Calcium sulfate, also known as gypsum, is a chemical compound with the formula CaSO4. It occurs naturally as a mineral and is commonly used in various industrial and agricultural applications.
In its natural form, calcium sulfate exists as a dihydrate (CaSO4.2H2O), which is also known as gypsum. Gypsum is a soft, white or gray mineral that is commonly used in the construction industry to make plaster and drywall.
Calcium sulfate is also used as a food additive, where it is known as E516. It is used as a firming agent, as well as to regulate acidity and as a nutrient supplement.
In addition, calcium sulfate is used in the production of cement, as a soil conditioner, and as a component in some fertilizers. It is also used in the production of paper and in various other industrial processes.
Calcium sulfate
Calcium sulfate (or calcium sulfate) is the inorganic compound with the equation CaSO4 and related hydrates. As γ-anhydrite (the anhydrous structure), it is utilized as a desiccant. One specific hydrate is otherwise called mortar of Paris, and another happens normally as the mineral gypsum. It has many purposes in industry. All structures are white solids that are inadequately solvent in water. Calcium sulfate causes extremely durable hardness in water.
Hydration states and crystallographic structures
The compound exists in three levels of hydration corresponding to different crystallographic structures and to minerals:
- CaSO4 (anhydrite): anhydrous state. The structure is related to that of zirconium orthosilicate (zircon): Ca2+ is 8-coordinate, SO2−4 is tetrahedral, O is 3-coordinate.
- CaSO4·2H2O (gypsum and selenite (mineral)): dihydrate.
- CaSO4·1/2H2O (bassanite): hemihydrate, also known as plaster of Paris. Specific hemihydrates are sometimes distinguished: α-hemihydrate and β-hemihydrate.
Calcium sulfite
Calcium sulfite, or calcium sulphite, is a chemical compound, the calcium salt of sulfite with the formula CaSO3·x(H2O). Two crystalline forms are known, the hemihydrate and the tetrahydrate, respectively CaSO3·½(H2O) and CaSO3·4(H2O). All forms are white solids. It is most notable as the product of flue-gas desulfurization.
Nomenclature of Calcium sulphate
The nomenclature of calcium sulfate is based on the compound’s chemical formula, which is CaSO4. The name “calcium sulfate” is derived from the elements that make up the compound: calcium (Ca) and sulfate (SO4).
In addition to its common name, calcium sulfate is also known by various other names, depending on its form and intended use. For example:
- Gypsum: This is the naturally occurring dihydrate form of calcium sulfate, which has the chemical formula CaSO4·2H2O. Gypsum is commonly used in the construction industry to make plaster and drywall.
- Anhydrite: This is the anhydrous form of calcium sulfate, which has the chemical formula CaSO4. Anhydrite is used in the production of cement and as a drying agent.
- Plaster of Paris: This is a specific form of gypsum that has been calcined (heated) to remove the water of crystallization. The resulting powder can be mixed with water to form a paste that hardens quickly and is commonly used for casting and mold-making.
- E516: This is the food additive code for calcium sulfate, which is used as a firming agent, as well as to regulate acidity and as a nutrient supplement.
In general, the nomenclature of calcium sulfate is straightforward and based on its chemical composition and intended use.
Case Study on Calcium sulphate
Here is a case study on the use of calcium sulfate in agriculture:
Agricultural Case Study: Using Calcium Sulfate to Improve Soil Quality
Background:
A farmer in the Midwest United States was struggling with poor soil quality and reduced crop yields. The soil in the area was naturally high in clay content, which made it difficult for water to penetrate and for plant roots to grow. The farmer had tried various methods to improve soil quality, such as adding organic matter and using different tillage techniques, but had not seen significant improvements in crop yields.
Solution:
The farmer consulted with a soil scientist, who recommended the use of calcium sulfate to improve soil quality. Calcium sulfate, also known as gypsum, is commonly used in agriculture to improve soil structure and water infiltration. It can also help reduce soil salinity and improve nutrient uptake by plants.
The farmer purchased a large quantity of calcium sulfate and applied it to the soil using a spreader. The calcium sulfate was worked into the soil using a tillage implement, and then the soil was left to rest for several weeks before planting.
Results:
The use of calcium sulfate had a significant positive impact on the soil quality and crop yields. The improved soil structure allowed for better water infiltration and root growth, leading to healthier plants and higher crop yields. The farmer also observed a reduction in soil salinity and an improvement in nutrient uptake by plants.
Conclusion:
The use of calcium sulfate can be an effective method for improving soil quality and crop yields in areas with high clay content. It can also help reduce soil salinity and improve nutrient uptake by plants. However, it is important to consult with a soil scientist or agronomist to determine the appropriate application rate and timing for a particular soil type and crop.
White paper on Calcium sulphate
Here is a white paper on calcium sulfate:
Introduction:
Calcium sulfate is a versatile and widely used chemical compound that has numerous applications across a wide range of industries. Also known as gypsum, calcium sulfate is a naturally occurring mineral that can be mined from the earth or produced synthetically.
Physical Properties:
Calcium sulfate is a white or grayish-white powder that is odorless and tasteless. It is slightly soluble in water, with a solubility of approximately 2 grams per liter at room temperature. Calcium sulfate has a melting point of 1,460 degrees Celsius and a boiling point of 3,000 degrees Celsius. Its density is approximately 2.3 grams per cubic centimeter.
Applications:
Calcium sulfate has a wide range of applications across various industries, including:
- Construction: Calcium sulfate is commonly used in the construction industry to produce plaster, drywall, and cement. It is also used as a filler in some types of concrete.
- Agriculture: Calcium sulfate is used as a soil conditioner in agriculture to improve soil structure and water infiltration. It can also help reduce soil salinity and improve nutrient uptake by plants.
- Food industry: Calcium sulfate is used as a food additive to regulate acidity, as a firming agent, and as a nutrient supplement. It is approved by the US FDA as a generally recognized as safe (GRAS) substance.
- Pharmaceutical industry: Calcium sulfate is used as a filler in tablets and capsules, as well as in topical preparations such as ointments and creams.
- Other industrial applications: Calcium sulfate is used in a variety of other industrial applications, such as in the production of paper, in the manufacture of textiles and ceramics, and as a component in some fertilizers.
Conclusion:
Calcium sulfate is a versatile and widely used chemical compound that has numerous applications across various industries. Its physical properties and chemical characteristics make it a valuable resource for a wide range of applications, from construction to agriculture to food and pharmaceuticals. As with any chemical compound, it is important to handle calcium sulfate with care and to follow appropriate safety precautions when using it in industrial or agricultural settings.