Originally Posted by
Waikaka
It’s an interesting one, when does hope meet reality. Hard one to quantify but clearly some really optimistic people.
Mine life is expected to be what 5-10 years? Steeply dipping ore bodies means minimal volumes for high installed infrastructure cost. Each extra meter won’t be many oz but will mean bigger fans etc.
Building an ore concentration plant elsewhere means trucking, double handling and huge storage costs. What do you need to concentrate ore? Primary crusher, then feed that to ball mill, slurry pumps to move material to primary cyclones. Probably not concentrated enough so some of the early stages of floatation and oxidisation tanks. Dam to dump tailings, then thicken up the concentrate by removing the water. Then off to final processing (i.e. autoclave and pressure tanks) and then refining.
Cost per oz will be prohibitive, trucking through communities unpopular and have a high social impact. Macreas is largely refractory ore, suspect they can’t take high grade narrow vein ore. Are you seriously considering putting it on the Cook Strait ferry to process in the South Island. Google tells me 14 hour drive from Karangahake to Reefton, 19 hours to Macreas. How many trucks are you taking? 4 day round trip for each truck? What would happen if a truck laden with mercury rich gold concentrates crashes and spills out.
Scale will only ever be a hobby mine and Worksafe/environmental conditions means it is just not possibly anymore. Building a second access, ventilation and water control/treatment system will be painfully expensive.
I was going to dive into facts and figures but thought it is summed up nicely that in Southern Cross Minerals, a former owner of the permit withdrew from much of the license area due to the negative local bodies and environmental pressure groups. That was in 1976 (taken from MR5214 published in 2015, 517 pages of prefeasibility study). Pretty sure everything will be harder than the 1970’s tougher H&S, environmental, more legal issues, RMA etc.
Hard to see a path to profitability. Many millions needed from where they are, to where they need to be. Holders need to be aware that cash calls will keep coming.