Search results
Results From The WOW.Com Content Network
The correct storage of spontaneously combustible materials is extremely important, as improper storage is the main cause of spontaneous combustion. Materials such as coal, cotton, hay, and oils should be stored at proper temperatures and moisture levels to prevent spontaneous combustion. Reports of spontaneous human combustion are not ...
Spontaneous combustion is caused when coal oxidizes and airflow is insufficient to dissipate heat; this more commonly occurs in stockpiles and waste piles, rarely in bedded coal underground. Where coal fires occur, there is attendant air pollution from emission of smoke and noxious fumes into the atmosphere.
Larger coal stockpiles have a reduced rate of heat loss, leading to a higher risk of spontaneous combustion. Travelling, luffing boom stackers that straddle a feed conveyor are commonly used to create coal stockpiles. Tunnel conveyors can be fed by a continuous slot hopper or bunker beneath the stockpile to reclaim material.
The autoignition temperature or self-ignition temperature, often called spontaneous ignition temperature or minimum ignition temperature (or shortly ignition temperature) and formerly also known as kindling point, of a substance is the lowest temperature at which it spontaneously ignites in a normal atmosphere without an external source of ignition, such as a flame or spark. [1]
This "spoil tip" at the Ronchamp coal mines is colored red due to combustion. In some spoil tips, the waste resulting from industries such as coal or oil shale production can contain a relatively high proportion of hydrocarbons or coal dust. Spontaneous subterranean combustion may result, which can be followed by surface fires. In some coal ...
Coal dust suspended in air is explosive—coal dust has far more surface area per unit weight than lumps of coal, and is more susceptible to spontaneous combustion. However, five elements are needed for an explosion to occur: oxygen, an ignition source, coal dust, dispersion of the coal dust, and confinement of the dust. [4]
A coal fire in China Open-cast mining continues near a fire at Jharia coalfield in India. A coal-seam fire is a burning of an outcrop or underground coal seam. Most coal-seam fires exhibit smouldering combustion, [1] particularly underground coal-seam fires, because of limited atmospheric oxygen availability. Coal-seam fire instances on Earth ...
Prior to its combustion, coal can be cleaned by physical and by chemical means. Physical cleaning of coal usually involves gravimetric processes, often in conjunction with froth flotation Such processes remove minerals and other noncombustible components of coal, exploiting their greater density vs that of coal. This technology is widely practiced.