Insoluble Humic Acid Prills
The Low-Moisture, High-Hardness Humic Granule That Survives Your Line
2–4 mm spray-granulated prill · 40% humic acid · 5% max moisture · 60% organic matter · high crush strength
Product Overview
Insoluble Humic Acid Prills is our highest-specification insoluble grade: spray-granulated to a dense, hard, low-moisture 2–4 mm prill built for processes that destroy ordinary granules.
Compare it directly against the standard granule and the difference is one number: moisture 5% maximum against 30%. That single specification changes how the material behaves. Low moisture means the prill is hard rather than soft, it does not slake or break down under load, it will not pick up water from urea in a blend, and it stays free-flowing through a humid season in a warehouse.
It was developed for three situations where the standard granule fails:
- Blending with urea — urea is strongly hygroscopic and will draw moisture out of a high-moisture granule, turning the blend into a cake.
- Aggressive mechanical handling — long conveyor runs, pneumatic transfer, repeated bagging.
- Long export transit — a container crossing an ocean through the tropics is a genuinely hostile environment for a soft granule.
If none of those apply, buy the standard granule and save the money. Insoluble Humic Acid Prills is a specification you pay for when the process demands it.
Key Benefits
5% maximum moisture — the number that matters
Most humic granules carry up to 30% moisture. At 5% the prill is dense and hard, does not pick up water from companion materials, and stays free-flowing where a standard granule would cake.
Survives blending with urea
Urea draws moisture aggressively from anything beside it. A high-moisture humic granule in a urea blend turns to cake; this prill does not, which is the main reason customers specify it.
High crush strength, minimal fines
Spray granulation produces a far harder particle than disc granulation. The prill survives long conveyor runs, pneumatic transfer, drops and repeated handling without generating fines.
Built for export transit
Temperature cycling and humidity inside a container on a long sea voyage destroy soft granules. This grade was developed specifically to arrive in the same condition it shipped in.
Matches granular NPK for clean blending
The 2–4 mm round prill sits in the same size and density band as standard MAP, DAP and urea, so it stays distributed rather than segregating to the bottom of the bag.
Guaranteed humic and organic content
40% minimum humic acid and 60% minimum organic matter, on a dry basis, with nitrogen at 2–5% — tested per batch and stated on the COA.
Technical Specification
| Parameter | Specification | Test standard |
|---|---|---|
| Humic acid (dry basis) | 40.0% min | GB/T 11957-2001 |
| Organic matter (dry basis) | 60.0% min | NY 525-2011 |
| Nitrogen (dry basis) | 2.0 – 5.0% | NY 525-2011 |
| Moisture | 5.0% max | GB/T 11957-2001 |
| pH (1:100) | 5.0 – 7.0 | GB/T 33804-2017 |
| Particle size | 2 – 4 mm | Sieve method |
| Particle shape | Round prill | Visual |
| Water solubility | Nil (insoluble by design) | — |
| Appearance | Black round prill | Visual |
| Product code | JFHA-HA-GP | — |
Specification values are guaranteed minimums on a dry basis, taken from the batch Certificate of Analysis and tested against the stated Chinese industry standards. Every shipment travels with its own COA stating the tested values.
Need the full Certificate of Analysis, MSDS, or TDS for your formulation or tender file?
Request COA / MSDS / TDSForm & Solubility
Form: dense black round prills, 2–4 mm, hard and dry to the touch. Noticeably heavier and harder than the standard disc-granulated granule. Dust-free.
In water: insoluble. The prill is dense and will slake very slowly rather than breaking up quickly. Not for fertigation, drip lines or liquid tanks.
Hardness: the defining property. The prill resists crushing between the fingers in a way the standard granule does not, which is the field test most buyers run when comparing the two grades side by side.
Moisture behaviour: at 5% maximum it does not give up or take on water readily. That is what allows it to sit alongside urea in a blend, and what allows it to cross an ocean in a container without arriving as a consolidated block.
Which insoluble grade fits your process?
| Grade | Form | Humic acid | Organic matter | Size | Best for |
|---|---|---|---|---|---|
| Humic Acid Powder | 80–100 mesh powder | 40–70% | 70–82% | 80–100 mesh | Granulation feed, soil conditioner base, blending |
| Humic Acid Crystal | 2–4 mm crystal | 60% min | — | 2–4 / 1–6 mm | Direct soil application, premium organic blends |
| Humic Acid Granule | 2–4 mm round granule | 40% min | 60% min | 2–4 mm | Bulk blending, broadcasting, organic fertilizer |
| Humic Acid Prills (this product) | 2–4 mm high-hardness | 40% min | 60% min | 2–4 mm | Urea/blending, mechanical spreading, export |
| Microbial Humic Granule | 2–4 mm inoculated | 40% min | 60% min | 2–4 mm | Bio-organic fertilizer, root-zone inoculation |
All five grades come from the same leonardite seam and carry the same heavy-metal declaration (Pb, As, Hg, Cd, Cr all below detection, GB 18877). They differ in particle form and where they fit in your process — not in origin.
Applications & Dosage
Specified where the process is hard on the material — hygroscopic companions, mechanical handling, or long transit:
| Application | How to use | Rate |
|---|---|---|
| Urea and NPK blending | The primary use. Blend with urea without the moisture transfer that cakes a standard humic granule. | 5–15% of blend |
| Export and long transit | Ship intercontinental without the material arriving degraded. Low moisture is what makes this possible. | per programme |
| Pneumatic and mechanical spreading | Hard prills survive pneumatic transfer and high-speed spinner spreaders without generating fines. | 300–750 kg/ha |
| Mechanised broadacre farming | For large-scale operations where the material is handled repeatedly before it reaches the field. | 300–750 kg/ha |
| Premium granular organic fertilizer | Use where the finished product has to look and handle like a conventional granular fertiliser. | 20–40% of formulation |
| Extended warehouse storage | Store through a humid season without caking, where a standard granule would consolidate. | per programme |
Packaging & Storage
| Pack size | Description |
|---|---|
| 20 kg / 25 kg | Woven PP bag with inner PE liner — standard export packing |
| 50 kg | Woven PP bag with inner liner — for high-volume programmes |
| 1000–1100 kg | Jumbo bag with discharge spout, 4 lifting loops |
| Custom | Private-label printed bag, OEM specification, retail sizes on request |
Storage: The most storage-stable grade in the insoluble range. At 5% maximum moisture the prill does not readily take up water, does not cake, and does not break down. Standard good practice still applies — under cover, on pallets, off bare concrete. Under those conditions the material stores for years without measurable change. This is the grade to specify if the material will sit in a warehouse through a wet season before use. Shelf life: 24 months in original, unopened packaging.
Custom packaging, private-label printing and OEM specifications are available on request. Packaging photos are available in the product gallery.
Successful Cases
Fertilizer blender, Middle East
Blends prills at 12% with granular urea for a date-palm programme. Had previously tried a standard humic granule and lost two containers to caking — urea pulled moisture out of the granule and the blend consolidated into blocks in the bag. Switched to the low-moisture prill and the problem disappeared; no complaints across four subsequent shipments.
Explore humic acid applications → Agriculture · Urea BlendingDistributor, West Africa
Imports in full containers with a six-week transit through tropical humidity. Standard granules arrived partially degraded with visible fines and several consolidated bags. The prill grade arrives free-flowing, which for them matters more than the price difference — a container they cannot sell is far more expensive than the specification premium.
Explore humic acid applications →Full case studies with crop data are published in our application sectors.
Frequently Asked Questions
How is this different from the standard Insoluble Humic Acid Granule?
Both are 2–4 mm round black granules at 40% humic acid, but they are made differently and behave differently. The standard granule is disc-granulated and carries up to 30% moisture; it is softer and adequate for normal blending and spreading. The prill is spray-granulated to 5% maximum moisture, making it much harder and far more resistant to moisture transfer. If urea, long transit or rough handling is involved, the prill is the correct specification.
Why does moisture matter so much?
Moisture is the mechanism behind most humic granule failures. A 30%-moisture granule sitting next to hygroscopic urea will give up water to it, and the blend cakes. In a humid container the same granule softens and consolidates. Dropping to 5% removes most of that failure mode, which is why buyers who have been burned by a caked shipment come back for this grade.
Can it be blended with urea and stored?
Yes — that is the main reason it exists. It can be blended with urea and stored far longer than a standard granule would allow. We would still not recommend indefinite storage of any urea blend, because urea itself is hygroscopic and will eventually draw moisture from the air regardless of what it is blended with. Blend to a realistic schedule.
Is it more expensive?
Yes. Spray granulation to a low moisture specification is an additional process, and it is reflected in the price. We recommend it only where the process genuinely requires it. If you are blending with MAP and spreading within a season, the standard granule will do the same job for less money, and we will tell you that rather than upsell you.
Does the higher hardness affect release in soil?
Marginally — a denser prill takes somewhat longer to break down than a softer granule. In practice the difference is weeks, not seasons, and both release across a growing season. If you need a rapid, measurable response within days rather than a season-long one, neither grade is right; use a soluble potassium humate or fulvate instead.
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