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Josemaria Copper-Gold Project – The Start of a New Mining District

Josemaría Resources is set to start construction of US$3bn copper-gold project this year with first operations to start in 2026.  The project was purchased in December 2021 by Lundin Mining for an equity value of approximately C$625m ($485m).

The mine will have a life expectancy of 19-years and will produce 131,000t/y copper, 224,000oz/y gold, and one million ounces of silver. The payback period from the start of processing is estimated at 3.8 years. The mine life is expected to increase with further drilling.

The project will be one of the first to be built from a major new deposit cluster that sits on the Argentina/Chile border. The Josemaria copper-gold project is located approximately 10km from the Chilean border and 140km from Copiapo, Chile. As with many South American mines, it is expected to be a tier 1 asset with long life and low cost


Exploration Background

  • The Josemaria deposit was a grassroot discovery. The initial drilling campaign by NGEx Resources was in 2004.
  • The initial target was high-sulphidation epithermal systems similar to Veladero and Pascua-Lama.
  • The first hole drilled intersected 280 metres grading 0.61% copper and 0.51 g/t gold.
  • Eleven drilling campaigns have been carried out at the Josemaria deposit between 2003 to 2020. Total drilling is 76,206 metres in 190 drill holes, of which 48 holes (17,535 m) are RC holes, and 142 holes (58,671 m) are core holes.
  • The project is a top-10 open pit copper asset in the Americas with an estimated 6.7 billion lb of copper, 7.0 million oz of gold and 30.7 million oz of silver in Mineral Reserves.

Construction and Infrastructure

  • Josemaría will generate 4,000 new jobs during construction and 1,000 while in production.
  • Given the ore bodies near surface location, the project will be developed as an open pit mine with a low stripping ratio (0.98) over its 19 mine life.
  • On-site infrastructure includes the road network, processing plant, mine support facilities, power and water supply and distribution, and water and sewage treatment facilities.
  • Off-site infrastructure includes the south access road, a 252 km high-voltage power line to the site, and the concentrate transport facilities.

Mining and Processing

  • Conventional open-pit mining method, involving drilling and blasting followed by loading and hauling by autonomous trucks.
  • The pit will consist of 15m benches with average slope angles of up to 43 degrees.
  • The mining fleet will include electrically powered hydraulic shovels supported by 360t haul trucks.
  • The technical study assumes autonomous drilling will be adopted whereby one drill controller is able to monitor/operate the four large production drills. As well, the two smaller drills are managed by a second controller on shift.
  • The Josemaria processing facility will have a daily throughput rate of 150,000 tonnes per day (tpd) for hard tonalite ore, and 160,000tpd for the softer ores
  • A 1.8 km conveying system will connect the plant to the 60,000t ore stockpile facility.
  • The stockpiled ore will be fed into three identical semi-autogenous (SAG) grinding circuits and three corresponding ball milling circuits.
  • The rougher tailings will be passed through a sampler and onward to two 90m-diameter tailings thickeners, while the final concentrate from the cleaner flotation circuit will be pumped into a high-rate copper concentrate thickener, and will be filtered, dewatered, and stored at the site.
  • The copper concentrate will be transported to a new road-to-rail intermodal facility near the  Albardon Station, San Juan, from where the concentrates will be transported by rail to the Port of Rosario 
  • The feasibility study incorporates the use of autonomous trucks and production drill fleets, as well as the option to incorporate green energy.

Next Steps

The Josemaría management team conitoues to aggressively progress the project by de-risking and optimize the process flowsheet with improvements in the crush/convey, grinding, flotation and tailings.

The company started a  65,000-metre drill program last November aimed primarily at providing development/infill geo-metallurgical data and acquiring additional site geotechnical information It is anticipated that up to 8 rigs will be active at the peak of the drilling program. Management has a high degree of confidence drilling will lead to mine life expansion and a significant portion of inferred material moving into reserves. 


The Josemaria, Filo del Sol (Filo Mining) and Los Helados (NGEx Minerals) are three major new copper/gold discoveries bordering Argentina and Chile.  The three projects represent the first new deposit cluster in the Argentina/Chile copper belt in decades.

For mining suppliers, this is important news since it further proves that South America is a key market to have a presence in. There is no other region in the world with the size and quality of projects as Peru, Chile, and now hopefully Argentina.  The three countries together have a substantial project pipeline with many of the projects considered tier one assets that are long life and low cost. 

Argentina has been its own worst enemy over the years but now the government is seeking to increase mining exports from the USD$2.6b to USD$10b by 2030. To do so, the government is making attempts to improve the mining industries competitivity. The hope is that the country will be able to overcome many of its challenges to become a premier mining destination where other mines such as Josemaría will be built in the coming years.

Ax Legal is an advisory firm that works with foreign companies in Latin America. Our team of legal and commercial advisors have a distinguished track record of helping foreign technology and services companies to grow and operate in Latin America. Over the years, we have worked with starts up, mid-size businesses, and publicly listed companies. The one common factor that connects are clients is that they are leaders in their field, providing innovative technologies and services to the industrial sectors.

To better understand how we can support you in the Region, please contact Cody Mcfarlane at cmm@ax.legal