General Process Information
Limestones are transported to the plant from the mine and goes through primary crushing and sieving.
The crushed limestone than goes through a washing and drying process and enters a secondary crusher to extract limestone for chemical usage (that will be additionally processed) and aggregates for construction
Quicklime is made by heating crushed and sorted limestone in either a rotary or shaft kiln. The limestone (CaCO3) breaks down into calcium oxide, i.e. quicklime, (CaO) and carbon dioxide (CO2). This reaction, termed calcination, requires temperatures of approximately 1100 degrees Celsius. In a rotary kiln the heating process lasts about six hours; in a shaft kiln calcination takes about 24-36 hours. When the quicklime comes out of the kiln it is in lumps, grains and powder.
The handling and storage of quicklime requires great care since it is very reactive. If it comes into contact with water, it reacts violently, giving off heat and converting into slaked lime.
Slaked lime is slaked by adding water to quicklime. The calcium oxide reacts with the water and is transformed to calcium hydroxide (Ca(OH)2), i.e. slaked lime, which is a dry, light-coloured powder.
The quicklime products are used in the manufacturing processes of steel, in upgrading processes of sulphide ore, in making paper pulp, and for cleaning drinking and waste water. Flue gases in coal-fired power plants are also cleaned with quicklime.
Slaked lime is used for cleaning drinking and waste water as well as in the metallurgical and building industries.