Potassium Carbonate Overview

Potassium carbonate is the primary component of Potash, which has been used from early history in textile bleaching, glass manufacture and soap production. In 1742, Potassium carbonate was first identified by Antonio Campanella as the primary component of potash. Potassium carbonate is also called as Carbonate of Potash, Dipotassium carbonate, Dipotassium salt, Pearl ash, Potash and salt of tartar.
 

Properties of Potassium carbonate

  • Potassium carbonate is soluble in water and insoluble in ethanol.
  • Potassium carbonate is a white salt at room temperature often appears as a wet solid.
  • Potash forms strongly alkaline solution with the water.
  • Vigorous reaction can occur when potassium carbonate is added to water. Dissociation of potassium carbonate in the water solution is an exothermic reaction.
  • The vapour pressure of the potassium carbonate is very low.
  • Potassium carbonate decomposes at a high temperature.
  • Potassium carbonate is a hygroscopic substance and therefore solid potassium carbonate slowly absorbs water from the air.

 

Preparation of Potassium carbonate

Potassium carbonate is commercially prepared by the electrolysis of Potassium chloride. The resulting Potassium hydroxide is then carbonated using carbon dioxide to form, Potassium carbonate, which is used to produce Potassium compounds.
2KOH + CO2 → K2CO3 + H2O

  • Drying Agent
  • Potassium carbonate is used as a drying agent in the laboratory for ketones, alcohol and amine. Potassium bicarbonate cannot be used as drying agent for highly acidic compound.

  • Glass Industry
  • Potassium carbonate is used in the manufacture of specialty glasses, such as optical lenses, television screens and cathode ray tubes. Potash is also used in the pottery industry for glazing pots.

  • Food Industry
  • Potassium Carbonate is used as a food additive in the production of grass jelly. It is used to tenderize tripe. German gingerbread recipes often use potassium carbonate as a baking agent. It is also used as a buffering agent in the production of mead or wine.

  • Fire extinguisher ingredient
  • Potassium carbonate is an efficient fire extinguishing agent for class B and class C type fire extinguishing agent. It can act as a scavenger of acidic fire ingredient by-products. Potassium carbonate is used as a dry powder fire extinguisher.

  • Fertilizer Industry
  • Potassium carbonate is used in the production of fertilizer industry for the manufacture of Potash. About 95% of Potash is used in the fertilizer industry. Potash is utilized in the fertilizer industry due to its advantages such as a taste enhancer to the fruits & vegetables, better restiveness power against diseases, better reservation of power, protection from drought & climatic conditions and to get stronger stems and roots. Potassium carbonate is used as an effective fertilizer for stabilizing pH of the soil and reduces the acidity of soil.

  • Chemical Industry
  • It is utilized in the manufacture of soap products. Soap with sodium carbonate is less mild than the commercial usage soaps. Potassium carbonate is used in the preparation of electrolyte for oxyhydrogen production. Potassium carbonate is also used in the water treatment industry for softening of hard water.

  • Pharmaceutical Industry
  • Potassium carbonate is used for stability in neurons to maintain equilibrium. In the pharmaceutical industry, Potassium carbonate is used as an antacid, electrolyte replinisher, excipient, leavening agent and pH control agent for medical formulations.

  • Other applications
  • Potassium carbonate is used in the polymerization of synthetic fibers and dehydrogenation of olefins. It is used as a detergent builder in detergents and also in cosmetics products. Potassium carbonate can also act as a high temperature polymer blowing agent.

PRODUCT IDENTIFICATION
CAS NO. 584-08-7
EINECS NO. 209-529-3
FORMULA K2CO3
MOL WT. 138.21
H.S. CODE 2836.40
TOXICITY Oral rat LD50: 1870 mg/kg
SYNONYMS
Potash; Salt of Tartar; Carbonic acid, Dipotassium salt;
DERIVATION
by the reaction of carbon dioxide with potassium chloride + magnesium oxide (Engel-Precht process) or electrolytic caustic lye.

PHYSICAL AND CHEMICAL PROPERTIES
PHYSICAL STATE

white powder or granular

MELTING POINT

891 C

BOILING POINT Decomposes
SPECIFIC GRAVITY 2.29
SOLUBILITY IN WATER

soluble (insoluble in alcohol)

pH 11.6 (Aqueous solution)

NFPA RATINGS

Health: 2 Flammability: 0 Reactivity: 1
FLASH POINT Not considered to be a fire hazard
STABILITY Stable under ordinary conditions

SALES SPECIFICATION
APPEARANCE white powder
ASSAY 98.5% min
CHLORIDES 0.1% max
SULPHATES 0.1% max
Fe 0.003% max
WATER INSOLUBLES 0.05% max
HEAVY METALS 10ppm max
MEAN PARTICLE SIZE 0.25 – 1mm