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

Secondary Aluminum
Production Industry
Maximum Achievable
Control Technology (MACT)
Training
40 CFR Part 63 Subpart RRR
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
such as aluminum scrap
shredding, thermal chip drying,
scrap drying/decoating/
delacquering; and furnace
operations (i.e., melting,
holding, refining, fluxing, or
alloying).
Secondary Aluminum
Production Facility
Any establishment using clean
charge, post-consumer aluminum
scrap, aluminum ingots, aluminum
foundry returns, dross from
aluminum production, or molten
aluminum as the raw material and
performing one or more of the
following processes:
•
•
•
•
•
•
Scrap shredding
Scrap drying/delacquering/decoating
Thermal chip drying
Furnace operations
In-line fluxing
Dross cooling
Example Secondary Aluminum
Facility
XYZ Aluminum
Company
E1
E2
Fabric Filter
Fabric Filter
Lime
E4
E3
Afterburner
Shredded
Scrap
Delacquering
Kiln
Feedstock
Charge
Well
(Sidewell)
Melting
Furnace
Hearth
Molten
Aluminum
Holding Furnace
Ingot
Casting
Solid Scrap
Degassing
Nat. Gas
or Fuel Oil (N2, Cl, CO)
Reverb Furnace Feed Rate
Scrap - 10 tons/hr
White
Dross
Delacquering Kiln Feed Rate
Shredded Scrap - 10 tons/hr
White
Dross
(NaCl, KCl, Cryolite)
Black
Dross
Salt Flux
Alloy
Agents
Holding Furnace Feed Rate
Molten Aluminum - 9.5 tons/hr
Secondary Aluminum
Sectors
• Secondary aluminum companies
• Sweat furnace operators
• May include die casters & foundries
Estimated Number of Secondary
Aluminum Sources Potentially
Affected
•
•
•
•
Approximately 400 (86 major)
320 die casting companies
1500 foundries
1650 sweat furnaces
Types of Hazardous Air
Pollutants (HAP’s) Emitted
• Organic HAP’s (e.g. benzene,
styrene, dioxins, and furans)
• Inorganic gaseous HAP’s (e.g.
hydrogen chloride, hydrogen
flouride, and chlorine)
• Particulate HAP metals (e.g.
arsenic, lead, and chromium)
History of Secondary Aluminum
Production National Emission
Standards for Hazardous Air
Pollutants (NESHAP)
• NESHAP was proposed, 2/11/99
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
Regulated Entities under Current
Rule
• Facilities that perform secondary
smelting and alloying of aluminum
• Secondary aluminum production
facility affected sources
collocated at:
• Aluminum sheet, plate, and
foil manufacturing facilities
• Aluminum extruded product
manufacturing facilities
• Other aluminum rolling and
drawing facilities
• Primary aluminum production
facilities
• Aluminum die casting
facilities
• Aluminum foundry facilities
Regulated HAPs
• Particulate matter emissions (PM)
(surrogate for HAP metals)
• Total hydrocarbon (THC)
emissions - surrogate for HAP
organics)
• Hydrogen chloride (HCl)
emissions - a HAP and a surrogate
for inorganic HAP’s including
hydrogen fluoride (HF) and
chlorine (Cl2)
• Dioxin and furan emissions at
secondary aluminum production
facilities that are major or area
sources
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
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
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
Rule Requirements
• Emission standards and operating
requirements
• Monitoring and compliance
provisions
• Notifications, reports, and records
Applicability and Description
of Affected Units
§63.1500
Applicability and Description of
Affected Units
• Secondary aluminum production
operations
• Affected sources
Secondary Aluminum Website:
http://www.epa.gov/ttn/uatw/alum2nd
.html
Secondary Aluminum
NESHAPS
Applicability
Flowcharts
Secondary Aluminum
Production Operations
• Preprocessing of scrap aluminum (size
reduction, removal of oils, coatings, and
other contaminants)
• Furnace operations (melting, infurnace fluxing/refining, tapping)
• Additional refining (in-line fluxing)
• Cooling of dross
Processing of Scrap
Aluminum
• Crushing, shredding, and grinding
• Drying
• Heating in a dryer or kiln
• Heating in a sweat furnace
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
Chip Dryers
• To reduce the size of scrap aluminum
• Emissions: Particulate matter (PM)
& HAP metals generated as dust from
coatings and other contaminants
Applicability and Description
of Affected Units
• Secondary aluminum production
operations
• Affected sources
Secondary Aluminum
Production Operations
• Preprocessing of scrap aluminum
(size reduction, removal of oils,
coatings, and other
contaminants)
• Furnace operations (melting, infurnace fluxing/refining, tapping)
• Additional refining (in-line
fluxing)
• Cooling of dross
Preprocessing of Scrap
Aluminum
• Crushing, shredding, and grinding
• Drying
• Heating in a dryer or kiln
• Heating in a sweat furnace
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
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
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)
• 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
Charging End of Delacquering Kilns
Discharge End of Delacquering Kilns
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
• Molten aluminum can be cast into
sows, ingots, or T-bars used as
feedstock for melting and refining
furnaces
• Emissions: Dioxins and furans
Sweat Furnace Charging
Sweat Furnace
Uncontrolled Sweat Furnace 1
Uncontrolled Sweat Furnace 2
Furnace Operations
• Melting
• Fluxing/refining
• Tapping
Melting
• Begins with charging of scrap into
furnace
• Chemistry of molten bath adjusted by
adding selected scrap or alloying
agents (e.g., silicon)
Charging Sidewell Furnace
Fluxing
• Done to refine molten aluminum
to improve product quality,
achieve product specifications, or
reduce material loss
• Fluxes may be added to remove
impurities and reduce aluminum
oxidation
• May be performed in the furnace
or outside the furnace by an inline fluxer
Fluxing Processes
• Addition of salts (cover flux)
• Addition of solvents
• Injection of gasses (demagging
and degassing)
Process Furnaces
• Refractory-lined metal vessels
heated by oil, gas, or electricity
that are used to melt scrap
• Types include melting, holding,
and refining furnaces
• Charging of scrap can be done
from the side, front, or top of the
furnace
Examples of Process
Furnaces
• Top charging and front charging
furnaces
• 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
Transferring Molten Aluminum to
Holding Furnace
Sidewell Furnace
Examples of Process Furnaces Continued
• Induction furnaces – heating
mechanism is electric energy
• Reverberatory furnaces – typically gas
Process Furnace Emissions
• HAP emissions from scrap and
fluxing agents include:
• Particulate metal HAPs
• Hydrogen chloride
• Dioxins and furans
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
Dross-only Furnaces Cont’d.
• Dross and salt flux are sole
feedstocks
• Emissions: Particulate matter
including metal HAPs
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
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
Tapping
• Transferring molten metal from
melting furnace to molds or to a
ladle
Cooling of Dross
• “Dross” - slags and skimmings
from melting and refining
consisting of fluxing agents,
impurities, and/or oxidized and
non-oxidized aluminum
Cooling of Dross - Continued
• Accomplished in rotating, watercooled drums
• Sole feedstock to dross-only
furnaces
• Emissions: Particulate matter
including metal HAPs
Rotary Dross Cooler
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
• 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/nonHAP-generating gases or agents
• Each new and existing:
– Sweat furnace
– Dross-only furnace
– Rotary dross cooler
• Each new and existing secondary
aluminum processing unit (SAPU)
–Group 1 furnace: processes nonclean charge; or processes clean
charge with reactive fluxing
–Combination of all group 1
furnaces and all in-line fluxers
within a secondary aluminum
production facility
Secondary Aluminum
Processing Units (SAPU)
• Existing SAPU – all existing group
1 furnaces and all existing in-line
fluxers
• 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
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
Affected Sources at Area
Sources of HAPs Cont’d.
• Each new and existing:
– Thermal chip dryer
– Scrap dryer/delacquering
kiln/decoating kiln
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
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
Affected Sources Cont’d.
– Do not operate a thermal chip
dryer, sweat furnace, or scrap
dryer/delacquering
kiln/decoating kiln
Clean Charge
•
•
•
•
Molten aluminum
T-bar, sow, ingot, billet, pig
Alloying elements
Uncoated/unpainted thermally
dried chips
Clean Charge - continued
• Scrap dried at ≥ 650 °F
• Scrap delacquered/decoated at ≥
900° F
• oil-, lubricant-free
unpainted/uncoated gates and
risers
Clean Charge - continued
• Oil- & lubricant-free
unpainted/uncoated scrap, shapes, or
products that have not been processed
in such a way that causes
contamination
Clean Charge - continued
• Runaround scrap
• Customer returns (clean material
which contain no paint or other solid
coatings)
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 nonthermal drying method, are not
runaround
Emission Standards and
Operating Requirements
§63.1505 and §63.1506
Emission Standards and
Operating Requirements
Emission Standards
§63.1505
Secondary Aluminum Website:
www.epa.gov/ttn/uatw/alum2nd/require/
requirement_tables.html
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
Format of Emission
Standard
• Emission limits
• Mass per unit (lb/ton) of
feed/charge (or production)
• Concentration (gr/dscf)
• Percentage reduction
Format of Emission
Standard - Continued
• Emission limits
• D/F in units of TEQ
• International method of
expressing toxicity
equivalents for D/F
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
Opacity Limit
• Sources with a PM add-on air
pollution control device -monitored with a continuous
opacity monitor (COM)
Opacity Limit Cont’d.
• Aluminum scrap shredders
monitored with a COM, or
monitored by visible emissions:
• Opacity limit = 10 percent
Aluminum Scrap Shredders
• 0.010 grain (gr) of PM per dry
standard cubic foot (dscf)
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
Thermal Chip Dryers Cont’d.
• D/F limit for units at major or
area sources
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
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
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
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
Dross-only Furnaces
• 0.30 lb PM per ton of feed
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
In-line Fluxers With No
Reactive Fluxing
• No HCl and PM limits apply
• Work practice – no reactive
fluxing
Rotary Dross Coolers
• 0.04 gr of PM per dscf
Clean Furnaces (Group 2)
• No emission limits
• Work practices – clean charge
only and no reactive fluxing – or
else
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
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
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
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
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
• 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
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
Sidewell Group 1 Furnace
Cont’d.
• Then, limits for sidewell apply for
combined hearth & sidewell
emissions
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
Secondary Aluminum
Processing Units (SAPU)
Cont’d.
• SAPU may comply by
demonstrating compliance of
each emission unit with its
applicable emission limit
Emission Standards and
Operating Requirements
- Continued
Operating Requirements
§63.1506
Capture/Collection Systems
• All sources and emission units
with an add-on air pollution
control device (APCD):
• Design and install a capture
and collection system in
accordance with American
Conference of Governmental
Industrial Hygienists (ACGIH)
guidelines
• Industrial Ventilation: A Manual
of Recommended Practice
- Chapter 3: Local Exhaust Hoods
- Chapter 5: Exhaust System
Design Procedure
• 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
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
• 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
• All emission limit compliance
calculations for SAPUs are
based on production
Labeling
• Post visible labels at each:
- group 1 furnace
- group 2 furnace
- in-line fluxer
- scrap dryer/delacquering
kiln/decoating kiln
• 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
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
• Group 1 furnace
• Must operate a bag leak detection
system or continuous opacity
monitor
• Except scrap shredders may
alternatively choose to monitor VE
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
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
•
•
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
Thermal Chip Dryer with
Afterburner
• Maintain average operating
temperature for each 3-hr period
 average operating temperature
during performance test
• Operate afterburner in
accordance with OM&M plan
• Operate dryer using only
unpainted aluminum chips
Scrap
Dryer/Delacquering
Kiln/Decoating Kiln Afterburner and Limeinjected Fabric Filter
• Maintain afterburner average
operating temperature for each 3hr period  than average
operating temperature from
performance test
• 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)
• 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
Sweat Furnace with
Afterburner
• If performance tested, maintain
each 3-hr. average temperature 
operating temperature of
performance test
• 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
• New sweat furnaces must meet
operating requirements by March
23, 2000 or upon startup,
whichever is later
• Operate in accordance with OM&M
plan
Dross-only Furnace with
Fabric Filter
• Must have bag leak detector or
COM
• Operate using only dross as feed
material
In-line Fluxer with Limeinjected Fabric Filter
• For continuous lime injection systems:
- Maintain free-flowing lime in the
hopper or silo at all times for
continuous injection systems
- 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
In-line Fluxer Using No
Reactive Flux Material
• Use no reactive flux
Group 1 Furnace with Limeinjected Fabric Filter
• Maintain average fabric filter inlet
temperature for each 3-hr period 
average temperature during
performance test (+ 25oF)
• Maintain reactive flux injection
rate at or below performance test
rate for each furnace cycle
• 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
• 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
• For sidewell furnaces Cont’d.:
• Add reactive flux only to
sidewell of the furnace unless
the hearth is also controlled
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
• 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)
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
• 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
Clean (Group 2) Furnace
• Use only clean charge
• Use no reactive flux