Lime Production Technology
Lime production technology refers to the process of producing lime from limestone or calcium carbonate (CaCO3) that has been heated to high temperatures in a lime kiln. This process is known as the lime cycle. It involves several different stages including quarrying, crushing, purifying, calcining, cooling and grinding.
The first stage in the lime cycle is quarrying. Quarries are used to extract limestone (or other forms of calcium carbonate) from the ground. The material is then transported to a crusher where it is broken down into broken chunks and then further crushed into a very fine powder.
Once the limestone has been crushed, it is heated in a lime kiln. Lime kilns reach temperatures of up to 1400°C, causing thermal decomposition of the limestone and producing quicklime (calcium oxide). The heat from the kiln also drives out impurities such as sand, dirt and clay.
The next stage is slaking. Slaking is the process of adding water to quicklime in order to turn it into calcium hydroxide (slaked lime). This reaction is exothermic, that is, it produces heat. This added heat can be used to further purify the lime.
The slaked lime is then cooled and fed into a calciner. In a calciner, the calcium hydroxide is heated at high temperatures (750-900°C) to convert it into calcium oxide (quicklime). The end result is a red-hot powder.
At this point, the lime is cooled. This can be done by adding in air, water or even lime stone from the quarry. This will reduce the temperature of the powder and improve its overall quality.
Finally, the cooled lime is ready for grinding. This can be done in a number of ways; ball milling, hammer milling, or attrition milling. Grinding breaks down the larger particles of lime and produces smaller particles which are suitable for use in a variety of products.
This is the basic outline of lime production technology. The process is designed to extract high quality lime from limestone, and to purify and transform it into a useful product. Lime is used in many industries, from agriculture to construction, and its production requires skill, precision and specialized equipment.
