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Acid Plant Database  October 29, 2019

Owner American Smelting and Refining Company - ASARCO

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Location Ray Complex Hayden Smelter
P.O. Box 8
640 Asarco Avenue
Hayden AZ
USA  85235
Background 1994 - Acquisition by Southern Peru Copper Corporation
1999 - Grupo Mexico purchases shares of Asarco for $2.2 billion (including debt); retains Asarco as wholly-owned U.S. operating subsidiary.
2005 - ASARCO files for Chapter 11 Bankruptcy
Website www.asarco.com
Plant Hayden Smelter
Coordinates 33º 0' 8" N, 110º 46' 22" W
Type of Plant Metallurgical
Gas Source Copper
Inco Flash Furnace (installed 1983)
Converter (installed 1969)
Plant Capacity 2820 MTPD
Emissions SO2: < 650 ppm, < 9,521 lb/h (annual average)
Opacity: < 20%
Status Operating
Year Built 1984
Technology MECS
Contractor MECS
Remarks Acid Plant Stack: Diameter: 17 ft, Height: 1000 ft, Exit Gas Velocity: 19 ft/s, Temperature: 303oF
Permits Arizona Department of Environmental Quality www.azdeq.gov/environ/air/permits
Air Quality Class I Permit
Permit No. Issue Date Expiry Date Details
1166 September 13, 1982 - Installation Permit
0308-85 April 9, 1984 - Operating Permit
1215 April 4, 1989 - Installation Permit
1240 August 7, 1992 - Installation Permit
1000276 February 13, 1996 - Minor Permit Revision
1000462 November 11, 1998 Minor Permit Revision
1000042 October 9, 2001 October 9, 2006 -
- - - -
General Hayden, Arizona, is located approximately 90 miles southeast of Phoenix on State Highway 177, along the Gila River, below the confluence of the Gila and San Pedro Rivers. The town was founded in 1912 to provide housing for the workers at the Ray open pit mine complex and the copper smelter complex, originally built by the Kennecott Copper Company. The town has a current population of approximately 900, and shares many services, including the local school district, with the town of Winkelman, population 600, located one mile to the south. The towns also share a common history regarding the emissions from the smelter operations.
There have been several smelters on the site of the current Asarco smelter, with emissions being discharged into the air in Hayden and Winkelman since operations began in 1909. Historic emissions contained large quantities of lead, arsenic, sulfur dioxide (SO2), particulate matter, and other materials. These contaminants drifted over the entire region in the air and many of the materials contained in these emissions fell out of the atmosphere and settled on the ground.
The first emission controls placed upon the smelters were installed in 1920. These electrostatic precipitators were designed to remove particulate matter from the stack emissions. The smelters within the complex operated with these minimal emission controls prior to 1969, when requirements under the forthcoming Clean Air Act amendments of 1970 required that controls be installed to limit SO2 emissions. Acid plants were added in 1969 and 1971 to reduce SO2 and particulate emissions. Additional controls were added to the current smelter in 1984, further reducing the SO2 emissions. The current smelter stack height was designed to elevate the emissions above the valley air shed and better facilitate dispersion.
The residential areas of Hayden are located on two ridges that run parallel to each other, in an east/west direction, east of Highway 177. Houses line the main street on the north ridge. Houses on the south ridge are scattered among several streets intersecting Velasco Avenue.
The main street in Hayden is Hayden Avenue, which runs east-west from the smelter property line on the eastern edge of town, to Fourth Street, a distance of approximately 3/8 mile. It is along this street that the primary business district is located.
The ASARCO smelter is a large complex of approximately 200 acres at the eastern end of the town. Two large emission stacks dominate the horizon. One is about 1,000 feet tall and the other is 250 feet tall. There are also several smaller stacks visible at buildings throughout the complex. A large slag pile, a solid glass-like waste material, is on the eastern end of the facility, adjacent to the town.
References Russell, M., Safe, P., Veek, A., Fernandez, A. and Parameswaran, K., "Asarco LLC Hayden Converter Retrofit Project - An Update", Copper 2019, Vancouver, Canada.
News December 15, 2016 - Citizens and businesses have the opportunity to comment on proposed rules drafted by the Arizona Department of Environmental Quality (ADEQ) for significantly decreasing the release two types of pollutants from copper smelters in Hayden and Miami to within federal regulations adopted since 2008.  The rules are aimed at reducing the release of airborne lead dust from the Hayden smelter (owned by ASARCO) and the release of sulfur dioxide from the smelters in Hayden and Miami (the latter owned by Freeport-McMoRan) in order to protect the public health and environment. They cover the use of specific control technologies and include recordkeeping and reporting requirements.
ADEQ opened the comment period on December 5. Interested parties will have until January 9, 2017 to file comments on the proposed rules, after which ADEQ will hold a public hearing to address any concerns and draft the final rules. Once finalized, the rules will be submitted to the U.S. Environmental Protection Agency (EPA) for incorporation in Arizona’s State Implementation Plan as required under Section 110 of the Clean Air Act.  Should ADEQ not produce these rules, EPA has the right under the Clean Air Act to draft and impose their own.  The need for the new ADEQ rulemaking began in 2008 when EPA revised its air quality standards for lead (last updated in 1979), strengthening them by nearly 90%. The new maximum allowable level of lead in ambient air is a rolling three-month average of 0.15 micrograms per cubic meter evaluated over a three-year period. In implementing the new National Ambient Air Quality Standards (NAAQS), EPA conducted a technical analysis in 2010 in the Gila and Pinal County townships around the Hayden smelter and decreed it in 2014 a nonattainment area in need of improvement. EPA in 2010 likewise revised the allowable level of sulfur dioxide emissions to 75 parts per billion per hour. Subsequent testing found both the Hayden and Miami areas to be not in compliance and were thus declared nonattainment areas around them.  In adopting the more stringent rules, EPA cited the negative health effects of those two pollutants. Breathing airborne lead dust can impair the sensory, motor and cognitive skills of developing children; and can impair the memory and visual skills of adults, as well as increase the likelihood of heart attacks. Breathing high levels of sulfur dioxide can damage the lungs, and cause asthma and other respiratory problems.  A substantial portion of ADEQ’s proposed rules cover the control of “fugitive lead dust.” Lead is found in the same ore holding copper and can be released during the smelting process as dust that can settle atop the areas around a smelter. For this reason, the rules would require ASARCO to daily sweep vacuum or use a wet broom on paved areas around the smelter compound to remove lead dust, and to spread dust suppressant on unpaved roads at least once a week. Vehicles traveling over these roads cannot exceed 15 m.p.h. and must be frequently cleaned. Wind fences are mandated.
  During high wind events, rules note when smelter operations must stop to avoid widespread lead dust dispersal. Equipping the facility with an Acid Plant Scrubber Blowdown Dryer System is to be required.  The smelter compound must be equipped with ambient lead monitors, and samples collected must be retained a minimum six days.  For sulfur dioxide containment, ADEQ proposes regulations governing furnace ventilators, filtering systems, and the installation of monitors to record sulfur dioxide concentrations with the compound. Contingency measures are to be implemented if an area fails to attain EPA standards.
ADEQ further proposes stringent measurement and recordkeeping requirements for both pollutants.  For their part, both ASARCO and Freeport-McMoRan proposed expensive upgrades to their copper smelters in early 2014 to reduce sulfur dioxide emissions as ADEQ was working on these proposed rules.  To meet the new EPA sulfur dioxide standards, ASARCO launched a converter retrofit program to replace the smelter’s five 13-ft. diameter converters with three 15-ft. diameter converters, install improved primary and secondary hoods, and an electrostatic precipitator for solids removal prior to recapturing sulfur dioxide in acid baths. Larger ladles (300 cu. Ft. instead of 200 cu. Ft.) will be installed to reduce the number of hot metal transfers. As a result, ASARCO said, about 99.7% of all sulfur dioxide produced during the copper smelting process would be removed.

October 11, 2014
- Owners of Arizona’s two copper smelters plan to spend hundreds of millions of dollars to reduce sulfur dioxide emissions that federal officials say have fouled the air in two Central Arizona communities.  Asarco is reportedly preparing to spend $110 million to upgrade its long-troubled Hayden smelter to meet tougher federal controls on its emissions. Asarco proposes to cut its SO2 emissions by nearly 85 percent by October 2018 from current levels. It has filed a permit application seeking the state’s approval of the upgrade.  At the same time, the congresswoman who represents the Hayden area, Ann Kirkpatrick, has warned that the smelter could be closed or its operations curtailed unless the Environmental Protection Agency and Asarco reach agreement soon on a related issue. It involves EPA allegations, denied by the company, that Asarco’s emissions of hazardous air pollutants, mostly heavy metals, have violated federal law.  Although the EPA and Asarco won’t discuss the enforcement-related matter, it appears that the smelter upgrade and the question of Asarco’s culpability for legal violations may have been folded together in negotiations.  Another multinational mining company, Freeport McMoRan Copper & Gold, plans to spend $450 million to improve emissions controls at its Miami copper smelter near Globe by mid-2017. It plans to expand production there at the same time.  That upgrade has already received a state permit, engineering work is underway, and construction is expected to go into full swing next year, Freeport said in a news release.  The upgrades are supposed to help the smelters comply with EPA rules on several fronts:  Since July 2013, the EPA has formally designated Hayden and Miami’s air as out-of-compliance with the federal sulfur dioxide air-quality standard. The agency significantly tightened the standard in 2010. The standard is set at 75 parts per billion, but SO2 levels averaged over three years reached as high as 111 in Miami and 259 in Hayden.  Hayden’s air was designated in August 2014 as out-of-compliance for lead, six years after the EPA considerably tightened the lead standard. Certified Arizona Department of Environmental Quality monitoring results for 2012 showed the area violated the standard. Preliminary results from Asarco monitors in 2013 and 2014 suggest that the violations continue, the EPA said.  The EPA is also pushing the two smelters and four other pollution sources in Arizona to reduce emissions to meet federal standards for visibility affecting national parks and wilderness areas.  The smelters’ emissions have affected views in 12 national parks and wilderness areas, mostly in Arizona, said Colleen McKaughan, associate director of the air division for the EPA’s Pacific Southwest regional office.  Hayden and Globe lie in Gila County, about 65 and 100 miles northeast of Tucson, respectively.The proposed upgrades come as the EPA and Asarco finish their third year of seeking to reach an agreement regarding a notice of violation of the Clean Air Act that the EPA sent the mining company over the Hayden smelter on Nov. 10, 2011.  That notice accused Asarco of illegally emitting illegal levels of lead, arsenic and eight other hazardous air pollutants since 2005. The company also hasn’t met federal requirements for performance testing, emissions monitoring, performance of pollution controls and development of plan to control dust, the EPA said.  Asarco has denied the accusations, ADEQ has agreed with the company, and the EPA and Asarco continue to negotiate over this issue.  In a recent letter to the EPA, Kirkpatrick, an Arizona Democrat whose district includes Hayden, asked the agency to give “top priority and adequate resources” to reaching a settlement with Asarco as quickly as possible.  Asarco has said it needs to get an agreement in time to order equipment for the upgrades by the end of 2014 to meet various compliance deadlines, Kirkpatrick’s Sept. 10 letter to EPA Administrator Gina McCarthy said.  “Failure to do so will force Asarco to choose between curtailing operations and closing down the smelter,” Kirkpatrick wrote.  She’s confident that all sides can find a balance between environmental protection and sustaining the mining industry’s economic benefits, Kirkpatrick wrote.  “More important, this facility, through the processing of copper, is vital to our national security,” Kirkpatrick wrote. “Please help us get this accomplished. We are so close.”  In reply, EPA Regional Administrator Jared Blumenfeld wrote Kirkpatrick that the EPA will continue to work with Asarco on finding an acceptable resolution. “We expect that Asarco will also commit the resources necessary to achieve a timely resolution that meets its commitments under the Clean Air Act,” he wrote.  The facilities are two of only three copper smelters left in the United States. The third, owned by Kennecott Utah Copper, a division of Rio Tinto, is in Salt Lake City. In the early 1980s, Arizona alone had seven copper smelters. “I think it should have happened a long time ago, but I’m happy to hear that the EPA is finally pushing this,” said Jill Corona, a former Hayden resident, about the proposed smelter upgrade. Raised in Hayden, she moved to Tempe about a decade ago, but still visits Hayden regularly.  “Sulfur dioxide is a very, very toxic gas,” Corona said. “It’s chronic, chronic exposure we’re talking about here. They have four years to come into compliance. That’s a long time.”  State Rep. Frank Pratt, a Casa Grande Republican, recently chaired a House committee hearing where the smelter upgrades were discussed. But he declined to comment on the upgrades because the Asarco permit is pending.  Asarco Vice President Tom Aldrich declined to discuss the smelter upgrade, since Asarco is now in negotiations with the EPA over various matters. The $110 million figure for Asarco’s upgrade was reported by the Copper Area News, a newspaper chain in Pinal County, but neither Pratt nor Arizona Mining Association President Kelly Norton could confirm it.  The upgrades will reduce the Hayden smelter’s sulfur dioxide emissions from more than 21,000 tons per year to fewer than 3,500 tons per year, says Asarco’s permit application. Emissions of standard particulates, which are typically dust, and hazardous air pollutant particulates will also be reduced by the upgrade, it says.  In Miami, meanwhile, Freeport said its smelter improvements will allow it to increase copper production by about 30 percent. At the same time, the smelter will then be able to capture more than 99 percent of its SO2 and other emissions, Freeport said.  The Arizona Department of Environmental Quality issued a permit for the Freeport smelter upgrade in July. It’s still reviewing Asarco’s permit application, filed June 24, and doesn’t expect to decide this year, said agency spokesman Mark Shaffer. EPA reviews all such permits before the state signs off on them.

The Hayden smelter, one of whose stacks stands about 1,000 feet tall, has been a fixture in the community since starting operations in 1912. With slightly more than 600 people working at Asarco’s Hayden operation, it’s by far the biggest employer in a town of fewer than 1,000 permanent residents.  In 2013, the Hayden smelter produced about 273 million tons of copper and 490,000 tons of sulfuric acid, and paid about $54 million in salaries and wages, the Arizona Mining Association told a state House committee in August.  The Freeport smelter in Miami, operating since 1915, employs about 1,000 people. It produces about 420 million pounds of copper and 725,000 tons of sulfuric acid annually, the association said.  The Hayden smelter has also been a continuing source of controversy over the past 15 years, with many of its neighbors saying it has damaged their health.  Asarco has upgraded the smelter many times since it first opened in 1912. But since the middle 2000s, the Hayden area has been under federal investigation under the EPA’s Superfund toxic waste cleanup program.  In 2002, for instance, more than 250 current and former residents of Hayden and nearby Winkelman, Kearny and Riverside signed class-action lawsuits, alleging that Asarco’s toxic releases had injured them, contaminated the environment, and devalued their homes.  The company wouldn’t comment directly, but officials said studies by the University of Arizona and the University of Pittsburgh found no connection between smelter operations and illness. The suit was later settled for $4.8 million.  In 2008 and 2009, Asarco spent $13.5 million to remove contaminated soil from 265 yards in Hayden under regulators’ oversight.

August 27, 2014 - Plans for a $110 million upgrade of the Hayden copper smelter that will bring the apparatus in compliance with new federal regulations concerning emissions of sulfur dioxide (SO2) have been filed by owner ASARCO/Grupo Mexico with the Arizona Department of Environmental Quality (ADEQ).  The rules issued by the US Environmental Protection Agency (EPA) require that SO2 emissions from the smelter be reduced from 140 ppb (parts per billion) to 75 ppd during a 24-hour period. The Hayden smelter has until Oct. 3, 2018 to meet this standard.  Meeting the standard is important to keep the Hayden copper smelting plant operating and providing employment for residents of the Hayden/Winkleman area.  To meet EPA’s goal, the plan ASARCO filed on June 24 with ADEQ describes a converter retrofit project that will replace the smelter’s five current 13-ft. diameter converters with three 15-ft. diameter converters. Also included in the plan are the installation of improved primary and secondary hoods, and an electrostatic precipitator for solids removal prior to SO2 recapture at the smelter’s existing acid plants. Larger ladles (300 cu. ft. instead of 200 cu. ft.) will be installed to reduce the number of hot metal transfers. Additional upgrades will capture secondary gases and direct them to the acid plant for conversion to a sulfuric acid product.  Overall the plan aims to reduce SO2 emissions at the Hayden smelter by 85 percent, with a total SO2 capture rate of 99.7 percent of what is produced during the copper smelting process.  The plans were made public during a meeting of the Arizona House Committee on Energy, Environment and Natural Resources held Aug. 22 at the Gila Community College Pueblo Campus in Globe.  ADEQ is expected to rule on the ASARCO plan by late September. If approved the plan will then go to EPA for an additional 45-day comment period. With EPA approval, ASARCO could begin work on the upgrades before year’s end.  Work on the converter retrofit will be performed as to not disrupt the operation of the smelter and keep all employees working their regular daily schedules, said Krishna Parameswaran, director of environmental services and compliance assurances at ASARCO. The smelting plant must operate within the EPA emission limits by Oct. 3, 2018.  The smelter and surrounding operations are an important parts of the Hayden economy. It employs 1,400 hourly and salaried workers, who are annually paid $140.8 million in wages, salaries and fringe benefits. The operations also generate $28.6 million in property, severance and sales taxes. The company annually generates spending of $345.8 million on materials, fuel and supplies into the Arizona economy.  Each year the Hayden smelter produces more than 300 million tons of copper that is important in all electrical products, electronic equipment, and even bringing electricity to homes, according to Kelly Norton, president of the Arizona Mining Association. The smelter also products more than 575,000 short tons of sulfuric acid each year.  Although originally built in 1912, the Hayden smelter has been expanded and upgraded on a regular basis, with the last major renovations taking place in 1989 and 1996. In 2012, ASARCO voluntarily undertook a $10 million project to reduce lead emissions through the addition of a monitor system to keep lead emissions to within EPA rules issued in 2008 that trimmed allowable emission levels to one-tenth of the former standard.  The EPA-required Hayden smelter renovation projects comes only a step behind a more expensive project for the smelter in Miami owned by Freeport-McMoRan. Budgeted at $450 million, the Miami smelter will receive new converter mouth covers, converter aisle canopy hoods and aisle scrubbers, an anode plant bag house and a smelter furnace upgrade to meet EPA SO2 emission limits.  Freeport-McMoRan received its permit on July 21 and has begun renovation work that could be completed by the end of 2017. The Miami smelter, which was originally built in 1915, also has undergone numerous upgrades, expansions and renovations in the interim.  Norton emphasized at the meeting that copper smelting is an important contributor to the Arizona economy. At present there are only three copper smelting plants in the US and two are in Arizona (Hayden and Miami). The third is in Salt Lake County, UT, Norton noted. (www.copperarea.com)

MTPD - Metric Tonne per Day           STPD - Short Ton per Day
MTPA - Metric Tonne per Annum      STPA - Short Ton per Annum
SA - Single Absorption
DA - Double Absorption

* Coordinates can be used to locate plant on Google Earth