Archived
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Location
Lexington, Kentucky
Start Date
6-5-2026 9:00 AM
End Date
6-5-2026 9:30 AM
Description
The basin is a 132-acre (534,200 square meter) coal combustion residual (CCR) disposal impoundment that has been undergoing closure-by-removal since 2021, with CCRs harvested for use in concrete manufacturing. Excavated CCRs are processed on-site through initial drying and screening before being routed through a thermal beneficiation process. Despite an extensive pre-closure CCR characterization program, pockets of material encountered in 2025 caused significant off-specification issues for the beneficiation feedstock that required immediate corrective action. To address this, a supplemental surveying, sampling, and on-site testing program was implemented to obtain additional grainsize and Loss on Ignition (LOI) data for active and upcoming excavation areas. Feedstock specifications include a maximum particle size of 3/8-inch (1 centimeter) and an LOI ≤ 13% for stable combustion. Supplemental sampling areas were selected based on excavation sequencing and depositional patterns to better define material characterization zones. Results showed that lower-elevation depositional pockets contained coarser, lower LOI (5 to 13%) material; near-surface elevations had finer-grained materials with elevated LOI values (>13% to 35%); and transitional zones included in-specification material, creating opportunities for targeted blending. This data was used to refine grainsize and LOI distribution mapping and adjust excavation blending proportions to produce composite loads meeting feedstock specifications while maximizing throughput and minimizing off-specification discard. The study reaffirmed that spatially resolved characterization improves material management efficiency, enhances combustion reliability, and reduces fuel conditioning costs.
Document Type
Presentation
Archival?
Archival
Included in
Energy Systems Commons, Environmental Indicators and Impact Assessment Commons, Environmental Monitoring Commons, Mining Engineering Commons, Oil, Gas, and Energy Commons, Structural Materials Commons, Sustainability Commons
Evaluating and Managing CCR Variability at an Active Beneficial Use Clean Closure Site
Lexington, Kentucky
The basin is a 132-acre (534,200 square meter) coal combustion residual (CCR) disposal impoundment that has been undergoing closure-by-removal since 2021, with CCRs harvested for use in concrete manufacturing. Excavated CCRs are processed on-site through initial drying and screening before being routed through a thermal beneficiation process. Despite an extensive pre-closure CCR characterization program, pockets of material encountered in 2025 caused significant off-specification issues for the beneficiation feedstock that required immediate corrective action. To address this, a supplemental surveying, sampling, and on-site testing program was implemented to obtain additional grainsize and Loss on Ignition (LOI) data for active and upcoming excavation areas. Feedstock specifications include a maximum particle size of 3/8-inch (1 centimeter) and an LOI ≤ 13% for stable combustion. Supplemental sampling areas were selected based on excavation sequencing and depositional patterns to better define material characterization zones. Results showed that lower-elevation depositional pockets contained coarser, lower LOI (5 to 13%) material; near-surface elevations had finer-grained materials with elevated LOI values (>13% to 35%); and transitional zones included in-specification material, creating opportunities for targeted blending. This data was used to refine grainsize and LOI distribution mapping and adjust excavation blending proportions to produce composite loads meeting feedstock specifications while maximizing throughput and minimizing off-specification discard. The study reaffirmed that spatially resolved characterization improves material management efficiency, enhances combustion reliability, and reduces fuel conditioning costs.
