The Relationship Between the Natural Compaction and the Spontaneous Combustion of Industrial-scale Coal Stockpiles

The companies necessarily store their coal needs in their stock areas in which stock fires occur due to long stay periods of coals and cause serious damages in terms of the economy and environment. In this study, in order to determine the conditions by which spontaneous combustion occurs due to long stays of coals under natural weather conditions, an industrial-scale coal stockpile was formed with 10-18 mm coal grain sizes. Temperature measurements were recorded by using temperature sensors placed at certain locations inside the stockpile. At the same time, the effects of atmospheric conditions on the stockpile were investigated by continuously measuring the values of weather temperature, weather humidity, atmospheric pressure, wind velocity, and direction that are the factors affecting these stockpiles. Stockpiles tend to be faced with compaction due to the gravitational effect under long-term stays and the vibrations resulting from the huge machines working closer to the stockpiles. For the purpose of measuring the magnitude of the compaction, digital photographs were taken at certain periods and then processed photogrammetrically using terrestrial photogrammetry software. Afterward, the relationship between the calculated compaction rate and the spontaneous combustion was determined.