Elements
(This tab is disabled when Optimisation | Stope Optimiser | Mine > Definition | Model | Block Model | Optimisation Value: Use value from field check box is selected.)
Elements are recovered from material bins by processing facilities, after which they can be sold to customers.
Elements should be defined for any the following purposes:
- Specifying the outputs from processing facilities.
- Specifying and reporting the grades of stockpiles.
- Producing breakdowns of volumes, masses, grades and revenues by element in Optimisation Results and Extractions reports.
Use the Model | Elements tab to specify the list of elements produced from the mine, along with the following settings for each one:
Name
Enter the name of the element produced.
This name is also used to build names for fields in report data sources and attributes for saved wireframes.
Block Model Field
Select the field in the block model file from which the element grade for each block should be sourced.
An expression can be used to apply a cut-off grade to the element.
Example: If the “Copper” field specifies the percentage of copper by mass, the following expression would apply a cut-off grade of 0.35% and return the percentage of copper to be used for the (sub-)block:
if [Copper] < 0.35 then 0 else [Copper] endif
Grade Representation
Select the units in which the element grades are specified.
The following grade representations are supported:
| Grade Representation | Description |
|---|---|
|
% mass |
Percentage of block mass represented by element |
|
ct/t |
carats (1 carat = 0.2 grams) per tonne |
|
g/t |
grams per tonne |
|
kg/t |
kilograms per tonne |
|
dwt/t |
pennyweights per (metric) tonne |
|
ozt/t |
Troy ounces (1 Troy ounce = 31.1034768 grams) per (metric) tonne |
|
lb/t |
avoirdupois pounds (16 ounces = 1 pound) per (metric) tonne |
|
USER GRADE |
Mass of element in block is calculated by multiplying specified value by mass (density * volume) of material in block without conversion. Useful for processing obscure combinations of units. |
|
BLOCK VALUE |
Expected revenue, after selling costs (which are proportional to mass of element, which cannot be determined), for block. Optimisation value for block is calculated by subtracting all other applicable costs from specified value. |
Diluting Grade
Specify the grade of the element to be assigned to material added as dilution.
If this value is not specified, then the diluting grade for the element is set to zero (0).