Wisconsin Administrative Code
Department of Natural Resources
NR 400-499 - Environmental Protection - Air Pollution Control
Chapter NR 440 - Standards of performance for new stationary sources
Subchapter II - Standards of Performance
Section NR 440.315 - Basic oxygen process steelmaking facilities for which construction is commenced after January 20, 1983

(a) The provisions of this section apply to the following affected facilities in an iron and steel plant: top-blown BOPFs and hot metal transfer stations and skimming stations used with bottom-blown or top-blown BOPFs.

(b) This section applies to any facility identified in par. (a) that commences construction, modification or reconstruction after January 20, 1983.

(c) Any BOPF subject to the provisions of this section is subject to those provisions of s. NR 440.31 applicable to affected facilities commencing construction, modification or reconstruction after January 20, 1983.

(a) "Basic oxygen process furnace" or "BOPF" means any furnace with a refractory lining in which molten steel is produced by charging scrap metal, molten iron, and flux materials or alloy additions into a vessel and by introducing a high volume of oxygen-rich gas. Open hearth, blast and reverberatory furnaces are not included in this definition.

(b) "Bottom-blown furnace" means any BOPF in which oxygen and other combustion gases are introduced to the bath of molten iron through tuyeres in the bottom of the vessel or through tuyeres in the bottom and sides of the vessel.

(c) "Fume suppression system" means the equipment comprising any system used to inhibit the generation of emissions from steelmaking facilities with an inert gas, flame or steam blanket applied to the surface of molten iron or steel.

(d) "Hot metal transfer station" means the facility where molten iron is emptied from the railroad torpedo car or hot metal car to the shop ladle. This includes the transfer of molten iron from the torpedo car or hot metal car to a mixer (or other intermediate vessel) and from a mixer (or other intermediate vessel) to the ladle. This facility is also known as the reladling station or ladle transfer station.

(e) "Primary emission control system" means the combination of equipment used for the capture and collection of primary emissions, e.g., an open hood capture system used in conjunction with a particular cleaning device such as an electrostatic precipitator or a closed hood capture system used in conjunction with a particulate matter cleaning device such as a scrubber.

(f) "Primary emissions" means particulate matter emissions from the BOPF generated during the steel production cycle which are captured by, and do not thereafter escape from the BOPF primary control system.

(g) "Primary oxygen blow" means the period in the steel production cycle of a BOPF during which a high volume of oxygen-rich gas is introduced to the bath of molten iron by means of a lance inserted from the top of the vessel. This definition does not include any additional, or secondary, oxygen blows made after the primary blow.

(h) "Secondary emission control system" means the combination of equipment used for the capture and collection of secondary emissions, e.g.:

(i) "Secondary emissions" means particulate matter emissions that are not captured by the BOPF primary control system, including emissions from hot metal transfer and skimming stations. This definition also includes particulate matter emissions that escape from openings in the primary emission control system, such as from lance hole openings, gaps or tears in the ductwork of the primary emission control system, or leaks in hoods.

(j) "Skimming station" means the facility where slag is mechanically raked from the top of the molten iron.

(k) "Steel production cycle" means the operations conducted within the BOPF steelmaking facility that are required to produce each batch of steel, including the following operations: scrap charging, preheating (when used), hot metal charging primary oxygen blowing, sampling (vessel turndown and turnup), additional oxygen blowing (when used), tapping and deslagging. Hot metal transfer and skimming operations from the next steel production cycle are also included when the hot metal transfer station or skimming station is an affected facility.

(L) "Top-blown furnace" means any BOPF in which oxygen is introduced to the bath of molten iron by means of an oxygen lance inserted from the top of the vessel.

(a) Except as provided under pars. (b) and (c), on and after the date on which the performance test under s. NR 440.08 is required to be completed, no owner or operator subject to the provisions of this section may cause to be discharged into the atmosphere from any affected facility any secondary emissions that:

(b) A fume suppression system used to control secondary emissions from an affected facility is not subject to par. (a) 2. and 3.

(c) A control device used to collect both primary and secondary emissions from a BOPF is not subject to par. (a) 2. and 3.

(a) Each owner or operator of an affected facility shall install, calibrate, operate, and maintain a monitoring device that continually measures and records for each steel production cycle the various rates or levels of exhaust ventilation at each phase of the cycle through each duct of the secondary emission capture system. The monitoring device or devices are to be placed at locations near each capture point of the secondary emission capture system to monitor the exhaust ventilation rates or levels adequately, or in alternative locations approved in advance by the department.

(b) If a chart recorder is used, the owner or operator shall use chart recorders that are operated at minimum chart speed of 3.8 cm/hr (1.5 in/hr).

(c) All monitoring devices required by par. (a) shall be certified by the manufacturer to be accurate to within " 10% compared to Method 2 of 40 CFR part 60, Appendix A, incorporated by reference in s. NR 440.17(1). The owner or operator shall recalibrate and check the devices annually and at other times as the department may require, in accordance with the written instructions of the manufacturer and by comparing the device against Method 2.

(d) Each owner or operator subject to the requirements of par. (a) shall report on a semiannual basis all measurements of exhaust ventilation rates or levels over any 3-hour period that average more than 10% below the average rates or levels of exhaust ventilation maintained during the most recent performance test conducted under s. NR 440.08 in which the affected facility demonstrated compliance with the standard under sub. (3) (a) 2. The accuracy of the respective measurements, not to exceed the values specified in par. (c), may be considered when determining the measurement results that are to be reported.

(e) If a scrubber primary emission control device is used to collect secondary emissions, the owner or operator shall report on a semiannual basis all measurements of exhaust ventilation rate over any 3-hour period that average more than 10% below the average levels maintained during the most recent performance text conducted under s. NR 440.08 in which the affected facility demonstrated compliance with the standard under sub. (3) (a) 1.

(a) In conducting the performance tests required in s. NR 440.08, the owner or operator shall use as reference methods and procedures the test methods in Appendix A of 40 CFR part 60, incorporated by reference in s. NR 440.17, or other methods and procedures as specified in this subsection, except as provided in s. NR 440.08(2).

(b) The owner or operator shall determine compliance with the particulate matter standard in sub. (3) as follows:

(c) In complying with the requirements of sub. (4) (c), the owner or operator shall conduct an initial test as follows:

(d) To comply with sub. (4) (d) or (e), the owner or operator shall use the monitoring device of sub. (4) (a) to determine the exhaust ventilation rates or levels during the particulate matter runs. Each owner or operator shall then use these rates or levels to determine the 3-hour averages required by sub. (4) (d) and (e).

(a) When determining compliance with mass and visible emission limits specified in sub. (3) (a) 2. and 3., the owner or operator of a BOPF shop that normally operates 2 furnaces with overlapping cycles may elect to operate only one furnace. If an owner or operator chooses to shut down one furnace, he or she shall be allowed a reasonable time period to adjust the production schedule before the compliance tests are conducted. The owner or operator of an affected facility may also elect to suspend shop operations not subject to this section during compliance testing.

(b) During compliance testing for mass and visible emission standards, if an owner or operator elects to shut down one furnace in a shop that normally operates 2 furnaces with overlapping cycles, the owner or operator shall operate the secondary emission control system for the furnace being tested at exhaust ventilation rates or levels for each duct of the secondary emission control system that are appropriate for single-furnace operating. Following the compliance test, the owner or operator shall operate the secondary emission control system at exhaust ventilation rates or levels for each duct of the system that are no lower than 90% of the exhaust ventilation values established during the most recent compliance test.

(c) For the purpose of determining compliance with visible and mass emission standards, a steel production cycle begins when the scrap or hot metal is charged to the vessel (whichever operation occurs first) and terminates 3 minutes after slag is emptied from the vessel into the slag pot. Consecutive steel production cycles are not required for the purpose of determining compliance. Where a hot metal transfer or skimming station is an affected facility, the steel production cycle also includes the hot metal transfer or skimming operation for the next steel production cycle for the affected vessel. Visible emission observations for both hot metal transfer and skimming operations begin with the start of the operation and terminate 3

(d) For the purpose of determining compliance with visible emission standards specified in sub. (3) (a) 1. and 3., the starting and stopping times of regulated process operations shall be determined and the starting and stopping times of visible emissions data sets shall be determined accordingly.

(e) To determine compliance with sub. (3) (a) 1., the owner or operator shall select the data sets yielding the highest and second highest 3-minute average opacities for each steel production cycle. Compliance is achieved if the highest 3-minute average for each cycle observed is less than 20% and the second highest 3-minute average is 10% or less.

(f) To determine compliance with sub. (3) (a) 2., the owner or operator shall determine the concentration of particulate matter in exhaust gases exiting the secondary emission collection device with Method 5 of Appendix A, 40 CFR part 60, incorporated by reference in s. NR 440.17(1). Compliance is achieved if the concentration of particulate matter does not exceed 23 mg/dscm (0.010 gr/dscf).

(g) To determine compliance with sub. (3) (a) 3., the owner or operator shall construct consecutive 3-minute averages for each steel production cycle. Compliance is achieved if no 3-minute average is more than 5%.