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Gypsum is moderately water-soluble (~2.0–2.5 g/L at 25 °C) [13] and, in contrast to most other salts, it exhibits retrograde solubility, becoming less soluble at higher temperatures. When gypsum is heated in air it loses water and converts first to calcium sulfate hemihydrate ( bassanite , often simply called "plaster") and, if heated ...
The construction industry is the number one user of phosphogypsum in 2020, with 10.5 Mt used as concrete set retarder and 3.5 Mt used in drywall. [13] It is also used as a chemical feedstock for producing sulfates, and as a soil conditioner similar to regular gypsum. [14]
In the form of γ-anhydrite (the anhydrous form), it is used as a desiccant. One particular hydrate is better known as plaster of Paris, and another occurs naturally as the mineral gypsum. It has many uses in industry. All forms are white solids that are poorly soluble in water. [5] Calcium sulfate causes permanent hardness in water.
Gypsum concrete is sometimes called gypcrete by construction professionals, [2] [3] as a generic name in common usage (but not in law), but that is an alteration of Gyp-Crete, a Maxxon trademark for its brand of gypsum concrete. [4] Other common brands of gypsum concrete include Levelrock [5] (from US Gypsum) and Firm-Fill. [6]
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
3) and water to also form gypsum while releasing CO 2: H 2 SO 4 + CaCO 3 + H 2 O → CaSO 4 · 2H 2 O + CO 2. Gypsum is relatively soluble in water (~ 1 – 2 g/L), so there is plenty of calcium and sulfates ions available for TSA. Simultaneously, carbonic acid (H 2 O + CO 2 ⇌ H 2 CO 3) dissolves calcite to form soluble calcium bicarbonate:
The most common use for portland cement is in the production of concrete. [17] Concrete is a composite material consisting of aggregate (gravel and sand), cement, and water. As a construction material, concrete can be cast in almost any shape desired, and once hardened, can become a structural (load bearing) element.
Cement powder in a bag, ready to be mixed with aggregates and water. [1] Cement block construction examples from the Multiplex Manufacturing Company of Toledo, Ohio, in 1905. A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together.