Barium compounds are essential industrial chemicals with a wide range of applications across oil and gas, chemical manufacturing, glass, ceramics, and water treatment industries. Two of the most commercially important are barium chloride dihydrate (BaCl₂·2H₂O) and barium hydroxide monohydrate (Ba(OH)₂·H₂O). Despite being derived from the same base element, they have fundamentally different chemical properties and industrial uses.
Barium Chloride Dihydrate: Properties and Key Applications
Barium chloride dihydrate (CAS 10326-27-9) is a white crystalline salt, highly soluble in water (37.5 g/100 mL at 25°C). It is one of the most water-soluble barium salts, making it the preferred barium source in applications where aqueous delivery is required.
- Formula: BaCl₂·2H₂O | MW: 244.26 g/mol | Ba content: ~56.2%
- Purity (industrial): 99% min BaCl₂
Major applications:
- Oil & gas drilling fluids: Barium chloride is used to increase the density of completion and workover brines (clear brine fluids). Combined with calcium chloride and calcium bromide, it formulates high-density brines used to control wellbore pressure without solids. Target densities up to 11.7 lb/gal (1.4 SG) are achievable with BaCl₂-based brines.
- Heat treatment of metals: Used as a component in salt bath furnaces for hardening, carburizing, and nitriding of steel. BaCl₂ salt baths operate at 820–1050°C, providing uniform heat transfer and protecting metal surfaces from oxidation during the process.
- PVC stabilizers: Barium-zinc (Ba/Zn) composite stabilizers — where barium chloride is a starting material — are widely used as thermal stabilizers in PVC processing, providing long-term heat stability and lubricity.
- Chemical synthesis: Used as a source of Ba²⁺ ions for precipitation reactions to produce other barium salts (barium sulfate, barium carbonate, barium chromate). Also used in analytical chemistry as a reagent for sulfate detection.
- Leather tanning: Historically used in the tanning industry to remove sulfate from hide processing liquors.
Barium Hydroxide Monohydrate: Properties and Key Applications
Barium hydroxide monohydrate (CAS 22326-55-2) is a strong base — one of the strongest soluble hydroxides commercially available. It is distinctly different from barium chloride in its alkaline chemistry and is used in applications that specifically require both a barium source and a strong base.
- Formula: Ba(OH)₂·H₂O | MW: 189.36 g/mol | Ba content: ~72.7%
- Purity (industrial): 95% min Ba(OH)₂·H₂O
- pH of 0.1M solution: ~13.4
Major applications:
- Sugar refining (defecation): Barium hydroxide is used in the Steffens process to remove sucrose from molasses by forming insoluble barium saccharate. While this application has declined with the rise of ion-exchange methods, it remains in use in some beet sugar refineries.
- Organic synthesis: Acts as a strong, relatively selective base in ester hydrolysis (saponification), aldol condensations, and Claisen condensations. Its low solubility in organic solvents makes it a useful heterogeneous base catalyst. Used in the synthesis of pharmaceuticals, agrochemicals, and fine chemicals.
- Epoxy curing agent: Barium hydroxide catalyzes the curing of epoxy resins, especially in electrical insulation and potting compound applications where ionic contamination from amine-based curatives is undesirable.
- Water treatment: Used for CO₂ absorption (as a Ba(OH)₂ solution to precipitate barium carbonate), and to remove dissolved sulfate from process water or waste streams as insoluble BaSO₄.
- Analytical chemistry: Standard solution for titrating weak acids, and reagent for detecting CO₂ (turns milky as BaCO₃ precipitates). Used in the preparation of barium oxide (BaO) by thermal decomposition.
Barium Chloride vs Barium Hydroxide: Key Comparison
| Property | Barium Chloride Dihydrate | Barium Hydroxide Monohydrate |
|---|---|---|
| CAS | 10326-27-9 | 22326-55-2 |
| pH (aqueous) | ~6–7 (neutral) | ~13.4 (strongly alkaline) |
| Water solubility | 37.5 g/100 mL | ~3.9 g/100 mL (limited) |
| Counter ion | Chloride (Cl⁻) | Hydroxide (OH⁻) |
| Primary use sector | Oil & gas, metallurgy, PVC | Organic synthesis, refining |
| Strong base character | No | Yes |
| Reacts with acids to | Produce BaCl₂ salts + HCl | Neutralize, produce Ba salts + H₂O |
Safety Considerations
All soluble barium compounds are toxic if ingested, affecting the cardiovascular and nervous system. Both barium chloride and barium hydroxide are classified as hazardous materials:
- Barium chloride dihydrate: UN 1564 (Class 6.1, Toxic solid). Handle with gloves and eye protection. Avoid creating dust.
- Barium hydroxide monohydrate: UN 1564 (Class 6.1, Toxic solid) with additional corrosive hazard due to strong alkalinity. Full PPE required including face shield and chemical-resistant gloves.
Both products should be stored in sealed containers away from acids, moisture, and food products. Consult MSDS documentation before handling.
Sourcing Barium Compounds from China
Hainan Unifarm Chemical supplies industrial-grade barium chloride dihydrate and barium hydroxide monohydrate to industrial buyers worldwide. Standard packaging is 25 kg polyethylene-lined woven bags on pallets. FCL and LCL shipments are available with full export documentation (COA, MSDS, customs declaration).