The use of fluid-bed combustor for burning by-products from an oil-shale retorting operation appears to be a viable method of increasing the useful energy that can be extracted from raw oil shale. It is, however, apparent that the chemistry and combustion characteristics of oil shale vary considerably and that the suitability of any particular oil shale for use in a fluid bed must be independently evaluated. In order to perform such an evaluation, it is necessary that pilot-scale screening tests be conducted using the oil shale being considered. Once a sufficient bank of test data for a variety of oil shales is available, the screening tests may no longer be necessary. 5 figures, 2 tables.