An Open Cut Dragline Mine in the Hunter Valley, NSW needed their LOM plan run in a value case comparison to compare 5 mining scenarios. They needed justification, through quantified and comparable results, to determine the best strategy to proceed with for the life of the mine. MEC took the clients previous LOM and truck haulage models, modifying them to achieve the required 5 scenarios. With the results from the MEC schedules the client was able to understand the lowest risk scenario and determine the feasibility of implementing the new scenario.
- Strip mining with mixed dragline methods, stacked and offset.
- Different dragline classes running in tandem on different passes.
- Variable dragline rehandle factors to match the schedule configuration.
- Achieve the same yearly coal target across all scenarios.
- Varying reserves, strip widths, strip designs, strip transitional phases; including bridge removal & pit deepening to access a seam spilt.
- Insure the same mining principles that site is currently using are followed.
- Make sure models are consistent and comparable.
- Haulage modeling needed to incorporate multiple haulage scenarios.
- Utilise multiple projection rules to quickly create reserves.
- Investigate the best prestrip removal without compromising coal release, achieved by reviewing strip layback angles and strip widths.
- Created multiple Deswik Workflows which apply the relevant dragline factors to each scenario.
- Apply client assumption to 5 XPAC schedule models.
- Modify previous Deswik Haulage model to be more accurate and allow a more direct haulage option.
- Create multiple dump reserves to match different reserves (different scenarios).
- Create a standardized process to allow multiple schedules to feed into one haulage model.
- Incorporate deeper seam extraction at pit floor and transition to this.
- Keep all coal release and current fleet to complete bridge removal.
- Minimise fleet use in early years for added value cases which significantly improved FOB costs during the current market challenges
BENEFITS TO CLIENT
By thoroughly investigating five distinct mining scenarios, using the latest software modelling and comparative analysis of the results; MEC was able to advise the client of the optimal scenario for their Life of Mine planning.