Abstract: Low rank coals such as subbituminous or lignites containing more than about 10 weight percent moisture are dried and passivated against reabsorption of moisture in a fluidized bed by heating the particulate coal with a warm inert gas passing upwardly through the bed and simultaneously coating the warm particulate coal with a heavy liquid hydrocarbon material. Such coating aids in the removal of the moisture and prevents the reabsorption of moisture by the coal and thereby prevents consequential heating and possibly spontaneous ignition of the coal during its subsequent transportation or storage.

Abstract: Low rank coals such as subbituminous or lignites containing more than about 10 wt. % moisture are first dried and then passed to a fluidized bed where the coal is passivated against reabsorption of moisture by coating the warm coal particles with a heavy liquid hydrocarbon material. Such coating substantially prevents the reabsorption of moisture in the coal, and thereby prevents autogenous heating and possible spontaneous ignition during subsequent transportation or storage of the passivated coal.