The issue with mining is dilution. The size of the front end...

The issue with mining is dilution. The size of the front end loader or excavator determines how much waste you have to take with the ore. If the bucket is 2 metres wide you take out 1.8 metres of crap to get the 0.2 metre of ore. The size of the equipment has to be matched to the orebody and largely determines the mining cost. If you have to drill and blast you also get dilution at that stage. Unless its going about 30 to 60 g/t gold you'll never mine 0.2m mineralisation.

It's all about materials handling and you then have to process it. For every tonne of waste you put through the plant, that's a tonne of ore you didn't treat.