What is Potassium Sulfate CAS 7778-80-5?

Potassium sulfate, also called sulfate of potash or SOP, is the dipotassium salt of sulfuric acid with the formula K2SO4. It is supplied as white or off-white crystals, powder or granules and used mainly as a chloride-free potassium and sulfur fertilizer.

Why choose Potassium Sulfate instead of potassium chloride?

Potassium sulfate supplies potassium without chloride, making it suitable for chloride-sensitive crops such as tobacco, grapes, citrus, fruit trees, vegetables and potatoes. It also provides sulfur, an essential secondary plant nutrient.

How is water-soluble Potassium Sulfate used in fertigation?

Water-soluble-grade SOP dissolves readily and is used in drip irrigation, foliar feeding and liquid fertilizer formulations. Selecting the water-soluble grade with low water-insoluble matter helps avoid clogging in emitters and spray systems.

How soluble is Potassium Sulfate CAS 7778-80-5?

Potassium sulfate is commonly cited as dissolving at about 110 g/L at 20 C, with solubility increasing as temperature rises. It is less soluble than potassium chloride, so water-soluble grade and proper agitation are important for concentrated stock solutions.

What are the main applications beyond fertilizer?

In addition to agricultural and horticultural fertilizers, potassium sulfate is used in industrial chemical processes, glass manufacture and certain food or pharmaceutical applications where an appropriate grade is permitted.

Which specifications should I check before ordering SOP?

Confirm K2O content, sulfur content, chloride, moisture, pH, water-insoluble matter and particle size. Agricultural and water-soluble grades usually differ in chloride and water-insoluble limits, so match the specification to fertigation or dry-fertilizer use.

Potassium Sulfate CAS 7778-80-5

Potassium Sulfate (CAS 7778-80-5) is a high-purity inorganic salt serving as a premium chloride-free fertilizer source in agricultural crop production and a setting accelerator in industrial gypsum board manufacturing. Chemically identified as Dipotassium sulfate or SOP (Sulfate of Potash), this white crystalline powder functions to deliver essential potassium and sulfur nutrients without inducing salinity stress in sensitive crops like tobacco and fruits. As a stable Sulfuric acid dipotassium salt, it is widely utilized in compound fertilizer blending and technical glass fabrication. We ensure bulk supply capabilities for this material, providing access to competitive factory pricing and customized specifications to meet specific solubility and granule size requirements. Full technical documentation, including MSDS, TDS, COA, is available to support compliance and safety protocols.

CAS: 7778-80-5
Synonyms: Dipotassium sulfate, SOP, Sulfate of Potash, Sulfuric acid dipotassium salt
Einecs: 231-915-5
Molecular Formula: K2SO4
Grade: Agricultural Grade / Water Soluble Grade
Package: 9.5kg, 25kg, 50kg PP/PE bags, or 1000kg/1200kg Jumbo bags (Customizable color bags available)

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Product Description

Potassium Sulfate is a white crystalline powder or granule that serves as a highly efficient source of Potassium and Sulfur for plants. Unlike Muriate of Potash (MOP), our SOP is virtually free of chloride (Cl ≤ 1.5%), making it the ideal fertilizer for high-value crops that are sensitive to chloride salinity, such as tobacco, fruits, vegetables, and nuts.

Our product is produced using the Mannheim process or natural brine extraction, ensuring high purity. It improves crop yield, quality, taste, and shelf life while enhancing the plant’s resistance to drought, frost, and disease. The water-soluble grade dissolves quickly, preventing clogging in drip irrigation and spray systems.

1 Physicochemical Properties

2 Applications

3 Storage Conditions

4 Safety Precautions

Physicochemical Properties

Parameter	Specification (Standard Export Grade)
Appearance	White powder or granular
Potassium Oxide (K₂O)	≥ 50.0% / 52.0%
Potassium (K)	≥ 41.5%
Sulfur (S)	≥ 17.5% – 18.0%
Chloride (Cl⁻)	≤ 1.5% (Low Chloride)
Moisture (H₂O)	≤ 1.5%
Free Acid (as H₂SO₄)	≤ 1.5%
Water Insolubles	≤ 0.5% (For water soluble grade)
pH Value	4.0 – 7.0 (Typically neutral to slightly acidic)
Solubility	Approx. 110g/L at 20°C

Applications

Chloride-Sensitive Crops: Essential for fertilizing tobacco, grapes, citrus fruits, tea, potatoes, and tomatoes where chloride can damage quality or burn roots.
Fertigation & Foliar Spray: The water-soluble powder is suitable for drip irrigation, sprinkler systems, and foliar application, ensuring rapid nutrient uptake.
Compound Fertilizer Raw Material: Used as a premium K-source for manufacturing NPK compound fertilizers.
Saline Soil Agriculture: Ideal for use in soils with high salinity levels as it has a lower salt index compared to Potassium Chloride.
Quality Enhancement: Increases sugar content in fruits, improves the burning quality of tobacco, and enhances the color of flowers.

For a related potassium fertilizer raw material with a different nutrient profile, see Monopotassium Phosphate.

Storage Conditions

Environment: Store in a cool, dry, and well-ventilated warehouse.
Moisture Protection: Although less hygroscopic than other fertilizers, it should still be kept away from rain and moisture. Keep bags tightly sealed.
Stacking: Store on pallets, avoiding direct contact with the floor. Do not stack too high to ensure stability.
Segregation: Keep away from sources of heat and incompatible materials.

Safety Precautions

Handling: Wear protective gloves, safety glasses, and a dust mask to avoid inhaling dust during application.
Skin Contact: Wash thoroughly with soap and water after handling. Prolonged contact may cause mild irritation.
Eye Contact: Rinse with plenty of water immediately if dust enters the eyes.
General: This product is non-toxic and non-flammable but should be kept out of reach of children and pets.

FAQ - Technical & Supply Chain

Q:
What is Potassium Sulfate CAS 7778-80-5?

A: Potassium sulfate, also called sulfate of potash or SOP, is the dipotassium salt of sulfuric acid with the formula K2SO4. It is supplied as white or off-white crystals, powder or granules and used mainly as a chloride-free potassium and sulfur fertilizer.
Q:
Why choose Potassium Sulfate instead of potassium chloride?

A: Potassium sulfate supplies potassium without chloride, making it suitable for chloride-sensitive crops such as tobacco, grapes, citrus, fruit trees, vegetables and potatoes. It also provides sulfur, an essential secondary plant nutrient.
Q:
How is water-soluble Potassium Sulfate used in fertigation?

A: Water-soluble-grade SOP dissolves readily and is used in drip irrigation, foliar feeding and liquid fertilizer formulations. Selecting the water-soluble grade with low water-insoluble matter helps avoid clogging in emitters and spray systems.
Q:
How soluble is Potassium Sulfate CAS 7778-80-5?

A: Potassium sulfate is commonly cited as dissolving at about 110 g/L at 20 C, with solubility increasing as temperature rises. It is less soluble than potassium chloride, so water-soluble grade and proper agitation are important for concentrated stock solutions.
Q:
What are the main applications beyond fertilizer?

A: In addition to agricultural and horticultural fertilizers, potassium sulfate is used in industrial chemical processes, glass manufacture and certain food or pharmaceutical applications where an appropriate grade is permitted.
Q:
Which specifications should I check before ordering SOP?

A: Confirm K2O content, sulfur content, chloride, moisture, pH, water-insoluble matter and particle size. Agricultural and water-soluble grades usually differ in chloride and water-insoluble limits, so match the specification to fertigation or dry-fertilizer use.

Ordering & Documentation

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