Potassium Carbonate
High purity inorganic compound used in glass production, soap making, food additive (E501), and fire extinguishers
Overview
Potassium Carbonate (CAS No: 584-08-7), also known as "potash," is a white, water-soluble salt. It is an important potassium compound produced on an industrial scale. Due to its alkaline properties, it is used in many industrial applications.
Potassium carbonate is hygroscopic and absorbs moisture from the air. It is highly soluble in water and forms a strongly alkaline solution. Historically obtained from wood ashes, it is now produced by electrolysis methods.
Applications
Potassium Carbonate has a wide range of industrial and commercial applications:
Glass Production
Used as a melting point depressant and stabilizer in the production of special glasses, particularly optical glass and television tubes.
Soap and Detergents
Used as a softening and cleaning agent in the production of liquid soaps and special cleaning products.
Food Industry
Used as an acidity regulator, stabilizer, and leavening agent with the code E501. Particularly important as an alkalizing agent in cocoa production.
Agriculture
Used as a potassium fertilizer. Regulates soil pH and provides necessary potassium for plants.
Fire Extinguishers
An effective fire-suppressing component in dry chemical fire extinguishers, especially for oil and electrical fires.
Other Applications
Used for various purposes in paint, ceramics, pharmaceutical production, and the textile industry.
Technical Specifications
| Property | Value | Unit | Test Method |
|---|---|---|---|
| Chemical Formula | K₂CO₃ | - | - |
| CAS Number | 584-08-7 | - | - |
| EC Number | 209-529-3 | - | - |
| Molecular Weight | 138.21 | g/mol | - |
| Appearance | White granule or powder | - | Visual |
| Odor | Odorless | - | - |
| Density (25°C) | 2.43 | g/cm³ | ASTM D4052 |
| Melting Point | 891 | °C | ASTM D1015 |
| Water Solubility (20°C) | 1120 | g/L | ASTM E1148 |
| pH Value (1% sol.) | 11.6 | - | ASTM E70 |
| Purity | ≥99.0% | % | ASTM E291 |
| Moisture Content | ≤0.5 | % | ASTM D95 |
| Chloride (Cl) | ≤0.01 | % | ASTM D512 |
| Sulfate (SO₄) | ≤0.01 | % | ASTM D516 |
| Heavy Metal Content (Pb) | ≤10 | ppm | USP |
| Iron (Fe) | ≤10 | ppm | ASTM D1068 |
Safety Information
Hazard Symbols and Statements
Irritant Health Hazard Environmental Hazard
Personal Protective Equipment (PPE)
- Chemical-resistant gloves (nitrile or neoprene)
- Dust mask (at high concentrations)
- Protective goggles
- Lab coat or protective clothing
Storage Conditions
- Store in a cool, dry, and well-ventilated place
- Keep in original, tightly closed packaging
- Storage temperature: 15-30°C
- Keep away from acids and moisture
- Protect from moisture as it is hygroscopic
Fire Fighting
- Suitable extinguishing media: Water spray, dry chemical, CO₂
- Decomposes at high temperatures, releasing potassium oxide and carbon dioxide
- Firefighting personnel should use appropriate respiratory protection
Handling and Storage
Handling
- Avoid breathing dust/fume/gas/mist/vapors/spray
- Wash thoroughly after handling
- Use only in well-ventilated areas
- Wear protective gloves/protective clothing/eye protection/face protection
- IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing.
Storage
- Store in a well-ventilated place
- Keep container tightly closed
- Store in a dry place
- Store in a corrosive resistant container
- Keep away from acids
Disposal Considerations
Dispose of contents/container in accordance with local/regional/national/international regulations. Do not discharge into drains or the environment.
Frequently Asked Questions
Is potassium carbonate safe for food use?
Yes, when used in accordance with good manufacturing or feeding practice, potassium carbonate (E501) is generally recognized as safe (GRAS) as a direct human food ingredient.
What is the difference between potassium carbonate and potassium bicarbonate?
Potassium carbonate (K₂CO₃) is more alkaline than potassium bicarbonate (KHCO₃). The bicarbonate form is often used as a leavening agent in baking, while the carbonate form is more commonly used in industrial applications.
Can potassium carbonate be used in organic farming?
Potassium carbonate is permitted for use in organic farming as a pH regulator, but its use is subject to certification requirements and may be restricted in some organic standards.
What should I do if potassium carbonate comes into contact with skin or eyes?
For skin contact: Wash with plenty of water. For eye contact: Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing. If irritation persists, seek medical attention.
How is potassium carbonate produced?
It is produced industrially by the electrolysis of potassium chloride or by the reaction of potassium hydroxide with carbon dioxide. Historically, it was obtained by leaching wood ashes and evaporating the solution.