Phosphate, like water, is essential for plant, animal and human life. It is found in virtually all natural food products and many processed products make use of this versatile mineral.
Plants absorb soluble phosphate from the soil in which they grow, and this phosphate is then ingested by animals and humans that consume these plants. Without the replenishment of phosphate in the soil, all soluble phosphate would quickly be depleted as a result of this cycle. This replenishment, particularly in the agriculture environment, is most often achieved by means of the addition of phosphate fertilizers.
Phosphoric acid production
The starting point for the production of these phosphate fertilizers is phosphoric acid, which is produced at Foskor’s Richards Bay plant by the reaction of concentrated sulphuric acid with phosphate bearing rock. The phosphoric acid is then concentrated by vacuum evaporation and sold locally and internationally to fertilizer producers. The phosphate bearing rock is railed some 800 km from Foskor’s mine in Phalaborwa.
Sulphuric acid is also produced on-site at Richards Bay by combusting elemental sulphur (imported from Canada and Brazil) with oxygen, to produce sulphur dioxide gas.
Fertilizer production
Foskor Richards Bay also produces its own fertilizer for local and international distribution. The process begins with the neutralisation of phosphoric acid with ammonia gas. The resulting sludge is transformed into small spheres in a drum granulator, after which it is screened, dried and bagged, and distributed to our wholesale customers.