Superphosphate is the product of the reaction:
Ca3(PO4)2+2H2SO4→Ca(H2PO4)2+2CaSO4
In the following reaction, we use phosphoric acid instead of sulphuric acid. The phosphatic rock used is called Fluorapatite - Ca5(PO4)3F. Although the product also contains some HF, it is removed as H2SiF6 when HF reacts with Silica impurities.
Ca5(PO4)3F+7H3PO4→5Ca(H2PO4)2+HF
The product of the above reaction is called triple - superphosphate. It contains more Phosphorus content than superphosphate and is more widely used.