The mill processed 94,589 tonnes of ore during the quarter at an average feed grade of 1.12% copper and 0.63%g/t gold.

Recovery of metal to concentrate was at 95.9% copper and 68.9% gold, while production of concentrate was 3,643t containing saleable metals of 978t of copper and 1,199 ounces of gold.

This brought the volume for the half-year period to 177,605t, up 9% year-on-year, at an average feed grade of 1.10% copper and 0.53g/t gold.

It noted that average recoveries to concentrate for the half year of 96.3% for copper and 68.3% for gold improved compared to the previous year's 95.3% copper and 60% gold. 

Rambler recovered a total of 1,801t of copper to concentrate in the first half of the 2018, down 5% on the year, while gold production rose 40% to 1,861oz.

CEO Norman Williams noted mine production had been the company's bottleneck for the first half of 2018, with mill throughput, recoveries and concentrate grades all improving.

"The single greatest limitation on plant utilisation, and therefore concentrate production, is the lack of feed at target grade from the mine. During the first half of 2018 the mine completed all remaining capital projects required to enable it to support our Phase 2, 1,250t per day targeted ore processing rate," he said.

A 24-week productivity improvement initiative at the Ming mine was started in June, with focus on mine planning, operations and mobile equipment maintenance.

The aim is to mine and haul 1,250tpd at a minimum 1.4% copper grade, delivering 18tpd copper in ore to the plant, while also hauling 485tpd of waste.

Williams noted by weeks seven and eight of the project, running over July 13-26, targets were being achieved.

He said over those two weeks, an average of 1,324tpd of ore was hauled to the surface grading 1.59% copper, an average of 20tpd of contained copper.  Over the same period, an average of 560tpd of waste material was mined and moved to a permanent storage location.

"Sustaining these production levels over the long-term requires increasing the development rate from the current 25 rounds per week to 30-35 rounds per week", he said.

"This uplift will be realised by a combination of increasing the number of development headings available each week, reducing the cycle time of the drill-blast-load-haul cycle, and cross training critical mining skills among the staff to allow key positions to be manned each day."