Triple superphosphate is a component of fertilizer that primarily consists of

monocalcium phosphate Monocalcium phosphate is an inorganic compound with the chemical formula Ca(H2PO4)2 ("AMCP" or "CMP-A" for anhydrous monocalcium phosphate). It is commonly found as the monohydrate ("MCP" or "MCP-M"), Ca(H2PO4)2·H2O. Both salts are colourless so ...

, Ca(H₂PO₄)₂. Triple superphosphate is obtained by treating

phosphate rock Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pento ...

with phosphoric acid. Traditional routes for extraction of phosphate rock uses sulfuric acid gives single superphosphate, an approximate 1:1 mixture of Ca(H₂PO₄)₂ and CaSO₄ phosphogypsum). Double superphosphate refers to some average of triple- and single superphosphate, resulting from the extraction of phosphate rock with a mixture of phosphoric and sulfuric acids. Many fertilizers are derived from triple superphosphate, e.g. by blending with

ammonium sulfate Ammonium sulfate (American English and international scientific usage; ammonium sulphate in British English); (NH4)2SO4, is an inorganic salt with a number of commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen a ...

and

potassium chloride Potassium chloride (KCl, or potassium salt) is a metal halide salt composed of potassium and chlorine. It is odorless and has a white or colorless vitreous crystal appearance. The solid dissolves readily in water, and its solutions have a sa ...

. Typical fertilizer-grade triple superphosphate contains 45% P₂O₅eq, single superphosphate 20% P₂O₅eq.

References

Food additives Phosphates Calcium compounds Inorganic fertilizers {{chem-stub