DH Process

Prayon Dh Process

The Prayon Dihydrate (DH) Process

The Prayon Dihydrate (DH) Process is widely used by producers due to its reliability, simplicity of operation and the use of proven equipment (Profile).

It consists in the attack of the phosphate rock under dihydrate conditions cooled by a specific flash cooler designed to limit the scaling. The square compartment reactor fitted with Prayon agitators provides the best available conditions on the market in terms of lifetime, maintenance and reaction efficiency.

Dihydrate slurry is filtered on a Prayon tilting pan filter to recover the phosphoric acid. Depending on the rock processed, the ex-filter acid strength is typically 25-29% P2O5 and the typical P2O5 recovery efficiency is 94-95%.


  • low investment and maintenance costs
  • flexibility to process all types of phosphates (sedimentary and igneous)
  • possibility of feeding phosphate slurry (from wet grinding or pipeline supply)
  • easily-controlled water balance (recycling of pond water, reduction and/or elimination of liquid effluent)
  • easy to operate after training


  • when low- to medium-cost rock is accessible
  • where low-cost energy is available (steam and electricity)
  • where gypsum disposal is possible

Interested ? Please contact

Hadrien Leruth

Hadrien Leruth
Business Development Engineer