Phosphate rock is formed in oceans in the form of calcium phosphate, called phosphorite. It is deposited in extensive layers that cover thousands of square miles. Originally, the element phosphorus is dissolved from rocks.
Some of this phosphorus goes into the soil where plants absorb it; some is carried by streams to the oceans.
In the oceans the phosphorus is precipitated by organisms and sometimes by chemical reaction. Phosphorus-rich sediments alternate with other sediments . Phosphorus-rich beds usually have very few fossils; however, deposits in Florida and North Carolina contain a large amount of marine fossils.
Uses :
Some phosphate rock is processed to recover elemental phosphorus. Pure phosphorus is used to make chemicals for use in industry.The most important use of phosphate rock, though, is in the production of phosphate fertilizers for agriculture. Some is used to make calcium phosphate nutritional supplements for animals.
P2 O5 (water and citrate soluble): 18% Min. (on dry basis).
Moisture: 4% Max.
Free Acidity as P2 O5: 4% Max.
Analysis: According to A.O.A.C method of analysis
Color: Grayish
Granulometry: 1-4.75 mm 95% Min.
Hardness: 3kg/granule Min.
