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Arizona Mining Review: Interview with ASARCO's Joe Wilhelm on Retrofit of the Hayden Copper Smelter

Factoid: The US Geological Survey estimates that every American born in 2008 will require over 1,300 pounds of copper in their lifetime.

Arizona Mining Review: Major Retrofit of ASARCO's Hayden Copper Smelter

Arizona’s sobriquet ‘the copper state’ is well-earned; more than 60% of America’s copper is extracted from copper porphyry deposits in Arizona’s Basin and Range Province. And two of the nation’s three copper smelters reside in southern Arizona.

ASARCO’s Hayden Copper Smelter, situated near the confluence of the San Pedro and Gila Rivers in Pinal County, started producing copper anodes in 1912; the year Arizona became a state. With the exception of a few rare hiatuses, e.g., during WW II, the smelter has operated continuously.

On 28 Sept. 2017, I drove to Hayden to interview long-time ASARCO employee Joe Wilhelm regarding the history and future of the Hayden Smelter. Mr. Wilhelm began working at the Hayden Smelter 29 years ago. Nine years ago he was appointed plant manager, making him responsible for the daily operation and maintenance of the plant.

The Hayden Smelter gets its copper concentrates (ore) chiefly from ASARCO’s three Arizona copper porphyry properties: Ray Mine (Pinal County), and the Mission and Silver Bell Mines (Pima County). ASARCO purchases another 10% of concentrates from other copper mines in the southwestern U.S.

Each year the smelter processes ~ 740,000 tons of copper concentrates, yielding 300 million pounds of copper. The plant produces 1,200 copper anodes (roughly 2.5 ft. x 2.5 ft.) daily, each weighing 810 pounds, for a daily production rate of ~ 972,000 pounds of copper. The anodes are shipped to ASARCO’s electrolytic refinery in Amarillo, Texas, to undergo further refinement before yielding rod that is sold to industry for reshaping. ASARCO Hayden Smelter employs ~ 600 people.

Retrofitting the Hayden Smelter for the next generation of copper miners

In 2009, the Environmental Protection Agency established new, more rigorous standards to reduce flue-gas emissions. ASARCO immediately began designing a smelter retrofit to meet and exceed these new standards. In 2015, the EPA and the Arizona Dept. of Environmental Quality permitted the engineering retrofit plans. According to Mr. Wilhelm, the smelter retrofit will result in a ‘world-class’ plant that captures 99+% of sulfur dioxide at the stack.

Five hundred contractors were brought on-site to do the retrofit, which is scheduled for completion by the end of 2018. Meanwhile, copper production continues unabated at the plant.

Sulfur dioxide captured during smelting is processed at Hayden’s onsite sulfuric acid plant and yields ~ 2,000 tons of sulfuric acid daily – the equivalent of 20 rail cars! The majority of the acid (H2SO4) goes to the Ray Mine, with ~ 500 to 600 tons per day delivered to the Silver Bell Mine. A small volume of the high-purity sulfuric acid is sold to other industries.

Once the plant retrofit is complete, the Hayden Smelter will be set for another generation or two of mining and refining copper in Arizona.

Arizona Mining Review: Major Retrofit of ASARCO's Hayden Copper Smelter

Note. ASARCO graciously provided drone video of the Hayden Plant, 25-seconds of which were incorporated in this interview.