The CANMET Energy Technology Centre (CETC), sponsored by Luscar Ltd. and the Alberta provincial government, carried out a series of combustion trials on a number of washery rejects to determine whether they could be burned in an environmentally acceptable manner using both conventional and fluidized bed combustion (FBC). The paper presents details of tests using CETC 0.8 MWth circulating fluidized bed combustor (CFBC). The starting bed material (silica sand) and fuel ash have very distinctive SiO2 and Al2O3 contents, therefore, the SiO2/Al2O3 ratio of the bed material may be used as an indicator of the chemical steady state. The three fuels burned in the reactor were: raw coal (Obed #4), Obed Jig Rejects (Obed #7) and Obed Jig Middlings (Obed #10). These fuels required an additive, Cadomin limestone, to achieve the allowable SO2 emission levels recommended under the Canadian National Guidelines for Stationary Sources. However, NOx levels were always below the allowable emission levels for all three fuels. Other emissions such as CO and N2O appeared to be low and unlikely to pose problems. The combustion efficiency associated with these fuels was high, as might have been expected with a very reactive fuel, and at 850 °C was typically about 99%. Therefore, the CFBC technology appeared to be an entirely satisfactory technology for burning these fuels.