yes as @salpetie would say "why reinvent the wheel" maybe a...

yes as @salpetie would say "why reinvent the wheel"
maybe a little innovation though with the container ?
Use two half height shipping containers , the bottom one possibly an open topped container , containing the dense copper concentrate and the top one that can be twist locked on that is a self bunded diesel fuel container .

Diesel in to the mine with a empty container for the Cu ,  - Cu concentrate in bottom container and empty piggy backed diesel container goes out

Would that be feasible from a ship Captain perspective ?

Yes there are  a couple of little peninsulars about 2 kms West of Kugluktuk , depth of water on Google Earth shows around 4 meters guessing would be good to tie  up to with some piling done ,  so ok for tugs and barges to transport out to an OGV with cranes  , I learnt a new acronym .