Showing posts from September, 2012

Kiln burning continued..

When lime of high purity is required continuous separate feed kilns are used. The kiln is similar to the kiln described above except that two or four fireplaces are provided by the side of the kiln near the bottom. In the fireplaces coal or wood are burnt and the hot gases of combustion move up the shaft of the kiln. The advantage of using wood as a fuel is that the long flames are produced and the temperature of the limestone is not raised too much. When coal is burnt same steam is introduced which maintains a low temperature and forms water gas. The water gas so produced burns and heats the kiln up to a greater height. Lime stone is supplied to the kiln from the top and the lime removed from the bottom.
The Rotary kiln used for the burning lime is similar to that used for cement manufacturing but is much smaller in size and is worked at a lower temperature. It consists of an inclined steel cylinder 1.5 to 2.5m in diameter and 15m to 45m long, lined with refractory bricks. Limestone…

Manufacturing of the Lime

Manufacturing of the lime:
The manufacturing of the lime is done by following the process of collection of the lime stones, calcination of the limestone, and then slaking of the limestone.
Lime is of the three types. It is fat lime, hydraulic lime and the poor lime. If we have to prepare the fat lime then the quality of the limestone should be such that it contains about 90 to 95% of the limestone and should contain less than 5% of the impurities.
Collection of the Limestone:  The stones of the required quality are collected at the site of the manufacturing. For fat lime the pure form of the limestone may be used and for the hydraulic lime the kankar(contains 30% of clay) may be used. The burning  of the limestone may be done either in the clamp or it may be done in the kilns. Fuel used for the burning of limestone: wood, coal, coke, coal gas, charcoal, cinder & oil etc.
Clamp Burning:
Clamps are the temporary structures and they are used when the demand of the limestone is not muc…