Abstract: A new process has been devised for the application of a mixture of calcium or magnesium chloride and a non-ionogenic wetting agent for the prevention of the spontaneous ignition of coal, especially during underground mining operations, by applying the same to the surface of the coal. The process involves boring of holes into the out-cropping coal and then forcing the mixture of calcium or magnesium chloride and wetting agent in an aqueous solution which contains 25 to 35% by weight of the mixture through the bore holes. A constant quantity of about 3 to 6 liters of solution per minute is pressed into the bore holes, the pressure being only sufficient to overcome the counter pressures occurring in the coal. The procedure greatly extends the time of effectiveness of the prevention of spontaneous ignition of the coal and eliminates to a large extent the expenditure of labor for supervision and retreatment of the surface of the coal now being experienced.

Abstract: A parachute-type mine stopping used in ventilation control comprises a parachute-like canopy suspended from straps or lines secured to a roof bolt or the like. After the lines are so secured, the stopping is erected by merely lifting the upper edge of the canopy into the airstream in the passage, the airstream causing the canopy to simply "pop" into place. In a preferred embodiment, a skirt is sewn to the peripheral edge of the canopy to improve sealing.

Abstract: A passive explosion barrier for suppressing the effects of an explosion in a mine gallery, or the like, comprises a receptacle containing an explosion suppressing substance adapted to be supported by framework adjacent the mine roof. In one embodiment, a corrugated face plate is hinged to the base of the receptacle on one side thereof. First and second support flanges are formed respectively on the upper end of the face plate and on the rim of the receptacle on the side thereof opposite the plate. The receptacle is mounted to the framework with the support flanges resting on first and second beams and with the face plate viewing the explosion source and oblique to a horizontal plane. The weight of the receptacle, and friction between the face plate flange and first beam, prevent the receptacle from releasing due to accidental disturbances. However, the force of wind accompanying an explosion acts against the face plate, causing it to both lift from the first beam and pivot toward the receptacle.

Abstract: A pressure sensitive exposion barrier which is activated by a static pressure rise. A liquid tight housing with a latched door contains the explosive suppression agent, usually water, until activation takes place. Upper hinges on the door allow it to be pivoted outwardly and its agent released. Normally a latch keeps the door locked until the pressure rise from the explosion causes a connected bellows assembly to be depressed. Once depressed, the latch is released and the door is forced outwardly by a biasing member to release the agent before the explosion arrives.