Production for the quarter amounted to 13,635 tonnes - a record for the company. Atalaya said the increase was driven by higher throughput, with higher recovery compensating a drop off in grade.
However, output was 5% below the estimate of Canadian bank BMO.
"The slight miss was largely on weaker-than-expected-grade (0.44% vs BMO 0.47%), which more than offset improved recovery of 86% (+1% vs BMO)," said BMO analyst Alexander Pearce.
Atalaya suggested the strong performance of its Riotinto plant would allow the company to make up any shortfall and hit its annual production guidance of between 55,000-58,000 tonnes of copper.
"Whilst the COVID-19 pandemic impacted production during the beginning of the quarter, the expanded plant after Proyecto Riotinto recommenced its operations on 6 April 2020 has consistently performed beyond expectations," said Atalaya.