interactive cloud hosted spreadsheets
Bench Slope Calculator
The Bench Slope Calculator allows one either to (i) calculate the IRA given a set of criteria (bench height, BFA, and catch bench); or (ii) calculate the catch bench width given the height, BFA, and IRA. The yellow shaded cells represent the input cells.

Single Bench Height (BH): is the input height of a single operating bench

No. of Benches between catch benches: is the input for single, double, or triple benching

Total Height (TH): is the calculated total height (# of benches X single bench height)

Bench Face Angle (BFA): is the input bench face angle, in degrees

Catch bench (CB): is the width of the catch bench, either as an input or a calculated value

InterRamp Angle (IRA): is the slope angle in degrees, either as an input or calculated value
For details, see blog "Pit Wall Angles and Bench Width – How Do They Relate".
Rock Value Calculator
The Rock Value Calculator has been created to calculate the dollar value of the insitu rock. Simply enter your own orebody data in the yellow shaded cells and the rock values are calculated on a “$ per tonne” basis. One must zero out the values for metals of no interest.

Price: represents the metal prices, in US dollars for the metals of interest

Ore Grade: represents the head grades for the metals of interest in the units as shown (g/t and %)

Process Recovery: represents the average percent recovery for each of the metals of interest

Payable Factor: represents the net payable percentage after various treatment, smelting, refining, penalty charges. This is simply an estimate depending on the specific products produced at site. For example, concentrates would have an overall lower payable factor than say goldsilver dore production

Insitu Rock Value: this output is the dollar value of the insitu rock (in US dollars), without any recovery or payable factors being applied

NSR Rock Value: this output represents the net smelter return dollar value after applying the recovery and payable factors. This represents the actual revenue that could be generated and used to pay back operating costs