The historic Cauquenes and Colihues tailings impoundments are man-made deposits that were generated as sites for the containment of tailings produced during the processing of copper-molybdenum ore at the El Teniente mine. Currently, feed to the plant is derived from two sources: fresh rougher tailings from the Codelco’s El Teniente concentrator and hydraulically recovered tails from the Cauquenes tailings impoundment. The mineralogy of the feeds varies, and the most recent mineralogy indicates that the main copper and molybdenum-bearing minerals are sulfide in nature. In the fresh tailings the majority of the copper (47%) occurs as chalcopyrite, with significant secondary copper sulfide forms: chalcocite, bornite, and covellite (40%). In the historic tailings, approximately 75% of the copper occurs as secondary copper minerals and about 17% of the copper occurs in the form of chalcopyrite. The portion of poor floating copper minerals (copper in iron oxides and sulfates) ranged from 7 to 13% for the historic and fresh tailings, respectively. In both tailings streams, the molybdenum occurs as molybdenite.

MVC has been in operation since 1992 and produces copper (Cu) and molybdenum (Mo) concentrates by reprocessing tailings produced by the El Teniente mine. Sources of mill feed include the fresh tailings from El Teniente and the tailings from the Cauquenes historic tailings deposit and Colihues historic tailings deposit.

MVC has valid contracts with Codelco’s El Teniente Division (DET) to process Fresh Tailings, the Colihues deposit and the Cauquenes deposit. MVC has the right to process tailings up to 2037.

Currently, feed to the plant is derived from two sources: fresh rougher tailings from the Codelco’s El Teniente concentrator and hydraulically recovered tails from the Cauquenes tailings impoundment.

El Teniente Tailings
The Fresh Tailings are transported via gravity to MVC via a 36 km long concrete open channel launder. The target fresh tailings concentrator throughput is 140,000 tpd. The term of the Fresh Tailings Agreement was extended from December 31, 2021 to December 31, 2037.

Colihues Tailings
In 2003, MVC commenced production from the Colihues deposit, and, in 2015, suspended operations from Colihues. The total tonnage of material extracted from the Colihues deposit, up to the end of December 2016 was 72,742,245 tonnes. The total quantity of copper produced from Colihues, up to the end of December 2016 was approximately 55,975 tonnes. Extraction of material from the Colihues deposit is planned to recommence in ........

- subscription is required.

MVC initially utilizes two separate circuits to produce copper and molybdenum concentrates from fresh and historic tailings: fresh rougher tailings from the Codelco’s El Teniente concentrator (TEN) and hydraulically recovered tails from the Cauquenes tailings impoundment (CQNS). Primary classification is performed on the tailings streams to separate the fine fraction for scavenging skim flotation in a cascade system and the coarse fraction is subjected to grinding before conventional flotation. The ground coarse fraction is transported to a conventional rougher/cleaner flotation circuit to produce a combined bulk copper-molybdenum concentrate. The bulk concentrate is reground and cleaned followed by selective flotation for molybdenum separation. Final tailings from both TEN and CQNS circuits report to thickening before final discharge to the El Teniente tailings channel and report to the Caren impoundment.

The current plant configuration treats approximately 185,000 tonnes ........