February 15, 2007 — After a full year of operation with its cupola emissions-control systems, Atlantic States Cast Iron Pipe, in Phillipsburg, NJ, is claiming to be the first metalcasting operation in North America to successfully implement technologies that substantially limit mercury emissions. The McWane Inc. subsidiary produces ductile-iron pressure pipe, and launched the $9.3-million investment in 2004 in order to meet federal Clean Air Act requirements, and the New Jersey Dept. of Environmental Protection's more stringent demands for mercury containment ahead of the 2010 compliance date.
Mercury is an element that occurs naturally, but it is also toxic, and exposure to mercury may cause serious health problems, or even death. Most mercury emissions are produced from fossil fuel combustion and solid waste incineration, and the emissions are transported through the atmosphere as vapor.
For Atlantic States and others that melt steel scrap, the most common source of mercury are automotive light switches that are expected to be removed by the scrap processors. When they're not removed, they can be melted with the steel and add mercury to the cupola's off-gases.
The core of Atlantic States's emission control system is a 80-tons/hour baghouse designed and supplied by Kuttner L.L.C., with mercury and particulate-reducing filters designed by Luehr Filter GmbH. The baghouse operates at a lower temperature than standard baghouses, around 280°F versus 500°-600°F.
NJDEP's forthcoming mercury regulations will require foundries to achieve a 75% removal rate for mercury, or in the case of Atlantic States, 35 mg/ton mercury per ton of pipe produced.
As reported by Atllantic States, a certified stack test conducted on December 5, 2006, showed the foundry achieved mercury emissions of less than 2 mg/ton and exceeded 99% removal. "As a result," the foundry states, "three years ahead of NJDEP's schedule, Atlantic States has voluntarily put systems in place that removed over 50 lb of mercury from its emissions in 2006, and will remove over 200 lb of mercury from its emissions before the new regulations become effective."
Atlantic States says the new system has reduces lead emissions dramatically: during the stack test, Atlantic States achieved lead emissions of 0.00039 lb/hr, or 99.9% removal. Other results showed that emissions of particulate matter and other metals had been significantly reduced, and CO emissions had been cut by 95%.
Atlantic States v.p. Mitchell Kidd stated: "We take great pride in the fact that Atlantic States is the industry leader in the reduction of mercury emissions, and that with the installation of our cupola emissions system, we have now set a standard for the industry that will produce significant benefits to the environment."