Chapada is an open pit copper-gold mine located 270 kilometres northwest of Brasília in Goiás state, Brazil. The mine reached commercial production in 2007 and is an open pit truck and shovel operation, with ore being treated through a flotation plant with capacity of 23.4 Mt per annum. The Chapada mine plan has three open pit mining areas including Corpo and Corpo Sul, which are currently being mined, and the Suruca deposit that Yamana plans to develop in the future. Exploration is ongoing to develop near mine targets at Suruca SW, Suruca NE, Baru and Interpits.
The Proven and Probable Reserves at Chapada total 754.9 Mt at a grade of 0.23% copper and 0.14 g/t gold containing approximately 1.7 Mt of copper and 3.3 Moz gold.* In October, an updated technical report was filed which outlines production through 2050.
Yamana, the previous owners, completed studies to evaluate several development opportunities at Chapada. These opportunities range in scope from plant optimization initiatives to enhance copper and gold recoveries, to a plant expansion to bring forward cash flows and pit wall pushbacks to expose higher grade ore zones. Lundin is currently evaluating these and other scenarios for expansion that would increase the processing rate up to 32 million tonnes per annum.
* Reserves are calculated using an NSR cut-off grade value of US$5.15/t based on US$3.45/lb copper and $1,725/oz gold and an exchange rate of USD/BRL of 4.25. The cut off value for gold only reserves is 0.19–0.30 in the Suruca open pit.
Lundin announced updated Mineral Resource and Reserve estimates for Chapada. As of June 2021, Measured & Indicated Resources (inclusive) are 1,075 Mt at 0.23% copper and 0.14 g/t gold and Proven & Probable Reserves are 754.9 Mt at 0.23% copper and 0.14 g/t gold. Successful infill drilling campaigns have enabled the conversion of previously Inferred mineral resources to the Indicated category.
Exploration expenditures in 2021 will focus on supporting in-mine and near-mine targets. Lundin Mining has a budget of $14.0 million for exploration work at Chapada in 2021.
A return to full production rates has been achieved at the Chapada mine. The return to full processing capacity was achieved following the installation of the repaired motor on the ball mill.