Resolute Mining Limited (ASX:RSG) has reduced life of mine all-in-sustaining costs for the Syama underground gold mine in Mali to US$746 per ounce from US$881.
The significant 18% reduction is outlined in the updated definitive feasibility study (DFS) for the Syama underground project, with mine life also increased by four years to 2032.
Probable reserve up 38%
Another positive outcome from the DFS was a 38% increase in the Syama underground probable reserve to 35.2 million tonnes at 2.7 g/t gold for 3 million ounces.
Managing director and CEO John Welborn said the company’s investment in technology and exploration had resulted in a substantial expansion to Syama’s scale, operating margins and value.
“Our ambition at Syama is to transform this world gold class deposit into a world-class gold mine,” he said.
“The updated DFS numbers capture the progress we have made in exploration, automation, and power, and confirm Resolute is transforming Syama into a robust, long-life, low-cost mine.
“We are developing a new underground mine and are on track to commence sub-level caving in December 2018.”
Shares were up 4% in early trade to $1.33.
The DFS update presents the results of an ongoing effort by Resolute to critically examine and pursue improvements in all aspects of its flagship operation in Mali’s south.
A focus has been the redesign and rescheduling of the underground mine following a 39% increase in mineral resources, which was announced in October 2017.
That resource is 55.9 million tonnes at 3.2 g/t gold for 5.7 million ounces.
Key drivers of the cost savings achieved are the automation of underground mining equipment and a power upgrade.
Welborn said: “The sub-level cave mine plan at Syama lends itself to automation.
“Our partnership with Sandvik to deliver autonomous haulage and trucking enables major productivity and cost improvements over the original DFS.
Autonomous Sandvik TH663 trucks will be used for the haulage of ore and waste.
“An upgrade of the Syama power station supports a further cost reduction in sulphide processing.
“Reducing operating costs and increasing production at Syama is consistent with our journey to build an operation that utilises best-in-class technology while maintaining flexibility to incorporate further advances in mining and processing.
“We aim to make Syama the best mine of its type in the world and to ensure we unlock the full potential of this outstanding ore body,” he said.
Resolute is continuing drilling at Syama with a further resource and reserve expansion expected.
The pursuit of world-class mining and processing had been accompanied by a renewed commitment to, and investment in, exploration, according to Welborn.
He said: “The exceptional drill results achieved over the past two years have been followed by a sophisticated and rigorous mine design and evaluation process.
“This has resulted in an increase of nearly 1 million ounces in contained gold in the Syama underground probable reserve.
“In addition, we have discovered and commenced the delineation of a new ore zone at Nafolo.
“This is a breakthrough in our understanding of the size and potential of the Syama mineralised system, and we are very confident of further growth in the resource base.
“The growing reserves at Syama, and our commitment to new technologies, offer significant opportunities for further optimisation, expansion and unit cost reduction.”
Studies for future expansion
Optimisation studies for future expansion confirm that increased processing throughput may be achievable.
A comparison of the typical design level from the original DFS and the DFS update.
The updated DFS is based on maintaining the planned mining rate of 2.4 million tonnes per annum.
This mining rate was originally programmed in the original DFS on the basis of the 2015 assessment of the available sulphide processing capacity at Syama.
Welborn said: “Our study focus at Syama will now turn to identifying the optimal future mining rate based on the improved automated infrastructure we have developed and the significant progress being made on our processing capabilities.
“There is obvious scope to increase the current planned mining rate of 2.4 million tonnes per annum to as much as 4 million tonnes.”
He added that there was an exciting and highly value creative pathway ahead for Resolute at Syama.