Ferrous Sulfate Heptahydrate Granules: Description and Applications Ferrous sulfate heptahydrate granules are a granular form of iron(II) sulfate with seven molecules of water of crystallization (FeSO₄·7H₂O). This compound appears as pale blue-green to greenish-yellow granules, depending on purity and storage conditions. It is highly soluble in water, making it suitable for various industrial, agricultural, and nutritional applications. Physical and Chemical Properties - Chemical Formula: FeSO₄·7H₂O - Molecular Weight: 278.02 g/mol - Appearance: Granular, free-flowing particles with a crystalline structure - Solubility: Readily dissolves in water (approximately 256 g/L at 20°C) - Stability: Slightly hygroscopic; may oxidize to ferric sulfate (Fe³⁺) upon prolonged exposure to air or moisture - Odor: Odorless - pH: Acidic in aqueous solutions (typically 3–4 for a 1% solution) Key Applications 1. Nutritional Supplement Ferrous sulfate heptahydrate is a widely used iron supplement to prevent or treat iron-deficiency anemia in humans and animals. The granules can be incorporated into fortified foods, animal feed, or pharmaceutical formulations to ensure adequate iron intake. 2. Water Treatment In wastewater treatment, it acts as a coagulant to remove phosphates and heavy metals. It also helps control hydrogen sulfide (H₂S) odors in sewage systems by precipitating sulfides as insoluble iron compounds. 3. Agriculture As a soil amendment, it provides essential iron for plant growth, particularly in alkaline or calcareous soils where iron availability is limited. It also corrects chlorosis (yellowing of leaves) in crops. 4. Industrial Uses - Pigment Production: Serves as a precursor for iron oxide pigments (e.g., red, black, or yellow oxides). - Chemical Synthesis: Used in the manufacture of other iron compounds, such as ferric sulfate and ferric chloride. - Wood Preservation: Acts as a component in wood-staining solutions. Handling and Storage - Store in a cool, dry place in tightly sealed containers to prevent moisture absorption and oxidation. - Avoid contact with strong oxidizing agents. - Use protective equipment (gloves, goggles) to prevent irritation upon direct exposure. Advantages of Granular Form - Improved flowability and reduced dust compared to powdered forms. - Easier dosing and handling in industrial processes. - Enhanced stability during storage and transport. Ferrous sulfate heptahydrate granules are a versatile and cost-effective iron source with broad utility across multiple sectors. Proper handling ensures optimal performance and safety in its applications.