Potassium carbonate is a white or slightly yellow crystalline compound formed by the reaction of potassium hydroxide and carbon dioxide. Its chemical formula is K₂CO₃. As a strong alkali, potassium carbonate is soluble in water and alcohol. It is a hygroscopic substance, meaning it absorbs moisture from the air.
The chemical and physical properties of potassium carbonate are as follows:
- Molecular weight: 138.205 g/mol
- Melting point: 891 °C
- Boiling point: Decomposes
- Density: 2.43 g/cm³
- Solubility: High in water and alcohol, low in ether
Potassium carbonate has many areas of use. It is most commonly used in the glass, ceramic, soap, fertilizer, food, pharmaceutical, cosmetic, and textile industries. Some products and processes where potassium carbonate is used include:
- Glass: Potassium carbonate is used as a flux in glass production. It enhances the brightness, durability, and heat resistance of glass. It is especially used in the production of optical glass, crystal glass, television tube glass, and laboratory glassware.
- Ceramics: In ceramics, potassium carbonate is used to improve the fluidity and plasticity of the clay body. It also helps improve the structure and color of ceramic glaze.
- Soap: Potassium carbonate is used in soap making to enable the saponification of fatty acids. It also increases the softness and lathering ability of the soap.
- Fertilizer: Potassium carbonate is used as a potassium source in fertilizer production. Potassium is an essential element for plant growth, photosynthesis, and disease resistance.
- Food: In the food industry, potassium carbonate is used as a pH regulator, leavening agent, color stabilizer, and flavor enhancer. For example, it is used in products like noodles, chocolate, cheese, and confectionery.
- Pharmaceuticals: Potassium carbonate is used as a solvent, buffer, and antacid in the pharmaceutical industry. It also helps improve the bioavailability of certain drugs.
- Cosmetics: In the cosmetics industry, potassium carbonate is used as a humectant, emulsifier, and viscosity regulator. It also helps dissolve other ingredients in cosmetic formulations.
- Textiles: Potassium carbonate is used as a dyeing assistant in the textile industry. It improves the dispersion and fixation of dyes in the dye bath.
Potassium carbonate is also used in metal processing, corrosion prevention, wood preservation, and laboratory chemistry. It is a versatile chemical compound with a wide range of applications across many industries.