Asante Gold says it is reviewing a new mining technique, Sustainable Mining by Drilling (SMD), for use at its Kubi gold project in Ghana.
SMD is a two-stage drilling method that enables direct mining of narrow vein deposits. The technology is being developed and commercialised by Anaconda Mining, in collaboration with Memorial University of Newfoundland, and uses technology proven in other industries, Asante said.
Anaconda’s SMD technology placed second in the recent Goldcorp #DisruptMining challenge held on the sidelines of the annual Prospectors and Developers Association of Canada event in Toronto on March 3, 2019.
“This concept is a complete surface mining option with a drilling rig as a main surface piece of equipment used in conjunction with several field-proven downhole technologies,” Anaconda said.
The mining process is divided into two campaigns: drilling the pilot holes and accurately mapping the vein, then enlarging the pilot holes to predetermined sizes to recover the ore.
Using an inclined mast drilling rig, an inclined pilot hole is to be drilled along the centre line of the vein (equidistant between the hangingwall and footwall) with directional drilling system.
Steering the pilot holes live with a survey tool will determine the current orientation and refine the 3D model of the vein used to plan the pilot hole enlargement.
“Once the pilot hole has been drilled, progressively larger hole-openers can be used to drill along the pilot hole’s trajectory up to 2 m,” Anaconda said.
Anaconda said the SMD technology is a “disruptor” in that it reduces the cost to extract ore by 50% over conventional underground narrow mining techniques; it places the operator in a safe location on the surface; can access areas not open to conventional mining; reduces the environmental footprint; and by passes the crushing and grinding circuits by moving the +/-2 mm drill cuttings in a slurry direct to the mill.
Douglas MacQuarrie, President and CEO of Asante Gold, said: “The new SMD mining technique slashes the mining costs, development time and capital required to take near-surface gold deposits to production.
“Our Kubi Main Zone gold resource is located in one of the best and safest gold mining destinations in the world, is road and power accessible, has an average width of 2 m, is near vertical, and appears to be well suited for the application of this technique. Previous metallurgical tests on Kubi mineralisation gave 35% to 40% recovery of the contained gold by gravity concentration from a coarse grind, which suggest a similar recovery might be expected directly from the SMD drill cuttings, giving a potential source of early cash flow. We are looking forward to the development and commercialisation of the SMD technology and its potential application at Kubi.”