DA-HF
About
Cutting-edge process to produce phosphoric acid with a high recovery efficiency
The Prayon DA-HF Process is a modern process developed and industrially implemented by Prayon. It is an economic and efficient solution to produce phosphoric acid and valuable gypsum as a co-product.
It consists in the attack of the phosphate rock under dihydrate conditions. Then, the gypsum slurry is converted to hemihydrate by the addition of sulfuric acid and steam in a specific circular reactor designed by Prayon. Hemihydrate slurry is filtered on a Prayon tilting pan filter to recover a good-quality calcium sulfate.
Depending on the rock processed, the ex-filter acid strength is typically 32-34% P2O5 and the typical P2O5 recovery efficiency is 97%.
Advantages
When should we select Prayon DA-HF Process?
Low investment cost
Especially considering the revamping of an existing Dihydrate plant
High P₂O₅ recovery
Low P₂O₅ content in the phosphogypsum
Suitable for cement and building applications
Self-drying phosphogypsum
With a final moisture around 10-12%
Limited grinding of the rock
Low cadmium in the product acid
Recommended
When should Prayon DA-HF Process be applied?
Where medium- to high-cost rock is accessible
Where energy cost is rather high
Steam and electricity
Where gypsum disposal is limited and/or where a potential market for gypsum has been identified
Cement or building applications
To increase production capacity by minimum 20%
With limited changes in an existing Dihydrate plant
For more information