Name: Quick lime
Quicklime (also known as marble), Chemical Formula：CaO , which is a common inorganic compound. It is usually made from the natural rock, which is mainly composed of calcium carbonate,is calcined at high temperature.Finally,it decompose into carbon dioxide and calcium oxide. All natural rocks,whose the main component is alcium carbonate , can be used to produce quicklime. such as limestone, chalk, dolomitic limestone, etc.
Lime can be divided into quicklime and hydrated lime. The main component of quicklime is calcium oxide (CaO), which is obtained by calcining limestone with high calcium carbonate (CaCO Å) content in a ventilated lime kiln to above 900 ℃. It has water absorption and can be used as a desiccant. It is commonly used by Chinese people to prevent debris from getting damp.
The process of producing calcium hydroxide by reacting quicklime (CaO) with water is called the maturation or digestion of lime, which reacts with water (releasing a large amount of heat at the same time), or absorbs moisture from moist air. This is also known as mature lime, also known as hydrated lime. Hydrated lime dissolves 1.56 grams (20 ℃) in one liter of water, and its saturated solution is called lime water, which is alkaline and absorbs carbon dioxide in the air to form calcium carbonate precipitation. The product of the reaction, calcium hydroxide, is called hydrated lime or hydrated lime.
When lime is matured, a large amount of heat is released, resulting in a volume increase of 1-2 times. Lime with good calcination and high calcium oxide content matures faster, and also increases in heat release and volume. There are two commonly used methods for curing lime on construction sites: the slaked lime slurry method and the slaked lime powder method.
In the lime slurry formed after the slaking of quicklime, the lime particles form a colloidal structure of calcium hydroxide, with extremely fine particles (approximately 1 particle size) μ m) It has a large specific surface area (up to 10-30 m2/g) and can adsorb a thick water film on its surface, which can adsorb a large amount of water, thus having a strong ability to retain water, i.e. good water retention. Mixing it with cement mortar to form a mixed mortar can significantly improve the workability of the mortar.