Wet Process Phosphoric Acid (WPA)

Wet Process Phosphoric Acid (WPA, 52-54% P₂O₅) is the workhorse phosphoric acid of the fertilizer industry, produced by reacting sulphuric acid with rock phosphate. WPA is the primary intermediate for manufacturing DAP, MAP, TSP, and granular NPK fertilizers. Dongkwang Poland facilitates WPA supply from North African and Middle Eastern production complexes, serving European fertilizer manufacturers and industrial phosphate consumers. As the foundational molecule of phosphate fertilizer chemistry, WPA trade volumes make it one of the most strategically important agricultural chemicals.

In the wet process, ground rock phosphate reacts with sulphuric acid at 70-80°C, producing phosphoric acid and calcium sulphate (gypsum) as a by-product. The crude acid (~28% P₂O₅) is concentrated by evaporation to merchant-grade (52-54% P₂O₅). For fertilizer manufacturing, WPA is neutralised with ammonia to produce MAP and DAP, or reacted with potash to produce MKP. WPA contains trace impurities (Fe, Al, F, Cd) from the rock phosphate source.

Ideal For

Store in HDPE, rubber-lined, or acid-resistant steel tanks. Highly corrosive (GHS Category 1B). Full PPE mandatory. ADR Class 8 for transport. Sludge formation may occur — agitate periodically. Store above 5°C to prevent crystallisation of fluorosilicic acid impurities.