the USA.
History of Cobalt Sources
Cobalt sources have changed over its history, from Norway, Sweden, Hungary and Germany (Saxony) to a dependence on the African Copper Belt from the 1970s. In more recent times, sources have diversified further with increasing amounts coming from nickel ores and recycling of scrap and cobalt-containing intermediates. The Democratic Republic of the Congo (DRC) holds over 50% of global reserves and is responsible for around 50% of global cobalt production.