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Acid Plant Database  October 29, 2019

Owner Freeport-McMoRan Copper & Gold Inc.
Phelps Dodge

Freeport-Logo.gif (2034 bytes)

Location Miami, Arizona
Background Formerly
- Inspiration Consolidated Copper Company
- Cyprus Amax Minerals Company
- 1999 Phelps Dodge acquires Cyprus
- 2007 Phelps Dodge acquired by Freeport-McMoRan
Website www.fcx.com
Plant Miami Smelter
Coordinates 33º 24' 52" N, 110º 51' 30" W
Type of Plant Metallurgical
Gas Source Copper
IsaSmelt technology (primary furnace)(1991).
Four Hoboken style converters
One Inspiration converter
Plant Capacity
SA/DA 3/1 DA
Emissions SO2: < 650 ppmv, < 820 lb/h, 3515 ton/a
Opacity: < 20%
NOx: < 97.5 lb/h, < 425 tons/a
Status Operating
Year Built 1972
Technology Lurgi - Outotec
Contractor -
Remarks 1995 - Rehabilitation of the contact and strong acid sections begin
2006 - Revamp of gas cleaning system
Permits Arizona Department of Environmental Quality  www.azdeq.gov
Facility ID:
Air Quality Class I Permit
Permit No. Issue Date Expiry Date Details
0310-84 August 1, 1984 - Operating Permit
1232 May 30, 1991 - Installation of IsaSmelt
1000340 May 30, 1996 - Revision to Permit 1232
1000266 December 24, 1997 - -
1000046 June 26, 2002 - -
Pictures     Freeport-Miami-Smelter-3.JPG (1215933 bytes)  Freeport-Miami-Smelter-4.JPG (2275340 bytes) 

Freeport-Miami-Smelter-5.JPG (2384326 bytes)  Freeport-Miami-Smelter-6.JPG (2336921 bytes)  Freeport-Miami-Smelter-7.JPG (2070121 bytes)  Freeport-Miami-Smelter-8.jpg (164756 bytes)

General The plant’s smelter was modernized in 1974 to meet Clean Air Act standards

The smelter is the only one in the United States to achieve International Organization for Standardization (ISO) 9001:2000 certification. In addition to copper concentrates, the smelter also recycles inorganic metal-bearing waste typically produced by high technology industries, extending the useful life of valuable metals and reducing disposal of metal-bearing waste in landfills. Copper and other precious metals are extracted during this process. In addition, the smelter produces by-product sulfuric acid.

References -Jones, D.M., Brandt, R., Nanda, A. and Piatkiewicz, A., "Environmental Upgrade at the Freeport McMoRan Miami Smelter", Copper 2019, Vancouver, Canada.
News September 20, 2017 - It is happening tomorrow night (Thursday September 21st ) in the Miami Town Hall beginning 6pm.  This is when the Arizona Department of Environmental Quality will be holding a public hearing on its plans to issue a Renewal Permit for the continued operations  of Freeport McMoRan’s copper smelter near Miami.  It was back in 2014 when Freeport announced it was planning a major smelter expansion project at its Miami operations which the company said would increase copper production and also comply with new tougher EPA standard.  The company went on to say upon completion of the project the copper concentrate throughput for the Miami smelter would increase by approximately 30 percent to a capacity of 900,000 tons per year from the current average during this period of time which was some 700,000 tons per year.  According to the Arizona Silver Belt  the expanded smelter capabilities  would comply with the new EPA ambient air quality standards for sulfur dioxide emissions.  In further details about the copper smelter expansion project here a major component of the expansion was to install a new smelting vessel which along with modifications to other facilities in the smelter was to allow for increased copper production.  The local press was also told much of the construction work would be related to emission control systems in order to  capture virtually all fugitive gases and particulate emissions. The expected result would be  the capture of over 99 percent of the sulfur dioxide and other emissions from the Miami operations.  The new smelting vessel was scheduled to be commissioned in the second quarter of this year ( 2017 ) with production ramping up shortly thereafter.  Up to several hundred construction workers were involved in the expansion. The company said it had plans to hire about 20 new employees to operate and maintain the new emission control systems and facilities.  To feed the expanded smelter here additional copper concentrate was to come primarily from Freeport’,s mines at Morenci, Arizona and Chino , New Mexico.  Concentrate would continue to be coming in from the company’s Serrita and Bagdad Arizona mines.  Interested persons who plan to go to the public hearing tomorrow night still have time to view the ADEQ’s Draft Renewal of the Smelter Permit and other documentation which are available for inspection at  the Miami Town Hall during regular business hours  at 500 Sullivan Street in the Town of Miami.  Or this paper work can be reviewed directly from the ADEQ web site.  Oral and written comments will be taken from the public by representatives of the  Arizona Department of Environmental Quality.  Grounds for comment are limited to whether the draft of the agency’s smelter permit renewal meets criteria for issuance spelled out in the state air pollution control laws or rules.

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.

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