(Sharecast News) - Vast Resources announced a 20% overall increase in third quarter production from its Baita Plai Polymetallic Mine in Romania on Friday.

The AIM-traded firm said that, as it flagged on 26 September, the last month of the quarter saw an increase in production through the use of the Mantis rigs.

That resulted in a "significant increase" in tonnes mined and the quality of the concentrate produced from an average of 16% in July and August to over 22%, with peaks of 28.5%.

September was the most successful month of underground production at Baita Plai, with the mine producing 7,900 tons of ore, accounting for 50% of underground production in the third quarter.

Production in July and August was affected by a requirement to change the working faces to enable the implementation of long hole stoping.

The initial downward perforation strategy for long hole stoping was subsequently adjusted to vertical drilling in level 17, to mitigate against the deflection of the drilling rods and the effective drilling strategy would now be maintained.

Vast said the fourth quarter started with a further increase in the rate of underground ore production, compared to the average rate achieved in September.

The current prepared accessible underground ore stood at about 290,000 tons, because of the change in the transition to mechanised mining.

It said the mine was currently working in four separate high productivity mining areas using long hole stope methodology, in addition to continuing production on two working faces with room and pillar mining method of extraction.

As a result, underground production was expected to continue its growth into the first quarter of 2023.

The completion of spiral number three would further increase the volume of underground ore production, which was intended to ensure the longevity of the mine from the second quarter of 2023.

Finally, the company confirmed that the sale of concentrate expected in mid-October would now occur in the first week of November.

"This has been a successful period which has seen us achieve the uptick in production from September that we have been working towards," said chief executive officer Andrew Prelea.

"I am wholly encouraged by the work that is continuing on the ground as we now plan for further increases in the remaining weeks of the fourth quarter, and again in the first quarter of 2023 and onwards."

At 1343 BST, shares in Vast Resources were down 12.5% at 0.33p.

Reporting by Josh White at Sharecast.com.