A mine plan might look good on paper but what happens when reality gets involved? Will you have the flexibility available to adapt to any unforeseeable or potentially foreseeable variation and uncertainty that will occur? In hindsight, would you have planned differently if you knew these unforeseen things would eventuate?
Flexibility in design is about providing easy access to a Plan B or C if Plan A does not work out. Can you easily adjust to minimise any negative effects before they become a problem? Or easily adjust to maximise any positive effects before they disappear?
An inflexible plan can result in:
- Mills not being filled due to lack of feed or unexpected downtimes with loss in revenue
- Certain material not able to be extracted or processed efficiently, or with lower than expected recoveries (and revenues)
- Rejection of off-specification product and hence lower revenue
Below we present some important questions to answer when considering uncertainty in mining project design:
- EQUIPMENT: What happens if one (or more) key pieces of equipment goes down? Are there sufficient stockpiles to allow downstream processes to continue, or can you cover the loss with other equipment and for how long? An example that comes to mind is a conveyor versus trucking decision. The conveyor may offer operating cost advantages, but trucks provide a diversification of risk. If one goes down, the shortfall may be covered by other trucks. If the conveyor system goes down, you may have to rely on stockpiles or bring a contract mining fleet in at short notice (and high cost). Relying heavily on one piece of equipment may lead to large (and expensive) storage of parts.
- FEED: What happens if the ore feed or product output isn’t as expected over a short time interval? Will recoveries rapidly deteriorate, or will product sales be rejected (or penalties apply)? Can the change be detected early and addressed through adjustment of process settings? Can the buyer of the product handle off-specification material for a short time (so long as it is corrected over the medium term)? Or do we need to build a sophisticated mine to plant blending/rehandle strategy in lieu of significant upstream design modifications to ensure that the right feed is provided, often at high cost.
- MINE DESIGN: What happens when the price of your commodity goes down? Or goes up? In the current climate, the urge to minimise those expensive, fuel driven haulage costs for the feasibility study may lead you to place your infrastructure (expensive infrastructure, like your mill) close to your pit or portal. That’s great for now; but most of us have seen the heady days of the mining boom and know how unlikely those additional resources will be able to pay for the cost of relocating significant infrastructure. Stepping in your design, increasing your cut off and stockpiling strategies can future-proof you against falling commodity price, but keep an eye to the future, better prices may be realised within the life of the mine. Scenario planning for significant infrastructure placement may enable you to realise those extra dollars at a relatively low cost.
The only certainty with mine planning is that things will not happen exactly as you think. If you only measure the value of a project based on what you expect to happen, you may be exposing the project to larger than necessary downsides or missing out on potential upsides. It is the ability to perform when the unexpected occurs (design flexibility) that will often determine realised project success or failure.
Project teams should brainstorm possible deviations from plan, and identify how the system would adapt to manage the deviation. Snowden, having worked across all disciplines and participated and led many feasibility studies, are ideally placed to help you get the right design and strategy for your project. Contact us at to discuss your project.