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Burning (calcination) of calcium carbonate in a lime kiln above 900 °C (1,650 °F) [4] converts it into the highly caustic and reactive material burnt lime, unslaked lime or quicklime (calcium oxide) and, through subsequent addition of water, into the less caustic (but still strongly alkaline) slaked lime or hydrated lime (calcium hydroxide ...
Carbonatation is a slow process that occurs in concrete where lime (CaO, or Ca(OH) 2 ) in the cement reacts with carbon dioxide (CO 2) from the air and forms calcium carbonate. The water in the pores of Portland cement concrete is normally alkaline with a pH in the range of 12.5 to 13.5.
Calcium hydroxide is moderately soluble in water, as seen for many dihydroxides. Its solubility increases from 0.66 g/L at 100 °C to 1.89 g/L at 0 °C. [8] Its solubility product K sp of 5.02 × 10 −6 at 25 °C, [1] its dissociation in water is large enough that its solutions are basic according to the following dissolution reaction:
CaO + H 2 O → Ca(OH) 2 Ca(OH) 2 + CO 2 → CaCO 3 + H 2 O. In a laboratory, calcium carbonate can easily be crystallized from calcium chloride (CaCl 2), by placing an aqueous solution of CaCl 2 in a desiccator alongside ammonium carbonate [NH 4] 2 CO 3. [10] In the desiccator, ammonium carbonate is exposed to air and decomposes into ammonia ...
Calcium oxide (formula: Ca O), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic , alkaline , crystalline solid at room temperature . The broadly used term lime connotes calcium-containing inorganic compounds , in which carbonates , oxides , and hydroxides of calcium, silicon , magnesium ...
Ca(OH) 2 or CaO · H 2 O: Calcium hydroxide (portlandite) C-S-H: 0.6–2.0 CaO · SiO 2 · 0.9–2.5 H 2 O, with variable composition within this range, and often also incorporating partial substitution of Al for Si: Calcium silicate hydrate: C-A-H: Phase more complex than C-S-H: Calcium aluminate hydrate C-A-S-H: This is even more complex than ...
Calcium bicarbonate, also called calcium hydrogencarbonate, has the chemical formula Ca(HCO 3) 2. The term does not refer to a known solid compound; it exists only in aqueous solution containing calcium (Ca 2+), bicarbonate (HCO − 3), and carbonate (CO 2− 3) ions, together with dissolved carbon dioxide (CO 2).
Monocalcium dialuminate, CaO·2Al 2 O 3 (CA 2) (occurring in nature as grossite [5]) Monocalcium hexa-aluminate, CaO·6Al 2 O 3 (CA 6) (occurring in nature as hibonite, a representative of magnetoplumbite group [6]) In addition, other phases include: Dicalcium aluminate, 2CaO·Al 2 O 3 (C 2 A), which exists only at pressures above 2500 MPa. [7]