US EPA announced new mercury and hydrocarbon emission limits for cement kilns built after December 2, 2005. The emission limits will reduce annual mercury emissions by about one ton and annual hydrocarbon emissions by about 1,100 tons. Kilns built before that time must meet work practice requirements, such as removing cement kiln dust when it no longer can be recycled and operating kilns properly to ensure complete combustion.
In addition, the amendments prohibit all cement kilns from using fly ash from utility boilers equipped with mercury emission controls where the fly ash mercury content has been increased through the use of activated carbon or any other sorbent, unless the cement kiln can demonstrate that use of that fly ash will not increase its mercury emissions.
In a separate action, US EPA announced that it will reconsider the mercury and hydrocarbon emissions for new kilns. This step is being taken because US EPA recently became aware of information and questions about mercury and hydrocarbon controls at cement kilns that were not available during the public comment period on the proposed rule. For more information, see:
- Fact Sheet;
- National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry: Final Rule (pdf, 210pp., 280kB); and
- National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry: Notice of Reconsideration (pdf, 12pp., 28kB).