Mining is Thriving in Globe-Miami

SMELTER AT SUNSET | PHOTO BY LCGROSS

By Patricia Sanders

Globe-Miami was built on mining – it was discoveries of silver and copper that brought workers, business, the railroad, and economic success to Globe and Miami in their earliest days. Even Globe’s name reflects its connection to mining – it’s said to refer to an Earth-shaped nugget of silver discovered nearby. And mining continues to drive Globe-Miami’s economy, providing employment, tax revenues, and valued partnerships in community development.

Silver mining came to the area in the 1870s, but those mines played out by 1880 – just in time for the immense boom in demand for copper, needed for wire as electricity and the telephone spread across the country.

Soon, the Old Dominion Copper Company, Miami Copper Company, Inspiration Consolidated, and others were pulling 10% to 12% copper ore from the hills surrounding Globe and Miami and roasting it in furnaces that could process 200 tons per day. During the early 1900s, trains were hauling out as much as 2 million pounds of copper in a month. One of the many smelter stacks constructed between 1880 and 1930 can still be seen along Highway 60.

By the time it closed in 1931, the Old Dominion – the area’s largest producer – had mined some 800 million pounds of copper, with production peaking in World War 1. That would make enough 12-gauge wire to circle the Earth 73 times.

The 1950s were a time of transition at GlobeMiami as the old underground operations transferred to modern, open-pit copper mining. Today, Globe-Miami continues to depend on copper mining for its economic livelihood. More than one in every five jobs in Globe and Miami are related to mining and the production of copper. In addition to copper, the mines also produce smaller amounts of gold and molybdenum.

The major mine operators in Globe-Miami as of 2022 include Capstone Copper, Freeport/McMoRan (FCX), Carlota Copper, and BHP Billiton.

AN EARLY MAP OF THE GLOBE-MIAMI AREA PUBLISHED IN 1878 OF THE GLOBE DISTRICT | PHOTO BY WESTLAND ENGINEERING & ENVIRONMENTAL SERVICES

Capstone, currently the second-largest employer in the district, contributes more than $270 million annually to Arizona’s economy. Capstone’s Pinto Valley operation features the only operating mill in the Globe-Miami mining district.

Freeport McMoRan operates a leaching operation, a smelter, and a rod mill in Miami. Its Miami operations generated nearly $199 million in economic benefits for Arizona in 2020, including almost $77 million for Gila County.

Freeport McMoRan’s Miami operation has been at the forefront of mining technology for at least 100 years, being among the first to have used vat leaching and precipitation plants to recover oxide minerals. With the introduction of SX/EW (solvent extraction-electrowinning) processes in the late 1970s, vat leaching was discontinued, and Miami’s flotation concentrator was closed in 1986.

Freeport McMoRan’s smelter has the distinction of being one of only three operational smelters in the United States. The smelter was updated in 1974 to meet Clean Air Act standards and was modernized again in 1992 and 2018. It processes copper concentrate into blister copper and, as a by-product, captures sulfuric acid, which is used in the company’s leaching operations.

Freeport McMoRan’s rod plant opened in 1966, the first of its kind to be located at a mine site. It produces continuous-cast copper rods from copper produced at the Miami mines and other mines across North America and ships the rod around the world to be made into wire and cables.

BHP Billiton holds a unique niche in the GlobeMiami mining community. As stewards of legacy assets, the company manages mine properties that are no longer operational, including the Old Dominion, Copper Cities, Miami Unit, and Solitude assets. BHP Billiton’s 70 local employees and contractors work to ensure these properties remain safe, stable, and non-polluting. The company monitors 2,500 locations in the area, operates 12 water treatment facilities, and, in 2021 alone, closed 237 open mine shafts.

BHP Billiton is also a major participant in Rio Tinto’s Resolution Copper project, located just east of Superior. Using innovative methods, this project will extract copper from a huge deposit located 5,250 feet underground. Resolution Copper is one of the largest undeveloped copper projects in the world and has the potential to become the largest copper producer in North America.

Copper is all around us – in the wiring within the walls of our houses and buildings, in our electronic devices, and in telecommunications cables that link the world. Globe-Miami is proud of the central role it has played – and continues to play – in making the modern world work. u