At our Elkview operation, the plant upgrade is now successfully commissioned and running at the forecast 6 million tonne annualized run rate. So we're pleased with that.
And finally, the feasibility study for the reopening of the Quintette mine is progressing and is expected to complete this quarter.
In our copper business unit on Slide 10. Overall production was up versus Q1 last year, with cathode production steady and concentrate production increasing. Production of copper in concentrate was up 6,000 tonnes, primarily due to higher ore grades and better recoveries at Carmen de Andacollo and Antamina. In addition, Antamina's mix of mill feed during the first quarter increased to 63% copper-only ore versus approximately 54% during the same period last year, as we continue to transition to a higher copper production.