Bringing The Mungana mine back to life

Following the acquisition of Atherton Resources in late 2015, we set ourselves numerous objectives, one being the reestablishment of operations at the Mungana underground mine. We made a promise to ourselves, to "deliver on our commitments" and it's amazing to see how far we have come.

The Mungana mine is located 15 kilometres west of Chillagoe in North Queensland and operated from 2006 to 2012 when the company went into administration and the mine entered a phase of "care and maintenance". Whilst in care and maintenance, the underground pumping infrastructure was removed and the workings allowed to flood, a sad time for all. The mine remained moribund until the arrival of the Auctus Team in January 2015. The Auctus Team, hit the ground running and following a period of due-diligence, they developed a detailed mine design and schedule with the aim of mining high grade ore bodies using a Sub Level Cave (SLC) methodology.

In June 2016, the first operational steps were taken to re-enter the mine, when dewatering activities commenced. A 300KW submersible pump was lowered 280m down the existing Return Air Rise and shortly afterward, discharge rates of approximately 80 litres /second of water were achieved. By August the water level had been lowered to a point where a ventilation system could be re-established allowing access for a geotechnical assessment of the exposed ground support, ground conditions and the first 130m of the escape way system.

In-line with the Auctus methodology to work with leading Third Party Experts, a geotechnical consultant inspected the workings in late August and confirmed that generally good rock mass conditions and the neutral PH of the water had had little adverse effect on the ground support, and that only limited rehabilitation would be required. This was excellent news and the Team progressed quickly in seeking tenders for a provision of a scope of works to rehabilitate the decline, re-establish the underground services and electrical supply and start waste development out to the orebody. Following a highly competitive tender process, Pybar, a major underground contractor mobilised to site on the 15th September 2016 and commenced work on that scope under a four month Early Works Agreement. By the end of December 2016, over 2000m of decline had been repatriated, and access development underway in the top four levels, 2225, 2200, 2175 and 2150, of the planned Sub-Level Cave. For the final months of 2016 the equipment fleet comprised of one jumbo, truck and loader achieving up to 300 meters per month of development. On 31st December 2016 the ore zone on 2225 level was accessed ahead of schedule.

The plan for 2017 at Mungana is to introduce a second jumbo to increase development rates especially on 2225 and 2200 level. Sample stoping on 2225 and a gold stope on 2200 will occur in the 1st quarter with focus on drawpoint development and Sub-Level Cave initiation and growth to follow. Production will ramp up during 2017, peaking in early 2018.

"It is a wonderful feeling to bring an operation back to life and to see all of the tangible benefits, in particular the faces of the people involved, Auctus employees, contractors and consultants, gainfully employed"
Steve Murdoch, Executive Chairman.