Utilisation of Mining Waste

This study investigates the potential use of black coal mining waste as a feedstock for plasma gasification. A national database of coal waste heaps was developed based on standardized criteria such as heap volume (>100,000 m3), accessibility, and environmental risk. From six initially sampled sites, two active and unreclaimed heaps—Jan Karel (Karviná) and Paskov D (Ostrava)—were selected for detailed material analysis due to their favorable characteristics. Subsequent plasma gasification experiments were conducted using sorted coal waste fractions at a temperature of 1600 °C in a pilot-scale plasma reactor. Four trials were performed with fuel flow rates of 15 and 20 kg/h and varying steam/fuel ratios (0.6, 1.0, and 1.3). The results revealed a high syngas yield of up to 92% by volume. Increasing the steam/fuel ratio led to higher hydrogen and carbon dioxide content in the syngas, while lower ratios favored carbon monoxide and trace methane formation. Volt-ampere characteristics of the plasma torch showed that higher nitrogen flow rates required higher voltage to maintain a stable arc. The findings confirm the technical feasibility and efficiency of converting selected coal mining waste into valuable syngas, supporting its future use in advanced waste-to-energy technologies.