what is needed is a reference to costs of mining , (before...

what is needed is a reference to costs of mining , (before processing)
They could use a Bucket wheel excavator as the chair referenced in a video , however they have a relatively low productivity rate for their size ie a mini BWE 75 tonne machine would be lucky to do 300 tonnes an hour and machinery is pretty much priced on a tonnes of steel used and is even more expensive for custom machines like BWEs

I am guessing the same weight generic Cat type 75 tonne excavator with a 4.5M cubic bucket would run 140 cycles an hour (easy) with a short swing to an an ancillary mobile reciprocating plate feeder so 600 BCMs or cc 1000 tones an hour which would be around what is needed for a 9 Mtpa operation (24/7) for 3 years on their 28 Mt resource .
mining cost guessing will use 90 liters of diesel an hour (350Kw* .25) * 2 = $$200 (inc for plate feeder )
depreciation $1000,000 /10000 hours 100
labour 100 an hour (inc servicing ) 100
consumables /maintenance 100
total $500 an hour
cost per tonne $500/ 1000 tonnes = $0.50 a tonne mining cost
Some mining ops need at least 2 personal on site for safety guess the process plant manager could double as that person .