1. Secondary Aluminum Production Industry Maximum Achievable Control Technology (MACT) Training
40 CFR Part 63 Subpart RRR

2. Secondary aluminum plants recover aluminum from scrap such as beverage cans, foundry returns, other aluminum scrap, and dross. Air toxics are released from preprocessing operations

3. such as aluminum scrap shredding, thermal chip drying, scrap drying/decoating/ delacquering; and furnace operations (i.e., melting, holding, refining, fluxing, or alloying).

5. Secondary Aluminum Production Facility
Any establishment using clean charge, post-consumer aluminum scrap, aluminum ingots, aluminum foundry returns, dross from

6. aluminum production, or molten aluminum as the raw material and performing one or more of the following processes:

7. Scrap shredding
Scrap drying/delacquering/decoating
Thermal chip drying
Furnace operations
In-line fluxing
Dross cooling

8. Example Secondary Aluminum Facility

10. Secondary Aluminum Sectors
• Secondary aluminum companies
• Sweat furnace operators
• May include die casters & foundries

11. Estimated Number of Secondary Aluminum Sources Potentially Affected
• Approximately 400 (86 major)
• 320 die casting companies
• foundries
• sweat furnaces

13. Types of Hazardous Air Pollutants (HAP’s) Emitted
• Organic HAP’s (e.g. benzene,
styrene, dioxins, and furans)

14. Inorganic gaseous HAP’s (e. g
Inorganic gaseous HAP’s (e.g. hydrogen chloride, hydrogen flouride, and chlorine)
Particulate HAP metals (e.g. arsenic, lead, and chromium)

16. History of Secondary Aluminum Production National Emission Standards for Hazardous Air Pollutants (NESHAP)
NESHAP was proposed, 2/11/99

17. History Cont’d.:
Final rule was promulgated, 3/23/00
Direct final rule; amendments, 6/14/02
Final rule; amendments, 9/24/02
Final rule amendments 12/30/03

19. Regulated Entities under Current Rule
Facilities that perform secondary smelting and alloying of aluminum

20. Secondary aluminum production facility affected sources collocated at:
Aluminum sheet, plate, and foil manufacturing facilities
Aluminum extruded product manufacturing facilities

21. Other aluminum rolling and drawing facilities
Primary aluminum production facilities
Aluminum die casting facilities
Aluminum foundry facilities

23. Regulated HAPs
Particulate matter emissions (PM) (surrogate for HAP metals)
Total hydrocarbon (THC) emissions - surrogate for HAP organics)

24. Hydrogen chloride (HCl) emissions - a HAP and a surrogate for inorganic HAP’s including hydrogen fluoride (HF) and chlorine (Cl2)

25. Dioxin and furan emissions at secondary aluminum production facilities that are major or area sources

27. Projected Environmental Benefits
Reduce HAP emissions by about 12,420 tons/year, a 70% reduction from current levels
Reduce HCl emissions by 12,370 tons/year, a 73% reduction

28. Projected Environmental Benefits (Continued)
Reduce metal emissions by 40 tons/year, a 60% reduction
Reduce dioxin/furan emissions by 0.88 pounds/year, a 79% reduction

29. Projected Environmental Benefits (Continued)
Reduce polycyclic organic matter emissions by 10 tons/year, a 25% reduction
Reduce PM emissions by 3,185 tons/year, a 30% reduction

31. Rule Requirements Emission standards and operating requirements
Monitoring and compliance provisions
Notifications, reports, and records

33. Applicability and Description of Affected Units §63.1500

34. Applicability and Description of Affected Units
• Secondary aluminum production
operations
• Affected sources
Secondary Aluminum Website:

36. Secondary Aluminum NESHAPS Applicability Flowcharts

42. Secondary Aluminum Production Operations
• Preprocessing of scrap aluminum (size reduction, removal of oils, coatings, and other contaminants)

43. Furnace operations (melting, in-furnace fluxing/refining, tapping)
Additional refining (in-line fluxing)
Cooling of dross

45. Processing of Scrap Aluminum
• Crushing, shredding, and grinding
• Drying
• Heating in a dryer or kiln
• Heating in a sweat furnace

46. Crushing, Shredding, and Grinding
To reduce the size of scrap aluminum
Emissions: Particulate matter (PM)
and HAP metals generated as dust
from coatings & other contaminants

47. Chip Dryers To reduce the size of scrap aluminum
Emissions: Particulate matter (PM)
& HAP metals generated as dust from
coatings and other contaminants

48. Applicability and Description of Affected Units
• Secondary aluminum production operations
Affected sources
We’ll discuss in general terms the types of operations that are considered to be part of a secondary aluminum production operation. Then we will identify “affected sources” as defined by the rule.

50. Secondary Aluminum Production Operations
Preprocessing of scrap aluminum (size reduction, removal of oils, coatings, and other contaminants)

51. Furnace operations (melting, in-furnace fluxing/refining, tapping)
• Additional refining (in-line fluxing)
• Cooling of dross

52. Preprocessing of Scrap Aluminum
Crushing, shredding, and grinding
Drying
Heating in a dryer or kiln
Heating in a sweat furnace

53. Crushing, Shredding, and Grinding
To reduce the size of scrap aluminum
Emissions: Particulate matter (PM) and HAP metals generated as dust from coatings and other contaminants

54. Chip Dryers
Evaporates oil and moisture from uncoated aluminum chips & borings
Generally operate at temperatures ranging between 300oF to 750oF
Emissions: Organic HAP’s including dioxins and furans
These are characteristics associated with “thermal chip dryers.” Pre-heating boxes, centrifuges, and other devices used to remove just water are not the same as thermal chip dryers.

55. Scrap Dryers/Delacquering Kilns/Decoating Kilns
Remove coatings and other contaminants that may be present in scrap prior to melting (e.g., oil, grease, lubricants, lacquers, rubber, and plastic laminates)

56. Heat scrap to exit temperature of 1000 °F
• Emissions: Inorganic HAP’s including particulate metal HAP’s and hydrogen chloride and organic HAP’s including dioxins and furans

57. Charging End of Delacquering Kilns

58. Discharge End of Delacquering Kilns

59. Sweat Furnaces Reclaim aluminum from scrap with high levels of iron
Operate in batch mode at a temperature high enough to melt the aluminum but not the iron

60. Molten aluminum can be cast into sows, ingots, or T-bars used as feedstock for melting and refining furnaces
Emissions: Dioxins and furans

61. Sweat Furnace Charging

62. Sweat Furnace

63. Uncontrolled Sweat Furnace 1

64. Uncontrolled Sweat Furnace 2

65. Furnace Operations
Melting
Fluxing/refining
Tapping

66. Melting • Begins with charging of scrap into furnace
Chemistry of molten bath adjusted by adding selected scrap or alloying agents (e.g., silicon)

67. Charging Sidewell Furnace

68. Fluxing
Done to refine molten aluminum to improve product quality, achieve product specifications, or reduce material loss

69. Fluxes may be added to remove impurities and reduce aluminum oxidation
May be performed in the furnace or outside the furnace by an in-line fluxer

70. Fluxing Processes Addition of salts (cover flux) Addition of solvents
Injection of gasses (demagging and degassing)
Chloride and fluoride salt fluxes are added to reduce oxidation. Flux gasses typically consist of chlorine or chlorine mixtures.

71. Process Furnaces
Refractory-lined metal vessels heated by oil, gas, or electricity that are used to melt scrap

72. Types include melting, holding, and refining furnaces
Charging of scrap can be done from the side, front, or top of the furnace

73. Examples of Process Furnaces
Top charging and front charging furnaces

74. Sidewell melting furnace – a furnace with an open well adjacent to the hearth used for charging scrap & solid flux or salt to the furnace, injecting fluxing agents, & skimming dross

75. Transferring Molten Aluminum to Holding Furnace

76. Sidewell Furnace

77. Examples of Process Furnaces - Continued
Induction furnaces – heating mechanism is electric energy
Reverberatory furnaces – typically gas

78. Process Furnace Emissions
HAP emissions from scrap and fluxing agents include:
• Particulate metal HAPs
Hydrogen chloride
Dioxins and furans

79. Dross-only Furnaces
Typically rotary barrel-designed furnaces dedicated to reclamation of aluminum from dross formed during melting, holding, alloying, or fluxing operations carried out in other process units

80. Dross-only Furnaces Cont’d.
Dross and salt flux are sole feedstocks
Emissions: Particulate matter including metal HAPs

81. In-line Fluxing
Fluxing performed in a device exterior to furnace, located in a transfer line from furnace
Involves injection of chlorine, argon, nitrogen, or other gases to achieve desired metal purity

82. In-line Fluxing - Continued
Found primarily at facilities that manufacture high quality aluminum or in facilities with no other means of degassing
Emissions: Hydrogen chloride and particulate matter

83. Tapping
Transferring molten metal from melting furnace to molds or to a ladle

84. Cooling of Dross
“Dross” - slags and skimmings from melting and refining consisting of fluxing agents, impurities, and/or oxidized and non-oxidized aluminum

85. Cooling of Dross - Continued
Accomplished in rotating, water-cooled drums
Sole feedstock to dross-only furnaces
Emissions: Particulate matter including metal HAPs

86. Rotary Dross Cooler

88. Affected Sources at Major Sources of HAP’s - §63.1500
Each new and existing:
Aluminum scrap shredder
Thermal chip dryer
Scrap dryer/delacquering kiln/decoating kiln

89. Each new and existing group 2 furnace:
Melts, holds, or processes only clean charge, and
Performs no fluxing, or
Performs fluxing using only non-reactive, non-HAP-containing/non-HAP-generating gases or agents

90. Each new and existing:
Sweat furnace
Dross-only furnace
Rotary dross cooler

91. Each new and existing secondary aluminum processing unit (SAPU)
Group 1 furnace: processes non-clean charge; or processes clean charge with reactive fluxing
Group 1 furnace is a furnace that processes non-clean (dirty) charge with or without reactive fluxing, or that processes clean charge and does reactive fluxing.

92. Combination of all group 1 furnaces and all in-line fluxers within a secondary aluminum production facility

94. Secondary Aluminum Processing Units (SAPU)
Existing SAPU – all existing group 1 furnaces and all existing in-line fluxers
Proposed amendments would allow adding an existing emission unit to a new SAPU.

95. New SAPU – any combination of new group 1 furnaces and new in-line fluxers constructed after 2/11/99
Group 1 furnaces and in-line fluxers are emission units within an existing or new SAPU

97. Affected Sources at Area Sources of HAPs
Emission limits for dioxins and furans and associated operating, monitoring, reporting, and recordkeeping requirements apply to affected sources located at area sources
Area sources that have emissions of dioxins and furans are also subject to the D/F emission limits as well as the operating, monitoring , reporting, and recordkeeping requirements.

98. Affected Sources at Area Sources of HAPs Cont’d.
Each new and existing:
Thermal chip dryer
Scrap dryer/delacquering kiln/decoating kiln

99. Affected Sources at Area Sources of HAPs Cont’d.
Sweat furnace
SAPU with one or more group 1 furnace emission units processing other than clean charge

101. Affected Sources
Does not include aluminum die casters, foundries, or extruders that:
Melt only clean charge and materials generated within the facility or returned clean materials originally from facility, and

102. Affected Sources Cont’d.
Do not operate a thermal chip dryer, sweat furnace, or scrap dryer/delacquering kiln/decoating kiln

104. Clean Charge Molten aluminum T-bar, sow, ingot, billet, pig
Alloying elements
Uncoated/unpainted thermally dried chips
As defined in the current rule.

105. Clean Charge - continued
Scrap dried at ≥ 650 °F
Scrap delacquered/decoated at ≥ 900° F
oil-, lubricant-free unpainted/uncoated gates and risers

106. Clean Charge - continued
Oil- & lubricant-free unpainted/uncoated scrap, shapes, or products that have not been processed in such a way that causes contamination

107. Clean Charge - continued
Runaround scrap
Customer returns (clean material which contain no paint or other solid coatings)

109. Runaround Scrap
Scrap generated on-site or returned that does not contain paint or solid coating
Machining chips that have not been dried ≥650° F, or by equivalent non-thermal drying method, are not runaround
As defined by current rule.

111. Emission Standards and Operating Requirements §63.1505 and §63.1506

112. Emission Standards and Operating Requirements§
Secondary Aluminum Website:
requirement_tables.html

113. Pollutants Regulated PM – surrogate for particulate metal HAPs
THC – surrogate for gaseous organic HAPs
D/F – limits apply to a major or area source
HCl – HAP & surrogate for chlorine & HF
Opacity

115. Format of Emission Standard
Emission limits
Mass per unit (lb/ton) of feed/charge (or production)
Concentration (gr/dscf)
Percentage reduction

116. Format of Emission Standard - Continued
Emission limits
D/F in units of TEQ
International method of expressing toxicity equivalents for D/F
Different isomers of dioxins and furans have differing levels of toxicity. Analytical results report concentrations of these isomers and the method provides a means of calculating toxicity on a uniform basis.

117. Format of Emission Standard - Continued
Except for D/F, apply to major sources only
Apply to all new and existing affected sources and emission units

119. Opacity Limit
Sources with a PM add-on air pollution control device -- monitored with a continuous opacity monitor (COM)

120. Opacity Limit Cont’d.
Aluminum scrap shredders monitored with a COM, or monitored by visible emissions:
• Opacity limit = 10 percent

122. Aluminum Scrap Shredders
0.010 grain (gr) of PM per dry standard cubic foot (dscf)

124. Thermal Chip Dryers
0.80 lb of total hydrocarbon emissions (THC) per ton of feed
2.50 micrograms of dioxins and furans (D/F) toxicity equivalents (TEQ) per megagram (Mg) of feed
A chip dryer that is not a thermal chip dryer, for example, a centrifugal dryer that only removes water, would not be subject to these limits.

125. Thermal Chip Dryers Cont’d.
D/F limit for units at major or area sources

127. Scrap Dryers/Delacquering Kilns/Decoating Kilns
0.08 lb PM per ton of feed
0.80 lb HCl per ton of feed
0.06 lb THC per ton of feed
0.25 micrograms of D/F TEQ per Mg of feed

128. Scrap Dryers/Delacquering Kilns/Decoating Kilns – Alternate Limit
Applies if afterburner has a design residence time ≥ 1 second, and operates at a temperature ≥ 1400oF
0.30 lb PM per ton of feed
Because the same process equipment can be used as a scrap dryer, a delacquering kiln o r a decoating kiln, an alternate emission limit was developed. The limits in the previous slide were are more stringent, but the afterburner design parameters are not required.
The alternate limits are less stringent, but the source must meet the afterburner design criteria.

129. Scrap Dryers/Delacquering Kilns/Decoating Kilns – Alternate Limit Cont’d.
1.50 lb HCl per ton of feed
0.20 lb THC per ton of feed
5.0 micrograms D/F TEQ per Mg of feed

131. Sweat Furnaces
0.80 nanograms D/F TEQ per dry standard cubic meter (dscm) at 11 percent oxygen
No test required if sweat furnace has afterburner with design residence time
≥ 2 seconds and operates at ≥ 1600oF
Under the proposed amendments, the residence time would be corrected and changed to 0.8 seconds.

133. Dross-only Furnaces
0.30 lb PM per ton of feed

135. In-line Fluxers
Limits are used to calculate the standard applicable to secondary aluminum processing units (SAPU)
0.04 lb HCl per ton of feed
0.01 lb PM per ton of feed
Note that in-line fluxers are emission units within the SAPU affected source.

136. In-line Fluxers With No Reactive Fluxing
No HCl and PM limits apply
Work practice – no reactive fluxing

138. Rotary Dross Coolers
0.04 gr of PM per dscf

140. Clean Furnaces (Group 2)
No emission limits
Work practices – clean charge only and no reactive fluxing – or else
Or else it becomes a group 1 furnace.

142. Group 1 Melting/Holding Furnaces (Clean Charge Only)
Limits are used to calculate the standard applicable to secondary aluminum processing units (SAPU)
0.80 lb PM per ton of feed
Like in-line fluxers, group 1 furnaces are emission units within a SAPU affected source.

143. Group 1 Melting/Holding Furnaces (Clean Charge Only) – Cont’d.
0.40 lb HCl per ton of feed, or 10 percent of the HCl upstream of an add-on control device
No D/F limit for clean charge furnaces – and only clean charge can be used

144. Group 1 Furnaces
Limits are used to calculate the standard applicable to secondary aluminum processing units (SAPU)
0.40 lb PM per ton of feed

145. Group 1 Furnaces Cont’d.
0.40 lb HCl per ton of feed, or 10 percent of the HCl upstream of an add-on control device
15.0 micrograms of D/F TEQ per Mg of feed

147. Group 1 Furnaces (Clean Charge Only)
Limits are used to calculate the standard applicable to secondary aluminum processing units (SAPU)
0.40 lb PM per ton of feed

148. 0.40 lb HCl per ton of feed, or 10 percent of the HCl upstream of an add-on control device
No limit on D/F – clean charge only

150. Sidewell Group 1 Furnace
If reactive fluxing (except cover flux) is done
- In the hearth, or
- In the sidewell when metal level falls below top of passage between sidewell and hearth, then

151. Sidewell Group 1 Furnace Cont’d.
Then, limits for sidewell apply for combined hearth & sidewell emissions

153. Secondary Aluminum Processing Units (SAPU)
No 3-day, 24-hour rolling average emissions of PM, HCl, or D/F in excess of the production-weighted emission limit for all units in the SAPU

154. Secondary Aluminum Processing Units (SAPU) Cont’d.
SAPU may comply by demonstrating compliance of each emission unit with its applicable emission limit

156. Emission Standards and Operating Requirements - Continued§

157. Capture/Collection Systems
All sources and emission units with an add-on air pollution control device (APCD):
Unless there have been complaints or direct observations of failures, an inspector might assume compliance. This is something that normally could not be determined during the inspection. The inspector can request to see records documenting the proper operation of the system (required in the monitoring requirements, ). Also, the inspector could request a copy of the design calculations showing adequate design and may include blueprints or drawings of the hood in relation to the process, information on plume temperatures, air velocity measurements, etc. for a later review by someone with experience in designing or evaluating hood systems.

158. Design and install a capture and collection system in accordance with American Conference of Governmental Industrial Hygienists (ACGIH) guidelines

159. Industrial Ventilation: A Manual of Recommended Practice
- Chapter 3: Local Exhaust Hoods
- Chapter 5: Exhaust System
Design Procedure
Chapter 3 describes hood types, hood design factors, and design for ventilation of hot processes. It provides the procedure for estimating the air removal rate that will capture emissions vented by a hot process for a given hood design.
2) Chapter 5 describes the design procedure for hooding and ducting systems, and provides the method for calculating required information for fan selection.

160. Vent captured emissions through a closed system (except dilution air fabric filter temperature control)
Operate in accordance with operation, maintenance, and monitoring (OM&M) plan

162. Feed/Charge Weight Measurement
All sources and emission units subject to production-based (lb/ton of feed) emission limits:
- Operate a device that records
the weight each charge, or
production weight

163. Operate in accordance with OM&M plan
May use production basis instead of feed if:
• Production is measured for all
emission units within a SAPU

164. All emission limit compliance calculations for SAPUs are based on production

166. Labeling Post visible labels at each: - group 1 furnace
- in-line fluxer
- scrap dryer/delacquering kiln/decoating kiln

167. Labels identify emission limits and means of compliance, including:
- Type of source or emission unit
- Applicable operational standards
and control methods
- Afterburner operating temperature
and residence time
Operational standards and control methods would include operating parameter ranges, type charge to be used, flux materials, etc.
2) Afterburner info for scrap dryer/delacquering kiln/decoating kiln

169. Affected Sources and Emission Units with Fabric Filters
Scrap shredders
Scrap dryer/delacquering kiln/decoating kiln
Dross-only furnace
Rotary dross cooler
In-line fluxer
For all of these sources with a fabric filter, the following operating requirements apply.

170. Group 1 furnace
Must operate a bag leak detection system or continuous opacity monitor
Except scrap shredders may alternatively choose to monitor VE

172. Fabric Filter with Bag Leak Detector
Initiate corrective action within 1 hour of alarm
Follow OM&M plan
Operate so that alarm does not sound more than 5% of operating time in 6-month period

174. Fabric Filter with COM
Initiate corrective action within 1 hour of a 6-minute average opacity  5%
Complete corrective actions in accordance with OM&M plan

175. Aluminum Scrap Shredder with Fabric Filter – VE Alternative
Initiate corrective action within 1 hr of any observed VE
Complete corrective action in accordance with OM&M plan

176. Thermal Chip Dryer with Afterburner
Maintain average operating temperature for each 3-hr period  average operating temperature during performance test

177. Operate afterburner in accordance with OM&M plan
Operate dryer using only unpainted aluminum chips

179. Scrap Dryer/Delacquering Kiln/Decoating Kiln - Afterburner and Lime-injected Fabric Filter

180. Maintain afterburner average operating temperature for each 3-hr period  than average operating temperature from performance test

181. Operate afterburner in accordance with OM&M plan
Maintain average fabric filter inlet temperature for each 3-hr period  average temperature during performance test (+ 25oF)

182. For continuous lime injection systems:
Maintain free-flowing lime in the hopper or silo at all times
Maintain lime feeder at setting established during performance test

184. Sweat Furnace with Afterburner
If performance tested, maintain each 3-hr. average temperature  operating temperature of performance test

185. If not tested, afterburner design residence time must be  2 seconds and operate at  1600oF
Existing sweat furnaces must meet operating requirements by the compliance date

186. New sweat furnaces must meet operating requirements by March 23, 2000 or upon startup, whichever is later
Operate in accordance with OM&M plan

188. Dross-only Furnace with Fabric Filter
Must have bag leak detector or COM
Operate using only dross as feed material

190. In-line Fluxer with Lime-injected Fabric Filter
For continuous lime injection systems:
- Maintain free-flowing lime in the
hopper or silo at all times for
continuous injection systems

191. - Maintain lime feeder at setting
established during performance
test
Maintain reactive flux injection rate  performance test rate for each operating cycle or time period used in performance test

193. In-line Fluxer Using No Reactive Flux Material
Use no reactive flux

195. Group 1 Furnace with Lime-injected Fabric Filter
Maintain average fabric filter inlet temperature for each 3-hr period  average temperature during performance test (+ 25oF)

196. Maintain reactive flux injection rate at or below performance test rate for each furnace cycle

197. For continuous injection systems:
• Maintain free-flowing lime in the
hopper or silo at all times
Maintain lime feeder at setting established during performance test

198. For sidewell furnaces:
- Operate so level of molten aluminum
is above the top of passage between
sidewell and hearth during reactive
flux injection, unless hearth is also
controlled

199. For sidewell furnaces Cont’d.:
Add reactive flux only to sidewell of the furnace unless the hearth is also controlled

201. Group 1 Furnace Without Add-on Controls
Maintain reactive flux injection rate  performance test rate for each operating cycle or time period used in performance test

202. Operate furnace within range of charge materials, contaminant levels, and parameter values established in site-specific monitoring plan
Use only clean charge (melting/holding furnace)

204. Site-specific Monitoring Plan
For group 1 furnaces without control devices - OM&M plan must include a section that documents work practices and pollution prevention measures, including procedures for scrap inspection

205. Site-specific monitoring plan and testing to demonstrate adequacy of the monitoring plan must be developed in coordination with, and approved by, the permitting authority

207. Clean (Group 2) Furnace
Use only clean charge
Use no reactive flux