The power industry in the United States disposes of more than 70% of coal combustion products, or ashes, annually, affecting the cost of electricity and posing a potential liability to the industry. Currently, the majority of the ash is used in the Portland cement and concrete industry as a cement replacement (up to 25%). The performance properties of these concretes is superior to concrete made without fly ash. The power industry goal is to have 50% of the ash used in beneficial uses by 2020. To accomplish this goal, the industry, with support of the Electric Power Research Institute, U.S. DOE and others, is examining a range of uses for the combustion products. Under WRI’s Ash Management Program, we are developing both new large-volume and niche uses for ash and are providing technical services, such as liner compatibility testing, to the ash management and utility industries. Beneficial uses being investigated at WRI include:
SYNAGTM – WRI’s patented process of manufacturing synthetic aggregate from power plants ashes meets ASTM and AASHTO specifications for normal and lightweight construction aggregate.
Ash Stabilization – WRI’s patented process uses specialty chemicals to modify the cementitious reactions of coal combustion ashes that are prone to expand, crack, and lose strength during disposal or beneficial use, thereby improving their dimensional stability and strength.
Ash-Based Grout – WRI has formulated grouts using ashes from coal-fired power plants that can be used to stabilize both dry and flooded mines. The grout is used to reduce subsidence, thereby allowing surface development above the mine.
Flowable Fills (Ready-FillTM ) – WRI has developed a variety of flowable fill materials from coal combustion ashes, such as ReadyFillTM that can be used for removable backfills, structural fills, isolation fills, and trench bedding.
Liner Compatibility Testing – Flexible membrane geosynthetic liners are used to prevent contamination of groundwater at controlled ash disposal sites. WRI helps technology developers evaluate effects of clean coal technology ash materials on the stability of geosynthetic liner materials.