Translations:Fertilizer/31/en

NPK fertilizers

Main article: NPK fertilizer

There are three major routes for manufacturing NPK fertilizers (named for their main ingredients: nitrogen (N), phosphorus (P), and potassium (K)):

1. bulk blending. The individual fertilizers are combined in the desired nutrient ratio.

Bulk blending. Ingredient kg/ton

Blend ingredient	NPK 17-17-17	NPK 19-19-19	NPK 9-23-30	NPK 8-32-16
ammonium nitrate	310
urea		256
diammonium phosphate (DAP)	376	421	500	462
triple superphosphate				261
potassium chloride	288	323	500	277
filler	26

1. The wet process is based on chemical reactions between liquid raw materials phosphoric acid, sulfuric acid, ammonia) and solid raw materials (such as potassium chloride).

• The Nitrophosphate Process. Step 1. Nitrophosphates are made by acidiculating phosphate rock with nitric acid.
• Nitric acid + Phosphate rock → Phosphoric acid + Calcium sulphate + hexafluorosilicic acid.
• Ca₅F(PO₄)₃ + 10 HNO₃ →6 H₃PO₄ + 5 Ca(NO₃)₂ + HF
• 6 HF + SiO₂ →H₂SiF₆ + 2 H₂O