Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock or minerals from the earth from an open-air pit, sometimes known as a borrow.
ASARCO is a mining, smelting, and refining company based in Tucson, Arizona, which mines and processes primarily copper. The company has been a subsidiary of Grupo México since 1999.
The Santa Rita Mountains, located about 40 miles (64 km) southeast of Tucson, Arizona, extend 26 miles (42 km) from north to south, then trending southeast. They merge again southeastwards into the Patagonia Mountains, trending northwest by southeast. The highest point in the range, and the highest point in the Tucson area, is Mount Wrightson, with an elevation of 9,453 feet (2,881 m), The range contains Madera Canyon, one of the world's premier birding areas. The Smithsonian Institution's Fred Lawrence Whipple Observatory is located on Mount Hopkins. The range is one of the Madrean sky islands.
Hudbay Minerals Inc. is a diversified Canadian mining company primarily producing copper concentrate and zinc metal. Much of its history has centered on Flin Flon, Manitoba, where it has mined for over 90 years. Hudbay currently has operations in Manitoba and Peru, and is working towards building a copper mine in southern Arizona. The company also has exploration properties in Canada, Peru, Chile and the United States.
Crandon mine was a mine proposed for northeastern Wisconsin, USA. It was to be situated near the town of Crandon and the Mole Lake Ojibwe Reservation in Forest County. The mine was the center of a multi-decade political and regulatory battle between environmentalists, American Indian tribes, sportfishing groups, and the State of Wisconsin and several large mining corporations. The purchase of the mine site in 2003 by the Sokaogon Ojibwe and Forest County Potawatomi marked a major victory for the tribes and environmental activists, and raised questions about the future of mining, economics, and tribal power in Wisconsin.
Kentucky Camp is a ghost town and former mining camp along the Arizona Trail in Pima County, Arizona, United States, near the community of Sonoita. The Kentucky Camp Historic District is listed on the National Register of Historic Places and has been since 1995. As it is located within Coronado National Forest, the United States Forest Service is responsible for the upkeep of the remaining buildings within the Kentucky Camp Historic District.
Pebble Mine is the common name of a proposed copper-gold-molybdenum mining project in the Bristol Bay region of Southwest Alaska, near Lake Iliamna and Lake Clark. Discovered in 1987, optioned by Northern Dynasty Minerals in 2001, explored in 2002, drilled from 2002-2013 with discovery in 2005. Preparing for the permitting process began and administrative review lasted over 13 years.
Environmental impact of the oil shale industry includes the consideration of issues such as land use, waste management, and water and air pollution caused by the extraction and processing of oil shale. Surface mining of oil shale deposits causes the usual environmental impacts of open-pit mining. In addition, the combustion and thermal processing generate waste material, which must be disposed of, and harmful atmospheric emissions, including carbon dioxide, a major greenhouse gas. Experimental in-situ conversion processes and carbon capture and storage technologies may reduce some of these concerns in future, but may raise others, such as the pollution of groundwater.
Silver mining in Arizona was a powerful stimulus for exploration and prospecting in early Arizona. Cumulative silver production through 1981 totaled 490 million troy ounces. However, only about 10% of Arizona's silver production came from silver mining. More than 80% of the state's silver was a byproduct of copper mining; other silver came as a byproduct of lead, zinc, and gold mining.
In Arizona, copper mining has been a major industry since the 19th century. In 2007, Arizona was the leading copper-producing state in the country, producing 750 thousand metric tons of copper, valued at $5.54 billion. Arizona's copper production was 60% of the total for the United States. Copper mining also produces gold and silver as byproducts. Byproduct molybdenum from copper mining makes Arizona the nation's second-largest producer of that metal. Although copper mineralization was found by the earliest Spanish explorers of Arizona, the territory was remote, and copper could seldom be profitably mined and shipped. Early Spanish, Mexican, and American prospectors searched for gold and silver, and ignored copper. It was not until the completion of the Southern Pacific Railroad in 1876 that copper became broadly economic to mine and ship to market.
Uranium mining in Arizona has taken place since 1918. Prior to the uranium boom of the late 1940s, uranium in Arizona was a byproduct of vanadium mining of the mineral carnotite.
In-situ leaching (ISL), also called in-situ recovery (ISR) or solution mining, is a mining process used to recover minerals such as copper and uranium through boreholes drilled into a deposit, in situ. In situ leach works by artificially dissolving minerals occurring naturally in a solid state. For recovery of material occurring naturally in solution, see: Brine mining.
Helvetia is a ghost town in Pima County, Arizona, United States that was settled in 1891 and abandoned in the early 1920s. Helvetia is an ancient name for Switzerland.
Harshaw is a ghost town in Santa Cruz County in the southeastern part of the U.S. state of Arizona. The town was settled in the 1870s, in what was then Arizona Territory. Founded as a mining community, Harshaw is named after the cattleman-turned-prospector David Tecumseh Harshaw, who first successfully located silver in the area. At the town's peak near the end of the 19th century, Harshaw's mines were among Arizona's highest producers of ore, with the largest mine, the Hermosa, yielding approximately $365,455 in bullion over a four-month period in 1880.
Mining in the United States has been active since the beginning of colonial times, but became a major industry in the 19th century with a number of new mineral discoveries causing a series of mining rushes. In 2015, the value of coal, metals, and industrial minerals mined in the United States was US $109.6 billion. 158,000 workers were directly employed by the mining industry.
The New World Mining District is an area of mineralization that sits within Gallatin National Forest to the northeast of Cooke City and Yellowstone National Park, in Park County, Montana, United States. The district hosts extensive deposits of gold, silver and copper in zones of carbonate replacement. These deposits are the result of Eocene hydrothermal alteration of Cambrian carbonates related to the Absaroka volcanic field. Alteration and mineralization occur primarily within carbonate clasts hosted in a volcanic breccia pipe and in carbonate rocks that lie adjacent to that breccia.
The Southeast Arizona Land Exchange and Conservation Act of 2013 is a bill that was introduced into the United States House of Representatives during the 113th United States Congress. H.R. 687 would authorize a land exchange in Arizona between the federal government and a mining company. Under H.R. 687, the United States Forest Service would convey about 2,400 acres of land in southeast Arizona to Resolution Copper Mining LLC in exchange for about 5,400 acres of company-owned land. Of the company land, about 1,200 acres would become part of the National Forest System, and about 4,200 acres would be administered as conservation areas by the Bureau of Land Management. If the property sought by Resolution Copper is appraised at more than the appraised value of the property that the company offers for exchange, the company could donate additional land or make a cash payment to the United States to make the final exchange of equal value. If the company’s property is appraised for more than the federal acreage, the difference in the value would be considered a donation to the federal government. According to the Committee Report on the bill, the "mine could provide up to one-quarter of the nation's estimated annual copper needs" and the mining company estimates that the "total economic impact of the mine will exceed $60 billion and support 3,700 jobs annually." Opponents of the bill argue that the swap has not been thoroughly studied, that the mining company has failed to indicate where it will get much needed water for the mine, and that Native American tribes have not been properly consulted.
Water in Arkansas is an important issue encompassing the conservation, protection, management, distribution and use of the water resource in the state. Arkansas contains a mixture of groundwater and surface water, with a variety of state and federal agencies responsible for the regulation of the water resource. In accordance with agency rules, state, and federal law, the state's water treatment facilities utilize engineering, chemistry, science and technology to treat raw water from the environment to potable water standards and distribute it through water mains to homes, farms, business and industrial customers. Following use, wastewater is collected in collection and conveyance systems, decentralized sewer systems or septic tanks and treated in accordance with regulations at publicly owned treatment works (POTWs) before being discharged to the environment.
The geology of Arizona began to form in the Precambrian. Igneous and metamorphic crystalline basement rock may have been much older, but was overwritten during the Yavapai and Mazatzal orogenies in the Proterozoic. The Grenville orogeny to the east caused Arizona to fill with sediments, shedding into a shallow sea. Limestone formed in the sea was metamorphosed by mafic intrusions. The Great Unconformity is a famous gap in the stratigraphic record, as Arizona experienced 900 million years of terrestrial conditions, except in isolated basins. The region oscillated between terrestrial and shallow ocean conditions during the Paleozoic as multi-cellular life became common and three major orogenies to the east shed sediments before North America became part of the supercontinent Pangaea. The breakup of Pangaea was accompanied by the subduction of the Farallon Plate, which drove volcanism during the Nevadan orogeny and the Sevier orogeny in the Mesozoic, which covered much of Arizona in volcanic debris and sediments. The Mid-Tertiary ignimbrite flare-up created smaller mountain ranges with extensive ash and lava in the Cenozoic, followed by the sinking of the Farallon slab in the mantle throughout the past 14 million years, which has created the Basin and Range Province. Arizona has extensive mineralization in veins, due to hydrothermal fluids and is notable for copper-gold porphyry, lead, zinc, rare minerals formed from copper enrichment and evaporites among other resources.
Twin Metals LLC is seeking approval to create and operate a copper sulfide mine near Ely, Minnesota, on Superior National Forest land. There has been significant opposition to the proposed mine, most notably because of its proximity to the Boundary Waters Canoe Area Wilderness, location within a watershed that drains into the BWCA, and the air, water, light and noise pollution and traffic effects of converting a forested area bordering the BWCA into a substantial industrial mining facility. Twin Metals is a subsidiary of the Chilean conglomerate Antofagasta, which is controlled by billionaire Andrónico Luksic. The original lease is a 1966 lease to the International Nickel Corporation.
