In the United States, copper mining has been a major industry since the rise of the northern Michigan copper district in the 1840s. In 2017, the US produced 1.27 million metric tonnes of copper, worth $8 billion, making it the world's fourth largest copper producer, after Chile, China, and Peru. Copper was produced from 23 mines in the US. Top copper producing states in 2014 were (in descending order) Arizona, Utah, New Mexico, Nevada, and Montana. Minor production also came from Idaho, and Missouri. As of 2014, the US had 45 million tonnes of known remaining reserves of copper, the fifth largest known copper reserves in the world, after Chile, Australia, Peru, and Mexico.[1]
Copper in the US is used mainly in construction (43%) and electric equipment (19%). In 2014, the nation produced 69% of the copper it used, relying on imports from Chile, Canada, Peru, and Mexico for the remaining 31%.[1]
Copper mining activity increased in the early 2000s because of increased price: the price increased from an average of $0.76 per pound for the year 2002, to $3.02 per pound for 2007.[2]
A number of byproducts are recovered from American copper mining. In 2013, American copper mining produced 28,500 metric tons of molybdenum, worth about $700–$800 million, which was 47% of total US production.[3] In 2014, copper mining produced about 15 metric tons of gold, worth $600 million, which represented 7% of US gold production.[4] Other byproducts of the copper extraction process included silver, and minor amounts of rhenium and platinum-group metals. Sulfuric acid is recovered at copper smelters.[5]
- ^ a b Mineral Commodity Summary - U.S. Geological Survey - January 2018
- ^ D.R. Wilburn, "Exploration review," Mining Engineering, May 2008, p.47.
- ^ Molybdenum US Geological Survey, Minerals Yearbook 2013.
- ^ Gold US Geological Survey, Commodity Updates, 2015
- ^ US Geological Survey, Sulfur, Minerals Yearbook, 2012.