THERMOCHEMICAL UTILIZATION OF COAL MINING WASTE: CHALLENGES AND TECHNOLOGICAL PROSPECTS
DOI:
https://doi.org/10.32782/3041-2080/2026-6-26Keywords:
coal mining waste, waste processing complex, gasification, ash content, producer gas, calorific valueAbstract
The manuscript addresses a relevant scientific and applied problem related to the thermochemical utilization of coal mining waste under conditions of its increasing accumulation and growing environmental risks in coalproducing regions. Despite global decarbonization trends, coal remains a significant contributor to the global energy balance, resulting in the formation of substantial volumes of technogenic waste, particularly waste rock dumps from coal mining operations. In this context, gasification is considered one of the most promising approaches to the thermochemical conversion of high-ash waste, as it enables both waste volume reduction and the production of energy-rich gaseous products. This study aims to identify the influence of ash content in coal mining waste on the yield and component composition of the combustible fraction of producer gas. For this purpose, waste samples collected from a spoil heap were crushed to obtain a uniform particle size distribution and subjected to ash content determination using a slow ashing method in a muffle furnace. Thermochemical conversion was carried out using an experimental-industrial installation that combines low-temperature pyrolysis with subsequent gasification of the solid residue using steam injection. The resulting producer gas was analyzed to determine the concentrations of its main components. The results indicate that the ash content of the investigated waste varies within the range of 70.3 – 92.1%, which has a substantial effect on its reactivity under gasification conditions. It was established that an increase in ash content leads to an exponential decrease in the concentrations of combustible components, such as CO, H2, and CH4, in the producer gas, accompanied by a reduction in its lower heating value from 3.46 to 1.21 MJ/m3. The obtained findings confirm the importance of considering ash content as a key parameter when optimizing gasification regimes for coal mining waste. Moreover, the results demonstrate the potential of thermochemical utilization as an integral element of circular production systems in the coal industry.
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