Unleashing innovation in mine planning
Mine planning is being transformed by recent advances in technologies, ranging from rugged devices in the field for monitoring equipment operation and scanning rock faces, to optimization software in the engineering office. The digital transformation sweeping the industry is enabling engineers and planners to spend less time on tedious detail work and instead consider a broader range of scenarios than was previously feasible. An exciting next phase of technological breakthroughs is emerging, relating to mine planning workflows.
With recent advances in decision-support software for all aspects of the mine planning cycle, every step of an existing mine planning workflow can now be examined with a fresh perspective, rooting out any aspects that are found to be legacy issues from technology of a prior generation. As an example, consider at a high level the well-established planning process for a surface mine. From a block model, a sequence of pushbacks is designed, comprising the ultimate pit. Building on these pushbacks, a long-range schedule is subsequently generated. RPMGlobal’s Schedule Optimization Tool, SOT, generates the ultimate pit and the strategic life-of-mine schedule in one process. Why might a planner then feel the need to formulate pushbacks from such a solution? Every time technology advances, this type of question can be posed across the planning cycle, in relation to individual steps of the process and more broadly. Gradually at times, and occasionally with step changes, new planning methodologies will emerge.
Several planning engineers and advisors are providing leadership in the industry by developing and sharing innovative workflows. Their expertise is being applied to the development of study roadmaps that aim to maximize the value derived from a mining property, exploiting the latest optimization software tools. For underground mining, the study roadmap will commonly include iteratively optimizing financial models, geological and structural models, stope designs, access designs, and schedules, with increasing detail as study of the property progresses. It’s important to know at any given stage what aspects of the plan require a more detailed formulation. Is it sufficient to know that a plant upgrade will be required after year 10, or is it important to have more clarity on the timing of the upgrade, because it impacts other aspects of the plan? Sensitivity analysis can be undertaken at a strategic level in a consistent and much less time-intensive manner than was possible with prior technologies.
Again taking an example from SOT, the planning engineer can evaluate the optimal timing for a plant upgrade that will increase capacity, relax blending constraints, and improve recoveries, assessing dozens of alternative scenarios in a matter of hours. Often the optimization software may produce a solution that the planner initially finds to be counterintuitive. After a thorough review, this can be an occasion for realizing that a conventional practice is actually limiting value in the case at hand. It is inevitable that in parallel with the development of these innovative workflows there will be a progression towards more facilitation of such processes on the software side, and towards the establishment of new best practices on the engineering side.
A primary benefit of these efforts by mine operators and software providers is, of course, financial. A significant increase in net present value is generated, or a solid business case is produced for the expansion of an operating mine. However, the improvement in mine plans is not only economic, it is also in relation to the quality of the plan. A multidisciplinary roadmap customized to the mining operation ensures that the input of various domain experts is brought into the planning process in a timely manner. Advanced software platforms on offer today provide transparency and a channel of clear communication among technical teams. They have continual access to the updated planning information, designs, and schedules to fine tune their input appropriately. Thus, all technical teams can weigh in from their respective areas of expertise early in the planning cycle. The outcome will be a safer, more robust, and higher-
value mine plan.
In addition to breaking down silos between technical teams, silos between facets of the planning process can also be addressed. Optimization of each facet in isolation limits value. This can be clearly seen in the example of a plant that is shared by mines that are each optimized separately. Not only will it be prohibitively difficult to get a consistent blend in the plant feed, but even the initial allocation of plant capacity across the two mines for the long-range plans can destroy value. SOT allows the simultaneous optimization of multiple mines, underground and surface, in one process. Across the industry, software platforms provide opportunities for process integration and an increasingly holistic planning approach.
Right timing for decisions
With improvements in technology, strategic planning decisions throughout the planning cycle are evidence-based and fully auditable. Some strategic decisions can now be made later in the planning cycle. How many years before mining a particular zone is it necessary to settle on the cutoff grade for that zone, or even the access points? In the years preceding its excavation, the product price projections will have changed, and the orebody will be better defined. A robust plan will allow the planning team to carry forward multiple options and decide when to decide. Whatever the strategic decision being contemplated, each domain expert will know when they have enough information to narrow the range of options with confidence. If there is an opportunity cost of postponing a strategic decision, that cost can be weighed against the availability of more information and resolved uncertainty.
Strategic mine planning workflows, leveraging the technological innovations of ever-increasing optimization capabilities and integration opportunities, create value and unlock creativity, helping mine planners stay ahead of the curve.
Lorrie Fava is SOT and Attain product manager with RPMGlobal (www.rpmglobal.com).