Wet process phosphoric acid (WPA) is produced by the attack of sulfuric acid on phosphate rock. The composition and purity of WPA depends mainly upon the composition of the rock used.

In spite of the great variety of rocks, different phosphoric acid processes and plant procedures, the problems associated with WPA production are basically similar.

Since rather low grade and low quality rocks are increasingly processed worldwide, there is an upward trend to add mineral modifiers such as clays and silicas (perlite included), to these rocks.

These amend rock behavior and overcome problems in WPA production. They increase gypsum filterability and washing, reduce corrosion and fluorine emission and improve the quality of the concentrated acid product and derived fertilizers.

Aegean Perlite grades are of superior quality amorphous silicates with one of the higher active silica content