Barium Hydroxide: A Comprehensive Technical Profile

1. Chemical Identity & Basic Properties

Systematic Name:Barium dihydroxide
CAS Number:17194-00-2 (anhydrous), 12230-71-6 (octahydrate)
EC Number:241-234-5

Key Characteristics:

• Hyroscopicity:Readily absorbs CO? from air to form barium carbonate

• Crystal System:

  • Anhydrous: Orthorhombic (Pnma space group)

  • Octahydrate: Monoclinic (P2?/c space group)

• Refractive Index:1.50 (octahydrate)

• Magnetic Susceptibility:-72.010?? cm/mol

2. Advanced Physical-Chemical Data

Thermodynamic Properties

Phase Behavior

• Eutectic Point:With water at -78C (35.7 wt% Ba(OH)?)

• Dehydration Steps:

  1. Octahydrate ? Trihydrate at 55C

  2. Trihydrate ? Monohydrate at 130C

  3. Monohydrate ? Anhydrous at 300C

3. Industrial-Scale Production

Modern Manufacturing Processes

1. Continuous Hydration Reactor System

   • BaO + H?O ? Ba(OH)? (?H = -105 kJ/mol)

   • Temperature control at 80-90C

   • Yield: >98% pure product

2. Electrodialysis Method

   • Membrane-based separation from BaCl? solutions

   • Energy consumption: ~3.5 kWh/kg

3. High-Purity Crystallization

   • Multi-stage vacuum crystallization

   • Produces 99.99% pure crystals for electronic applications

Quality Specifications (Industrial Grade)

4. Advanced Applications

Emerging Technological Uses

• Superconductor Precursor:For YBCO thin film deposition

• Solid Oxide Fuel Cells:Electrolyte dopant

• Perovskite Solar Cells:Intermediate layer fabrication

Specialty Chemical Applications

• Organobarium Synthesis:Grignard-type reactions

• Polymer Stabilization:For high-temperature resins

• Nuclear Applications:Neutron shielding compositions

5. Safety & Toxicology

Exposure Limits

Ecotoxicity Data

• Daphnia magna EC50:2.1 mg/L (48h)

• Algal Growth Inhibition:0.8 mg/L (72h)

• Soil Microorganism Toxicity:LC50 = 45 mg/kg

6. Analytical Methods

Quantification Techniques

1. Gravimetric Analysis:

   • Precipitation as BaSO?

   • Detection limit: 0.1 mg/L

2. ICP-OES:

   • Wavelength: 455.403 nm

   • Linear range: 0.01-100 ppm

3. Ion Chromatography:

   • Column: Dionex IonPac CS12A

   • Eluent: 20 mM methanesulfonic acid

7. Storage & Handling Protocols

Optimal Storage Conditions

• Temperature:15-25C

• Humidity:<40% RH

• Container Type:Polyethylene with double sealing

• Shelf Life:24 months (unopened)

Spill Management

1. Small Spills:

   • Absorb with vermiculite

   • Neutralize with dilute sulfuric acid

2. Large Spills:

   • Contain with sand bags

   • Professional hazardous material team required

8. Global Market Overview

Production Capacity

Price Trends (2023)

• Industrial Grade:$1,200-1,500/ton

• Electronic Grade:$8,000-12,000/ton

• Pharma Grade:$15,000-20,000/ton

9. Recent Research Developments

Cutting-Edge Studies (2022-2023)

1. CO? Capture:

   • Absorption capacity: 2.3 mmol CO?/g at 25C

   • Regeneration efficiency: 92% after 50 cycles

2. Battery Applications:

   • Solid electrolyte additive for Li-S batteries

   • Improves cycle life by 300%

3. Nanomaterial Synthesis:

   • Template for BaTiO? nanowires

   • Aspect ratio control up to 1:500

10. Regulatory Update

Recent Changes (2023)

• EU REACH:New restrictions on industrial uses

• US EPA:Added to Toxics Release Inventory

• China:New export controls on high-purity grades

Conclusion

Barium hydroxide continues to evolve as a technically significant compound, finding new applications in advanced materials and green technologies while facing increasing regulatory scrutiny. The development of safer handling technologies and closed-loop production systems will likely determine its future industrial viability. Ongoing research into its nanoscale applications suggests potential breakthroughs in energy storage and environmental technologies, positioning this classic chemical for 21st century challenges.