Gypsum is an inert mineral and it is composed of calcium sulfate dehydrate (CaSO4.2H20). It is usually found in sedimentary rock formations that are mined or quarried then crushes and powdering it, and calcines it to remove chemically bound water. Gypsum is usually white and colorless, (or greyish in color). it can also be found in the shades of different colors (such as pink, yellow, brown, and light green, mainly due to the presence of impurities). Gypsum crystals can be quite large, and are considered to be some of the largest crystals found in nature. When it is transparent and cleavable, it is called Selenite. Granular and opaque one is called Alabaster and used in ornamental and jewellery industry.
Gypsum has a wide field of application and used in almost everything due to its softness and sturdiness. Its industrial use importance is outstanding. According to historians, for centuries (especially in Medieval and Renaissance times) plaster of paris mixed with glue had been applied to wood panels, plaster, stone, or canvas to provide the ground for oil painting by engineers and artists.
The density, color, configuration are all included in grading and some place produce such astonishing gypsum that they are legendary, such as Turkey has the best quality gypsum plaster reserves in the world.
Applications Of Gypsum
Plaster of Paris
Hard Wall Plaster
Hard Finish Plaster
Self levelling screeds
Set retarder in portland cement
In making fertilizer and tofu
Gypsum is a source of fertilizer sulfur. Gypsum Decreases Loss Of Fertilizer Nitrogen to the Air. Calcium from gypsum can help decrease volatilization loss of ammonium nitrogen from applications of ammonia, ammonium nitrate, urea, ammonium sulfate, or any of the ammonium phosphates. It is a coagulator in making tofu.
- Regular use of gypsum is essential to the sustainability of most irrigated soils. It provides a greater stability of soil organic matter, more stable soil aggregates, improved water penetration into soil, and more rapid seed emergence. From 25 to 100 percent more water is available in gypsum-treated soils than in nontreated soils.
- It provides calcium which is needed to flocculate clays in acid and alkaline soil.
- It helps reclaim sodic soils.
- Gypsum-treated soil has a lower bulk density compared with untreated soil.
- It is a calcium source which is a major mechanism that binds soil organic matter to clay in soil which gives stability to soil aggregates and it is also essential to the biochemical mechanisms by which most plants nutrients are absorbed by roots.
- It has an ability to decrease and prevent the crust formation on soil surfaces which result from rain drops or from sprinkler irrigation on unstable soil.
- it decreases the swelling and cracking associated with high levels of exchangeable sodium on the montmorillonite-type clays.
- The sulfate in gypsum that is taken up by plants and metabolized releases the associated oxygen which is a source of oxygen to plant roots although a limited source.
- It is a source of calcium which is a major mechanism that binds soil organic matter to clay in soil which gives stability to soil aggregates.
- It improves the solute concentration of low-solute water used for irrigation and also helps breaking up compacted soil and decrease penetrometer resistance.
- It improves water infiltration rates into soils and also the hydraulic conductivity of the soil.
- It quickly decreases the pH of sodic soils or near sodic soils from high values to the acceptable values for growth of most crop plants and is resulted in a large increase in water retention at a given tension compared with controls.
- The calcium in gypsum also acts as a regulator of the balance of particularly the micronutrients, such as iron, zinc, manganese and copper, in plants.
- In shampoos and toothpastes ( binding and thickening property of gypsum)
- Pigments and/or Fillers for cosmestics and drugs
- Control the tartness when wine making.
- Making surgical splints and orthopedic casts in dental use.
- Subsidence control in underground mines
- Glass Making