SODIUM SULPHATE ANHYDROUS: THE VERSATILE INDUSTRIAL WORKHORSE

Sodium sulphate anhydrous (Na₂SO₄) is an essential inorganic salt with widespread applications across multiple industries. This white crystalline powder, free from water molecules, serves as a key component in detergents, glass manufacturing, and chemical synthesis. With global production exceeding 6 million metric tons annually, it remains one of the most commercially significant sulphate salts.

Key Properties & Specifications

Physical & Chemical Characteristics

• Molecular Weight: 142.04 g/mol
• Appearance: White free-flowing powder
• Density: 2.66 g/cm³
• Melting Point: 884°C
• Solubility:
  • 4.76 g/100 mL (0°C)
  • 42.7 g/100 mL (100°C)
• pH: 7-9 (5% solution)

Technical Specifications

Major Industrial Applications

1. Detergent Industry (40% of global use)

• Function:
  • Filler and processing aid in powder detergents (10-30% content)
  • Improves flow properties and bulk density
• Case Study: Leading detergent brands use Na₂SO₄ to reduce production costs by 15-20% while maintaining cleaning efficiency

2. Glass Manufacturing (30%)

• Role:
  • Fluxing agent in glass melts (reduces melting point)
  • Prevents scum formation (0.5-1.5% of batch)
• Performance:
  • 1 ton Na₂SO₄ produces ~15 tons of glass
  • Reacts with silica at 1200-1400°C to release SO₂ gas

3. Textile Industry

• Dyeing Process:
  • Levels dye absorption (5-20 g/L in baths)
  • Improves color fastness
• Viscose Production:
  • Coagulation bath component

4. Chemical Synthesis

• Intermediate for:
  • Sodium sulphide production
  • Kraft pulping process
• Drying Agent:
  • For organic liquids (alternative to MgSO₄)

5. Food & Pharmaceutical

• Food Additive (E514):
  • Processing aid in caramel production
  • Diluent in powdered foods
• Pharmaceuticals:
  • Tablet disintegrant (5-15% w/w)
  • Laxative preparations

Production Methods

1. Natural Mining

• From mirabilite deposits (Na₂SO₄·10H₂O)
• Major sources: Canada, China, US

2. Chemical Synthesis

• Mannheim Process:
  • NaCl + H₂SO₄ → Na₂SO₄ + 2HCl (600°C)
• Byproduct Recovery:
  • From HCl neutralization
  • From rayon production

3. Environmental Recovery

• Flue gas desulfurization (FGD) systems
• Waste acid neutralization

Safety & Handling

✅ Non-Toxic: Generally recognized as safe (GRAS)
⚠ Handling Precautions:

• Dust may cause mild respiratory irritation
• Use N95 masks for powder handling
• Store in dry conditions (hygroscopic)

♻ Environmental Profile:

• Readily dissolves without bioaccumulation
• Low aquatic toxicity (LC50 >1000 mg/L)

Market Insights

Global Production

• Leading Producers:
  • China (40% of supply)
  • Canada (Natural Resources)
  • US (Elementis, Searles Valley)
• Price Range: $80-150/ton (bulk quantities)

Emerging Trends

• Circular Economy: Increased recovery from industrial waste streams
• High-Purity Demand: Growth in battery electrolyte applications
• Alternative Sources: Seawater extraction technologies

Comparison to Hydrated Forms

Conclusion

Sodium sulphate anhydrous continues to be an indispensable industrial material due to its chemical stability, low cost, and multifunctional properties. As industries evolve toward sustainable practices, new opportunities are emerging for this versatile salt in energy storage and waste recovery applications.