Assessing Different Coal Combustion Residue Scenarios in Opencast Coal Mines, Mpumalanga, South Africa
Vicente, Annalisa (1); Nel, Jaco (1); Reynolds-Clausen, Kelley (2)
1: The University of the Western Cape, South Africa; 2: Eskom Holdings SOC, Research, Testing and Demonstration
This study assesses the flow and transport characteristics of backfilling opencast coal mines with coal combustion residues (CCR’s), in order to assess its feasibility. Generic models were constructed to simulate six backfilling scenarios, which include: (1) No CCR’s (2) CCR’s above water table, (3) CCR’s below water table, (4) CCR’s in middle of pit, (5) CCR’s down gradient, and (6) CCR’s below weathered zone. Results indicate that all scenarios have the potential to contribute to a less negative environmental impact. This paper demonstrates the model setup and approach using Scenario 5 where a rise in water levels in the pit was achieved, reducing acid mine water generation and re-directing plume migration.