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Potassium carbonate (K₂CO₃) is a widely utilized inorganic compound with a long history of applications in glassmaking, soap production, food processing, and chemical manufacturing.
This article presents an in-depth analysis of potassium carbonate, covering its nomenclature, physical and chemical properties, methods of production, applications across industries, environmental impact, safety considerations, and future research directions.
By synthesizing available data, this article provides a holistic view of the compound’s role in modern industry and science.
Introduction
Potassium carbonate is an alkali metal carbonate that has been industrially important for centuries. Historically known as potash, it was one of the earliest potassium salts obtained from wood ashes and later through systematic production from potassium hydroxide.
Today, potassium carbonate is a critical raw material in diverse fields such as glass manufacturing, detergents, fertilizers, food processing, and pharmaceuticals. Its high solubility, moderate alkalinity, and ability to act as a buffering agent make it highly versatile.
Nomenclature and Identifiers
Chemical Name: Potassium Carbonate
Molecular Formula: K₂CO₃
Molar Mass: 138.205 g/mol
CAS Number: 584-08-7
EC Number: 209-529-3
UN Number (Transport): UN 1813 (Class 8, corrosive solid)
InChI: InChI=1S/CH2O3.2K/c2-1(3)4;;/h(H2,2,3,4);;/q;+1;+1/p-2
Synonyms:Carbonic acid, dipotassium salt,Dipotassium carbonate,Pearl ash,Potash
Salt of tartar
Historical Development
Early Production
Potassium carbonate has been known since antiquity, primarily derived from the ashes of hardwood trees.
When leached with water and evaporated, the soluble potassium salts, including potassium carbonate, remained as a residue.
This early material was referred to as potash, a name derived from "pot ashes."
Industrial Revolution Advances
With the expansion of glass and soap production in the 18th and 19th centuries, demand for potassium carbonate rose significantly.
Potash was exported extensively from regions with dense forests, such as Eastern Europe, Canada, and Russia.
Modern Production
In contemporary times, potassium carbonate is produced via industrial-scale synthesis, often by the reaction of potassium hydroxide with carbon dioxide.
This controlled method yields high-purity potassium carbonate suitable for specialized applications.
Chemical and Physical Properties
Structural Information
Crystal System: Monoclinic (anhydrous form)
Coordination: Ionic lattice composed of K⁺ cations and CO₃²⁻ anions.
Physical Properties
Appearance: White, hygroscopic, odorless solid (granular or powder).
Melting Point: ~891 °C (decomposes at higher temperatures).
Boiling Point: Not applicable (decomposes before boiling).
Density: 2.43 g/cm³ at 20 °C.
Solubility: Highly soluble in water (112 g/100 mL at 20 °C).
Hygroscopicity: Strongly hygroscopic, absorbs moisture from air.
pH (aqueous solution): ~11.6 at 1% solution.
Chemical Properties
Alkalinity: Moderately strong base in aqueous solution.
Reactivity:
Reacts with acids to form potassium salts and carbon dioxide.
Stable under normal storage conditions.
Absorbs CO₂ and moisture from the atmosphere.
Thermal Decomposition: At high temperatures, decomposes to potassium oxide (K₂O) and CO₂.
Production Methods
Traditional Methods
Historically produced by leaching wood ashes and evaporating the solution, yielding crude potash containing potassium carbonate, potassium hydroxide, and potassium chloride.
Modern Industrial Production
Reaction with Carbon Dioxide
Potassium hydroxide solution reacts with carbon dioxide to produce potassium carbonate:
2 KOH (aq) + CO₂ (g) → K₂CO₃ (aq) + H₂O (l)
The solution is evaporated and crystallized to yield solid potassium carbonate.
Double Decomposition Method
Potassium carbonate can also be prepared by reacting potassium chloride with ammonium carbonate, followed by crystallization.
Electrochemical Routes
Less common but used in specialty applications, involving electrolytic conversion of potassium salts.
SAFETY INFORMATION ABOUT POTASSIUM CARBONATE
First aid measures:
Description of first aid measures:
General advice:
Consult a physician.
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
If inhaled:
If breathed in, move person into fresh air.
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately.
Wash off with soap and plenty of water.
Consult a physician.
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
If swallowed:
Do NOT induce vomiting.
Never give anything by mouth to an unconscious person.
Rinse mouth with water.
Consult a physician.
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment.
Avoid breathing vapours, mist or gas.
Evacuate personnel to safe areas.
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste.
Keep in suitable, closed containers for disposal.
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place.
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles.
Faceshield (8-inch minimum).
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
Skin protection:
Handle with gloves.
Gloves must be inspected prior to use.
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product.
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices.
Wash and dry hands.
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls.
If the respirator is the sole means of protection, use a full-face supplied air respirator.
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions.
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company.
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product
