NPK bulk blend fertilizer (BB fertilizer) is crucial for precision fertilization. Its production quality directly depends on the characteristics of the raw materials. A high-quality NPK blending fertilizer production line has strict requirements for the input materials – only raw materials meeting the standards can guarantee the uniformity and nutrient effectiveness of the final fertilizer.
1.Physical Requirements
Uniform Particle Size (1-4mm optimal): Individual fertilizer particles need very similar sizes (variation within 30%). Recommended materials include rotary drum granulator or extrusion granulated urea, DAP, etc. Avoid directly blending powdered and granular materials.
Moisture Content ≤ 2%: High moisture causes material caking and equipment clogging. Special attention is needed for hygroscopic materials like MOP (muriate of potash) and SOP (sulfate of potash).
Similar Bulk Density: The density difference between components should be within ±20%. Typical density range: 0.9-1.2 g/cm³.
2.Chemical Requirements
Chemical Compatibility: Avoid direct mixing of urea with SSP (single superphosphate) (risk of moisture release). Fertilizers containing nitrate nitrogen are incompatible with liming materials.
Neutral pH: Ideal pH range: 6.5-7.5. Strongly acidic or alkaline materials require pre-treatment.
3.Raw Material Selection Suggestions
Nitrogen Source: Granular urea (large particle), ammonium sulfate (particle size 2-3mm).
Phosphorus Source: MAP (monoammonium phosphate), DAP (diammonium phosphate).
Potassium Source: Granular red MOP (muriate of potash), SOP (sulfate of potash).
Secondary or Micronutrients: Require chelation or coating treatment.
By strictly controlling raw material parameters like particle size, moisture, and density, and by scientifically designing the production process, NPK blending fertilizer production lines can produce high-quality, uniform nutrient, easy-to-apply fertilizers.