Challenge : substantially hard sector for the fans because of the corrosion and abrasion met almost always.
Solution : large fans with special material as Duplex, Uranus B6 or hard rubber lining for all parts in contact with the air.
References : phosphate production or other fertilizers, the main actors are multiple. Ecophos, OCP Morocco, Timac, Potasco, DCM, Cargill, … references on demand.