Secondary P-sources
Inescapable process solution to turn your P-residues, sewage sludge, fly ashes, tailings, slimes into a valuable product
Prayon, a main competitor in the phosphate innovation has strong commitment to develop sustainable processes. We are always looking for closing the Cycle of the Phosphorus and are committed to process any source of Phosphorous. This includes beneficiation residue, sewage sludge, fly ash and many other applications.
Prayon has developed specific applications and solutions to recover a wide variety of streams containing Phosphorous. In our production site we are able to collect, purify and reuse those streams. Prayon offers solutions to valorise tailings and slimes from phosphate mines, greatly improving their sustainability by increasing their reserve and efficiency.
The solution for your P-source is a combination of one or two of these technologies:
- Fly Ash Process
With Prayon, fly ashes from the incineration of sewage sludge get a new life. The Prayon Ecophos Loop Process recycles these fly ashes into technical grade phosphoric acid. Moreover, side streams can be converted into de-icing products (Ca/Mg Cl solutions) or reused in wastewater treatment plant (Al/Fe Cl solutions).
The process is safe, sustainable and can be easily implemented at the incinerator site.
As every ash is different, we can test and validate the best solutions for our customers to recycle the ashes in our R&D pilot and semi-industrial operation facilities in Belgium and in Bulgaria.
For more information:
ENDownload our brochure Prayon Ecophos Loop - GetmoreP Process
In Module 2A, the secondary P-source is selectively digested in the diluted sulfuric acid (H2SO4).
On one side, it leads to the formation of gypsum containing most of the impurities from the secondary P-source (sand, iron, aluminum, heavy metals…).
On the other side, the phosphate solution is recovered by vacuum filtration. In the following Module 2B, the phosphate solution is neutralised with limestone, quicklime, or slacked lime to crystallise the phosphate as dicalcium phosphate – DCP.
- Ecophos Process
The first module is Module 1A where the secondary P-source is selectively digested in the diluted hydrochloric acid (HCl). This reaction produces a slurry of undigested rock as a solid with phosphate and calcium chloride (CaCl2) in solution.
In Module 1B, the phosphate solution is treated with CaCO3 to obtain dicalcium phosphate dihydrate (CaHPO4.2H2O, DCP) crystals and CaCl2 in the liquid phase.
In Module CCP, the CaCl2 solution is purified. In Module 4 (optional), CaCl2 is converted back to HCl by reaction with sulfuric acid after filtration, the HCl is returned to the rock digestion module, with a co-product of very pure and white gypsum.
- PUMA Process
Specific impurities originating from the secondary P-source can be removed by a membrane purification process.
More about Membrane Technology – PUMA
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