Muriate of Potash (MOP), chemically known as Potassium Chloride (KCl), is the most widely used potash fertilizer and a primary source of potassium (K) for crops. Containing 60–62% K₂O equivalent, MOP is a highly concentrated and cost-effective fertilizer that improves crop yield, water regulation, disease resistance, and overall plant strength.
Product Identification
| Parameter | Specification |
|---|---|
| Chemical Name | Potassium Chloride |
| Chemical Formula | KCl |
| Fertilizer Grade | 0-0-60 / 0-0-62 |
| Category | Water-soluble potassic fertilizer |
| Nature | Naturally occurring mineral, refined |
Chemical Composition & Structure
| Component | Typical Content |
|---|---|
| Potassium (as K₂O) | 60–62% |
| Chloride (Cl⁻) | 45–47% |
| Sodium (Na) | ≤ 2% |
| Magnesium (Mg) | ≤ 0.5% |
| Moisture | ≤ 0.5% |
MOP is an ionic compound composed of K⁺ and Cl⁻ ions, naturally mined from sylvinite and carnallite ores and refined for fertilizer use. It is fully water-soluble and readily available to plants.
Physical Properties
| Property | Typical Value |
|---|---|
| Appearance | Crystalline / granular solid |
| Color | Red, pink, white |
| Bulk Density | 1.1 – 1.2 g/cm³ |
| Particle Size | 1 – 4 mm (fertilizer grade) |
| Solubility | Fully water-soluble |
| Hygroscopicity | Low |
| Melting Point | ~770 °C |
Mechanical Properties (Granule Handling)
✔ Granule crush strength: 3–6 kg/granule
✔ High abrasion resistance
✔ Very low dust formation
✔ Low caking tendency under dry conditions
📌 MOP is mechanically one of the strongest fertilizer granules, ideal for bulk storage, transport, and mechanical spreading.
Strengthening & Crystallization Behavior
Granule strength arises from:
✔ Natural cubic crystal lattice
✔ High ionic bonding energy
✔ Controlled crystallization or compaction during processing
📌 No metallurgical behavior applies (inorganic salt)
Thermal & Chemical Behavior
Thermal Stability:
Highly stable under storage conditions
Does not decompose
Melts only at very high temperatures (~770 °C)
Chemical Reactivity:
Neutral salt in soil solution
Chloride ion is highly mobile
Compatible with most fertilizers (except certain nitrate blends)
Key Agronomic Characteristics
✔ Supplies potassium – a vital macronutrient
✔ Regulates water balance and stomatal function
✔ Activates enzymes and improves photosynthesis
✔ Enhances disease resistance and crop quality
Chloride Benefits (Moderate Levels):
✔ Improves turgor pressure
✔ Enhances photosynthetic efficiency
Processing & Refining Properties
✔ Mining of potash ores
✔ Crushing and grinding
✔ Flotation or crystallization
✔ Drying and screening
✔ Compaction and anti-caking coating
Process Control:
Crystal size uniformity
Moisture removal
Chloride purity
Available Forms
Granular MOP (field application)
Powder MOP (fertilizer blending)
Red MOP (higher iron content)
White MOP (high purity, fertigation use)
Applications
Agriculture:
Rice, wheat, maize, sugarcane, cotton, oilseeds
Basal and top dressing applications
Industrial:
Chemical industry (KOH production)
Food-grade salt (after purification)
Pharmaceuticals and water softeners
Advantages of MOP
Agronomic:
✔ Highest potassium concentration
✔ Rapid potassium availability
✔ Improves stress tolerance
✔ Cost-effective nutrient source
Commercial:
✔ Globally traded commodity
✔ Excellent storage stability
✔ Easy handling and blending
✔ Lower cost than SOP
Limitations & Considerations
Not suitable for chloride-sensitive crops such as:
Tobacco, potato, grapes, citrus
Excess chloride may increase soil salinity
MOP vs Other Potassic Fertilizers
| Parameter | MOP | SOP | KNO₃ |
|---|---|---|---|
| K₂O (%) | 60 | 50 | 44 |
| Chloride | High | Nil | Nil |
| Sulfur | Nil | Yes | Nil |
| Cost | Lowest | High | Very High |
| Crop Sensitivity | Moderate | Low | Very Low |
Why Choose MOP?
✔ Best value potassium source
✔ Suitable for most field crops
✔ Strong granules for bulk handling
✔ Easy blending with N & P fertilizers
✔ Reliable global supply
Storage & Handling
Store in dry, ventilated warehouses
Avoid prolonged moisture exposure
Use plastic-lined or coated steel bins
Follow FIFO inventory management
Soil Suitability Summary
| Soil Type | Suitability |
|---|---|
| Neutral soils | Excellent |
| Acidic soils | Excellent |
| Saline soils | Use cautiously |
| Sandy soils | Good (split application) |