Dense Soda, also known as Heavy Sodium Carbonate or Na₂CO₃, is an alkaline inorganic salt that appears as a white, odorless, coarse-grained crystalline solid.
Unlike Light Soda Ash, the dense grade has higher bulk density and larger particle size, making it suitable for processes that require greater physical strength or slower dissolution rates.

Chemical Structure of Dense Soda

Chemical Name: Dense Sodium Carbonate
Chemical Formula: Na₂CO₃
Structure: Ionic crystalline lattice composed of Na⁺ and CO₃²⁻ ions
CAS Number: 497-19-8
EC Number: 207-838-8
Molecular Weight: 105.99 g/mol

Physical and Chemical Properties

Property	Description
Physical State	White crystalline solid, coarse granules
Apparent Density (20°C)	Approx. 1.04 g/cm³ (depending on compaction)
Bulk Density	1.0 – 1.2 g/cm³ (typically 1.1 g/cm³)
True Density	2.53 g/cm³
Boiling Point / Decomposition	Decomposes at high temperature to Na₂O and CO₂
pH (1% aqueous solution)	Approximately 11.4 – 11.6
Odor	Odorless
Corrosiveness	Non-corrosive under normal conditions; alkaline and irritating to skin and eyes
Chemical Stability	Stable under normal conditions; tends to cake when exposed to moisture

Applications of Dense Soda

Glass Industry

One of the three primary raw materials in glass manufacturing (along with silica and lime)
Reduces the melting point of silica and improves molten glass properties

Water Treatment

Used to adjust pH and reduce temporary hardness
Neutralizes acids and enhances precipitation efficiency

Detergent Manufacturing

Used in industrial laundry powders to increase alkalinity and remove hardness ions
Enhances the cleaning efficiency of surfactants

Pulp, Paper, and Textile Industries

Used for recovery of cellulose fibers and pulp cleaning
Controls acidity in bleaching and dyeing processes

Metallurgical and Petrochemical Industries

pH regulator in metal extraction processes
Alkaline cleaning agent or pH stabilizer in chemical plants

Advantages of Dense Soda

Higher bulk density → lower consumption compared to light soda ash
Reduced dusting → safer and cleaner handling and storage
High thermal and chemical stability
Cost-effective and readily available on an industrial scale
Compatible with a wide range of industrial systems

Disadvantages of Dense Soda

Strongly alkaline → requires care to avoid skin and eye contact
Reacts with acids → generates heat and releases CO₂ gas
Hygroscopic → absorbs moisture, leading to caking if improperly stored
Must be stored in dry conditions, away from acids and moisture sources

Safety and Handling Information

GHS Classification: Irritant – H319 (Causes serious eye irritation), H315 (Causes skin irritation)
Skin Contact: Use rubber or nitrile gloves
Eye Contact: Use safety goggles or face shield
Dust Inhalation: Wear filtered respirator masks in confined or dusty areas
Packaging: Multi-layer moisture-resistant bags, typically 25 kg or 50 kg
Storage Conditions: Store in a cool, dry, well-ventilated area, away from acids and humidity
Transportation: Non-hazardous solid; standard dry cargo classification