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Phosphoric Acid

Phosphoric Acid Plants Technology

Desmet Ballestra offers plants based on the Prayon Mark 4 di-hydrate process© (DPP)
Ballestra know-how includes DPP based plants with procuction capacity ranging from 150TPD to 700TPD.

Product characteristics
DPP process allows the production of 54% concentration Phosphoric Acid. This acid is mainly used as feedstock component in the fertilizers production plants.

By-products
The DPP based plants allow the recovery of fluosilicic acid as process by-product. The fluosilicic acid recovered has concentration up to 18%. The acid can be stored and sold to the market as valuable product or shall be neutralized for disposal.

Air pollution control, by means of a dedicated scrubber, to contain the plant emissions to the minimum level required by the most stringent laws and standards.

High quality construction materials and well proven know how in material selection to grant acid resistance.

High efficiency in conversion of phosphate included in the phosphate rocks and phosphate losses controls, granted by the best available technology together with Prayon process design, allowing for unlikely plant packing risk and an extended plant availability.

Tailor made configuration. DBI Phosphoric Acid plants are highly customizable to process several types of phosphate rocks and maximize the plant efficiency.

Phosphoric Acid Plants Technology

Desmet Ballestra offers plants based on the Prayon Mark 4 di-hydrate process© (DPP)

This process has been widely applied in most of the phosphoric acid projects becoming the leading process in the market due to its advantages:

  • Well proven process
  • Ability to efficiently convert different types of phosphate rock (sedimentary and igneous)
  • Lower maintenance cost and higher operating factors
  • Single stage filtration
  • Ease of operation/shut-down, flexibility and easy transport of gypsum
  • Lower grades of construction materials required
  • Easier control of water balance. 


The DPP technology incorporates the most updated Prayon technological solutions:

  • Multi-compartment reactor design, allowing flexibility and easy control of the sulphate in the attack section, reducing P2O5 losses in the calcium sulphate.
  • Sulphate gradient of the slurry in the attack tank, which minimizes the insoluble losses.
  • The level of sulphate gradient from one zone to the other can be adjusted based on process parameters and the origin of phosphate rock.
  • Low Level Flash Cooler (LLFC), which is more accurately controllable than air cooling, especially when the cooling rate must exceed nominal capacity.
  • Prayon Proprietary Agitators, having high efficiency and low power consumption, which is a critical parameter for the economical sustainability of the phosphoric acid production.
  • Prayon Tilting Pan Filter, incorporating the latest development (“fast drain” cells, central valve, the inverting track design), which is the best known filter in the phosphoric acid industry, having the highest washing efficiency.