"You are right to question the strip ratio.....as it will be the biggest cost before any DSO ore can be mined.
If you take the average depth to ore( Cyclone dep) at 60m.....1200 length.....350 width...then total minimum volume is 25.2m m3 × 2.7 sg
= 68m tonnes.
Mining costs as per Sandfire Motheo deposit....to drill, blast, excavate and cart to an area outside pit perimeter was $2.87 US / t = $4 AU approx.
The cost to strip the overburden becomes quite large.....circa $240m ?"
Yes the strip is relevant I get a strip of around 15:1 which I welcome others to find fault with as below :
The MRE from 30th jan 24 page 40 shows Cyclone as 1450* 625 * 125 deep = 113,281,250 BCMs
lets say pit walls at 45 degree so base of pit at say 100 meters (lets assume 125 depth is only for a small part of the pit) is the following dimension
1250 * 425 * 100
so average pit size is 1350 * 525 * 100 = 70.9M BCMS or 191 M tonnes at your SG 2.7
Inferred resource for Cyclone is 12.1 M Tonnes
(191- 12.1) /12.1 = 15:1 strip ratio
cost per tonne for mining in the MRE is US $5.00
5 * (15 + 1 ) = $80 .00 a tonne of ore
process cost is $10.00 a tonne (from MRE )
G&A is 12.00 a tonne (from MRE)
Total cost per tonne is $102.00 a tonne
recovered grade of ore post ore sorting is 0.9% Cu ( 1.2% * 75% recovery being optimistic )
lets say Cu price is $US 9000 a tonne so 0.9% * 9000 = $81 .00 for ore
So with out any other costs I am getting a loss of $25.00 a tonne
Welcome to be shown where I am wrong in my calculations as this only took 20 minutes to do and I have no mine qualifications
(20min delay)