Atalaya Mining issued an operations update for the first quarter of 2018 on Wednesday, reporting that copper production at Proyecto Riotinto increased to 9,441 tonnes from 8,805 tonnes at the same time last year, representing an increase of 7.1%.
The AIM-traded firm said it was its second-highest quarterly production on record.
Ore milled was said to have been consistent with previous quarters, and in line with management's expectations.
Copper head grade was improved compared to the fourth quarter of 2017, in line with expectations.
The increase in copper production was primarily put down to to a record average recovery of 88.47%.
The company said it was maintaining its previously-stated copper production guidance for 2018 of between 37,000 tonnes and 40,000 tonnes.
"Mining operations are running at similar levels to previous quarters," the board reported in its statement.
"On a combined basis, ore, waste and marginal ore amounted to 3.0Mm3 in the first quarter versus 3.1Mm3 in the fourth quarter of 2017.
"During the first three weeks of March, 460 litres/m2 of rainfall were registered, which for such a short period of time was significant in the region."
Atalaya said the open pit lower benches were partially affected by the heavy rainfall.
Mining operations were rescheduled, and mine planning was adjusted with no impact reported on production.
Improvements to the processing plant saw not only higher copper recovery, but also better utilisation rates, the board added
The company said its continuous improvements programme saw the installation of an additional secondary cone crusher, with completion estimated during the second quarter.
Modifications to current screening and crushing arrangements were under evaluation as part of a debottlenecking exercise.
Structural steel fabrication of the dome to cover the coarse ore stockpile was said to be well advanced, with construction scheduled to commence in the second quarter, with completion of the dome estimated by the middle of the third quarter.
"Dewatering of the Atalaya pit is ongoing as previously reported," the board explained.
"Dewatering of Cerro Colorado has been restarted after the heavy rainfall in March and is expected to be completed by end April."
On-site concentrate inventories at the end of the quarter were approximately 1,121 tonnes.
All concentrate in stock at the beginning of the quarter and produced during the quarter was delivered to the port at Huelva.
Copper prices rose during the period, with an average realised price per pound of copper payable, including the QPs closed in the period, of $3.03/lb compared with $2.87/lb in the fourth quarter of 2017.
The average spot copper price during the quarter was $3.08/lb, with the realised price during the period excluding QPs approximately $3.12/lb.
Cash operating costs and all-in sustaining costs for the period were expected to be within the 2018 cost guidance ranges provided.
"Exploration has successfully performed a validation process of the Cerro Colorado drill hole database.
"The database incorporates all exploration drilling completed since April 2016.
"An updated resources and reserves estimate is well advanced and is expected to be released before the end of the second quarter."
Atalaya said results of the VTEM survey had been received, with targets prioritised for drilling in the coming months.
The archaeological exploration programme under way in a section of the northern wall of the Cerro Colorado pit remains on schedule, and it was expected to last for the duration of 2018.
Atalaya said the expansion project to 15 Mtpa was progressing according to schedule.
Overall progress completion was currently 27%, with procurement reporting 26% and engineering 60% completed.
Civil engineering works at the new concentrate handling area were said to be "well advanced", while earthworks at the flotation area were progressing according to internal expectations.
The milling area was the critical path to completion.
The expansion project was scheduled for mechanical completion at the end of the second quarter of 2019.
Over at Proyecto Touro, the board said perimitting was continuing as anticipated.
"Detailed reports have been expanded to address certain project improvements and recommendations received from the public hearing process.
"These reports will be submitted to the authorities during the second quarter."
As it had previously reported, Atalaya said an NI-43-101 compliant pre-feasibility study would also be released during the second quarter.
Geological mapping and geochemistry were ongoing on exploration concessions around Proyecto Touro.
Results of the VTEM survey were received, and were currently under internal assessment.
"It has been a strong operational quarter for the company, with reported production figures ahead of internal expectations," said CEO Alberto Lavandeira.
"The operational expertise demonstrated by the wider team at Atalaya Mining positions us well to take advantage of the ongoing developments taking place at both Proyecto Riotinto and Proyecto Touro."
Lavandeira said he was "pleased" to see restarted construction activity on site, which he asserted demonstrated the strength of the company's primary asset, Proyecto Riotinto.
"At Proyecto Touro, the additional independent studies that have been completed confirm our approach, and we look forward to providing further updates to the market in due course.
"We maintain our 2018 production guidance of 37,000-40,000 tonnes."