Match the grade to the end use
Ammonium chloride (NH₄Cl, CAS 12125-02-9) is graded by purity and by which impurities are controlled. The assay figures look similar across grades; what differs is what has been measured.
| Grade | Purity | Form | Primary use |
|---|---|---|---|
| Agricultural | ≥99.0%, N ≥25% | Powder or granular | Fertiliser and soil amendment |
| Technical / industrial | ≥99.0–99.5% | Powder or crystal | Metalworking flux, textiles, chemical processing |
| Battery | ≥99.5%, very low heavy metals | Crystal | Zinc-carbon and zinc-chloride dry cells |
| Pharmaceutical | ≥99.5%, BP/USP | Powder or crystal | Expectorants, IV acidifier |
| Food (FCC) | ≥99.0–99.5% | Powder | Yeast nutrient, flavouring, pH adjustment |
Battery grade is the one buyers most often underestimate. Dry cells are sensitive to heavy metal contamination, which causes self-discharge and shortens shelf life, so battery material is controlled well beyond what a technical certificate reports.
Key physical properties
| Property | Value |
|---|---|
| Chemical formula | NH₄Cl |
| CAS number | 12125-02-9 |
| Molecular weight | 53.49 g/mol |
| Appearance | White crystalline powder or granules |
| Nitrogen content | 26.19% by weight |
| Chloride content | 66.28% by weight |
| pH (5% solution) | 4.5–6.0 — mildly acidic |
| Sublimation point | 338 °C — sublimes rather than melting |
| Density | 1.527 g/cm³ |
| Solubility in water | 37.2 g/100 mL at 20 °C |
The sublimation behaviour is what makes it useful as a flux — it vaporises at soldering and galvanising temperatures, cleaning the metal surface, rather than melting into a residue.
As a fertiliser: nitrogen source and soil acidifier
Ammonium chloride supplies 26% nitrogen in ammonium form. Compared with the alternatives, it is a moderate-nitrogen, acidifying source — which makes it well suited to some crops and unsuitable for others.
| Fertiliser | Nitrogen | Soil pH effect | Well suited to |
|---|---|---|---|
| Ammonium chloride | 26% | Acidifying | Rice, wheat, vegetables |
| Urea | 46% | Slightly acidifying | Broad spectrum |
| Ammonium sulphate | 21% | Strongly acidifying | Rice, tobacco, oilseeds |
| Calcium ammonium nitrate | 27% | Near neutral | Broad spectrum |
| DAP | 18% | Slightly acidifying | Wheat, maize, oilseeds |
| Crop | Typical rate | Timing |
|---|---|---|
| Rice (paddy) | 100–150 kg/hectare | At transplanting, plus topdressing |
| Wheat | 80–120 kg/hectare | Basal, plus topdressing |
| Sugarcane | 120–180 kg/hectare | Split application |
| Cotton | 80–100 kg/hectare | Pre-sowing, plus topdressing |
| Vegetables | 50–100 kg/hectare | Fertigation or broadcast |
The chloride content is the limiting factor. Chloride-sensitive crops — tobacco, potatoes, some fruit and certain vegetables — can be damaged by repeated application, and chloride accumulates in soils with poor drainage. On already saline or sodic ground, which is a real constraint across parts of Punjab and Sindh, ammonium sulphate or urea is usually the better nitrogen source.
Other applications and their grade implications
- Metal fluxing — galvanising, soldering and tinning, where the material sublimes to strip surface oxide; technical grade, with low residue mattering more than assay
- Dry cell batteries — electrolyte salt in zinc-carbon cells, requiring battery grade with tight heavy-metal control
- Pharmaceutical — expectorant formulations at 125–250 mg per 5 mL in syrup, and hospital IV solutions for correcting metabolic alkalosis, against BP or USP grade
- Textile and leather — buffer salt in ammonia dyeing systems, typically 2–4 g/L alongside ammonia solution to hold pH between 8.5 and 10
- Food — yeast nutrient in baking and flavouring, requiring FCC grade
- Animal feed — prevention of urinary calculi in sheep and goats, relevant given the size of Pakistan's livestock sector
Storage and handling
- Hygroscopic — it absorbs moisture and cakes, so store sealed, off the floor and under cover
- Mildly acidic in solution and corrosive to many metals, particularly copper and its alloys; keep it away from electrical equipment and copper pipework
- On heating or in damp conditions it releases a faint ammonia odour — noticeable but not usually hazardous at ambient conditions
- Dust is an irritant; a P1 or P2 mask, eye protection and gloves are appropriate for bag handling
- Do not store with strong alkalis, which liberate ammonia gas, or with strong oxidising agents
What to put on the RFQ
- Grade and end use — "battery grade" or "agricultural grade, N ≥25%", not "ammonium chloride"
- Form — powder, crystal or granular — since fluxing and fertiliser applications favour different physical forms
- Heavy metal limits where the end use is a battery, food or pharmaceutical application
- Moisture limit and anti-caking treatment if required
- Quantity per delivery and annual volume
- Pack — 25 kg or 50 kg bags, or jumbo bags — and whether moisture-barrier lining is needed
- Delivery city and available storage conditions
What drives the price
- Production route — most industrial material is a coproduct of soda ash manufacture, so its availability moves with soda ash production rather than with its own demand
- Grade, with battery and pharmaceutical material priced well above agricultural
- Ammonia and salt feedstock costs for directly synthesised material
- Pack format, with jumbo bags materially cheaper per tonne
- Freight and delivery city
- Exchange rate and duty, since Pakistan is supplied primarily by import
Sourcing considerations in Pakistan
- Most supply is imported, much of it as a soda ash coproduct, so lead times track that industry
- It is not a dangerous good for transport, which keeps logistics straightforward
- For fertiliser use, confirm nitrogen content on the certificate rather than assuming it from the assay
- For battery, food or pharmaceutical use, require the heavy-metal results on the batch certificate rather than a general conformity statement