Electrostatic Separation of Coal Macerals

Present threats of energy shortages have placed an increasing importance on coal as a fossil fuel. Government restrictions on the maximum permissible S02 content in coal burning plant effluents have necessitated sulphur reduction processes. By using an apparatus developed by the researchers at the University of Western Ontario, it has been demonstrated that constituent macerals of the coal may be successfully triboelectrified and then separated in electrostatic fields. The electrification and separation of the pyrite maceral from coal by means of dilute phase fluidization and electric fields is discussed. Some results are also presented on the separation of the vitrinite, fusinite, exinite, and micrinite macerals as well as of coal fractions with high ash content. The results show the effectiveness of the triboelec-trification of the macerals in contact with one another and with the material used in the construction of the separator.