I thought I’d ask for a little insight from my brother who previously was heavily involved in the management and operation of a quarry in Australia and also an investor in FFX. In response to some of your issues:
“Tailings ready to go, functional feed of a lower grade. Also on a plant requiring refurb the lack of high abrasive material (because all the big rock and junk has already been processed) is significantly safer and more reliable. OEE (overall equipment effectiveness) of a mine that has run tailings a decade then thrown back onto full scale hard rock wouldve been abysmal. Needed the refurbished first. Also stripping. Stripping is one of the largest up front costs in mining.
Viper their now mining however were stripping, even though it was previously mined, move would have been required. That's potentially months theyve been running load and haul for 0 benefit. You can't just start mining and get gold. Skimming the overburden off the top of the resource (stripping) takes months and costs basically the same as traditional load and haul. Also if you try and process it it'll never go through the plant. It'll block and fail as overburden is mud, sticky, vegetation etc to block crushers screens and chutes”

”see all this depth, that’s stopped overburden depth.”
”Costs are the same? False. Thats a generator powered plant. The biggest costs are fuel and wear. A crusher operating at load vs no load can be over a 100% increase in current draw. = direct increase in fuel burn. Also dramatically increases wear. Even things like belts take an increased beating from large material processing. Tailings have already been through scalping, screening and crushing so theyre a more consistent product with less oversize = much less demand.”
”Processing tailings is basically like running in idle”
”A primary crusher on a 3- 4 mtpa plant would be like 200 amps at idle, pulling down 500-700 under peak load”
pitty he doesn’t post on here, he loves a good argument