Define Maximum Waste Percentage

Note: This topic relates to dilution settings in MSO.

In MSO, setting a maximum waste percentage defines the upper limit for how much waste can be included in each optimized stope shape. It is applied as a constraint during the optimization process, ensuring that stopes do not exceed a specified fraction of waste material, regardless of economic value or geometric feasibility.

This helps prevent the generation of impractical or uneconomic stopes that would contain too much dilution and may not meet operational standards.

Use this to restrict excessive dilution in final stopes. This can be especially helpful in narrow vein operations or when working with selective mining methods where excess waste would undermine profitability.

Maximum Waste Percentage is applied using a a slider to define the maximum allowable waste as a percentage of total stope tonnage, or you can just enter a value straight into the field.

Waste in Shape Frameworks

The waste percentage limit principle is similar for both Prism and Slice frameworks, with subtle differences:

In a Slice framework dilution is managed by controlling where stopes are seeded, how they grow, and which results are accepted, rather than by directly reshaping stope geometry.
- Stope testing controls determine which framework cells or locations are evaluated.
- Slice orientation and growth settings influence how stopes expand through the orebody.
- Economic and dilution constraints limit which grown stopes are considered acceptable.

Together, these controls ensure that slice-grown stopes maximise value while limiting unnecessary inclusion of waste.

Unlike Prism optimisation, Slice optimisation does not explicitly modify crowns or apply trough geometry. Dilution arises primarily from slice growth decisions and ore boundary alignment, and is controlled indirectly through testing scope, orientation, and acceptance criteria.

In a Prism framework:
- A Maximum Waste Percentage constrains total stope dilution.
- A Crown Dilution constrains where dilution may occur.