Fines Generation and Its Impacts at Morupule Underground Coal Mine, Botswana

Fines generation is one of the common problems associated with coal mining, such as mine accidents, land subsidence, water contamination, and air pollution. Mining companies spend a lot of money annually to reduce and mitigate the impact of fines generation. A study was conducted to identify the causes of fines generation at Morupule Coal Mine and evaluate its economic and environmental impacts. Twelve coal samples of 20 kg were collected from each of the four operating mining sections and conveyor belts. They were tested for their mechanical and chemical properties. The results show that coal from section SM 3/1 is the most brittle, with a value of 31.25%, while the coal from section SM 4/5 is the least brittle, with a value of 15.5%. The fines generated vary from 3 to 13%. The transfer points account for the highest (up to 9%), while the fastest conveyor belt contributes about 8% of fines. The fines cause blockages at the tail ends of the conveyors, causing approximately a loss of 575 tons/shift. Targets are also not met at the wash plant due to more fines. In terms of air quality and health hazards, the environmental impact of fines generation is negligible as the mine employs strict dust control measures.