Don Sixto, Argentina
The Don Sixto, or “La Cabeza” mine is located in the Mendoza province of Argentina, close to the city of General Alvear. The Don Sixto mineral deposit was discovered in 1996 by the company Argentina Mineral Development, and this company performed the initial exploration and development of the mineral deposit. In 2003, it was purchased by Exeter Resource Corporation, a Canadian gold mining company which focuses on mineral deposits in Latin America. In 2005, they estimated that the Don Sixto mineral deposit held at least 890,000 ounces of gold.
In 2007, Exeter Resources received the necessary permits from the local and provincial government to begin preliminary construction at the site and began drilling holes into the gold veins in April 2007. However, on June 22, 2007 the province of Mendoza passed a law, Law 7.722, prohibiting the use of certain chemicals that are typically used for gold extraction and processing such as cyanide, mercury, and sulfuric acids . This law forced Exeter to put the Don Sixto project temporarily on hold.
This cyanide ban was part of a broader push across Argentinian provinces to end open-pit mining and to stop the potentially destructive environmental effects that are associated with cyanide processing. Mendoza’s ban follows similar bans in the provinces of Chubut, Rio Negro, and Tucumán which were largely pushed for by environmentral activists and community assemblies.
Exeter tried to fight the law shortly after it was passed by presenting a case to the Supreme Court of Mendoza claiming that Law 7.722 was unconstitutional, a case which still has no resolution . The Don Sixto mining project is still on hold.
 Macías, F. and Rodríguez, L. “To Cyanide or Not to Cyanide? Some Argentinian Provinces Banned Use of Cyanide in Mining Activities: Is This Prohibition Legal?” Rocky Mountain Mineral Law Foundation, 46: 2009. p. 237-250