Study of Long-Term Leachability of Major and Trace Elements in Coal Mining Wastes

Results of approbation of the methodology developed at NUST MISIS for assessing the long-term leachability of major and trace elements out of coal mining wastes are presented. This methodology is used to assess the impact of such wastes on the environment when they are placed in dumps or used for reclamation. Three coal mining wastes of various mineral and chemical compositions have been tested. The results have demonstrated that the prolonged treatment of waste with a high sulphur content leads to the oxidation of sulphur-containing compounds, resulting in a significant increase in concentration of water-soluble forms of sulphur, calcium, iron, potassium, sodium and magnesium after the 6th week of treatment, as well as in a decrease in the total sulphur content after the 9th week of processing.