The fertilizer coating machine is a specialized rotary device used for the final stage of fertilizer processing; its primary function is to apply a solid protective film to the surface of formed fertilizer granules to prevent caking. Additionally, it allows for the targeted incorporation of slow-release agents, trace elements, and antimicrobial additives to produce slow-release fertilizers and functional bio-organic fertilizer granules.

How does a fertilizer coating machine work?

Fertilizer granules are fed via a bucket elevator into the inlet of an inclined rotating drum. As the drum rotates continuously at low speed, internal lifting flights constantly lift and scatter the granules, creating a uniform, tumbling curtain of material.

Atomizing spray nozzles apply the coating agent onto the dispersed granules, ensuring each one is evenly coated with the film-forming material. Low-temperature hot air is introduced into the rear section of the drum to evaporate the solvent from the coating agent, allowing the protective film to cool, solidify, and fully encapsulate the granule surface.

The drum's inclination angle controls the material's forward speed, the rotation speed determines the frequency of granule tumbling, and the spray flow rate is matched to the feed capacity; the coordination of these three parameters ensures effective coating coverage. Standard industrial-grade equipment achieves a coating coverage rate of over 93%, with virtually no uncoated granules.

What are the performance advantages of the fertilizer coating machine?

Uniform and stable coating

Utilizing a whole-drum tumbling and atomized spraying method, the machine ensures consistent coating thickness on every fertilizer granule, even during high-volume processing—avoiding the uneven thickness and missed spots often associated with manual coating methods.

Suitable for continuous, long-term operation

The machine’s drive components are reinforced for wear resistance, ensuring a low failure rate during 24-hour continuous factory production and making it ideal for large-scale assembly line operations.

Versatile and customizable

By adjusting the spray gun and feeding mechanisms, the machine can switch between processes such as slow-release coating, anti-caking coating, and microbial inoculant protection; the drum liner material can also be customized to handle acidic or corrosive coating agents.

Economical use of coating materials

High-pressure atomization technology breaks the coating agent into ultra-fine droplets, ensuring high adhesion rates and minimizing material waste, thereby reducing consumable costs over the long term.

Enclosed processing with reduced dust

The entire drum operates within an enclosed system equipped with an exhaust dust removal unit, resulting in minimal workshop dust and an improved production environment.

Coating machine solutions for different fertilizer types

Standard compound fertilizers: Coated with mineral oil and liquid anti-caking agents, primarily to prevent caking during summer storage.

Granular bio-organic fertilizers: Coated with talc powder to block moisture and protect the beneficial active bacteria inside the granules.

Slow- and controlled-release fertilizers: Coated with resin or sulfur; nutrient release duration is regulated by the porosity of the coating, making them suitable as long-lasting base fertilizers for fruit trees and field crops.

Water-soluble fertilizer granules: Coated with water-soluble materials that dissolve rapidly upon contact with water, ensuring no coating residues clog drip irrigation equipment.

The fertilizer coating machine is a key piece of equipment for upgrading the quality of granular fertilizers; effective coating not only resolves the issue of caking but also enables the production of various functional slow-release fertilizers. During the plant construction phase, the coating process must be integrated with the granulation, drying, and cooling equipment; ensuring compatibility across the entire production line is essential for the consistent output of high-quality coated granular fertilizer.