of extractable copper and 2,525 tonnes molybdenum in concentrate from the 72,000 tonnes per day concentrator. Work is now under way on the Andina Phase I Development Project which aims to raise mill capacity to 92,000 tonnes per day and is expected to be complete by November 2009. Pre feasibility studies on raising mill capacity to over 200,000 tonnes per day by 2014 should be complete this year. Deep drilling to prove up resources to sustain such a production rate continue. No estimates of the likely copper output at a milling rate of 200,000 tonnes per day have been given and cannot be until the deep drilling campaign is complete. One of the mysteries of Andina is why it did not buy Compania Minera Disputada de las Condes when Peñarroya was prepared to sell it for a very low price in 1972. It went to Enami who subsequently sold it for a handsome profit to Exxon Minerals for US$97 million. It would have given Codelco complete control of the district. When Exxon finally did decide to sell in 2002, Codelco expressed interest but were not prepared to match the US$1.3 billion that Anglo American were prepared to give for it. Rock glaciers have been seriously intervened by Andina since the late 1980s, when it started to deposit several million tons of waste rock on top of rock glaciers, resulting in their acceleration and partial destabilisation. Since then, 2.1 km2 of rock glaciers with a water equivalent of more than 15 million cubic metres have been affected by Andina, including the partial removal of rock glaciers. El Teniente Situated 44 km east of Rancagua and 75 km south of the capital, Santiago, El Teniente claims to be the largest underground copper mine in the world (see below). The El Teniente orebody has been known and worked on a small scale for many years. In the 16th century it became the property of the Jesuits as it was located on their Hacienda de la Compañia de Jesús. They operated a small mine known as the Socavón de los Jesuitas. Following their expulsion, the hacienda was acquired in 1768 by Don Mateo de Toro y Zambrano y Ureta. Between 1819 and 1823 his heirs restarted and enlarged the workings, bringing in a mining engineer to help. However, these and subsequent attempts to establish anything more than a small scale mine failed for lack