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Mercury Contamination from Metal Scrap Processing Facilities – A Study by Ohio EPA. Radhica Sastry, James Orlemann and Paul Koval – Ohio EPA Presented by Radhica Sastry. Origin Hg occurs as a mineral oar called cinnabar (mercury (II) sulfide) - PowerPoint PPT Presentation
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Division of Air Pollution ControlJune 25, 2001
Mercury Contamination from Metal Scrap Processing Facilities –
A Study by Ohio EPARadhica Sastry, James Orlemann and
Paul Koval – Ohio EPA
Presented byRadhica Sastry
Division of Air Pollution ControlJune 25, 2001
Mercury Origin & Applications• Origin
– Hg occurs as a mineral oar called cinnabar (mercury (II) sulfide)
– Extracted by heating mercury (II) sulfide in air to form mercury (II) oxide
– Only metal that is a liquid at room temperature
• Applications– Lighting devices
– Dental amalgam
– Switching devices
– Measuring devices
Division of Air Pollution ControlJune 25, 2001
Mercury Toxicity• Persistent toxic substance• Extremely volatile• Bacteria convert mercury into methyl
mercury and bioaccumulates in living organisms
• Accumulates in brain cells • Symptoms include headache, numbness,
balance problems, etc.
Division of Air Pollution ControlJune 25, 2001
Mercury in the Environment
Division of Air Pollution ControlJune 25, 2001
Anthropogenic Emissions • Mercury production
• Mercury from manufacturing/combustion – Chlor-alkali plants– Coal combustion
• Mercury from disposal– Incineration
•Mercury from recycling
–Scrap processing
Division of Air Pollution ControlJune 25, 2001
Scrap Processing
• Mini-mills mainly use metal scrap to produce steel• Scrap comes from recycling facilities • End-of-Life Vehicles are sent to auto-dismantling
yards• Autos are shredded/crushed• Processed scrap sent to mini-mills to be melted• Main concern is Mercury Switches in the scrap!!
Division of Air Pollution ControlJune 25, 2001
Life Cycle of a Mercury Switch
Division of Air Pollution ControlJune 25, 2001
Mercury Switches• What are mercury Switches?
– Tilt switches that use mercury to make contact
Division of Air Pollution ControlJune 25, 2001
Mercury Switches - UsesWhere are mercury
switches used?– Chest freezers
– Sump pumps
– Clothes washers
– Automobiles
– Clothes irons
– Space heaters
Why are they used?– Hermetically sealed
construction– Consistent operation– High load capability– Moderate cost– Available in different
shapes, sizes and electrical ratings
Division of Air Pollution ControlJune 25, 2001
Mercury Switches • Most vehicles equipped with mercury switches• Applications are:
– Trunks & Hoods
– ABS systems
– HID lamps
• Each switch contains 0.8-1 gram Hg.• U.S. auto industry uses ~ 22,000 lbs. Hg each year
(1995 industry report)
Division of Air Pollution ControlJune 25, 2001
Division of Air Pollution ControlJune 25, 2001
Ohio EPA’s Initiative• Enforcement case revealed high amounts of
mercury emissions from a mini-mill• Studies were conducted to determine source of
mercury emissions using different scrap types• Results from tests show correlation between
melting of shredded scrap and No. 2 bundles and amount of mercury emissions
• Results prompted Ohio EPA to conduct studies at other facilities
Division of Air Pollution ControlJune 25, 2001
Scrap Grades
Scrap Grade Description
Shredded scrap Homogenous iron and steel scrap, originating from automobiles, miscellaneous bailing and sheet scrap.
Bundled No. 2 Wrought iron or steel scrap, black or galvanized. Auto body and fender stock may constitute a maximum of 60% by weight
Shredded auto* Auto scrap that is shredded
Division of Air Pollution ControlJune 25, 2001
Correlation between type of scrap & mercury emissions
0.07470.0716
0.0464
0.0160.0222 0.0247 0.0254
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
Type of scrap
Am
t. of
Hg.
em
issi
ons
(lbs/
hour
)
Scrap Type Normal A B C D E F
Shredded (frag) 20 30 30 10 10 0 0
Bundles 2 10 0 0 25 0 0 20
Division of Air Pollution ControlJune 25, 2001
Details of study• Survey questionnaire sent to 70 facilities operating
electric arc furnaces /cupolas/induction furnaces– Type of scrap melted and the amount– Amount of scrap melted per heat
• Response received from 52 facilities• 7 facilities were using shredded scrap and/or No. 2
bundles while remaining 45 used different type of scrap
• Letters were sent to these 7 facilities requesting them to test for mercury emissions
Division of Air Pollution ControlJune 25, 2001
Survey Results FACILITY Furnace # No. 1 Shredded No. 2 Heavy No. 2 BundlesNo. 2 Shredded Shredded
NAME (tons/yr) Melt (tons/yr) (tons/yr) (tons/yr) Auto (tons/yr)Facility A A - 1 0 53,200 3,700 0 9,000
B - 1 0 19,946 0 240,277 30,000Facility B B - 2 0 0 0 52,130 0
B - 3 0 0 0 52,130 0
Facility C C - 1 28,908
C - 2
Facility D D - 3 3,840 5,648
D - 4 92,160 135,544
Facility E E - 1 39,559
(foundry) E - 2 11,817Facility F F - 1 300,000 0 0 436,000 0
G - 1 1,462
Facility G G - 2 21,159
(foundry) G - 3 33,450
G - 4 30,877
Division of Air Pollution ControlJune 25, 2001
Stack test results
• Out of 7 facilities, 5 were mini-mills; 2 were foundries
• 1 facility claimed bankruptcy
• 2 submitted test results conducted 2 years ago
• 2 facilities conducted the test
• 2 foundries refused to test
Division of Air Pollution ControlJune 25, 2001
Stack Test Results
Facility D
• Av amt of frag used = 31,345 lbs/heat
• Steel tonnage rate during test ~ 40 tons/hr.
• Max. capacity ~ 110 tons/hr.
• Extrapolating for max capacity conditions:– Amt of frag = 43,970 lbs/hr
– Amt of Hg. ~ 0.029 lbs/hr.
Facility D - Stack Test
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
Run 1 Run 2 Run 3Run #
Am
t. of
Hg.
(lbs
/hr)
19,208 lbs/hr
0 lbs/hr
21,317 lbs/hr
Division of Air Pollution ControlJune 25, 2001
Conclusions & Future Steps
• Definite increase in mercury emissions when shredded scrap is melted
• Mercury switches are a significant source of high mercury emissions
• Future study will include shredding facilities• Ohio is looking into starting a mercury switch
removal program• We are envisioning that we will get same facilities
to re-test
Division of Air Pollution ControlJune 25, 2001
Questions/Ideas?
Division of Air Pollution ControlJune 25, 2001
Thank you
Contact details
[email protected](614) 728-1354