Escondida

Duyvesteyn, W. P. C. Sabacky, B. J. Ammonia Leaching Process for Escondida Copper Concentrates (Reprinted from Extractive Metallurgy of Copper, Nickel, and Cobalt. Vol. 1, 1993). Trans. Inst. Min. Metall. Sect. C-Miner. Process. Extr. Metall. 1995, 104, C125-C140. 

Benito Serrano-Rosales, Programa de Ingenierla Quimica, Unidad Academica de Ciencias Qmmicas, Universidad Autonoma de Zacatecas, Km.6 Carretera a Guadalajara, Ejido La Escondida, Zacatecas, Zac., 98160, Mexico... 

Alpers C. N. and Brimhall G. H. (1988) Middle Miocene climatic change in the Atacama desert, northern Chile evidence for supergene mineralization at La Escondida. Geol. Soc. Am. Bull. 100, 1640-1656. 

Crossflow ventilation is a technology that has been designed into the cellhouse structure in the past to reduce acid mist. Amplats Rustenberg plant in South Africa applied a cross flow principle first and this was applied on a larger scale at the zinc EW cellhouses in Canada (Cominco Trail in early 1980 s) and Kidd Creek. From the mid 1990 s until the more commonplace application of cell hoods, the large tankhouses in Chile typically used combinations of positive crossflow ventilation, balls and foams. The DESOM crossflow ventilation configuration, which became common practice in Chile, was first applied to the El Teniente SX-EW operation in 1985. Cerro Colorado, Quebrada Blanca, Chuqui SBL, Quebrada M and Escondida Coloso followed in 1994. 

Copper SX has also been successfully achieved using leach systems other than sulfuric acid. The Arbiter plant in Anaconda, Montana, treated an ammoniacal leach liquor from a sulfide concentrate using LIX 64N (Anon 1973). More recently, BHP Minerals (now BHPBilliton) developed the Escondida process in which copper concentrates are leached with anunonia and ammonium sulfate, and then purified by SX... 

Duyversteyn, W. C. and Subacky, B. J. 1993. The Escondida process for copper concentrates. In The Paul E. Queneau international symposium extractive metallurgy of copper, nickel and cobalt, vol. 1, Fundamental aspects, eds. R. G. Reddy and R. N. Weizenbach, 881-910. Warrendale, PA The Minerals, Metals and Materials Society. 

Long pipelines are used to transport concentrate. At Cuajone, in Peru, an open launder is used to transport taUings from an altitude of 3000 m (10,000 ft) down to sea level. The potential energy drop is used to overcome the friction losses of the launder. In Escondida, Chile, copper concentrate flows by gravity from an altitude in excess of 2500 m (8200 ft) above sea level over a distance in excess of 200 km (125 mi) to a port at sea level. 

One of the largest copper mines in the world is operated by Minera Escondida Ltd. in Chile. The mine is located at an altitude of 3100 m (10,170 ft) above sea level. To transport the copper concentrate a pipeline was constructed. The pipeline uses a single pump station at the beginning of the pipeline and gravity throughout the remainder. The pipeline spans 165 km (103 mi) of mountainous terrain and transports the slurry at a cost of 1-1.5 dollars per metric ton. This style of transportation is considerably cheaper than the alternative option of trucks and railroads. Nordstrom valves were used on the pipeline (Bog-gan and Buckwalter, 1996). 

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