VANCOUVER (miningweekly.com) – Base metals producer Lundin Mining saw about 21% of its TSX-listed equity wiped out on Thursday after it reported a disappointing long-term production outlook on Wednesday.

The Toronto-headquartered company punted significant investments in both the Candelaria copper mine and mill, in Chile, which will increase copper production going forward from 2021. However, the guidance for 2018 and 2019 have been cut as the life-of-mine pit plan is being reworked to address localised pit wall instability after a recent landslide.

Output is expected to climb to top-end forecasts in 2020 of 201 000 t of copper, 244 000 t of zinc, and 16 000 t of nickel.

Lundin also advised that, despite expecting lower zinc output in 2018 from the Neves-Corvo expansion project, in Portugal, output will rise in 2019 and again by 60% in 2020 over 2018 levels. First production is on schedule for the second half of 2019.

Meanwhile, Lundin expects its nickel output to remain in line with the company's previous guidance of up to 17 000 t in 2018, 13 000 t in 2019, and 16 000 t in 2020. The company has received the final approval to develop and mine the Eagle East nickel/copper deposit, in Upper Michigan. Lundin expects to receive final approval to treat Eagle ore at its Humboldt mill by mid-2018, and the Eagle operation is expected to hit full capacity by 2020.

The company also advised that the expansion of the mill at the Zinkgruvan zinc/lead mine, in Sweden, to 1.35-million tonnes a year, was completed on schedule and within budget in mid-2017. The focus has now turned to improvement projects in the process plant, including initiatives to improve ore feed characteristics, throughput, metal recoveries and overall concentrate quality.

Lundin also has stakes in operating mines in Spain and the Democratic Republic of Congo.