Pardon me....if I may interrupt
This means the disc at ground level will
have to be, at minimum, 1,050 metres in diametre. Using geometry, it calculates
that about 65 million cubic metres of overburden has to be mined, hauled, stored
and dammed up (about 130 million tonnes)
This size of pipe can be excavated(over burden) in 3 stages using stage 2 and 3 overburden to infill previous stage excavations.Less upfront costs and lower unit rates for disposal and restoration.
The example pipe mine, under 100 metres of overburden,
would cost, maybe $1,400,000,000. Compare this with the Ekati cost and assume
a slightly higher mining rate and you get a rough, very rough, minimum grade
threshold of about 1.64 times the Ekati grade to get the same rate of return at 100
metres of overburden.
Excuse me....100 meter deep overburden would more likely encourage an underground model if grades merit costs.Not all diamond mines are open pit...;)
Over burden is only one piece of the mine puzzle....not the only piece as Mr. Bouley intones. |
