Nordkalk
Limestone-based solutions for industry, agriculture and environmental care
Products
Use of products
Quicklime and slaked lime
Quicklime
Quicklime or calcium oxide is sold with brand name Nordkalk QL.
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.
Nordkalk produces quicklime at five locations in Finland, two in Sweden and one in Estonia and Russia. In Norway Nordkalk is a co-owner in NorFraKalk AS, which has a lime kiln in Verdal.
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
The brand name for slaked lime or calcium hydroxide is Nordkalk SL.
Slaked lime is used for cleaning drinking and waste water as well as in the metallurgical and building industries.
Nordkalk manufactures slaked lime at two locations in Finland and at one in Sweden.
The 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.