Spray-Dried Monocalcium Phosphate Monohydrate for Soluble Phosphate Fertilizer

Abstract

Monocalcium phosphate monohydrate (MCPM) was obtained by water extraction of triple superphosphate. The solubility of MCPM is 783.1 g/L, and is entirely soluble. Saturated MCPM solution dissociates into free phosphoric acid and monetite (CaHPO 4 ), but evaporation to dryness by spray drying forms MCPM during crystallization. Complete characterization by infrared, X-ray diffraction, and scanning electron microscopies and NMR is reported for MCPM and the derived pyrophosphates.