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Coal Ash Recycling Rate Increases in 2020

While the increase reverses declines in previous two years, the report doesn’t have good news for the concrete industry. Use of coal fly ash in concrete decreased 12 percent to 11.1 million tons as several regional markets were affected by shifting supply dynamics associated with closures of coal-fueled power plants.

Fifty-nine percent of the coal ash produced during 2020 was recycled –increasing from 52 percent in 2019 and marking the sixth consecutive year that more than half of the coal ash produced in the United States was beneficially used rather than disposed. The overall recycling rate had declined over the previous two years from its high of 64 percent in 2017.

American Coal Ash Association “ACAA” today released its annual “Production and Use Survey” which also showed that harvested ash is beginning to play a meaningful role in beneficial use activities. Nearly 4 million tons of previously disposed ash was utilized in a variety of beneficial uses in 2020, including coal ash pond closure activities, for cement kiln raw feed, and for gypsum panel manufacturing.

“The reversal of a downward trend in recycling rates and the utilization of a significant volume of harvested coal combustion products “CCP” shows that beneficial use markets are adapting to the decline in coal-fueled electricity generation in the United States,” said Thomas H. Adams, ACAA Executive Director. “New logistics and technology strategies are being deployed to ensure these valuable resources remain available for safe and productive use. We must continue to support these practices that safely conserve natural resources while dramatically reducing the need for landfills.”

According to ACAA’s 2020 survey, 40.8 million tons of coal combustion products were beneficially used in 2020, a volume approximately level with the previous year. But production of new CCP declined from 78.6 million tons in 2019 to 69.2 million tons in 2020 as utilities consumed less coal for generating electricity.

“Coal ash” is a generic term that encompasses several coal combustion products that can be beneficially used in a wide variety of applications. Highlights of CCP production and use in 2020 include:

•            Use of coal fly ash in concrete decreased 12 percent to 11.1 million tons. Concrete producers and consumers indicated a desire to use more fly ash, but several regional markets were affected by shifting supply dynamics associated with closures of coal-fueled power plants. Fly ash improves concrete durability and significantly reduces greenhouse gas emissions associated with concrete production.

•            Use of all coal combustion products in cement production declined 4 percent to 4.8 million tons.

•            Utilization of a key “non-ash” coal combustion product posted a modest increase. Synthetic gypsum is a byproduct of flue gas desulphurization units, also known as “scrubbers,” located at coal-fueled power plants. Use of synthetic gypsum in panel products (i.e. wallboard) increased 3 percent to just under 10 million tons.

•            Synthetic gypsum use in agricultural applications – in which the gypsum improves soil conditions and prevents harmful runoff of fertilizers – increased 34 percent to 847,704 tons

•            Use of CCP in pond closure activities increased 44 percent to 3.4 million tons. This activity is driven by utility compliance with coal ash regulations enacted in 2015 that effectively require an end to the practice of wet disposal. Fly ash, bottom ash, and synthetic gypsum were all used in construction of new permanent disposal facilities.  

•            Use of CCP in structural fills continued a multi-year decline in 2020, dropping 52 percent to 816,543 tons.

•            Production of boiler slag declined 14 percent, but utilization in the production of blasting grit and roofing granules increased 11 percent to 273,548 tons.

•            For the first year in survey history, no cenospheres were reported sold in 2020. The downturn was likely linked to increased closure of disposal ponds from which cenospheres are harvested.

 “As America’s electricity grid changes, the coal ash beneficial use industry is evolving as well,” said Adams. “As we work diligently to utilize the nearly half of coal combustion products that are still disposed annually, our industry is also taking significant strides in developing strategies for improving the quality and availability of these materials.”

Adams explained that increasing beneficial use requires ash marketers to ensure that products are consistent and available when customers need them – requiring large investments in technology and logistics. Additionally, the coal ash beneficial use industry is actively deploying technologies and strategies for harvesting coal ash materials that were previously disposed.


About Coal Ash Recycling

Coal is the fuel source for approximately one-quarter of electricity generation in America and produces large volumes of solid coal combustion products — primarily ash and synthetic gypsum from emissions control devices.

There are many good reasons to view coal combustion products as a resource, rather than a waste. Recycling them conserves natural resources and saves energy. In many cases, products made with CCP perform better than products made without it. For instance, coal fly ash makes concrete stronger and more durable. It also reduces the need to manufacture cement, resulting in significant reductions in greenhouse gas emissions – about 11 million tons in 2020 alone.

Major uses of coal combustion products include concrete, gypsum wallboard, blasting grit, roofing granules, and a variety of geotechnical and agricultural applications.

About ACAA’s Production and Use Survey

American Coal Ash Association – an organization that advances the environmentally responsible and technically sound use of coal ash as an alternative to disposal – has conducted a survey quantifying the production and use of coal combustion products in the United States each year since 1966. Data is compiled by directly surveying electric utilities and utilizing additional data produced by the U.S. Energy Information Administration. The survey’s results have been widely utilized by federal agencies including the U.S. Environmental Protection Agency and U.S. Geological Survey.

Click Fly Ash and Production Charts to download charts summarizing overall production and use data of fly ash since 1991.


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