Powdery monoammonium phosphate at 60 % total nutrient is the top of the standard powder range. Pure NH₄H₂PO₄ would assay 12.2 % N and 61.7 % P₂O₅ — a total of about 74 % — so a 60 % commercial powder is running at roughly four-fifths of the theoretical maximum, which is close to the practical ceiling for wet-process material that has not been through a purification step. It is specified where the finished formulation leaves no headroom for diluent, and where freight distance makes nutrient density decisive.
Substance identity
| Field | Value |
|---|---|
| Active compound | Monoammonium phosphate, NH₄H₂PO₄ |
| CAS | 7722-76-1 |
| PubChem CID | 24402 |
| Molar mass | 115.03 g/mol |
| Theoretical maximum (pure compound) | 12.2 % N + 61.7 % P₂O₅ ≈ 73.9 % total |
| Grade basis | 60 % = N + P₂O₅ combined |
Specification
Typical commercial range — confirm on certificate of analysis:
| Parameter | Typical |
|---|---|
| Total nutrient (N + P₂O₅) | ≥ 60 % |
| Nitrogen (N), ammoniacal | ≈ 11 – 12 % |
| P₂O₅, total | ≈ 48 – 49 % |
| Moisture | ≤ 1.5 – 2.5 % |
| Physical form | free-flowing powder |
| Appearance | white to light grey / light brown |
| Water-insoluble matter | lowest of the standard powder tiers; declare on CoA |
Properties
-
Closest standard powder tier to the theoretical compound. At roughly 81 % of the theoretical nutrient content of pure NH₄H₂PO₄, the remaining balance is moisture plus residual rock-derived impurity.
-
Generally lighter in color than lower tiers, because color in wet-process phosphates tracks iron and organic carry-over from the rock. Color is a rough indicator only and is not a substitute for an analysis.
- Solution behavior unchanged from any MAP: a 1 % solution runs around pH 4.0–4.5.
- Thermal limit unchanged: decomposition with ammonia evolution on strong heating, reported near 190 °C.
Applications
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High-analysis NPK compound production, where the formulation mass balance will not close on a lower-grade phosphate feed.
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Premium powder blends and buyer-side reprocessing.
- Long-haul supply, where the delivered cost per unit of P₂O₅ favors the densest available tier.
- Solution use — verify first, do not assume. Some 60 % powders are marketed as suitable for solution applications. Whether that is true for a given lot depends entirely on its water-insoluble matter, and that figure must be read off the certificate of analysis for the specific lot. Where a genuinely clear, emitter-safe solution is required, the correct product remains purified technical-grade MAP at [CAS?], not a wet-process powder of any tier.
Handling and storage
Dry covered storage in sealed packaging; dust extraction at transfer and bagging points; eye and respiratory protection for open handling. Avoid prolonged storage under compressive load. Keep segregated from lime, basic slag and other alkaline materials, and from heat. Fine, low-moisture powder flows and fluidizes readily — bunker and hopper design should account for flooding at discharge.
Notes
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60 % is total N + P₂O₅ — roughly 11–12 % N and 48–49 % P₂O₅.
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Because 60 % is near the practical ceiling for unpurified material, claims materially above this tier for a wet-process powder should be treated as requiring documentary support.
- Conversion reminder: P₂O₅ × 0.436 = elemental P.