La Negra mine is a silver mine in the
Mexican state of
Querétaro, owned by
Excellon Resources.
Description
La Negra is a silver mine in Querétaro, Mexico.
The mine has thirteen known ore bodies, overwhelmingly of silver, but also with smaller quantities of gold, zinc and lead.
The mine has a processing mill that can process 3,000 tons-per-day.
Tailings from the mine are held behind five
tailings dams
In mining, tailings are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different to overburden, which is the waste rock or other material that overlie ...
.
The dams are located upstream of the Maconí River which, which after five kilometers reaches the
Moctuzuma River.
When active, it produced up to three-million ounces of silver-equivalent per year.
In 2023, the mine had 15.1 million ounces of silver in reserves.
History
The mine started operating in 1970 and was owned by Industriales Peñoles S.A. de C.V. at the time.
Production stopped in 2000.
Aurcana Corporation became the primary owner of the mine in 2006, expanding its share of ownership to over 99% in 2012. In 2009, production of ore was 1,000 tonnes per day, increasing in 2012 to 2,500 tonnes per day and 3,000 tonnes per day in 2013.
In 2014, Aurcana
increased quarterly production to 997,530 ounces, and facing reducing global silver prices, improved efficiency by reducing the workforce size.
The 2013 study ''Influencia de Jales Mineros Sobre El Río Maconí, Queretaro, y Evaluación Del Proceso de Atenuación Natural Por Dispersión'' (
English
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: ''Influence of mining tailings on the Maconí River, Queretaro, and evaluation of the natural attenuation process by dispersion''), published in ''Boletín de la Sociedad Geológica Mexicana'' (the journal of the
Mexican Geological Society) reported that "concentration in the water-soluble fraction exceeds 0.5 mg/L (permissible level indicated in NOM-147)" downstream of tailings dam number three.
In 2023, the mine was purchased from Dalu
S. à r. l. by
Excellon Resources for $50 million.
See also
*
Mining in Mexico Mining in Mexico represented 2.4% of the nation's gross domestic product in 2023 and employed 350,000 people in 2020. Mexico is the world's largest producer of silver and a globally significant producer of gold, copper and zinc. In 2020, Mexico prod ...
Notes
References
External links
MEXICAN OFFICIAL STANDARD NOM-147-SEMARNAT/SSA1-2004
{{Mining in Mexico
Silver mines in Mexico
1970 establishments in Mexico