Studies of Washing Characteristics of Low Grade Coal and Design of a Coal Washing Plant

Abstract

A low grade coal is a coal which contains impurities which on burning pollute the environment. It contains Sulphates, Calcite, Pyrite, Silica, CaCO3, and Sulphates of CaCO, Sulphates from oxides which combine with silica to form complexes. It tends to form coal ash.Also, it contains sulphates which tends to decrease its Clinkering temperature.
All of the above lead to adopt various techniques to clean coal before using. One such method is Coal Washing. Various coal cleaning methods depending on the physical property difference, i.e. difference in their specific gravity or wetting characteristics. Specific graviy of pure coal is 1.2 to 1.7 and for impure coal is 1.7-4.9. In present work, an attempt has been made to study the different characteristics of coal washing by Float-and-Sink test. A design of a washing plant has been made with the help of data collected from this test.
The data collected simply shows the washing characteristics of washing of coal from which the coal can be varied from easy-to-wash to difficult-to-wash coal.