The Thermal History of Select Coal-Waste Dumps in the Upper Silesian Coal Basin, Poland

Coal mining generates a great amount of waste that is typically dumped in the vicinity of the mines. In some cases, the dumps undergo self-heating and/or combustion during which gaseous pollutants are formed. These processes occur in some dumps in Upper Silesian Coal Basin, e.g. Starzykowiec-, Rymer Cones-, and Marcel dumps dating from the beginning of the 1900s. The heating dynamics are reflected in comparisons between air temperatures and temperatures measured on the surface, at a depth of ∼ 1 m, and also in CO, CO2, and O2 contents. The Rymer Cones dump is an excellent example of where air blowing into the dump interior can enhance these processes; heating is more intense in the western- and southern part of the dump most exposed to the wind. Temperatures can reach even 600°C there whereas, on the eastern side of the dump, they commonly lie in the range 60–80°C. In the other two dumps, temperature changes reflect the seasons. In these old dumps, it is very difficult to deal with hot spots and prevent temperatures from rising. Regular monitoring allows the identification of hot spots though it seems that the only way to deal with these is to intensify the combustion by enhancing air access and allowing the waste rocks to overburn.