Open Pit Mine Setup
Use the Design > Open-Pit tab to set slope restrictions for a default region (and the extents and slope restrictions of up to 10 sub-regions). Use the buttons on the local toolbar to Manage the rows in the list.
The regions must not overlap, and a parent block should not be assigned to more than one region.
Use Regions Defined By
Min/Max coordinates
Select to delineate regions for which different pit design parameters apply by ranges of coordinate values.
Wireframes of type
Select to delineate regions for which different pit design parameters apply by wireframes of a specified type.
Block model slope field
This field specifies the field in the block model that contains the slope angles required for each block. The regions are defined as being all of the blocks with similar slope angles. Select this option to delineate regions for which different pit design parameters apply by the regions defined by the values in a block model field.
Open-Pit Mining Costs
Ore
Specify the cost per mass or volume incurred when mining a block as ore. This is the cost of blasting, mining and haulage of ore.
Ore units
Select the Volume or Mass unit of measurement from the menu opened by clicking the ellipsis.
If you select Custom from the menu, expressions can be used to vary the cost by the depth of mining and/or the distance of the block from the plant.
Diluted and recovered
Select this to specify that the mining cost for ore applies to the ore mass (or volume) after mining dilution and recovery has been included, and not to the in situ ore mass (or volume).
Waste
Specify the cost per unit mass or volume incurred when mining a block as waste. This is the cost of waste blasting, mining and haulage. This cost is applied to the recovered material. (Dilution is not applied to waste.)
Waste Units
Select the Volume or Mass unit of measurement from the menu opened by clicking the ellipsis.
If you select Custom from the menu, expressions can be used to vary the cost by the depth of mining and/or the distance of the block from the plant.
Slope Restriction Options
Number of benches for dependencies
The number of benches that are used to generate the pit slopes will affect the accuracy of the results and the time taken to perform the optimisation. If this is set to 0, or left blank, which is the default setting, dependencies to model the specified slope angles will be generated from each block to the surface of the pit. This will produce the most accurate modelling of the pit slopes; however, it may require more memory and processing time to complete the optimisation.
You can experiment. However, as a rule of thumb, to minimise the number of dependencies generated for pit slopes within the range of 40-50 degrees, divide the largest horizontal dimension of the block by the height of the block and multiply by 8.
Example: For blocks with dimensions X=45, Y=35, Z=30 this would require a value of (45 / 30) * 8 = 12 benches
In general, increasing the number of benches will result in a more precise pit.
Slope Restriction Regions
Specify the following settings for each region within the block model for which a different pit design is required:
Min East
(Min/Max coordinates only.) Specify the easting coordinate for the lower extremity of the region.
Min North
(Min/Max coordinates only.) Specify the northing coordinate for the lower extremity of the region.
Min Z
(Min/Max coordinates only.) Specify the elevation (Z) coordinate for the lower extremity of the region.
Max East
(Min/Max coordinates only.) Specify the easting coordinate for the upper extremity of the region.
Max North
(Min/Max coordinates only.) Specify the northing coordinate for the upper extremity of the region.
Max Z
(Min/Max coordinates only.) Specify the elevation (Z) coordinate for the upper extremity of the region.
Wireframe Name
(Wireframes of type only.) Select the wireframe of the specified type that defines the region.
Slope Restrictions
Select the form set that specifies the slope restrictions for each region.
Click left on the icon to select an existing form set.
Click right on the icon and select New to create a new form set. When prompted, enter the name to be assigned to the new form set and press OK.
Click right on the icon and select Edit, or press F4, to edit the specified form set.
The Slope Restrictions form set will be displayed.