mining co valuation methods

Would like to hear how mining sector "Copperites" value a company based on production data.

Am interested in what range of "multiples" of pre or after tax profit would be considered as normal within the industry

Eg.

Mine life 5 years
Treatment rate 1 mtpa
Average LoM grade 1.93 g/t
Gold contained 310,900 oz
Gold recovered 289,200 oz
Plant recovery 93%
LoM gold price $584/oz (US$330/oz)
LoM Exchange Rate US56.5c
Direct cash costs $404/oz (exclusive of Perth office costs)
Cost of production $24.4/t
Capital cost $5.1m
Working capital $3.7m (2 months of 1st year total operating
costs)
Total start-up capital $8.8m
LoM revenue $169m
LoM net cash flow $26.3m
NPV @10% discount $14.5m (after tax)
IRR 87% (after tax)
Cum Cash Positive After 15 months (after tax), after 11 months
(before tax)

Abbreviations used above are defined as:

LoM = Life of Mine
IRR = Internal Rate of Return
NPV = Net Present Value
mtpa = Million Tonne per Annum
Cum = Cumulative
$ = Australian Dollar
US$ = United States Dollar