Name of the Mine
Franke mine.
Location
The southern part of the Antofagasta region, the most prominent copper producing province in Chile.
Mine Owner/s
KGHM Polska Miedź SA acquired the entire Franke mine with the acquisition of Quadra FNX in 2012.
Brief Description
Franke is located in one of the most prospective locations for copper worldwide.
The claim areas belonging to Franke include San Guillermo, Franke and Pelusa, and are located at an altitude of about 1 730 m above sea level, within a radius of about 5 km from the solvent extraction-electrowinning (SX-EW) plant infrastructure.
Brief History
The Franke deposit has a copper mining history spanning almost 100 years. Initially, the ore was extracted by independent miners, called “pirquineros”, conducting artisanal ore extraction from deposits at surface. In the second half of the previous century, the deposit was explored by many companies, but mining did not start until 2009 when a new SX-EW plant was built.
Primary Metals/Minerals
Copper.
Secondary Metals/Minerals
None.
Geology/Mineralisation
Geological units in the Franke mining area correspond to the volcanic-sedimentary sequence deposited in tectonic basins. Lavas of andesite and basaltic composition, as well as marine and continental sequences of sedimentary rocks, are dominant. Diorites, monzonites and granodiorites can be distinguished among the local igneous intrusions, as well as numerous andesite dykes.
Rock alterations are heavily variable and do not cover large areas. Locally, it is a combination of enrichment with silica, carbonate and sodium, with varying proportions and intensity. Chloritisation is common, as well as deeper epidotisation of the rocks.
The rocks are sometimes influenced by regional metamorphism and hydrothermal changes.
In the Franke and San Guillermo areas, the copper mineralisation is of the manto type, where lithology is the main factor controlling the spatial distribution of minerals. For the southern areas of the Pelusa concession, including the China Sur deposit launched in 2020, primary sulphide mineralisation is associated with structurally controlled veins, stockwork, and the hydrothermal breccia of iron and copper oxides. The main tectonic structure responsible for mineralisation was identified over 750 m with an azimuth of 340°.
The main oxide minerals in the deposits are atacamite and chrysocolla. Among the sulphide minerals, in the eastern portion of the claim area, chalcocite with silver is dominant, while primary copper sulphides (mainly chalcopyrite, with minor bornite and locally coexisting covellite and chalcocite) dominate in the Pelusa area.
Reserves
Not stated.
Resources
Not stated.
Mining Method
Conventional openpit methods.
Major Infrastructure and Equipment
The mine includes crushing and agglomeration processes, with ore deposited on heaps for leaching with a sulphuric acid solution. The copper-enriched solution obtained after leaching is directed to a SX-EW plant to produce high-quality copper cathodes – the final product of the process.
Prospects
Franke still holds areas that are prolific for further campaigns targeted to explore new and expand already identified oxide and sulphide ore deposits.
Contact Details
KGHM
Tel +48 76 74 78 280
Email ir@kghm.com
Website https://kghm.com/
Sources
KGHM. https://kghm.com/ (accessed September 6, 2021).
KGHM. Integrated Report 2020.