Dry granulation method-Use double roller granulator to make fertilizer

Dry granulation is a widely used method in the production of fertilizers. This technique involves transforming powdered materials into granules without the use of liquid binders or solvents. One of the key tools in dry granulation is the double roller granulator, a machine that plays a pivotal role in shaping raw materials into compact and uniform fertilizer granules. In this comprehensive guide, we will delve into the dry granulation method, focusing on the application of the double roller granulator in creating high-quality fertilizer products.

Understanding Dry Granulation

Dry granulation is a process that is favored for various reasons in the fertilizer industry. Unlike wet granulation, which employs liquids to agglomerate particles, dry granulation operates without the need for water or solvents. This offers several advantages, including reduced energy consumption, elimination of drying steps, and the ability to handle materials that are sensitive to moisture. In addition, dry granulation can result in more stable and free-flowing granules.

The Role of Double Roller Granulator

One of the key components in dry granulation is the extrusion granulation, often referred to as the compactor or roller press. This machine is instrumental in shaping fine powdered materials into dense and well-defined granules. Let’s explore the various stages and functions of the double roller granulator in the fertilizer manufacturing process.

Stage 1: Material Feeding

The process begins with the feeding of raw materials into the double roller granulator. These materials typically consist of a blend of powdered fertilizers, binders, and sometimes additives. The exact composition varies depending on the desired fertilizer formula. The roller granulator must evenly distribute these materials to ensure uniform granule formation.

Stage 2: Compression

Once the materials are fed into the double roller granulator, they pass through a pair of counter-rotating rollers. These rollers exert high pressure on the material bed, compacting it into a dense sheet. The compression force applied here is crucial for forming strong and uniform granules.

Stage 3: Size Reduction

After compression, the compacted sheet of material passes through a breaker mechanism. This breaker serves to reduce the sheet into smaller agglomerates. The size and shape of the agglomerates can be adjusted by modifying the roller gap, roller speed, and the amount of pressure applied during this step.

Stage 4: Granule Formation

The reduced agglomerates exit the double roller granulator in the form of granules. These granules are characterized by their spherical or cylindrical shape, depending on the design of the machine. The granules are typically of a consistent size, making them ideal for fertilizer applications where precise dosing and distribution are required.

Advantages of Using Double Roller Granulator

The use of a double roller granulator in the dry granulation process offers numerous advantages for fertilizer manufacturers:

  1. Cost Efficiency: Dry granulation consumes less energy compared to wet granulation, as it eliminates the need for drying processes. For this, the cost of double roller granulator plant is affordable.
  2. Improved Product Quality: The double roller granulator produces uniform and dense granules, reducing the risk of segregation and ensuring consistent nutrient content in the final product.
  3. Environmentally Friendly: Since no liquid binders or solvents are used, dry granulation generates less waste and has a lower environmental impact.
  4. Versatility: Double roller granulators can handle a wide range of materials, including those that are sensitive to moisture or heat.
  5. Customization: The machine’s settings can be adjusted to produce granules of varying sizes and shapes to meet specific fertilizer formulation requirements.


In the realm of fertilizer production, the dry granulation method, utilizing the double roller granulator, stands as a reliable and efficient approach. Its ability to transform powdered materials into uniform and high-quality granules while offering cost savings and environmental benefits makes it a preferred choice for many fertilizer manufacturers. As the agricultural industry continues to evolve, dry granulation with the double roller granulator remains a pivotal technique in producing fertilizers that contribute to global food security and sustainable agriculture.

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