(Sharecast News) - Randgold Resources revealed that production at its Kibali mine in the Democratic Republic of Congo has risen more than expected on the back of the optimisation of its automated underground operation.Randgold told investors on Wednesday that it was on track to beat its guidance of 730,000 ounces for this year thanks to a second-quarter free of lost-time injuries.Production at Kibali was moved from outsourced contractors to in-house earlier in July and is expected to deliver "significant cost and efficiency benefits", as well as transferring skills to the mine's Congolese workforce."Kibali hosts one of the world's largest underground gold mines and the aim of owner mining is to give us complete control over the day-to-day operations, with everyone focused on the same goal and compliance with the mining plan," said Randgold chief executive Mark Bristow."We're confident that we'll achieve the same results here as we did at Loulo, but we've tweaked that model a little to take into account the lessons we learned there as well as Kibali's specific circumstances," he added.Elsewhere, a further major milestone was passed with the commissioning of Azambi, Kibali's third and last hydropower station, which was expected to start delivering power into the grid "within the next month".As of 1630 BST, Randgold shares had climbed out an earlier hole and were up 0.11% at 5,546p.