ANALYSIS OF GASEOUS EMISSIONS FROM SPONTANEOUS COAL COMBUSTION AT THE KLEINKOPJIE COLLIERY (WITBANK, SOUTH AFRICA)

The concentration of trace gases released during the spontaneous combustion of coal and their dependence on meteorological conditions are investigated. Industrial and urban activities in and around Witbank, South Africa have released huge amounts of pollutants into the atmosphere. Spontaneous combustion at the Kleinkopjie Colliery has contributed to this problem.

Direct, automated, and continuous monitoring of trace gas concentrations concurrently with meteorological parameters were done with mobile monitoring-automated weather stations. The measurement of gaseous pollutant concentrations at different locations downwind of each emission source is necessary to monitor air quality. Wind direction is important for identifying the direction traveled by pollutants relative to the monitoring station and the source of pollution. Utilizing this information, pollutants associated with spontaneous combustion can be identified and selected for analysis.

Findings reveal that nitrogen oxide concentrations were higher than average for the Highveld, which is the industrial capital of South Africa, where Witbank is located. Summer SO2 concentrations were lower than average for the entire region. In winter, temperature inversions and stable conditions played a significant role in increasing pollutant concentrations at night and in the early morning hours. CO and CO2 concentrations were very high, reaching 6999 ppb and 495 ppm respectively, exceeding the analytical range of the instrumentation utilized.