Different fertilizer granulation processes have their own advantages and disadvantages, and the choice should be made based on specific needs (such as crop type, fertilization scenario, and cost budget). Below is a detailed comparison of common granulation processes and an analysis of their applicable scenarios:

1. High-tower Granulation Process

• Advantages:

  • High uniformity of granules: Each granule has essentially the same nutrient content, ensuring uniform nutrient release and significantly improving fertilizer absorption efficiency.
  • Fast fertilizer effect: Good water solubility and easy dissolution make it suitable for top-dressing.
  • Strong moisture resistance: The granules have micropores inside and cool rapidly, making them less prone to moisture absorption and caking.

• Disadvantages:

  • Raw material limitations: The nitrogen content cannot be too low, and the phosphorus content cannot be too high (usually up to around 15% phosphorus content). It is generally only suitable for producing high-nitrogen compound fertilizers.
  • High diureid content: The diureid content is close to the national upper limit (1.5%), which may have certain effects on crops.
  • High equipment investment: The cost of high-tower granulation equipment is relatively high, and energy consumption is also relatively high.

• Applicable Scenarios: Suitable for various field crops and cash crops, such as wheat, corn, rice, and cotton, for both basal and top-dressing applications.

2. Ammoniation Granulation Process

• Advantages:

  • High nutrient content: The nitrogen content can reach over 14%, and the water-soluble phosphorus can be as high as 95% or more, providing good fertilizer efficiency.
  • Stable quality: The granules have high strength and are less prone to caking, being relatively safe for seeds.
  • Wide applicability: Suitable for various soils and a wide range of crops, including wheat, corn, fruits, peanuts, vegetables, beans, flowers, fruit trees, and other economic crops.

• Disadvantages:

  • Technical threshold: Compared to spray granulation, the ammoniation granulation process requires slightly higher technical expertise.
  • Cost considerations: Equipment investment and operating costs may be slightly higher than some traditional processes.

• Applicable Scenarios: Suitable for basal fertilization, seed fertilization, and top-dressing, with particularly noticeable yield-increasing effects on economic crops when used as basal fertilizer.

3. Spray Granulation Process

• Advantages:

  • Uniform nutrient distribution: The product has uniform nutrient content and good water solubility.
  • Mature technology: The process is mature, with a high product qualification rate.

• Disadvantages:

  • Relatively low nutrient content: The nitrogen content is low, typically only around 12%, and the water-soluble phosphorus is also low, about 80%, resulting in lower utilization efficiency compared to ammoniation granulation.
  • High energy consumption: Strict control over slurry concentration and viscosity is required, leading to relatively high energy consumption.

• Applicable Scenarios: Suitable for scenarios where nutrient content requirements are not particularly high but emphasis is placed on fertilizer uniformity and water solubility.

4. Drum Granulation Process

• Advantages:

  • Simple process: The processing is relatively simple and can produce products of various specifications.
  • Low cost: Equipment investment is low, making it suitable for large-scale production.

• Disadvantages:

  • Less uniform nutrient mixing: Nutrient mixing is generally uniform but not as precise as high-tower or ammoniation granulation.
  • Lower water solubility and utilization rate: Prone to nutrient loss and relatively short fertilizer effect.
  • Lower granule strength: The granules have a general appearance, low hardness, and are prone to pulverization and caking, with poor storage resistance.

• Applicable Scenarios: Effective for top-dressing short-growth-period crops during dry years, providing relatively quick results.