How to fix weak fertilizer granules from a rotary drum granulator?

Weak granules from a rotary drum granulator lead to high breakage during transport, easy powdering in storage, and hurt your product's competitiveness.

1.Adjust the Raw Material Mix

Insufficient Organic Stickiness: If bio-organic materials (like manure, straw) have too much fiber or aren't decomposed enough, granule strength suffers. Add binders like bentonite or humic acid.

Control Moisture Better: The best moisture range for drum granulation is 30%-40%. Too high makes loose granules; too low makes forming difficult.

2.Optimize Granulation Settings

Adjust Rotation Speed: Too slow and granules aren't dense enough; too fast and they break easily. Keep speed around 15-25 rpm, fine-tuning for your material.

Optimize the Tilt Angle: The rotary drum granulator's angle affects how long material stays inside. Keep it around 1°-3°. Too steep an angle pushes granules out before they round properly, hurting strength.

3.Improve Drying and Cooling

Dry Low and Slow: Fast, high-heat drying makes a hard shell but a crumbly inside, causing breakage. Use staged drying (low heat first to remove moisture, then gradually increase heat) for even drying throughout.

Cool Thoroughly: Cooling granules right after drying stabilizes their structure, reducing cracks from heat stress and boosting strength.

4.Add Strengthening Steps

Round Them Out: Adding a rounding machine after granulation improves shape and smoothness, reducing weak edges.

Coat Them: Using an anti-caking coating (like mineral oil) strengthens granules and improves moisture resistance.

In short, weak granules from a rotary drum granulator can be fixed by improving your raw materials, fine-tuning the process, and adding post-treatment steps. Getting these right will significantly boost granule quality and reduce breakage.