Around 92% of all the chromium produced in the world is consumed in steel, to which it brings a high resistance to corrosion, temperature and wear. The steel which uses chromium most extensively is stainless steel – stainless steel consumes more than 80% of the chromium used in steel applications. Stainless steel accounts for only 2% of global steel output, however the average tonne of stainless steel has a chromium content of 18%. Most non-stainless steel does not contain chromium, however certain alloy steels and rebar grades do have a significant chromium content.
Chrome ore contains too many impurities to be added directly into a steelmaking furnace. Prior to being consumed in steelmaking, chrome ore must be smelted in an electric furnace together with a carbon reductant, which eliminates most of the impurities in the ore and produces a product known as ferrochrome. Ferrochrome is an alloy containing 48-75% chromium, 0-8% carbon and 0-6% silicon, with most of the remaining content being iron. For making stainless steel, most of the necessary ferrochrome is added directly into the steelmaking furnace, with only a minority of the required ferrochrome being added in the secondary steelmaking stage following decarburisation. When ferrochrome is used in non-stainless steels, it is mostly added during secondary steelmaking. Chromium is highly recyclable from stainless steel scrap. About 30% of the global consumption of chromium in steel comes from remelted scrap, with the remaining 70% coming from ferrochrome.
The global ferrochrome industry is concentrated in four countries, which together account for more than 90% of world ferrochrome production. These countries are South Africa, China, India and Kazakhstan. Almost all producers of ferrochrome in Kazakhstan and South Africa own their own sources of chrome ore, as do most major producers in India. China is the only major ferrochrome producing country where most of the ferrochrome producers do not own their own source of chrome ore, and therefore have to import it from third parties.
More than half of the chrome ore imported into China now comes from South Africa, providing a growing market opportunity for independent South African chrome ore suppliers, such as Commodity Partners.
An increasing percentage of South African chrome ore supply is in the form of fines, concentrated to reduce impurities such as silica. Developments in furnace technology have significantly increased the ability of ferrochrome smelters in both South Africa and China to use fine chrome ore concentrate, which usually trades at a competitive discount to traditional high-grade lumpy ores.
At its plant in Benoni, South Africa, Clover Alloys produces two grades of metallurgical chrome ore concentrate – one grading 44% Cr2O3 and the other grading 42% Cr2O3. Both grades comfortably meet the normal specifications for South African metallurgical chrome ore concentrate, and are produced by reprocessing used high-grade foundry sand from foundries.
Typical specifications for Clover Alloys' two grades of metallurgical chrome ore concentrate are as follows: