Predicting Total Dissolved Solids Release From Overburden in Appalachain Coal Fields.

Historically, the Appalachian coal industry has been very successful in developing technologies to identify, handle, treat and isolate potentially acid-forming overburden materials at coal mines in the region. However, the techniques to predict acid mine drainage potential to not adequately predict the release of total dissolved solids (TDS). This often leads to handling plans that actually increase TDS release due to the blending of net acid-forming and alkaline strata. As part of a larger project with a goal of developing methods to predict TDS release from overburden materials in the Appalachian region, our objective was to determine the effect of particle size on constituent release. Three overburden samples from a surface coal mining site in West Virginia were chosen to encompass the widest expected range of properties. A subsample was ground and sieved to 500 μm, 250 μm and 106 μm mesh sieves. The material remaining on the 250 μm and 106 μm mesh sieves were used for the particle size analysis. Two liters of 0.0159M HNO₃ were combined with 3.00 g of each size fraction in 2 L Nalgene bottles, in triplicate. Bottles were placed on a reciprocation shaker for 14 days. Aliquots were collected approximately every other day; pH, EC, major and micro elements were determined. Preliminary results show no major difference between the two particle sizes.