RE: The drills in the ground go round and round...9 Mar 2021 12:13
Cygnus
Good post.
I’ve also been trying to work out the volume against very limited drill results. The main problem is, as you say, is that the shape will not be a cuboid so by using the basic calculation of LxBxH would produce an inflated volume figure.
The link below has volume calculators for different shapes. I think the most likely shape will be one of: Ellipsoid, Capsule or Conical Frustum
https://www.calculator.net/volume-calculator.html?
If you use the cuboid shape as a base case (although it won’t be that shape) then using the same L B H values to determine volume for the cuboid shape. Using the same base values for the other shapes you can work out the reduction. The approximate reduction against other more likely shapes are as follows:
Capsule = 80% of cuboid
Ellipsoid = 60% of cuboid
Conical = 50% of cuboid
I am using a base case of 940 x 560 x 660 as cuboid dimensions of mineralisation. This means the total ore volume at 2.7 t cubic mtrs = 938,000,000 for a cuboid shape.
Adjusting this figure for a more likely shape we have:
Capsule = 750,000,000
Ellipsoid= 563,000,000
Conical = 469,000,000
After deciding which shape best reflects the mineralisation, multiply this by the cu grades % to get the approximate contained copper amount.
Obviously this is a very ‘rough and ready’ way of determining the contained copper, but it will give an indication. My view is that a Capsule shape is probably most appropriate and a copper grade of circa 0.35% is most probable.
So that’s a contained copper value of circa 2.6M tonnes against current drill results. Obviously that will change as more drill results are known.
Others will have different views.
I believe the biggest factor in trying to determine the future anticipated sp is the contained copper value. Once you have determined this, it becomes easier (not easy) to determine the future anticipated sp imho.