Calcium sulfate

Calcium sulfate (CAS 7778-18-9), also sold as calcium sulphate anhydrous, is an inorganic mineral used across food, pharmaceutical, construction, and agricultural markets. It functions primarily as a filler, desiccant, and setting agent. In food manufacturing, it acts as a firming agent and calcium fortifier in products such as tofu, bread, and canned vegetables. Construction producers use it as a base component in plaster and wallboard compounds.

Pharmaceutical formulators incorporate it as a tablet diluent and binder, particularly in solid dosage forms requiring low moisture sensitivity. It is also used in agriculture to improve soil structure in clay-heavy soils. The material supplies calcium and sulfur to crops without significantly altering soil pH. Calcium sulfate is available as a fine white powder and in granular form, with particle size varying by intended use.

Recognized grades include food-grade (FCC), USP, and technical grade, each carrying different purity and impurity thresholds. These standards ensure the material meets specific safety and performance requirements. Anhydrous material is standard for desiccant and pharmaceutical applications, while hemihydrate and dihydrate forms serve construction and food sectors respectively. This versatility makes it a staple in industrial chemistry.