New Chemical Solution Fixes Tainted Fly Ash for Concrete Applications

FlyAshDirect and BASF in a join development developed a new chemical solution to fix activated carbon tainted fly ash for concrete applications

FlyAshDirect - a coal combustion product management firm - announces today that in a joint development partnership with BASF, the companies have developed a new chemical solution to beneficiate fly ashes used in concrete that have been exposed to Powder Activated Carbon (PAC), a material widely accepted as a method to control mercury emissions at coal burning power plants.

PAC injection systems, when installed prior to the power plants' particulate control device, will deposit activated carbon onto the fly ash as it travels through the flue gas, subsequently elevating the level of carbon or Loss on Ignition (LOI) in the fly ash byproduct. PACs, which can be up to a thousand times more absorptive than Natural Carbon, will absorb air entraining admixtures when used in concrete to provide freeze thaw durability, rendering the fly ash unusable. Due to ongoing air pollution legislation, environmental agencies are mandating mercury controls at hundreds of coal burning power generating stations across the U.S. and Canada, which have already negatively impacted the quality of millions of tons of fly ash. Over 10 million tons of fly ash is beneficially used in concrete as a partial replacement for cement every year in the U.S.

FlyAshDirect originally developed the technology to address the affects of "Natural or Unburned" carbon, which is caused by low NOx burners or other inefficient burning conditions in the boiler. Realizing the benefits of the technology, BASF Construction Chemicals Division saw an opportunity to assist FlyAshDirect in further developing the chemistry to address the more aggressive challenge posed by PAC tainted fly ashes and are now prepared to commercialize the new technology. CarbonBlocker is specifically designed to provide an efficient method to apply minute quantities of liquid chemistry to alter the properties of fine powders in a bulk flow environment. This is a key benefit that FlyAshDirect and BASF believe can be expanded to other new and unique chemistries for the purpose of treating a wide array of construction materials such as fly ash, cement and slag, providing unlimited opportunities.

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