Zinc Sulfate Monohydrate (ZnSO₄·H₂O)
Zinc Sulfate Monohydrate (ZnSO₄·H₂O), also known as zinc sulfate monohydrate, is a white crystalline powder or granules with a molecular formula of ZnSO₄·H₂O and a molecular weight of 179.47 g/mol. Its CAS registry number is 7446-19-7. It is odorless, has a density of 3.28 g/cm³, and is highly soluble in water but insoluble in alcohol. Its aqueous solution is acidic, with a pH of 4.0-5.6 (50g/l, H₂O, 20°C). It is non-flammable and stable under normal storage conditions. Below is a detailed introduction to Zinc Sulfate Monohydrate:
Physical and Chemical Properties
Zinc Sulfate Monohydrate is a coordination compound formed by zinc ions and sulfate ions. It exhibits high thermal stability and remains stable when stored away from oxygen and moisture. Its linear formula is ZnSO₄·H₂O. It is highly reactive and can easily catalyze various organic reactions. Its hydrolytic sensitivity is classified as level 0, indicating it forms stable aqueous solutions. When heated above 680°C, it decomposes into sulfur dioxide gas and zinc oxide fumes, both of which are hazardous.
Production Methods
Zinc Sulfate Monohydrate can be produced by reacting zinc-containing materials (such as zinc metal, minerals, oxides, etc.) with sulfuric acid. For example, zinc oxide can be treated with sulfuric acid to produce zinc sulfate solution, which is then crystallized and dried to obtain the final product. It can also be recovered through acid leaching of zinc oxide ore, zinc hydroxide, or industrial by-products.
Applications
Agriculture: Zinc Sulfate Monohydrate is an important trace element fertilizer in agriculture. Zinc is one of the essential nutrients for plant growth, involved in physiological processes such as photosynthesis, respiration, and growth hormone synthesis. It promotes plant growth and development. Zinc deficiency in plants can lead to symptoms like yellowing, dwarfing, and leaf deformation, affecting yield and quality. Zinc Sulfate Monohydrate can correct zinc deficiencies in crops such as wheat, rice, corn, and citrus fruits. It can be applied as a foliar spray, basal fertilizer, or seed treatment. For foliar spraying, a solution of 1-2 kg/ha is generally recommended. As a basal fertilizer, it is typically applied at 3-5 kg/mu, depending on soil conditions and crop requirements.
Animal Feed: As a zinc source additive in animal feed, Zinc Sulfate Monohydrate plays a vital role in the healthy growth of animals. Zinc is an essential trace element in animals, widely involved in physiological processes such as the immune system, skin health, bone development, and appetite regulation. It enhances animal immunity, promotes bone and skin health, improves feed conversion efficiency, and supports growth. It is usually added to animal feed in powder or granular form. Common addition rates vary by species and growth stage, typically 50-100 g of zinc per ton of feed.
Pharmaceutical Industry: Zinc Sulfate Monohydrate is widely used as a zinc supplement in the pharmaceutical industry to treat zinc deficiency. Zinc is crucial for maintaining the immune system, promoting wound healing, and supporting growth and development. It is commonly used to address conditions such as poor appetite, immune deficiency, and skin disorders. It is also an ingredient in topical medications like astringents and antifungal agents.
Industrial Applications: In the electroplating industry, Zinc Sulfate Monohydrate is used as an additive in electroplating solutions to improve the uniformity, smoothness, and corrosion resistance of plated layers. It is also used to produce zinc salts, zinc oxides, and other compounds, which are applied in rubber, pigments, paints, and other fields. Additionally, it serves as a coagulant in rayon production, a leather preservative, an electrolyte in zinc electroplating, a mordant in dyeing, a zinc supplement in brewing, and a corrosion inhibitor in cooling systems and industrial pipelines.
Water Treatment: Zinc Sulfate Monohydrate acts as a clarifying agent to improve water quality by aiding in the removal of impurities and controlling algae growth in ponds, reservoirs, and water systems.
Cosmetics and Personal Care: Due to its antimicrobial properties, Zinc Sulfate Monohydrate is a component in anti-dandruff shampoos and acne treatments.
Safety and Handling
Zinc Sulfate Monohydrate is non-flammable but may release toxic zinc oxide fumes and sulfur oxides when heated to decomposition. It is corrosive to the skin and eyes. During handling, operations should be conducted in well-ventilated areas, and protective clothing, gloves, and masks should be worn. In case of accidental contact with the skin or eyes, rinse immediately with large amounts of water and seek medical attention. Store in a cool, dry, and well-ventilated environment, sealed and protected from moisture and heat. Keep away from oxidizing agents and incompatible materials.
Zinc Sulfate Monohydrate is a versatile compound with unique physical and chemical properties. It plays a significant role in agriculture, animal feed, pharmaceuticals, and industrial processes. However, due to its corrosive nature, strict safety measures must be observed during handling and use to ensure safe application.