Coal Ash-Derived Aluminosilicate Precursors: A Chemical Engineering Approach To Geopolymer Characterization,
2026
University of Louisiana at Lafayette
Coal Ash-Derived Aluminosilicate Precursors: A Chemical Engineering Approach To Geopolymer Characterization, Abdullah Bashir, Abdur Raafey, Dilip Depan
World of Coal Ash Proceedings
The chemical and microstructural evaluation of coal-derived aluminosilicate precursors is critical for understanding their suitability in advanced construction material systems. In this study, a characterization of Class F fly ash, ground granulated blast furnace slag (GGBFS), and Silica Fumes (SF) was conducted to elucidate their morphological and elemental features. Scanning Electron Microscopy (SEM) was used to assess particle morphology and surface characteristics (porosity, particle diameter, particle geometry), and Energy-Dispersive X-ray Spectroscopy (EDS) to determine elemental composition and distribution. The analysis revealed distinct morphological and compositional differences among the precursors, including spherical fly ash particles, calcium-rich slag phases, and ultra-fine silica …
Zero-Waste And High-Value Valorization Of Coal Combustion Residues Via Critical Minerals Recovery And Cementitious Materials Production,
2026
Missouri University of Science and Technology
Zero-Waste And High-Value Valorization Of Coal Combustion Residues Via Critical Minerals Recovery And Cementitious Materials Production, Hongyan Ma
World of Coal Ash Proceedings
Coal combustion residues (CCRs) pose significant environmental and disposal challenges, yet they also represent an untapped resource rich in aluminosilicates and critical minerals. This work presents a zero-waste, high-value valorization pathway that integrates critical mineral recovery with the production of cementitious materials. Advanced separation and extraction techniques are employed to recover strategically important elements such as gallium and rare earths, while the mineral-rich residues are simultaneously processed into supplementary cementitious materials (SCMs) for blended cements and concretes. This integrated approach not only offsets the environmental burden of CCR disposal but also supports domestic supply chains of critical minerals and reduces …
State Permitting Program Update,
2026
Barnes & Thornburg LLP
State Permitting Program Update, Jessica Reiss
World of Coal Ash Proceedings
State Permitting Program Update Jessica L. Reiss, Barnes & Thornburg LLP, 11 South Meridian Street, Indianapolis, IN 46204 KEYWORDS: states, permitting, permit program, rulemaking ABSTRACT At the end of 2016, the United States Congress authorized states to establish permit programs for coal combustion residuals (CCR) surface impoundments and landfills.[1] Since then, several states have established such programs, and the United States Environmental Protection Agency (U.S. EPA) has approved programs for Oklahoma,[2] Georgia,[3] Texas,[4] and North Dakota,[5] proposed approval for Wyoming,[6] and denied approval for Alabama.[7] Other states, such as Indiana,[8] are actively working through the state rulemaking process and plan …
Probing The Critical Element Chemistry Of Coal-Combustion Fly Ash: Electron Microbeam Investigations Of The Spent Ash From The Pilot-Scale Acid Extraction Of Rare Earth Elements From A Beneficiated Kentucky Fly Ash, James Hower
World of Coal Ash Proceedings
Fly ash derived from the combustion of an eastern Kentucky high volatile bituminous coal blend was beneficiated to yield a <75-μm product with a reduction in the carbon and spinels and reacted with a strong acid in a pilot-scale unit to extract rare earth elements. Electron microscopy showed a wide range of rare earth-bearing minerals. The acid-extracted fly ash had a rim that was depleted in REE and in most other elements except silicon.
From Clogs To Compliance: Overcoming Persistent Leachate Head Issues In Ccr Landfills,
2026
TRC
From Clogs To Compliance: Overcoming Persistent Leachate Head Issues In Ccr Landfills, Breanne Kahnk, Zachary Bauman
World of Coal Ash Proceedings
State and federal regulations require that landfills, including coal combustion residual (CCR) landfills, be designed and operated to maintain leachate head levels of less than 30 centimeters (approximately 1 foot). While proper leachate collection system design and routine maintenance are critical for meeting this requirement, challenges such as clogging of drainage media, pipes, fittings and/or pipeline perforations, settlement of collection pipes, and breaks in the piping system can lead to elevated leachate levels, posing risks to compliance and long-term system performance. TRC will provide an overview of leachate collection system regulatory requirements along with design, operation, and maintenance strategies that …
Revolutionizing Closure Systems: The Performance Advantages Of Structured Geomembranes,
2026
AGRU America
Revolutionizing Closure Systems: The Performance Advantages Of Structured Geomembranes, Scott Perugia
World of Coal Ash Proceedings
Coal combustion residual (CCR) containment facilities have traditionally been closed using methods that have changed little over several decades, but structured geomembranes are now reshaping closure design by improving slope stability, increasing interface friction, enhancing drainage, and providing long-term durability. Two systems are emerging as leading solutions: a structured geomembrane paired with a geotextile and vegetative cover, and a structured geomembrane paired with engineered turf. This presentation compares these approaches using field performance data, laboratory testing, and lessons learned, with emphasis on key factors such as infiltration control, drainage efficiency, slope stability, constructability, and regulatory compliance. The engineered turf system …
Plasma Coal Ash Processing For Enhanced Recovery Of Rare Earth Elements & Precious Metals: Proven From R&D To Commercial Plants,
2026
Plasma System LLC USA
Plasma Coal Ash Processing For Enhanced Recovery Of Rare Earth Elements & Precious Metals: Proven From R&D To Commercial Plants, George Paskalov, Victoria Campbell, Jason Honigberg
World of Coal Ash Proceedings
Our Radio-frequency Plasma System is an ash pretreatment before the application of extractive metallurgy and addresses current elemental, methodological, and technological limitations of complex and refractory coal ash. Our system data shows from 10-20% improved recovery, to 9x-100x. RFP can access all metals contained in coal ash. Our focus is not on the alteration of established methodologies, such as cyanidation for non-refractory ore, which has a proven return and capacity to achieve target revenue at-scale. Using the RFP systems, no waste is created, overburden can be more easily dealt with, and no metal content will be left behind. We assert …
Developing Concentrated Brines / Salt Slurries For Disposal Of Coal Ash Wastewaters.,
2026
Xylem
Developing Concentrated Brines / Salt Slurries For Disposal Of Coal Ash Wastewaters., Lance Edling
World of Coal Ash Proceedings
If coal ash wastewater is not fully concentrated to the greatest extent possible, then this results in greater disposal volumes and costs. However, concentrating a wastewater stream high in scaling compounds can be difficult. Membranes are prone to scale and Vacom thermal systems are higher in operating cost. This presentation will discuss the need to minimize disposal volumes by concentrating wastewater that is readily prone to scale and foul. The discussion will present past project examples of waste streams that were concentrated until salt crystals formed and the method used to minimize fouling and scaling during the concentration process. In …
Recinis™ Wet Beneficiation Process For Landfilled Coal Ash,
2026
ReVanTEC Solutions
Recinis™ Wet Beneficiation Process For Landfilled Coal Ash, Tim Sambrook
World of Coal Ash Proceedings
The decline of coal-fired power generation has reduced fresh “Run-of-Station” ash availability, increasing reliance on reclaimed ash from landfills to meet supplementary cementitious material (SCM) demand. This shift has lowered OPC replacement rates and raised concrete costs due to inconsistent ash quality. ReCinis™ offers a low-capex wet beneficiation solution for landfill-aged, saturated, and variable-quality coal ash. With over 5 billion tons of ash impounded in the U.S., this process enables long-term supply security where dry beneficiation is unsuitable. Combining proven mineral processing techniques with coal ash expertise, ReCinis™ can be deployed as a 150,000 tpa skid-mounted plant or scaled to …
Lessons Learned From A Full-Scale Discrete In-Situ Stabilization Project For Ccr Impoundment Closure,
2026
ENTACT, LLC
Lessons Learned From A Full-Scale Discrete In-Situ Stabilization Project For Ccr Impoundment Closure, Tony Moran, Paul Jennings, Jacob Susser, Tim Silar
World of Coal Ash Proceedings
ENTACT, in collaboration with Silar Services, Inc., the patent holder of Discrete In-Situ Solidification (DISS) technology, has successfully performed a full-scale implementation of DISS in a Coal Combustion Residual (CCR) impoundment. DISS hydraulically isolates ash from surrounding groundwater by constructing a low-permeability barrier at the impoundment bottom to treat a layer of ash and tying into underlying natural soil layers. DISS enables targeted stabilization within a designated treatment zone, minimizing the disturbance of overburden compared to traditional excavation methods and reducing the use of costly cementitious reagents. The process starts with Reagentless Drilling of the overburden CCR utilizing a specialized …
Standardization Of Coal Ash Testing, Classification, And Harvesting,
2026
EPRI
Standardization Of Coal Ash Testing, Classification, And Harvesting, Benjamin Gallagher, Chris Frishcosy, Eric Hageman
World of Coal Ash Proceedings
Standards such as product specifications, test methods, practices and guides play a crucial role in supporting both commerce and science. Standardization helps build consistency and reliability whether it pertains to the performance of an ingredient in a product or in the measurement of a material characteristic. Coal combustion products, such as coal ash and synthetic gypsum, exhibit unique characteristics and many standard have been developed to characterize these materials and support their beneficial use. ASTM is a voluntary, consensus-based organization, and publishes many standards related to coal combustion products. Currently, there are seven ASTM standards related to chemical analysis of …
Ccr 2026: The Plot Thickens—Your Complete Guide To What’S Next,
2026
Burns & McDonnell
Ccr 2026: The Plot Thickens—Your Complete Guide To What’S Next, Mark Rokoff
World of Coal Ash Proceedings
The landscape of CCR management is poised for significant transformation with the proposed EPA regulation introduced in early 2026. This presentation will provide a clear and enhanced summary of the key points in the proposed rule, highlighting the significant changes and implications for the industry. Where appropriate, it will be further enhanced by benchmarking data to compliment the key points and the effect to the “CCR Universe”. The proposed regulation aims to adjust the requirements for effective CCR management, introducing new compliance measures and timelines that will impact owner/operators across the board. Key discussion points will include: • Summary of …
Leachate Quantification And Reduction – One Facility’S Path To Zld,
2026
EOT, LLC
Leachate Quantification And Reduction – One Facility’S Path To Zld, Cedric Ruhl
World of Coal Ash Proceedings
The Environmental Protection Agency (EPA) promulgated Effluent Limitation Guidelines (ELG) that govern liquids discharged from energy production facilities. According to the ELG, energy production facilities that burn coal beyond December 31, 2034 must convert to a Zero Liquid Discharge (ZLD) system by December 31, 2029*. This presentation focuses on one coal-burning facility’s strategy to meet ZLD requirements. The predominant source of liquid that will be treated by the proposed ZLD system is leachate from an active coal combustion residual (CCR) landfill. Is the ZLD’s design capacity suitable for average leachate flow conditions? Is there enough leachate storage volume to manage …
Ai-Guided Upcycling Of Coal Combustion Residues In Blended Cement And Concrete,
2026
Missouri University of Science and Technology
Ai-Guided Upcycling Of Coal Combustion Residues In Blended Cement And Concrete, Hongyan Ma
World of Coal Ash Proceedings
Coal combustion residues (CCRs), including fly ash, bottom ash, desulfurization gypsum, etc., on specification or off-specification, remain an abundant yet underutilized byproduct of power generation. While these materials have long been considered as supplementary cementitious materials (SCMs), their variable chemical and physical characteristics limit broader adoption in blended cement and concrete. This study introduces an AI-guided framework to accelerate the upcycling of CCRs into high-performance construction materials. By integrating materials informatics, machine learning models, and experimental validation, the framework enables rapid property prediction and performance-based preprocessing recommendation or mix design optimization for diverse CCR sources. Preliminary results demonstrate the ability …
Comparison Of Residuals From Neighboring Power Stations With Different Coal Combustion Technologies,
2026
U.S. Geological Survey
Comparison Of Residuals From Neighboring Power Stations With Different Coal Combustion Technologies, Allan Kolker, Denise Levitan, Brett Valentine
World of Coal Ash Proceedings
Due to the ongoing need for critical minerals, coal combustion residuals (CCR), like fly ash, have been evaluated as a potential source of critical minerals, particularly rare earth elements (REEs). Previous studies have found that REEs in fly ash are largely contained within aluminosilicate glass from which they are difficult to extract. However, these studies have predominantly studied CCR from conventional pulverized coal fired (PCF) plants. PCF plants use higher temperatures (≥1300°C) than do circulating fluidized-bed (CFB) plants (~900-950°C). Samples of feed coal, fly ash, and bottom ash were collected from two adjacent Vietnamese coal-fired power stations, one with a …
Impacts Of Updating Background Groundwater Statistics For Ccr Compliance,
2026
HDR
Impacts Of Updating Background Groundwater Statistics For Ccr Compliance, May Raad, Molly Reeves
World of Coal Ash Proceedings
In 2017, many power utilities adopted statistical methods to comply with the EPA’s Coal Combustion Residuals (CCR) Rule under the Hazardous and Solid Waste Management System. By 2017–2018, most owners completed initial statistical evaluations for detection and assessment monitoring to meet CCR deadlines. Groundwater sampling and analysis requirements in Parts 257.95, 257.98, and 257.102 are critical for compliance, yet implementation is complex. Subsections 257.93(f) and (g) lack clarity on which statistical tests to apply or how to address distributions and outliers. Additionally, the Rule does not specify when or how to update background threshold values (BTVs), though EPA’s Unified Guidance …
Advancing Ccr Site Management With Rapidly Deployable Gccm Technology For Runoff And Drainage Control,
2026
Concrete Canvas, USA
Advancing Ccr Site Management With Rapidly Deployable Gccm Technology For Runoff And Drainage Control, Nathan Ivy
World of Coal Ash Proceedings
GCCM’s were first invented over 20 years ago. These products combine both a concrete – hard armor – top surface for protection and durability and a geomembrane bottom surface for lower permeability. Originally used for erosion control, smaller drainage channel and remediation projects, this presentation discusses the newest iteration in GCCM technology. This product incorporates a 12 mil LLDPE backing which allows for thermal bonding and significant reduction in seepage at the joints. It can be used in a wide variety of applications from drainage ditches and swales to water and wastewater conveyance along with slope protection and erosion control …
Benefits Of Containerized Water Treatment Systems For Coal-Fired Power Plants,
2026
GWTT - Ground/Water Treatment Technology
Benefits Of Containerized Water Treatment Systems For Coal-Fired Power Plants, Andrew Vincent
World of Coal Ash Proceedings
Containerized systems deliver many of the same functional benefits as housing treatment equipment in permanent buildings, while significantly reducing engineering, construction, and installation costs. By containerizing a water treatment system, a substantial portion of fabrication, assembly, and testing can be completed in a controlled shop environment rather than in the field. This approach greatly reduces on-site labor requirements, mobilization duration, and overall installation complexity. Once delivered to site, containerized systems can be used as permanent installations. Alternatively, they offer the flexibility to be relocated within a plant or transferred between different sites as operational needs change. Multiple containerized systems can …
Rare Earth Element Distribution And Mineral Host In Coal Derived Ash From South African Power Stations,
2026
University of Johannesburg,
Rare Earth Element Distribution And Mineral Host In Coal Derived Ash From South African Power Stations, Sanki Biswas, Nicola Wagner, Oftense Moroeng
World of Coal Ash Proceedings
The global shift toward low-carbon energy systems, electric mobility, and digital technologies has sharply increased the demand for critical minerals, including rare earth elements (REY) vital for permanent magnets, batteries, wind turbines, photovoltaic cells, semiconductors, and modern defence applications. Coal by-products—particularly coal fly ash (CFA) and coal bottom ash (CBA)—are emerging as promising secondary sources of REY, but their economic viability depends on effective enrichment and extraction methods. South Africa’s coal-fired power plants generate nearly thirty million tonnes of coal-ash each year. This study investigates REY concentrations in CFA and CBA collected from five major power stations (PS-1 to PS-5) …
Thermal And Mechanical Activation Of Estonian Oil Shale Cfbc And Hydrated Legacy Fly Ash As An Alternative Binder System For Opc Replacement,
2026
Tartu University
Thermal And Mechanical Activation Of Estonian Oil Shale Cfbc And Hydrated Legacy Fly Ash As An Alternative Binder System For Opc Replacement, Peeter Paaver
World of Coal Ash Proceedings
This study investigates high volume of Ordinary Portland Cement (OPC) substitution with fly ash based calcium sulfoaluminate binder. The utilization of circulating fluidized bed combustion (CFBC) boilers imposes limitations on the recycling of fly ash due to its lower combustion temperature inhibiting the formation of reactive calcium silicate minerals resulting in diminished pozzolanic properties of the ash paste. Our previous research (Paaver et al., 2020, 2022) has demonstrated that the mechanical activation of sulfur and calcium-rich Estonian oil shale CFBC fly ash produces calcium sulfoaluminate (CSA) type active binder allowing high-volume OPC replacement of up to 50%, with a reduction …
