W Resources PLC (AIM:WRES) said first-quarter production from its La Parrilla mine in Spain was lower than expected as heavy rain restricted access to higher-grade ore, although output picked up last month.
Total tungsten and tin concentrate production fell 31% from the fourth quarter of 2020 to 92.4 dry metric tonnes (dmt). Tungsten concentrate output dropped 36% to 63.5dmt, while tin concentrate dipped 13% from the preceding quarter to 28.9dmt.
“Due to high water constraints, we did not have access to high grade ore areas and the ore that we used was of lower grade, less fresh and with high levels of ultrafines through much of March,” said chairman Michael Masterman.
“This has clearly impacted production, such that whilst production picked up towards the end of March, we did not achieve the record production we were anticipating for the quarter.”
The AIM-quoted company said work is underway to reduce the high water levels at the mine and introduce a permanent solution to resolve the issue. Once this work is completed, it will be able to access the high-grade ore bodies again.
During the quarter, the company successfully completed a plant improvement programme at the mine.
“The initial scheduled four-week closure for plant improvements was reduced to two weeks and recovery rates improved. Frustratingly, heavy rain hampered progress and for safety reasons we had no option but to halt production for an additional week,” Masterman said.
The plant improvement shutdown and the unseasonal weather restricted production in the first quarter to 45 days, compared to 52 days for the fourth quarter of 2020.
The plant operated mostly on a five-day week for 10 of the 13 weeks in the period, the company said, adding that it plans to return to a seven-day working week in the fourth quarter of 2021.
Going forward, Masterman said the quality of ore fed into the plant has improved in April, as has the production of concentrate.
The company expects annual production of concentrate to be between 880dmt and 1,000dmt.