1. Construction

• Efflorescence Prevention: It reacts with soluble sulfates present in clay or shale during brick and tile manufacturing. This reaction prevents the formation of efflorescence, a white powdery residue on the surface of fired ceramics.
• Glaze Production: It acts as a flux in ceramic glazes, lowering the melting temperature and improving the glaze's durability and appearance. 

2. Metal treatment

• Chlor-alkali process: It is used to remove sulfate impurities from brine, which is a critical step in the chlor-alkali process to avoid damaging electrolysis cells.
• Preparation of Barium Compounds: It is a common starting material for synthesizing barium-containing compounds, like ferrites.
• Metal Surface Treatment: It plays a role in steel carburizing and metal surface treatment processes, potentially contributing to hardening or protective coatings.

3. Lubricants & Automobiles

• Increased Density: By adding barium carbonate, lubricants become denser, potentially reducing the risk of blowouts in certain applications.
• Vibrational Damping: It is used as a filler in vibrational mass damping applications, improving the performance of materials like brake linings and acoustic foams.
• Additive in Barium-Based Lubricants: It is a key component in barium-based grease and oil formulations, contributing to their lubricating and sealing properties.

4. Water Treatment

• Neutralizing Acids: It is a basic compound and reacts with acidic water, such as water with sulfuric acid, to neutralize it. This reaction reduces the acidity of the water, making it less corrosive and protecting pipes and equipment.
• Removing Sulfates: It reacts with sulfate ions in the water to form barium sulfate (BaSO4), which is a very insoluble compound. The barium sulfate precipitates out of the water, making it easy to remove through filtration.

5. Polymers & Resins

• Filler: It increases the volume and density of the polymer, improving its mechanical properties like impact bending strength, tensile strength, and scratch resistance.
• Stabilizer: It acts as a stabilizer, enhancing the thermal resistance and heat stability of the polymer.
• Sulphate Resistance: In polymers exposed to high sulphate concentrations, barium carbonate can improve the material's resistance to sulphate attack.