The Escalones Copper Project is an open-pit copper porphyry deposit with an oxidised copper mineralisation and is located in the Santiago Metropolitan Region, Central Chile.
Owned by World Copper Ltd., the Escalones deposit was discovered by Ralph Fitch, former president and CEO of General Minerals Corporation, and Felipe Malbran, former Vice President of Exploration, South America, through greenfield exploration in 1996.
Recommended White Papers
World Copper filed a Preliminary Economic Assessment (PEA) of the project with an effective date of 15 February 2022 and an issue date of 22 March 2022.
As per the PEA, the project has an average annual copper production of 124.7Mlb (56,520 tonnes) for the first five years and a life of mine average of 114.9Mlb (52,131 tonnes) and a 20-year mine life.
Escalones Location and Site Access Details
The Escalones Copper Project is located approximately 97km southeast of Santiago in Central Chile and 9km west of the Chile-Argentina border. The project lies near the headwaters of the Maipó River.
The Los Pelambres to El Teniente porphyry copper belt hosts the project. The belt runs north to south through the Chile-Argentina border in the Central Andes Mountains.
The underground El Teniente Copper Mine is located approximately 35km east of the Escalones site.
Escalones is accessible by a paved road from San José de Maipó Town to Romeral and San Gabriel followed by a dirt road along the ECOGAS pipeline following the Maipó River to Quebrada Escalones.
The base camp lies along the western edge of the project at an elevation of 2,400masl.
Drill access roads totaling 46km were constructed between 1997 and 2000 by TMI Chile. The roads connect the base camp and the ECOGAS pipeline access road to the Meseta and the Escalones Alto portions of the project.
Additional drill roads run along the eastern side of Escalones Alto from the Argüelles River.
Escalones covers a total area of 161km2. Of the total covered area, 46km2 is covered by 19 exploration concessions subjected to an option agreement between Trimetals Mining Chile, a wholly owned and an indirect subsidiary of World Copper.
The rest 115km2 is covered by TriMetals’ 40 exploration concessions.
Escalones Ownership History
Under the direction of Fitch and Felipe Malbran, the project was optioned by General Minerals SCM, Chile in 1996 after General Minerals became a wholly owned subsidiary of South American Silver.
Currently, Pablo Caglevic, a representative of the Sociedad, is managing the Escalones option.
General Minerals signed a joint venture agreement with ASARCO in June 1999 under which ASARCO could earn 60% equity in the project after completing additional payments to General Minerals and a bankable feasibility study.
In 2001, South American terminated its interest in the project due to the low price of copper, poor economic viability, and high ongoing option payments.
In 2004, South American acquired its interest back in the project. 2004 saw no exploration but many companies tried to find a joint venture partner for the project.
South American signed a joint venture agreement with Minerva Aurex (Chile), a subsidiary of Phelps Dodge Corporation, in March 2005.
As per the agreement, up to a 72% joint venture interest could be earned by Minerva in Escalones through payments to South American, exploration expenditures, and completing a feasibility study.
The joint venture agreement was slashed by Minerva in May 2007. At the end of 2007, a total of 30 drill holes (12,666m) were drilled on the project.
Southern American changed its name to TriMetals Mining in March 2014 and to Gold Springs Resource in November 2019.
In May 2019, Wealth Minerals acquired the project from Gold Springs Resource by signing a share purchase agreement. In July 2020, Wealth Minerals became World Copper.
Escalones Geology and Mineralisation
The Escalones Project is located within the Pelambres-El Teniente porphyry copper belt of the Miocene to Pliocene age.
The copper belt hosts El Teniente Copper Mine, the world’s largest underground copper mine, and other copper mines.
The mineralisation of the project consists of two types: lithological skarn mineralisation and disseminated porphyry-style stockwork mineralisation.
The lithological skarn mineralisation is hosted with altered shale/sandstone, sills, and intrusive dykes.
The disseminated porphyry-style stockwork mineralisation includes underlying granodiorite and diorite.
Gold, silver, and molybdenum are found associated with copper mineralisation as per the rock geochemistry.
The skarn mineralisation consists of minerals like calcareous and feldspathic sediments, magnetite, and calcsilicate.
The other minerals found in the skarn mineralisation are garnet, pyroxene, sandstone, carbonate, and calcareous shale with chalcopyrite and pyrite.
The porphyry mineralisation consists of moderate to intense potassic alteration, granodiorite, and hornfelsed sandstone.
Due to supergene weathering and copper mobilisation, a stratification has developed at the subparallel level to the current surface.
The stratification is clear in the core where copper and iron oxides dominate the upper portion and sulphides in fractures.
Mineral Resource Estimate
At a density of 2.69 tonne/m3, the total inferred mineral resource estimate of the project is 426Mt containing 3,447Mlbs copper at a grading of 0.367%.
Mining Methods and Processing of Ore
For the Escalones Copper Project, the conventional open-pit mining method is selected to mine ores.
A triple bench format was used by Ms. Lane of Global Resource Engineering for the open-pit area. The format consists of triple 10m*13m (vertical benches*horizontal catch bench) for three vertical benches.
The haul roads and ramps are built using 227-tonne haul trucks and haul roads have a minimum width of 34m and a maximum gradient of 10%. The mine will produce 50,000 tonnes of copper ore per day (tpd).
The processing of ore will consist of conventional sulphuric acid heap leaching, solvent extraction, and electrowinning resulting in cathode copper.
The processing will work for 365 days per year on a 24-hour basis. The targeted production is 50,000 tonnes per day of mineralised material producing Grade-A copper cathode at an average rate of 52,000 annual tonnes.
The run of mine will be transported to a primary jaw crusher near the proposed open pit followed by a secondary crushing circuit to the heap through several conveyors.
The heap leach will leach copper and transfer it to the copper recovery circuit in the form of pregnant leach solution.
The pregnant leach solution will undergo direct processing in the solvent extraction (SX) plant resulting in a copper depleted weak raffinate which will be recycled to the raffinate pond.
The copper rich electrolyte will enter the electrowinning circuit consisting of electrowinning cells with cathodes and anodes producing Grade-A copper cathode which will be ready for shipment in bundles.
Escalones Infrastructure
The existing infrastructure of the project includes a seasonal base camp of 50 persons accommodation lying along Rio Maipó River, re-opened three drill access roads (9km, 14km, and 22km), and power and other supply Queltehues Hydroelectric Plant through the right-of-way pipeline.
The new infrastructure will consist of power supply, access and haul roads, process water supply, mine, and plant facilities, cathode storage and transport system, camp, and ground material transport.
The power needed for the project is approximately 150MkW from the Queltehues Hydroelectric Plant located 53km downstream.
The Queltehues Hydroelectric Plant will be connected to the project via high-voltage transmission lines.
Contractors Involved
The 2022 PEA of the project was prepared by Global Resource Engineering and Hard Rock Consulting.
World Copper’s wholly owned Chilean subsidiary, TriMetals Mining, signed a letter of intent with Desaladora Rosario to construct pipeline meant to supply desalinated water for the project.
Desaladora will construct a desalination plant of 2,000 litres per second design capacity in the Cardenal Caro Province. A pipeline will connect the plant and the project.
For 15 years, the project will receive a part of the design capacity of the plant.
In February 2022, World Copper signed a Memorandum of Understanding (MoU) with the Advanced Mining Technology Centre, Faculty of Physics and Mathematics, University of Chile to research, develop, and implement sustainable and innovative solutions for mining, exploration, and processing of ore for the project.
A technical report of the project was filed by World Copper in October 2021 prepared by Hard Rock Consulting.
World Copper selected Liviakis Financial Communications in September 2021 and signed an agreement to provide investor relations services.
