The Buenavista mine, historically known as the Cananea copper mine, is a large open pit

copper mine Copper extraction refers to the methods used to obtain copper from its ores. The conversion of copper consists of a series of physical and electrochemical processes. Methods have evolved and vary with country depending on the ore source, loca ...

located in the north-west of

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

Cananea Cananea is a city in the Mexican state of Sonora, Northwestern Mexico. It is the seat of the Municipality of Cananea, in the vicinity of the U.S−Mexico border. The population of the city was 31,560 as recorded by the 2010 census. The p ...

Sonora Sonora (), officially Estado Libre y Soberano de Sonora ( en, Free and Sovereign State of Sonora), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is d ...

. It lies south of the international border near

Nogales, Arizona Nogales (English: or , ; ) is a city in Santa Cruz County, Arizona. The population was 20,837 at the 2010 census and estimated 20,103 in 2019. Nogales forms part of the larger Tucson–Nogales combined statistical area, with a total population ...

. Buenavista mine represents one of the largest copper reserves in

and in the world. As of 2013, it had estimated reserves of 36 million tonnes of ore grading 0.69% copper, 3.3% zinc and 33.4 million oz of silver. Cananea represents one of the largest copper reserves in

and in the world, having estimated reserves of 4.52 billion tonnes of ore with a grade of 0.42% copper.

History

Greene Consolidated Copper Company (1896-1907)

Copper has been mined at the site continuously as far back as 1899. The mine was originally owned by the American businessman

William Cornell Greene Colonel William Cornell Greene (August 26, 1852 – August 5, 1911) was an American businessman who was famous for discovering rich copper reserves in Cananea, Mexico, and for founding the Greene Consolidated Copper Company in 1899. By 1905, G ...

. The mine was the location of the Cananea strike in 1906.

Anaconda Copper (1907-1972)

The mine was run for some time by the American company

Anaconda Copper The Anaconda Copper Mining Company, known as the Amalgamated Copper Company between 1899 to 1915, was an American mining company headquartered in Butte, Montana. It was one of the largest trusts of the early 20th century and one of the largest min ...

Government of Mexico (1972-1990)

The Mexican government mandated that ownership of the mining sector be gradually put into Mexican hands in 1961. Ownership was handed over to the company ''CIA Minera de Cananea SA'' in 1971, which was majority controlled by the Mexican government. Anaconda soon sold off its remaining minority interest. The privatization process began in 1988, but there were several failed auctions before the mine was successfully sold. In 1990, the state company was declared bankrupt.

Grupo México (1990-present)

In 1990, the Mexican government sold the mine to a joint bid by ''Mexicana de Cananea'' headed by Jorge Larrea, and the Belgian mining company Acec-Union Miniere. By 2003, the mine was run by

Grupo México Grupo México is a Mexican conglomerate that operates through the following divisions: Mining (Minera Mexico), Transportation ( GMxT), Infrastructure and Fundacion Grupo Mexico. Its mining Division is the leading Copper producer in Mexico and t ...

. Organized by the National Union of Mine and Metal Workers, about 1,200 workers on the mine went on strike demanding higher pay. The mine was reopened in 2010 after being closed for three years during a strike, and the mine was renamed the Buenavista mine.

2014 wastewater disaster

In August 2014, a major ecological disaster took place at the mine when 40,000 cubic meters of wastewater spilled into the Bacanuchi and

rivers. The wastewater carried

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...

and it is believed to also have carried

cyanide Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...

. The event prompted 88 schools to close temporarily. Mine officials have been criticized for not reporting the accident to the authorities until after 24 hours, when the residents had noticed the river water turned orange. In the wake of the disaster, Grupo Mexico set up a $151 million clean up fund, while continuing operations. However, according to reports from El Informador, the fund was closed before 1% of funds were distributed to those affected, prompting pressure from the

Office of the United Nations High Commissioner for Human Rights The Office of the United Nations High Commissioner for Human Rights, commonly known as the Office of the High Commissioner for Human Rights (OHCHR) or the United Nations Human Rights Office, is a department of the Secretariat of the United Nati ...

for full compensation.

References

{{reflist Copper mines in Mexico Silver mines in Mexico Zinc mines in Mexico Tailings dam failures