Sodium carbonate

Sodium Carbonate, commonly known as Soda Ash, Washing Soda, or Soda Crystal, is a white, odorless, inorganic compound that appears as a fine powder or granular solid.
It is one of the most widely used basic chemicals in the world and is supplied in three main grades: Light Soda Ash, Dense Soda Ash, and High-Purity Grade.

Chemical Structure

• Chemical Name: Sodium Carbonate

• Chemical Formula: Na₂CO₃

• Structure Type: Ionic, containing two Na⁺ ions and one CO₃²⁻ ion

• CAS Number: 497-19-8

• Molecular Weight: 105.99 g/mol

• Crystal Structure: Monoclinic (Anhydrous form)

• EC Number: 207-838-8

Physical and Chemical Properties

Applications of Sodium Carbonate

1. Glass Manufacturing

• The largest global application of sodium carbonate.

• Reduces the melting temperature of silica (SiO₂) and improves the flow of molten glass.

• Essential raw material in flat glass, container glass, and fiberglass production.

2. Detergents and Cleaning Products

• Acts as a strong alkaline builder in powdered and liquid detergents.

• Helps remove hardness ions (Ca²⁺ and Mg²⁺) and enhances surfactant performance.

• Used in industrial cleaning agents and laundry formulations.

3. Water Treatment

• Used to raise water pH and remove temporary hardness by precipitating calcium and magnesium ions.

• Applied in municipal, industrial, and boiler water treatment systems.

4. Food Industry (E500)

• Approved as Food Additive E500 (Sodium Carbonate).

• Used as a pH regulator, anti-caking agent, and leavening agent.

• Helps control acidity in carbonated beverages and acts similarly to sodium acid pyrophosphate in food formulations.

5. Metallurgy

• Used to desulfurize iron ore and assist in alumina extraction and copper refining processes.

• Acts as a fluxing and purifying agent in metal smelting.

6. Other Industries

• Leather tanning – pH control and neutralization

• Textiles – dyeing and finishing operations

• Pulp and Paper – delignification and pH control

• Paints and Coatings – pH buffer and pigment dispersion

• Petrochemical Processes – neutralizing and refining applications

Advantages of Sodium Carbonate

✅ Widely available and cost-effective
✅ Chemically stable under normal storage and handling conditions
✅ Environmentally friendly in permitted grades
✅ Non-toxic and safe to transport
✅ Efficient alkaline source for pH adjustment
✅ Suitable replacement for Sodium Hydroxide (NaOH) in many applications

Limitations

⚠️ Irritating to skin and eyes upon direct contact with aqueous solutions
⚠️ Absorbs CO₂ from air over time, forming sodium bicarbonate (NaHCO₃)
⚠️ Hygroscopic – tends to absorb moisture and form lumps during humid storage
⚠️ Limited use in processes sensitive to sodium ion contamination

Safety and Storage

• GHS Classification:
  Skin Irritant (Category 2); Eye Irritant (Category 2); STOT SE 3 (Respiratory Irritant)

• Personal Protective Equipment (PPE):
  Chemical-resistant gloves, safety goggles, dust mask or respirator

• Inhalation:
  May cause irritation of respiratory passages at high concentrations

• Skin/Eye Contact:
  Rinse immediately with plenty of cold water for at least 15 minutes

• Packaging:
  25 kg or 50 kg polypropylene bags, palletized, moisture-resistant

• Storage Conditions:
  Store in a cool, dry, well-ventilated area away from moisture

• Chemical Incompatibility:
  Avoid contact with strong acids (CO₂ evolution) and high humidity environments

Summary

Sodium Carbonate (Na₂CO₃) is an essential alkaline raw material used globally in glass manufacturing, detergents, water treatment, and numerous industrial processes.
With its strong basicity, high stability, and versatility, it remains one of the most important and cost-effective inorganic compounds in the chemical industry.