Section NR 256.31 - Specialized definitionsThe following definitions are applicable to terms used in this chapter:
(1) "Cast iron" means an iron containing carbon in excess of the solubility in the austentite that exists in the alloy at the eutectic temperature, or any iron-carbon alloy that conta ins 1.2 % or more carbon by weight.(2) "Discrete wet scrubbing device" means a distinct, stand-alone device that removes particulates and fumes from a contaminated gas stream by bringing the gas stream into contact with a scrubber liquor, usually water, and from which there is a wastewater discharge, including but not limited to spray towers and chambers, fixed and variable venturi scrubbers, wet caps, packed bed scrubbers, quenchers and orifice scrubbers. It does not include aftercoolers, ancillary scrubber operations such as fan washes and backwashes, or semi-wet scrubbing devices.(3) "Ductile iron" means a cast iron treated while molten with a master alloy that contains an element such as magnesium or cerium to induce the formation of free graphite as nodules or spherules, which imparts a measurable degree of ductility to the cast metal.(4) "Gray iron" means a cast iron that gives a gray fracture due to the presence of flake graphite.(5) "Malleable iron" which means a cast iron made by a prolonged anneal of white cast iron in which either decarburization or graphitization, or both, eliminate some or all of the cementite, and where graphite is present in the form of temper carbon.(6) "Multiple ferrous melting furnace scrubber configuration" means a configuration where 2 or more discrete wet scrubbing devices are used in series in a single melting furnace exhaust gas stream.(7) "Primary metal cast" means the metal that is poured in the greatest quantity at an individual plant.(8) "Semi-wet scrubbing device" means a device to which water is added and totally evaporates prior to dry air pollution control.(9) "Steel" means and iron-base alloy containing manganese, carbon at less than 1.2 % by weight, and often other alloying elements.Wis. Admin. Code Department of Natural Resources NR 256.31
Cr. Register, June, 1989, No. 402, eff. 7-1-89