Gypsum mineral is non-toxic. It is a very common sulfate and represented as CaSO4.2H2O and chemically known as calcium sulfate dihydrate. It consists of water and calcium sulphate attached to oxygen. Gypsum is helpful to animals, humans, and plants. Calcium sulphate, generally called natural gypsum, is obtained from nature in different forms, often as dihydrate (CaSO 4 2H 2 O) and as anhydrite (CaSO 4 ), which are the result of total or partial evaporation of inland seas and lakes. Both anhydrite and dihydrate exist in nature in a variety of forms. Depending upon the types, the uses of gypsum varies.
Uses of Gypsum Powder
Heating produces a white powder from gypsum stone. This fine powder is smooth and is called gypsum powder. It is first crushed, heat-dried and then powdered.
1. Gypsum is applied as fertilizer.
2. Gypsum helps to prevents soil erosion, improves soil composition, helps water and air movement, and promotes growth of plant root.
3. Gypsum helps to balance micronutrients present in soil.
4. Gypsum powder has an important role in making drywalls.
5. Gypsum powder has application in the preparation of various types of tofu.
Applications of Gypsum in Agriculture
Interest in using gypsum as a management tool to improve crop yields and soil and water quality has recently increased. Flue gas desulfurization (FGD) gypsum, a by-product of cleaning sulfur from coal-fired power plants, has been widely available in major agricultural-producing regions over the past two decades. Currently, reports on the long-term sustainability of FGD gypsum use in agricultural systems is rare. Consequently, the American Society of Agronomy has produced a Community on “By-product Gypsum Uses in Agriculture” and a unique collection of technical research articles on FGD gypsum applications.
Gypsum has significant application for providing nutrients to plants and condition soil for agricultural production.
1. Gypsum gives nutrients to plants by providing sulphur and calcium. Calcium helps plants absorb nutrients through the roots, and sulphur helps to improve crop yield.
2. It can improve acid soils.
3. It uses in treating aluminium toxicity.
4. Adding lime or gypsum to dispersive soils decreases the sodium exchange percentage, reduces dispersion, and increases stable soil structure.
Gypsum in Construction
An overview of the origins, genesis, varieties, and properties of gypsum follows by a discussion of the most commonly produced material from gypsum, known in France as ‘plaster of Paris’. (β-semi-hydrate), in the USA under that of ‘calcined gypsum’, and in Germany under that of ‘Stuckgips’.
The article also describes in detail the properties of plaster paste (setting, expansion, adhesion) and those of hard plaster (strength, weight, thermal expansion, volume and linear changes under the influence of humidity fluctuations, absorption water, paintability, corrosion, thermal and acoustic insulation behaviour and fire resistance).
Sustainable benefits of gypsum products as a construction material
In recent years, interest has been growing in the use of gypsum as one of the most sustainable mineral binders. This chapter covers a range of gypsum products based on different modifications of gypsum binders.
The sustainability of gypsum products during their life cycle is considered. A sustainable life cycle includes the energy efficiency of different manufacturing technologies for gypsum products, the use of industrial wastes containing calcium sulphate dihydrate as substitutes for natural gypsum and the recycling of the wastes from gypsum-based construction materials (plasterboards, moulds) where they arise.
Sustainable uses of fgd Gypsum in Agricultural system
Interest in using gypsum as a management tool to improve crop yields and soil and water quality has recently increased. The abundant supply and availability of flue gas desulfurization (FGD) gypsum, a by-product of scrubbing sulfur from combustion gases at coal-fired power plants in major agricultural producing regions within the last two decades, has contributed to this interest.
Sustainable uses of fgd gypsum in the agricultural system focus on three general areas:
- Mercury and other trace element impacts
- Water quality impacts
- Agronomic responses and soil physical changes
Sustainable agricultural production systems can benefit from the use of FGD gypsum. The environmental impacts of FGD gypsum are primarily positive, with only a few negative results observed, even when applied at rates representing cumulative 80-year applications. Thus, FGD gypsum, if adequately managed, represents an vital potential input into agricultural systems.
Gypsum for crop grain production
Gypsum s mainly used in tropical and subtropical agriculture when subsoil acidity is a crucial yield-limiting factor. However, the conditions that promote increased crop yield due to gypsum addition in no-till (NT) systems still need to be clarified. A field trial examined the effects of newly and previously surface-applied gypsum in a long-term NT system on the soil chemical properties, nutrition, and yield of corn, wheat, and soybean.
Gypsum applies on surface at 0 and 6 Mg ha−1 in 2004 on plots that had received gypsum previously at 0, 3, 6, and 9 Mg ha−1 in 1998. Surface-applied gypsum newly and previously improved exchangeable Ca and SO4–S availability throughout the soil profile and increased the cumulative grain yield of the crops. The loss of exchangeable K through leaching by gypsum application was low. And more significant mobility of exchangeable Mg than exchangeable K in soil was found due to gypsum addition.
An increase in Ca content in the corn, wheat, and soybean leaves and S content in the corn and wheat leaves occurred following the gypsum application. The use of gypsum showed economic viability to maximize crop grain production in long-term NT soil with a sufficient level of exchangeable Calcium (≥8 mmolc dm−3) and low levels of exchangeable Aluminium (≤4 mmolc dm−3) and Aluminium saturation (≤15%) in the subsoil layers (20–60 cm).
The Use of gypsum spheres for water flow routes determination
Firstly, Gypsum or plaster of Paris has been cast into spheres and placed in soils. The weight loss determines the relative water flow routes. Theoretical considerations and laboratory experimentation show that solutional weight loss of the material increases with increasing water flow.But it is independent of pH above pH 4. It results for gypsum sphere weight loss presents for soils. The tensiometres are used for the independenr measurement of moisture conditions. The data recommends that the weight loss method provides a viable time-integrated demonstration of relative water flow routes.
Other Benefits of Gypsum
- Uses of Gypsum Board
Gypsum board is also called plasterboard, drywall or wallboard. It contains a paper surface and a non-combustible core. These boards are easy to install, and it has distinguished fire resistance. It helps in sound isolation by prohibiting the transfer of unnecessary sound. Also Gypsum is cheap and has excellent durability.
It helps prevent cracks by performing as wadding in gypsum wallboard mixed compound. It also serves in the production of ornaments.
Supporting the life
Gypsum hels to purify still water by seperating the impurities. For example, adding gypsum to ponds, so the dirt particles settle down without harming the aquatic life.
It helps in treating orthopaedic and surgical casts.
Humans can consume it, and so it is present in food as additive ice cream, flour, blue cheese, white bread etc.