| 摘要 |
<p>A granular fertilizer comprises a nitrate, sulphate, and water-soluble P2O5. At least 60% of the P2O5 is in the form of triple superphosphate and up to 40% is in the form of one or more of single superphosphate, monoammonium phosphate and diammonium phosphate. The mol. ratio of sulphate to monocalcium phosphate (as triple superphosphate and, if present, mono superphosphate) is 1-3. The nitrate is ammonium, sodium, potassium or magnesium nitrate. The sulphate is ammonium, sodium, potassium or magnesium sulphate or ammonium sulphate nitrate. The composition may also contain potassium chloride and urea. The proportion of nitrogen in the composition is 2-25%. The proportion of P2O5 in the composition is 7-30%. The mol. ratio of potassium chloride to ammonium nitrate is preferably at least 1. Granulating is effected in a rotating drum in the presence of 1-5% of water, followed by drying in hot air or burnt gas and screening. 90% ammonium nitrate solution at 90 DEG C. may be added to the other ingredients and recycled fines in the granulator.</p> |
