This product combines high-pressure hydraulic pressing with a colour marker. The relevant interaction is that a denser, harder granule with a lower dust fraction retains an applied colour better than a friable one, because colour loss in practice is mostly a consequence of abrasion. Where a colour marker has to survive a long handling chain and still be doing its job at the point of use, granule hardness is not a separate consideration from colour — it is the main one.
Substance identity
| Chemical name | Ammonium chloride |
| Synonyms | Sal ammoniac, muriate of ammonia |
| Formula | NH₄Cl |
| CAS | 12125-02-9 |
| Molar mass | 53.49 g/mol |
| Appearance | Coloured dense granules; base salt white, colour entirely from added colourant |
Specification
| Parameter | Value | Basis |
|---|---|---|
| NH₄Cl content | ≥ 94–96 % | Typical commercial range for agricultural material |
| Nitrogen (N) | ≥ 25.0–25.4 % | Typical commercial range |
| Moisture | ≤ 0.5–1.0 % | Typical commercial range |
| Particle size | 2–4 mm typical cut | Typical commercial range |
| Bulk density | Toward the upper end of the granular range, approximately 1.0 t/m³ or above | Typical, approximate; confirm per lot |
| Crush strength | Specify a measured minimum and a test method | To be agreed — no representative figure quoted |
| Colourant | Identity, loading and application point to be declared | To be declared |
Properties
Chemically identical to any other ammonium chloride: freely soluble at approximately 37 g per 100 g water at 20 °C, endothermic on dissolution at about +14.8 kJ/mol, acidic in solution at pH 4.5–6.0 for 5 %, dissociating to ammonia and hydrogen chloride on heating with apparent sublimation near 337.6 °C. Neither pressing nor colouring alters this.
The hydraulic route is a compaction route: the salt is bonded by plastic deformation under pressure, without a binder. The trade description distinguishes it from roll compaction by claiming higher density and hardness. Treat that as a claim to be verified, not as a specification — the meaningful statement is a measured bulk density, a measured crush strength and a measured dust fraction, and those numbers should be requested rather than inferred from the process name.
Applications
Suited to supply chains with many transfer points, extended storage, or mechanical handling that would degrade a softer granule — and specifically to cases where a colour marker must remain legible through all of that. Denser granules also throw further and more consistently in spinner spreaders, increasing achievable working width. In bulk blends the same size- and density-matching rules apply as for any granular component; note that an unusually dense granule can segregate from lighter blend partners even when the sizes match well.
Handling and storage
Dry, sealed storage. Lower surface area means slower moisture uptake and better caking resistance than powder or a friable granule, but the critical relative humidity of the salt — around 77 % at 30 °C — is unchanged, so the improvement is in kinetics, not in equilibrium. Assume the colourant stains wet surfaces. Keep separate handling equipment from uncoloured product. No contact with alkaline materials; protect copper alloys and unprotected steel in humid conditions.
Notes
“Hydraulic” describes a manufacturing route, not a product property, and there is no standard definition of it. A purchase specification should be written in measurable terms — density, crush strength, dust, size distribution, and colour uniformity assessed against a retained sample — so that the product can be verified on arrival rather than accepted on the basis of its description.