It was discovered in Sweden in 1735 by Georg Brandt. It is a lustrous, silvery blue, hard metal, which is ferromagnetic. It is obtained from silver ores (arsenides and sulphides) and Ni, Cu and Pb arsenide ores. The ore is roasted and Co is precipitated as the hydroxide and then reduced to Co with carbon.
The structure of this metal alters from hcp below 417°C to ccp until its melting point.
It is stable in air and unaffected by water, but slowly attacked by dilute acids. It absorbs hydrogen strongly. 60Co is a useful radioisotope.
It is an essential requirement in the diet of most species. For humans, cobalt generally has low toxicity by ingestion, but can produce vomiting. Cobalt is a suspected carcinogen.
Relative Atomic Mass
Although Lipmann Walton & Co Ltd usually carries some stock in the form of broken cathodes our main interest in this market is in the form of cobalt bearing scrap, residue, or alloys of alnico & kovar for remelting.
As cobalt over recent years has shown itself to be one of the most volatile markets, the use of scrap has assisted consumers to modify their unit costs. Russia remains an important source of both material and alloy.
Cobalt is also a highly political market and market traders have over the years become a factor in their own right – tussling over much needed supply from difficult parts of the world such as Zambia, the Democratic Republic of Congo & Russia.
Meanwhile cobalt is almost too large and diverse a market to fall into the category of a minor metal.
A shortlist of its uses would include hard metals (where it is used with Tungsten) batteries, chemicals (catalysts adhesives, feedstuff, colours), magnets and super alloys.
Both Kovar and Alnico are Nickel-Cobalt based alloys which arise in scrap form from Russia and are generated by the dismantling of plant and equipment from the paper and computer industry or military. Kovar usually occurs in the form of strip, bar or coil or re-melts, typically containing Ni 29% approx. Co 17%, balance Fe. Our prices to suppliers will be based on a calculation of Nickel & Cobalt values less yield charges based on form and impurities.
Alnico is basically magnet scrap and most commonly arises in Russia in a grade equivalent to Western Alnico 5 containing approximately Co 23-24%, Ni 14.5% approx. Al 8%, Cu 3%, balance Fe. Both Alnico and Kovar are used as good raw material for Ni-Co additions for new magnet shot.