The Value of Calcium Sulfate, Anhydrous (Synthetic Anhydrite) in Pre-Packaged Dry-Mix Compounds

15 May 2024

In the ever-evolving construction industry, materials that offer superior performance and versatility are highly sought after. One such material is Calcium Sulfate, Anhydrous, commonly known as Synthetic Anhydrite. This compound is increasingly used in pre-packaged dry-mix compounds for various applications such as road repair patches, screeds, self-leveling underlayment (SLU), self-leveling flooring, tile adhesive, industrial grouts, and anchors. Synthetic Anhydrite serves as an excellent binding material, replacing traditional cement and providing numerous benefits.

Benefits of Using Synthetic Anhydrite

  1. Enhanced Fluidity for Self-Leveling Synthetic Anhydrite improves the fluidity of self-leveling compounds, ensuring a smooth and even surface. This property is particularly beneficial for flooring and underlayment applications.
  2. Improved Dimensional Stability Dimensional stability is crucial in construction materials to prevent cracking and warping. Synthetic Anhydrite offers excellent stability, ensuring the longevity and durability of the finished product.
  3. Excellent Mechanical Strength With superior mechanical strength, Synthetic Anhydrite enhances the structural integrity of the construction, making it ideal for industrial grouts and anchors.
  4. Superior Thermal Conductivity This compound also boasts high thermal conductivity, which is advantageous for applications requiring efficient heat transfer, such as in underfloor heating systems.

 Applications Beyond Construction

While its primary use is in construction, Synthetic Anhydrite is also valuable in other industrial fields. It plays a significant role in cement production, improving the properties of the final product. Additionally, it is used in the fertilizer industry, contributing to the nutrient content and effectiveness of fertilizers.

Production Methods of Synthetic Anhydrite

There are two primary methods of producing Synthetic Anhydrite: Flue Gas Desulfurization (FGD) and Hydrofluoric Acid (HF) production.

FGD is a process designed to remove sulfur dioxide (SO2) from the flue gases of power plants that burn coal or oil. FGD Anhydrite is a byproduct of this process, formed when calcium sulfate precipitates out of the flue gas.

  • Benefits:
    • High Purity: FGD Anhydrite has a very high purity level, making it an excellent ingredient for pre-packaged dry-mix materials.
    • Low Impurities: It contains minimal contaminants, such as heavy metals, making it safe for construction applications.
    • Consistency: FGD Anhydrite is consistent in quality, simplifying its use in pre-packaged dry-mix materials.

HF Anhydrite is produced through a chemical reaction between calcium carbonate and hydrofluoric acid.

  • Benefits:
    • Fast Setting: HF Anhydrite has a fast-setting time, beneficial for pre-packaged dry-mix materials that require a short drying time.
    • High Compressive Strength: It has a high compressive strength, making it a robust ingredient for pre-packaged dry-mix materials.

Conclusion

Synthetic Anhydrite, whether derived from FGD or HF processes, offers distinct advantages for pre-packaged dry-mix compounds in the construction industry. Understanding the differences between these production methods and their respective benefits can help industry professionals choose the right type of Anhydrite for their specific applications.