Concrete Products covers the issues that attract producers of ready mixed and manufactured concrete focusing on equipment and material technology, market development and management topics.
Issue link: http://concrete.epubxp.com/i/75186
NEWS SCOPE BY CP STAFF author and senior toxicologist/risk as- sessor with engineering giant AECOM, "is the most environmentally conservative approach possible. This analysis esti- mates exposure to children who live on top of a coal ash pile 24 hours a day. Even under these unrealistic conditions, the metals contained in coal ash do not rise to a level that warrants more than a BASF EYES ASH TREATMENT Cleveland-based BASF Construction Chemicals Division has entered a part- nership to advance treatment of fly ashes exposed to Powder Activated Carbon (PAC), widely accepted to con- trol coal burning power plants' mer- cury emissions. When installed prior to a particulate control device, PAC injection systems deposit activated carbon onto the fly ash as it travels through the flue gas, subsequently elevating the byprod- uct's level of carbon or Loss on Igni- tion. Measured at up to a thousand times more absorptive than natural carbon, PAC absorbs air-entraining admixtures when used in concrete, rendering the fly ash unusable. The BASF partnership will parlay a tech- nology, CarbonBlocker, which applies minute quantities of liquid chemistry to alter the properties of fine powders in a bulk flow environment. CarbonBlocker is installed at five Ohio Valley generating stations and has been deployed to treat more than 2 million tons of ASTM C618-grade fly ash. The technology's Cincinnati-based proprietor holds separate patents on the injection system and chemistry, originally developing the technology to address the effects of "Natural or Un- burned" carbon caused by low-NOx burners or other inefficient burning conditions in the power plant boiler. BASF Construction Chemicals saw an opportunity to further develop the CarbonBlocker chemistry to ad- dress the more aggressive challenge posed by PAC-tainted fly ashes, while expanding the chemistry to treating a wide array of construction materi- als, including cement and slag. Its partnership follows an investment Sika AG announced earlier this year in New York-based Ash Improvement Technology. — Don Marsh JULY 2012 | 15 screening level evaluation using U.S. EPA established guidelines." Her report assesses coal ash from each of the five power plants for which new government data is available. Compar- isons are made to the levels of metals in background soils based on previous USGS data the Electric Power Research Insti- tute compiled in 2010.