Organic fertilizer granulation machines
Granulators are usually chosen from a catalogue of capacities. That is the wrong order: the machine has to suit the material's plasticity, the binder
01
Granulation route selection
| Route | How it works | Best for | Watch out for |
|---|---|---|---|
| Disc (pan) granulator | Rotating inclined disc builds granules layer by layer | Organic powder with a binder; simple, visible, easy to adjust | Footprint and dust; requires steady feed moisture |
| Rotary drum granulator | Material tumbles in a rotating drum with spray | Higher capacities, blends with mineral additions | Longer residence, more recycle, sensitive to moisture |
| Stirring-tooth granulator | High-speed rotor forms granules with less binder | Organic material with fibrous structure | Wear parts, power demand, sensitivity to contamination |
| Double-roller extrusion | Material is extruded through dies at low moisture | Dry, mineral-containing and heat-sensitive formulations | Sheet quality, die wear, limited to specific formulations |
| Flat-die pellet mill | Material pressed through a flat die | Fibrous organic material, animal bedding type products | Die and roller wear; throughput falls with moisture |
02
Moisture, binder and the dryer load
Water is added during granulation to give the material plasticity. That water must then be removed in the dryer, and it is the single biggest driver of drying energy. A plant that granulates at 30% moisture and dries to 13% evaporates about 200 kg of water per tonne of product; at 24% inlet it evaporates around 130 kg. The difference shows up directly in fuel consumption, dryer size and running cost.
Binder selection is the lever. Organic binders such as starch, molasses, lignosulfonate or clay minerals can achieve strong granules with less water than plain water addition. The design basis states the binder, its addition rate and its effect on the declared analysis of the product — because a binder that adds 3% of a mineral also changes what the label says.
03
Granule quality targets
| Parameter | Typical target | How it is checked | If it fails |
|---|---|---|---|
| Size distribution | 80% within 2–4 mm | Sieve set, sample per shift | Adjust granulator speed, angle, binder or recycle ratio |
| Crushing strength | 8–15 N per granule | Manual granule strength tester | Increase binder, reduce drying rate, review feedstock |
| Moisture | 12–14% after cooling | Oven or moisture meter | Adjust dryer temperature and residence time |
| Abrasion / fines | < 5% fines after handling | Sample after bagging, sieve | Increase cooler retention, reduce drop heights, review coating |
| Bulk density | consistent within ±5% | Measure per batch | Check feedstock blend and granulator settings |
04
Granulation line drawing
05
Screening, recycle and coating
- A twin-deck screener after cooling splits product into saleable, oversize and fines; oversize is crushed and returned, fines return to the granulator.
- The recycle ratio — typically 0.5–1.5 times the fresh feed — is a process variable, not a waste: it stabilises granule formation and moisture.
- Coating with a light oil, wax or powder reduces caking and fines, and can carry a bio-inoculant or a slow-release component.
- Cooling before screening matters more than most plants expect: warm granules deform in the screen and cake in the bag.
Configure a granular line
Send the cured material moisture, the target granule size and your fuel options; we return the granulation route, dryer sizing and utility demand.
FAQ
Plant engineering questions
Which granulator suits organic fertilizer best?
Disc granulators dominate for organic powder because they are visible, adjustable and tolerant of variation; drum granulators suit higher capacities and blended formulations; extrusion suits low-moisture and mineral-containing recipes.
How much fuel does the dryer consume?
Roughly 30–60 kg of standard coal equivalent, or its gas or biomass equivalent, per tonne of product, depending on inlet and outlet moisture. The figure is calculated in the mass and energy balance rather than estimated from experience.
Do granules need a binder?
Often, yes. Organic material alone frequently forms weak granules. Starch, molasses, lignosulfonate or clay binders improve strength and reduce the water that has to be evaporated.
Can powder and granular products be made on the same line?
Yes. The shared sections are grinding, screening and bagging; the granular route adds granulation, drying, cooling and coating. Plants usually run one route at a time, changing over between campaigns.
Send us your design basis
Tell us the feedstock, the daily tonnage and the product you want to sell. The engineering team replies with the plant configuration, the equipment scope and the information we still need before layout drawings start.
- Feedstock profile — type, moisture, contamination, seasonal peaks
- Capacity — t/day fresh material or t/h finished fertilizer
- Product — powder, granules, bagged retail, bulk compost
- Site — available area, power supply, water, access road
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