building a decline, page-40

swuzzle another option is to pre concentrate the ore underground ie using a grizzley or photo sorting the ore from the gangue therefore what comes up is more concentrated.
You are on the right track they need to keep dilution of ore to the minimum, possibly performance payments to air leggers based on gold extracted rather than rock stoped out could help to.
One of the gecko plants gecko makes can be totally installed underground so in theory (taking out the swell factor) no ore would come to the surface except for gold dust.