Triple superphosphate is a component of

fertilizer A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...

that primarily consists of monocalcium phosphate, 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 Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular fo ...

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 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 salt ...

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

References

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