Phosphate ore processing for phosphoric acid production: classical and novel technology

Abstract

Phosphoric acid (H₃PO₄, PA) is an industrial acid, produced from two main types of phosphate rock: sedimentary and igneous. In the classical wet process, wet process PA is produced by a reaction between the ore and sulphuric acid, forming 30% solids thick slurry, in three stages: acidulation, filtration and concentration to produce a 50%P₂O₅ acid. In a novel process, the phosphate ore is treated with HCl with the formation of PA and CaCl₂; the PA is separated by a solvent extraction technology, obtaining a highly concentrated, food grade PA and recovering the organic solvent. The PA industry has a high level of corrosion risk; therefore, special corrosion resistant materials (metallic and plastic) are applied according to the chemical, mechanical and thermal conditions of the process. Cases of PA production of different qualities and concentrations, by diverse methods in Mexico and Israel, are presented.

Keywords

PHOSPHATE ROCK PHOSPHORIC ACID WET PROCESS SOLVENT EXTRACTION CORROSION

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