A comprehensive analysis of common compound fertilizer production processes

Compound fertilizer production processes are diverse, with core differences focusing on raw material processing, granulation methods, and energy consumption control. Different processes are suited to different fertilizer types and production capacity requirements. The following outlines the core characteristics and application scenarios of four major processes, providing a reference for production selection.

Rotary drum granulation is a traditional mainstream wet process. Raw materials are sprayed, mixed, and granulated in a rotary drum, followed by drying, cooling, and screening to complete production. Its advantages include high production capacity and uniform granules, making it suitable for general-purpose NPK compound fertilizers; its disadvantages include high energy consumption and strict control over raw material moisture content.

Spray granulation emphasizes high efficiency and integration. The raw material slurry is directly sprayed into a granulation tower, where it is rapidly dried and formed by hot air, without the need for additional mixing. It offers uniform nutrient distribution and high efficiency, making it suitable for large-scale production of high-concentration compound fertilizers, but it requires high equipment investment and has stringent requirements for slurry viscosity.

Dry extrusion granulation is an environmentally friendly and energy-saving process. Dry raw materials are directly pressed into shape using a double roller press granulator, eliminating the need for water addition and drying. Energy consumption is more than 30% lower than wet processes, and there is no wastewater or exhaust gas. It is suitable for various raw materials and small-to-medium-scale environmentally friendly production, although the granule strength is slightly lower.

Blending granulation focuses on flexibility. Single fertilizers are mixed according to the formula using a double axis paddle mixer, and then granulated or made into BB fertilizer as needed. It offers flexible formulations and convenient product changes, making it suitable for customized production, but it requires high consistency in raw material particle size.

Can urea granulation technology improve agricultural productivity?

Urea, as a core nitrogen fertilizer in agriculture, has an application efficiency that directly impacts crop yield and quality. Urea granulation technology, through morphological optimization and process upgrades, addresses pain points from multiple dimensions and is a key technological support for boosting productivity.

Granulation technology optimizes urea characteristics. After screening raw materials with uniform particle size using a fertilizer screener machine, powdered urea is converted into granular urea with uniform particle size and moderate strength through processes such as rotary drum granulation and spray granulation. This solves the problem of caking during transportation and storage, and also extends the nutrient release cycle. Granular urea releases nitrogen slowly after being applied to the soil, reducing high-temperature volatilization losses, avoiding waste, and providing continuous fertilization.

Granulation technology improves application efficiency. Granular urea is compatible with mechanized fertilization equipment, enabling precise broadcasting and band application, significantly improving efficiency, adapting to large-scale planting bases, and reducing labor input; uniform granules prevent localized nutrient excess that can burn seedlings, ensuring crop growth. Some granulation processes add slow-release agents and efficiency enhancers, extending fertilizer efficiency and reducing the number of fertilizations, indirectly lowering planting costs.

Granulation technology contributes to green agriculture. Granular urea reduces nitrogen loss and pollution to soil and water bodies, aligning with the needs of green transformation; its stable characteristics facilitate mixing with phosphorus and potassium using a fertilizer mixer to produce compound granular fertilizers, achieving balanced fertilization and improving crop yield and quality. High-quality granular urea allows crops to fully absorb nutrients and grow robustly, directly boosting yield per unit area and contributing to increased agricultural productivity.