Fly Ash Recovery

As coal-fired power plants retire and ash ponds are closed, utilities and material processors are faced with a growing challenge: recovering millions of tons of stored fly ash for beneficial reuse rather than leaving it in place indefinitely.

The problem is moisture.

Much of the fly ash stored in ponds and landfills contains too much moisture to be used in high-value applications like supplementary cementitious materials (SCMs). Traditional drying methods often rely on large natural gas-fired systems that require significant capital investment, consume large amounts of energy, and increase operating complexity — all while adding a combustion source to the process.

Shockwave developed a technology to solve this challenge without relying on natural gas or added heat.

Recover More Than Fly Ash

Our technology transforms wet fly ash into a drier, finer material for evaluation as an SCM, through a single continuous process that simultaneously dries and mills the material.

Unlike conventional systems that require separate drying and milling operations, Shockwave combines both into one fully electric process. One system replaces a separate dryer and mill, and the process eliminates the need for natural gas entirely. This also simplifies permitting and reduces the facility’s overall environmental footprint.

How the Technology Works

Feed — Fly ash from ponds, landfills, or active collection systems enters the processing system.

Dry — A high-velocity airflow removes moisture without combustion or natural gas, preparing the material for reuse.

Mill — As moisture is removed, the material is simultaneously milled to create a more consistent particle size for downstream applications.

Recover — The result is a drier, finer fly ash, consistent and ready for qualification testing as an SCM.

Why Utilities and Material Processors Choose Shockwave

• Recover valuable fly ash from ponds and landfills
• Reduce moisture and improve material consistency
• Eliminate natural gas from the drying process
• Combine drying and milling into one continuous operation
• Reduce equipment footprint and operational complexity
• Support beneficial reuse and sustainability initiatives

Proven Through Results

Shockwave has completed both an internal R&D trial and a utility-commissioned pilot on coal fly ash, consistently reducing moisture from roughly 15–19% down to approximately 3–4% using ambient air only — no natural gas or inlet heat required. In the most recent pilot, fly ash sourced directly from an active utility ash pond was dried from 14.88% to 3.75% moisture, with throughput ranging from roughly 11,600 to 14,600 lbs/hr and 88% of finished product finer than 53 microns. Results have been consistent across trials conducted more than a year apart on feedstock from different sources, supporting the platform’s commercial readiness.

Beneficial Reuse Opportunities

Recovered fly ash can be used in a variety of applications, including:

• Supplementary cementitious materials (SCMs)
• Ready-mix and precast concrete
• Brick and aggregate manufacturing
• Road base stabilization
• Flowable fill

Ready to Evaluate Your Material?

Every material is different. Our team can review your application, discuss your processing goals, and determine the best path forward — including pilot-scale testing.

Next Steps

• Discuss your application
• Schedule a pilot trial
• Evaluate your processing goals

Contact us to start the conversation.