Terms in this subpart are defined in the Clean Air Act (Act), in subpart A of this part, or in this section as follows:

Bag leak detection system means a system that is capable of continuously monitoring particulate matter (dust) loadings in the exhaust of a baghouse in order to detect bag leaks and other upset conditions. A bag leak detection system includes, but is not limited to, an instrument that operates on triboelectric, light scattering, light transmittance, or other effect to continuously monitor relative particulate matter loadings.

Capture system means the equipment (including hoods, ducts, fans, dampers, etc.) used to capture or transport particulate matter generated by an affected submerged arc furnace.

Casting means the period of time from when molten ferroalloy falls from the furnace tapping runner into the ladle until pouring into molds is completed. This includes the following operations: ladle filling, pouring alloy from one ladle to another, slag separation, slag removal, and ladle transfer by crane, truck, or other conveyance.

Crushing and screening equipment means the crushers, grinders, mills, screens and conveying systems used to crush, size, and prepare for packing manganese-containing materials, including raw materials, intermediate products, and final products.

Fugitive dust source means a stationary source from which manganese-bearing particles are discharged to the atmosphere due to wind or mechanical inducement such as vehicle traffic. Fugitive dust sources include plant roadways, yard areas, and outdoor material storage and transfer operations.

Furnace power input means the resistive electrical power consumption of a submerged arc furnace, expressed as megawatts (MW).

Malfunction means any sudden, infrequent, and not reasonably preventable failure of air pollution control equipment, process equipment, or a process to operate in a normal or usual manner which causes, or has the potential to cause, the emission limitations in an applicable standard to be exceeded. Failures caused in part by poor maintenance or careless operation are not malfunctions.

Metal oxygen refining (MOR) process means the reduction of the carbon content of ferromanganese through the use of oxygen.

Open submerged arc furnace means an electric submerged arc furnace that is equipped with a canopy hood above the furnace to collect primary emissions.

Operating time means the period of time in hours that the affected source is in operation beginning at a startup and ending at the next shutdown.

Plant roadway means any area at a ferromanganese and silicomanganese production facility that is subject to plant mobile equipment, such as fork lifts, front end loaders, or trucks, carrying manganese-bearing materials. Excluded from this definition are employee and visitor parking areas, provided they are not subject to traffic by plant mobile equipment.

Primary emissions means gases and emissions collected by hoods and ductwork located above an open furnace or under the cover of a semi-closed or sealed furnace.

Sealed submerged arc furnace means an electric submerged arc furnace equipped with a total enclosure or cover from which primary emissions are evacuated directly.

Semi-closed submerged arc furnace means an electric submerged arc furnace equipped with a partially sealed cover over the furnace. This cover is equipped with openings to allow penetration of the electrodes into the furnace. Mix is introduced into the furnace around the electrode holes forming a partial seal between the electrodes and the cover. Furnace emissions generated under the cover are ducted to an emission control device. Emissions that escape the cover are collected and vented through stacks directly to the atmosphere.

Shop means the building which houses one or more submerged arc furnaces.

Shutdown means the cessation of operation of an affected source for any purpose.

Startup means the setting in operation of an affected source for any purpose.

Submerged arc furnace means any furnace wherein electrical energy is converted to heat energy by transmission of current between electrodes partially submerged in the furnace charge. The furnace may be of an open, semi-sealed, or sealed design.

Tapping emissions means a source of air pollutant emissions that occur during the process of removing the molten product from the furnace.

Tapping period means the time from when a tap hole is opened until the time a tap hole is closed.

[64 FR 27458, May 20, 1999, as amended at 71 FR 20462, Apr. 20, 2006]