Fertilizers

Fertilizers, Detergents and other phosphate-based products

Phosphoric acid, at various stages of purification, is the main product used for the production of phosphate-based end products:

• Fertilizers: SSP, GSSP, TSP, SCU

Phosphoric acid, at various stages of purification, is the main product used for the production of phosphate-based end products:

• Fertilizers: SSP, GSSP, TSP, SCU

SSP: Simple Super Phosphate comes in the form of powder and is produced by mixing ground phosphate rock and a sulphuric acid solution and then allowing it to react to produce this superphosphate - a mixture of CaSO4 and Ca(H2PO4)2.H2O.
GSSP: The SSP (above mentioned superphosphate) is then granulated to give particles no more than 4 mm in diameter.

TSP: Triple Super Phosphate is:

• either produced by the action of concentrated phosphoric acid containing 45 - 48% available P2O5 on ground phosphate rock to produce the powder form of TSP. The same process of granulation as GSSP can be performed to granulates.
• or produced by the action of concentrated phosphoric acid containing 40 - 42% available P2O5 ground phosphate rock to produce granulated form of TSP

TSP production is performed in two steps :

• Production of phosphoric acid solution by acid attack of the phosphate rocks. The process is a dihydrate route using sulphuric acid solution as acid. The phosphoric acid concentration is 40 to 42% P2O5.
• Production of TSP granules, by mixing of phosphate rock and above mentioned produced phosphoric acid solution, mixture granulation and drying.

SCU: Sulphur-Coated Urea, is a slow release fertilizer. It is produced by coating urea with sulphur, and encapsuling this inside a sealant. The rate of release of nitrogen is regulated by the choice and thickness of sealant.