The Cobre Panama copper mine is a large open-pit copper mine located in the Colon Province of Panama. Canadian miner First Quantum Minerals holds a 90% interest and is the operator of the mine, while the remaining 10% is held by Korea Resources Corporation (Kores).
Previously known as the Petaquilla copper project, the property was acquired by Inmet Mining in 2008. First Quantum acquired an 80% ownership in the project in 2013 which was increased to 90% in August 2017.
Developed with an estimated investment of £5.3bn ($7bn), the copper mine commenced commercial production in September 2019. It produced 47,480 tonnes (t) of copper, 60,074 ounces (oz) of gold, and 1.1 million ounces (Moz) of silver in 2019.
The Cobre Panama operation has however been temporarily suspended due to the Covid-19 pandemic since April 2020.
At full capacity, the mine is estimated to produce 320,000t of copper, 100,000oz of gold, 3,500t of molybdenum, and 1.8Moz of silver a year, over an estimated mine life of 36 years.
Location, geology, and mineralisation
The Cobre Panama project is situated in the Donoso and Omar Torrijos Herrera Districts of the Colon Province, approximately 20km south of the Caribbean Sea coast and approximately120km west of Panama City.
The Cobre Panama deposit consists of four large copper porphyry deposits including, Botija, Colina, Valle Grande, and Balboa, as well as the smaller deposits that include Abajo, Brazo, Botija, and Medio.
Hosted within volcanic-sedimentary and andesite-basalt sequences, the deposits lie at the southern margin of a large granodiorite batholith belonging to mid-Oligocene age.
The mineralisation mostly occurs in granodiorite, feldspar-quartz-hornblende porphyry, and andesite volcanics.
Ore reserves at Cobre Panama
The Cobre Panama copper mine was estimated to hold 3.14 billion tonnes of proven and probable reserves grading 0.38% copper, 59.38ppm molybdenum, 0.07ppm gold, and 1.27ppm silver, as of December 2019.
Mining and ore processing
The conventional open pit mining involving a drill, blast, load, and haul operations is implemented at the Cobre Panama copper mine. The seven pits present in the project area will be mined in phases.
The extracted is hauled to an in-pit crushing and conveying (IPCC) circuit that comprises up to five semi-mobile, independent, gyratory crushers.
The crushed ore is transported via an overland conveyor to a nearby processing plant where it undergoes secondary crushing, two-stage grinding in a semi-autogenous grinding (SAG), and a ball mill, before passing through the froth flotation circuit for separating copper and molybdenum minerals from non-commercial minerals.
The obtained minerals further undergo differential flotation for separating the copper and the molybdenum minerals from each other.
The copper and molybdenum concentrates are filtered and dewatered before packaging and the final concentrate products are transported to the port of Punta Rincon on the Caribbean Sea for shipping to the customers in Asia, Europe, and South America.
The Cobre Panama mine can be accessed through the southern Pan-American Highway from Panama City to Penonome.
The electricity for the project is sourced from a 300MW coal-fired power plant at Punta Rincón through a 230kV transmission line.
The potable water for the project is sourced from the local rivers and the process water is reclaimed from the tailings management facility and is collected from surface drainage ponds.
The project site also houses a number of camps capable of accommodating more than 10,000 people.
Joint Venture Panama, a joint venture led by SNC-Lavalin and including GyM and Techint International Construction, was awarded an engineering, procurement, and construction (EPC) contract worth £2.5bn ($4bn)for the Cobre Panama project in November 2010.
A joint venture of Salini and Impregilo was contracted for the mine’s stripping services in December 2012.
Contromation provided the design of a 1.6Mtpa material handling plant while Stracon was engaged for the construction of a tailings management facility (TMF), electric transmission line, and related works.
The laboratory flotation test work was conducted by ALS Metallurgy in 2014, while CNI provided geotechnical engineering services for the project.