ABSTRACT
During mining and processing of higher-grade coals, low-grade coals may be created (Couch, 1989).
A 1989 survey by Couch, summarized in a report by the Low-grade Coal Committee of the World Energy Conference, collected information on deposits of low-grade coal in countries generally known to possess significant quantities. Couch (1989 and 1988) and Christov and Todoriev (1989) defined low-grade coal as coal with a calorific value less than 16 MJIkg (approximately 4000 kcallkg) as mined. This differs only slightly from the working definition outlined in Chapter 1 (17.5 MJIkg, as mined, plus fuels with high impurity content). he data are presented in Table 3.1.
