Abstract: A rock dusting composition composed of rock dust, e.g., limestone or other mineral dust, water, pumping aid, and polymer, e.g., acrylamide homopolymers, acrylamide copolymers, and combinations thereof, and a method for applying the composition to the surface of a mine. The composition has a water content and a polymer content sufficient to allow the polymer to (i) disperse water molecules within the composition and, upon drying of the composition, (ii) dissipate forming void spaces in the dried composition. The composition is useful for suppressing propagation of a flame and/or fire caused by ignition of coal dust and/or gas within a coal mine.

Abstract: A rock dusting apparatus comprising: a housing; a tank mounted within the housing which comprises a removable top wall member, a sidewall member and a bottom wall member configured to form an internal tank compartment for holding and mixing a rock dust composition; a mixer positioned on the bottom wall member for mixing the rock dust composition; a tank discharge port positioned on the bottom wall member or a lower portion of the sidewall member through which the rock dust composition can be discharged from the tank; a conduit extending from the tank discharge port to a housing discharge port; the conduit comprising a pump for transporting the rock dust composition through the conduit and through a discharge line operatively connected to the housing discharge port; and one or more motors mounted within the housing for powering the mixer and the pump.

Abstract: A rock dusting apparatus comprising: a housing; a tank mounted within the housing which comprises a removable top wall member, a sidewall member and a bottom wall member configured to form an internal tank compartment for holding and mixing a rock dust composition; a mixer positioned on the bottom wall member for mixing the rock dust composition; a tank discharge port positioned on the bottom wall member or a lower portion of the sidewall member through which the rock dust composition can be discharged from the tank; a conduit extending from the tank discharge port to a housing discharge port; the conduit comprising a pump for transporting the rock dust composition through the conduit and through a discharge line operatively connected to the housing discharge port; and one or more motors mounted within the housing for powering the mixer and the pump.

Abstract: A rock dusting composition composed of rock dust, e.g., limestone or other mineral dust, water, pumping aid, and polymer, e.g., acrylamide homopolymers, acrylamide copolymers, and combinations thereof, and a method for applying the composition to the surface of a mine. The composition has a water content and a polymer content sufficient to allow the polymer to (i) disperse water molecules within the composition and, upon drying of the composition, (ii) dissipate forming void spaces in the dried composition. The composition is useful for suppressing propagation of a flame and/or fire caused by ignition of coal dust and/or gas within a coal mine.

Abstract: In a safety closing device for gas pipe systems (1) with a valve (2) which is capable of being pressed against a valve seating (9) in a housing, especially a tubular housing, the valve (2), as a disc valve capable of being moved in the axial direction of the tubular housing (1), is movably supported against the force of a spring (5). The cross-section area of the valve head (7) is made smaller than the clear cross section of the housing (1) and is kept at a distance from the inner wall of the tubular housing, and, furthermore, the gas supply connection (20) is provided on the side of the valve head (7) facing away from the spring (5).