I think this must be in South America, and they are referring to a plant which just happens to be at 3,800 metres because of the topotgraphy, like this one:

http://images.google.com/imgres?imgurl=http://www.raura.com/...

The Mining Equipments flow produced by our company can provide you with all-around technical support. The whole line consists of vibrating feeder, jaw crusher, vibrating screen,Ball Mill ,Magnetic Separator,Flotation Machine,Spiral Classifier,Dryer,Mixer,Concentrator,Fiter press and belt conveyor and so on. According to specific requirements, we can combine different models together to meet various needs.

Construction of a 6000 tonne-per day integrated mine and concentrator at the Voisey’s Bay site in Labrador was completed in November 2005. ...

Belvedere awarded Environmental Permit for Luikonlahti mine and concentrator. October 21st, 2008. As the November issue of International Mining leaves to be ...

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Note added at 48 mins (2008-11-02 17:21:30 GMT)
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Lots of hits for concentrator + mining (175,000 ) and concentrator plant + mining (250,000) on Google -


http://www.google.com/search?hl=en&rlz=1T4GGIH_enES213ES214&...
http://www.google.com/search?hl=en&rlz=1T4GGIH_enES213ES214&...