LEXINGTON, Ky. — The World of Coal Ash Conference drew more than 1,200 international researchers, industry leaders and policymakers to Lexington in May, cementing the University of Kentucky's position as a global leader in coal combustion product research and innovation.

The biennial conference, hosted jointly by UK's Center for Applied Energy Research and the American Coal Ash Association, attracted 1,273 registered attendees from 589 organizations across 13 countries and 45 U.S. states. The May 4-7 event at the Central Bank Center was the 11th gathering in the conference series and marked a historic transition as longtime researcher Tom Robl stepped down after more than 50 years of leadership in the field.

Coal combustion products—the solid materials left behind after coal burns in power plants—have emerged as valuable resources with applications ranging from concrete manufacturing to rare earth element extraction. UK CAER researchers have developed fast-drying concrete products and continue exploring uses for coal ash in sustainable construction and environmental remediation.

The conference featured 11 simultaneous technical sessions covering groundwater compliance, impoundment closure, fly ash beneficiation and low-carbon concrete supply chains, offering more content than any previous meeting. Robert Jewell, CAER associate director, credited the breadth of technical exchange to dedicated organizers and speakers who brought together academics, regulators and innovators.

UK President Eli Capilouto underscored the university's commitment to energy innovation, noting that the conference reflects "the power of bringing together research, industry and public partners to tackle complex challenges with rigor and shared purpose."

Robl, who arrived as a graduate student in geology in the early 1970s, transformed coal combustion research from a niche industrial concern into a globally recognized scientific field. Under his guidance and that of American Coal Ash Association Executive Director Tom Adams, WOCA expanded from hundreds of participants to more than 1,000, with coal ash increasingly used in concrete manufacturing to reduce greenhouse gas emissions and improve durability.

The conference demonstrated the field's continued evolution, with participation spanning federal regulators, startup technology companies and established industry players working collaboratively to advance sustainable use of coal combustion byproducts.