Wisconsin Administrative Code › Department of Natural Resources › NR 400-499 - Environmental Protection - Air Pollution Control › Chapter NR 463 - National Emission Standards For Hazardous Air Pollutants For Metals Treating And Processing › Subchapter I - Chromium Emissions from Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks › Section NR 463.02 - Definitions

Current through June 24, 2024
For terms not defined in this section, the definitions
					 contained in chs.
					 NR
					 400 and
					 460 apply to the terms used in
					 this subchapter, with definitions in ch. NR 460 taking priority over
					 definitions in ch. NR 400. In addition, the definitions in this section apply
					 to the terms used in this subchapter. If this section defines a term which is
					 also defined in ch. NR 400 or 460, the definition in this section applies in
					 this subchapter rather than the definition in ch. NR 400 or 460. In this
					 subchapter:
(1) "Add-on air pollution
				  control device" means equipment installed in the ventilation system of chromium
				  electroplating and anodizing tanks for the purposes of collecting and
				  containing chromium emissions from the tanks.
(2) "Air pollution control technique" means
				  any method, such as an add-on air pollution control device or a chemical fume
				  suppressant, that is used to reduce chromium emissions from chromium
				  electroplating and chromium anodizing tanks.
(3) "Base metal" means the metal or metal
				  alloy that comprises the workpiece.
(4) "Bath component" means the trade, brand
				  or chemical name of each component in trivalent chromium plating baths.
Note
Since for trivalent chromium baths, the
					 bath composition is proprietary in most cases, the trade or brand name for each
					 component may be used. However, ss.
					 NR 463.103(2)
					 (n) and
					 463.106(9) (a) 3.
					 require identification by chemical name of the wetting agent contained in that
					 component.
(5) "Chemical
				  fume suppressant" means any chemical agent that reduces or suppresses fumes or
				  mists at the surface of an electroplating or anodizing bath.
Note
Another term for fume suppressant is mist
					 suppressant.
(6) "Chromic
				  acid" means the common name for chromium anhydride (CrO3).
(7) "Chromium anodizing" means the
				  electrolytic process by which an oxide layer is produced on the surface of a
				  base metal for functional purposes, such as corrosion resistance or electrical
				  insulation, using a chromic acid solution. In chromium anodizing, the part to
				  be anodized acts as the anode in the electrical circuit, and the chromic acid
				  solution, with a concentration typically ranging from 50 to 100 grams per liter
				  (g/L), serves as the electrolyte.
(8) "Chromium anodizing tank" means the
				  receptacle or container along with the following accompanying internal and
				  external components needed for chromium anodizing: rectifiers fitted with
				  controls to allow for voltage adjustments, heat exchanger equipment,
				  circulation pumps and air agitation systems.
(8m) "Chromium electroplating tank" means the
				  receptacle or container along with the following accompanying internal and
				  external components needed for chromium electroplating: rectifiers, anodes,
				  heat exchanger equipment, circulation pumps and air agitation
				  systems.
(9) "Composite mesh-pad
				  system" means an add-on air pollution control device typically consisting of
				  several mesh-pad stages. The purpose of the first stage is to remove large
				  particles. Smaller particles are removed in the second stage, which consists of
				  the composite mesh pad. A final stage may remove any reentrained particles not
				  collected by the composite mesh pad.
(10) "Decorative chromium electroplating"
				  means the process by which a thin layer of chromium (typically 0.003 to 2.5 mm)
				  is electrodeposited on a base metal, plastic or undercoating to provide a
				  bright surface with wear and tarnish resistance. In this process, the part
				  serves as the cathode in the electrolytic cell and the solution serves as the
				  electrolyte. Typical current density applied during this process ranges from
				  540 to 2,400 amperes per square meter (A/m2) for total plating times ranging
				  between 0.5 to 5 minutes.
(11)
				  "Electroplating or anodizing bath" means the electrolytic solution used as the
				  conducting medium in which the flow of current is accompanied by movement of
				  metal ions for the purposes of electroplating metal out of the solution onto a
				  workpiece or for oxidizing the base material.
(12) "Emission limitation" means the
				  concentration of total chromium allowed to be emitted expressed in milligrams
				  per dry standard cubic meter (mg/dscm), or the allowable surface tension
				  expressed in dynes per centimeter (dynes/cm).
(12m) "Enclosed hard chromium electroplating
				  tank" means a chromium electroplating tank that is equipped with an enclosing
				  hood and ventilated at half the rate or less than that of an open surface tank
				  of the same surface area.
(13)
				  "Existing" means any hard chromium electroplating tank, decorative chromium
				  electroplating tank or chromium anodizing tank the construction or
				  reconstruction of which was commenced on or before December 16, 1993.
(14) "Facility" means the major or area
				  source at which chromium electroplating or chromium anodizing is
				  performed.
(15) "Fiber-bed mist
				  eliminator" means an add-on air pollution control device that removes
				  contaminants from a gas stream through the mechanisms of inertial impaction and
				  Brownian diffusion. These devices are typically installed downstream of another
				  control device, which serves to prevent plugging, and consist of one or more
				  fiber beds. Each bed consists of a hollow cylinder formed from 2 concentric
				  screens; the fiber between the screens may be fabricated from glass, ceramic
				  plastic or metal.
(16) "Foam
				  blanket" means the type of chemical fume suppressant that generates a layer of
				  foam across the surface of a solution when current is applied to that
				  solution.
(17) "Fresh water" means
				  water, such as tap water, that has not been previously used in a process
				  operation or, if the water has been recycled from a process operation, it has
				  been treated and meets the effluent guidelines for chromium
				  wastewater.
(18) "Hard chromium
				  electroplating" or "industrial chromium electroplating" means a process by
				  which a thick layer of chromium (typically 1.3 to 760 mm) is electrodeposited
				  on a base material to provide a surface with functional properties such as wear
				  resistance, a low coefficient of friction, hardness and corrosion resistance.
				  In this process, the part serves as the cathode in the electrolytic cell and
				  the solution serves as the electrolyte. The hard chromium electroplating
				  process is performed at current densities typically ranging from 1,600 to 6,500
				  A/m2 for total plating times ranging from 20 minutes to 36 hours depending upon
				  the desired plate thickness.
(19)
				  "Hexavalent chromium" means the form of chromium in a valence state of
				  +6.
(20) "Large, hard chromium
				  electroplating facility" means a facility that performs hard chromium
				  electroplating and has a maximum cumulative potential rectifier capacity
				  greater than or equal to 60 million ampere-hours per year (A-hr/yr).
(21) "Maximum cumulative potential rectifier
				  capacity" means the summation of the total installed rectifier capacity
				  associated with the hard chromium electroplating tanks at a facility, expressed
				  in amperes, multiplied by the maximum potential operating schedule of 8,400
				  hours per year and 0.7, which assumes that electrodes are energized 70% of the
				  total operating time. The maximum potential operating schedule is based on
				  operating 24 hours per day, 7 days per week, 50 weeks per year.
(22) "New source" or "new tank" means any
				  hard chromium electroplating, decorative chromium electroplating or chromium
				  anodizing source or tank the construction or reconstruction of which is
				  commenced after December 16, 1993.
(22m) "Open surface hard chromium
				  electroplating tank" means a chromium electroplating tank that is ventilated at
				  a rate consistent with good ventilation practices for open tanks.
(23) "Operating parameter value" means a
				  minimum or maximum value established for a control device or process parameter
				  which, if achieved by itself or in combination with one or more other operating
				  parameter values, determines that an owner or operator is in continual
				  compliance with the applicable emission limitation or standard.
(24) "Packed-bed scrubber" means an add-on
				  air pollution control device consisting of a single or double packed bed that
				  contains packing media on which the chromic acid droplets impinge. The
				  packed-bed section of the scrubber is followed by a mist eliminator to remove
				  any water entrained from the packed-bed section.
(25) "Research or laboratory operation" means
				  an operation whose primary purpose is for research and development of new
				  processes and products, that is conducted under the close supervision of
				  technically trained personnel, and that is not involved in the manufacture of
				  products for commercial sale, except in a de minimis manner.
(26) "Small, hard chromium electroplating
				  facility" means a facility that performs hard chromium electroplating and has a
				  maximum cumulative potential rectifier capacity less than 60 million
				  A-hr/yr.
(27) "Stalagmometer" means
				  an instrument used to measure the surface tension of a solution by determining
				  the mass of a drop of liquid by weighing a known number of drops or by counting
				  the number of drops obtained from a given volume of liquid.
(28) "Surface tension" means the property,
				  due to molecular forces, that exists in the surface film of all liquids and
				  tends to prevent liquid from spreading.
(29) "Tank operation" means the use of a tank
				  for chromium electroplating or a chromium anodizing through the application of
				  current or voltage. Tank operation ceases when the current or voltage is turned
				  off.
(30) "Tensiometer" means an
				  instrument used to measure the surface tension of a solution by determining the
				  amount of force needed to pull a ring from the liquid surface. The amount of
				  force is proportional to the surface tension.
(31) "Trivalent chromium" means the form of
				  chromium in a valence state of +3.
(32) "Trivalent chromium process" means the
				  process used for electrodeposition of a thin layer of chromium onto a base
				  material using a trivalent chromium solution instead of a chromic acid
				  solution.
(33) "Wetting agent"
				  means the type of chemical fume suppressant that reduces the surface tension of
				  a liquid.