Abstract: Compositions and methods of using rock dust are disclosed. A mine rock dust may be capable of being applied in a wet form. A moisture tolerant mine rock dust may include a hydrophobic inorganic particulate material. A moisture tolerant mine rock dust may be capable of being dispersed by a light blast of air. A method may include applying a mine rock dust at a concentration having little or no respirable mine rock dust. A method of applying a mine rock dust may include applying a mine rock dust in a wet form. The mine rock dust may be applied at a concentration having little or no respirable mine rock dust. The mine rock dust may include a hydrophobic inorganic particulate material.

Abstract: A heterogeneous composition for use as rock dust is disclosed. The heterogeneous composition includes a fine, wet ground inorganic particulate material treated with at least one fatty acid, a salt thereof, or an ester thereof, and a coarse, untreated, dry ground inorganic particulate material. Also disclosed is a heterogeneous composition including coal dust and mine rock dust including a fine, wet ground inorganic particulate material treated with at least one fatty acid, a salt thereof, or an ester thereof, and a coarse, untreated, dry ground inorganic particulate material. The amount of mine rock dust may be sufficient to render the coal dust explosively inert. The fine, treated, wet ground inorganic particulate material may be calcium carbonate. The coarse, untreated inorganic particulate material may be calcium carbonate. The fatty acid may be stearic acid.