Mines of the future: smaller, modular, reusable and cheaper
A look at how mines of the future might be smaller, modular, reusable – and, perhaps, cheaper.
Mining Innovation Director, Axora
In a recent article, I suggested that mines of the future, rather than becoming more expensive on account of the need to meet ESG and other sustainability metrics, could actually become cheaper. I appreciate that this is a fairly contrary view; most people in the industry are resigned to mining costs rising on account of the need to invest in being part of the green energy revolution. For example, Rio Tinto has announced that it expects to invest an additional $7.5bn between now and 2030, on top of existing investments.
So let me describe the ways in which I think mines of the future might be smaller, modular, reusable – and, perhaps, cheaper.
Step 1: Finding the deposits
This is going to be the easiest part of the process, and here’s why.
As a rule of thumb, if the size of a deposit means the lifespan of the mine needed to extract it all is likely to be less than 10 years, then that mine is probably not going to be built today. Too short a mine life means it probably will not be economically worthwhile; the return just wouldn’t be high enough unless the deposit is next to an existing mine.
As a result, mining history is littered with exploration projects that produced a result that was deemed to be “too small” to be taken forward as things stand.
However, what this means is that there is a significant number of known deposits that have yet to be mined. Their whereabouts, size and quality have already been determined; for someone wanting to mine such deposits, there is no near-term need to find a brand new, previously unknown deposit. Better still, many of these deposits are in stable jurisdictions with strong infrastructure and mining skills, such as Canada and Australia.
Step 2: Permitting
Permitting a mine is usually the hardest, most complex, and most fraught with danger step in the whole process: frequently, permits for even geologically exceptional deposits will be denied, for any of a million reasons. Examples include Pebble in Alaska (environmental concerns) or Rosa Montana in Romania (perceived dangers of cyanide which caused local opposition).
It’s often the case that, once a local or national population decides it doesn’t want a mine, political heads follow; the mine is then duly opposed, as has happened in Jadar in Serbia. Generally, miners are able to do little about this – but there are cases we will be able to make in the future:
Smaller mines will generally mean smaller holes, smaller impacts, less dust, less blasting, and less waste material. This should reduce opposition on environmental grounds.
We – mining – are getting smarter about the processes we use and the substances we use. For example, we are now able to eliminate the use of cyanide (an emotive substance for the public) and replace it with alternatives.
We’re also getting smarter about the tailings produced by mining. The process of dry stacking or better yet paste/CRF back into the void will dramatically cut waste; we are increasingly considering reusing the tailings for another purpose and completely eliminating the risks.
Step 3: Construction
Because mining currently and significantly favours “big” over “small”, mines typically take significant time and huge amounts of capital to construct – precisely because they’re large. Processing plants are custom-designed and shipped to be assembled on-site, and the sheer scale of these projects inevitably leads to other issues, delays, and costs. To reduce the risk of delays and costs, the mine of the future could be modular, with process plants pre-designed, pre-packaged and – governed by the constraints of shipping containers – pre-assembled to whatever degree is possible.
For mining itself: open-pit will always be faster – but, for reducing impact and ease of permitting, underground is the way to go. In fact, hybrid is best: it leads more quickly to production and provides a location for tailings if it’s suitably locked up (drystack, paste or CRF). This could cut waste storage by 60%-90%.
Step 4: Mining
The mining itself, mentioned above, deserves closer examination. The best solution for mining is in-situ leach: it requires minimal actual mining, and – today – might be further advanced with reuse and adaption of the technology used in fracking. However, there are issues, most notably the release of chemicals into groundwater. This is such a major issue that we will discount this method for our future mine.
With the aim of zero-entry mining in production, we will instead use an open pit, with either a trolley line or in-pit crushing. Machines will be autonomous or semi-remote – the technology for these already exists. Operators will be based in ROCs and mining will be provided ‘as a service', providing a market for and access to the best operators. This will improve safety in the pit slope and reduce the stripping ratio, reduce our costs for waste movement and reduce the volume of material we need to remove.
For the underground part of the mine, the decline will be external to the pit, enabling us to reuse the space for tailings. This mine has no shaft – a shaft will not be needed, as well as being inappropriate due to CapEx and time constraints. Instead, raises will be bored from below and used for either haulage out or minimal ventilation/communications/paste.
For haulage, we can either use the raises, trucks, or a conveyor decline. As before, all equipment will be either semi or fully autonomous, reducing the requirements for clean air and fans, and consequently reducing the power demand.
In this mine of the future, there will be only concentration, and product will be shipped elsewhere for smelting.
Step 5: Closure
Our mine of the future has always been planned to have a short lifespan, so we also need to plan for closure quickly and cost-effectively. So, the material will be replaced in the voids; the land will be reclaimed; we should also expect to replace of damaged flora and fauna, and for the mine infrastructure to provide for the local community e.g., roads, rail, power etc. Finally, and vitally, all equipment and facilities will be reused, ideally onto the next mine.
A pipedream? In the near term, perhaps. But most of the key technology needed to create these mines of the future already exists; much of it you can find on the Axora marketplace. And many of the environmental, social, governance, political, economic, and financial metrics that will drive (or even mandate) this kind of mining are rapidly moving in such a direction that will make such mines viable, especially for less-abundant minerals and metals. The reduced barriers to entry inherent in this new type of mining may also give rise to a new, disruptive type of mining organisation, new entrants unencumbered by any attachment – financial or cultural – to legacy approaches to mining. So, as I said in the first article: watch this space.
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