June 25, 2001 Division of Air Pollution Control 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

June 25, 2001 Division of Air Pollution Control 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

June 25, 2001 Division of Air Pollution Control 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.

June 25, 2001 Division of Air Pollution Control Mercury in the Environment

June 25, 2001 Division of Air Pollution Control Anthropogenic Emissions Mercury production Mercury from manufacturing/combustion –Chlor-alkali plants –Coal combustion Mercury from disposal –Incineration Mercury from recycling –Scrap processing

June 25, 2001 Division of Air Pollution Control 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!!

June 25, 2001 Division of Air Pollution Control Life Cycle of a Mercury Switch

June 25, 2001 Division of Air Pollution Control Mercury Switches What are mercury Switches? –Tilt switches that use mercury to make contact

June 25, 2001 Division of Air Pollution Control Mercury Switches - Uses Where 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

June 25, 2001 Division of Air Pollution Control Mercury Switches Most vehicles equipped with mercury switches Applications are: –Trunks & Hoods –ABS systems –HID lamps Each switch contains gram Hg. U.S. auto industry uses ~ 22,000 lbs. Hg each year (1995 industry report)

June 25, 2001 Division of Air Pollution Control

June 25, 2001 Division of Air Pollution Control 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

June 25, 2001 Division of Air Pollution Control Scrap Grades Scrap GradeDescription Shredded scrapHomogenous iron and steel scrap, originating from automobiles, miscellaneous bailing and sheet scrap. Bundled No. 2Wrought 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

June 25, 2001 Division of Air Pollution Control Correlation between type of scrap & mercury emissions Scrap TypeNormalABCDEF Shredded (frag) Bundles

June 25, 2001 Division of Air Pollution Control 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

June 25, 2001 Division of Air Pollution Control Survey Results

June 25, 2001 Division of Air Pollution Control 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

June 25, 2001 Division of Air Pollution Control 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. ~ lbs/hr.

June 25, 2001 Division of Air Pollution Control 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

June 25, 2001 Division of Air Pollution Control Questions/Ideas?

June 25, 2001 Division of Air Pollution Control Thank you Contact details (614)