It is vital that incorporating renewable technologies is considered at a project’s design stage.
How can mining companies ‘future proof’ their projects so they can incorporate advances in mine design that lower carbon emissions?
That question is testing the mining sector like never before. Most mining companies understand the benefits of reducing carbon emissions as part of their environmental, social and governance (ESG) strategy. But planning for that change is complex.
Oliver Shaw, a senior mining engineer at SRK Consulting, said existing conventional mining projects often find it challenging to transition to renewable technologies when they are part way through their mine life, with technologies more viable when used over longer timeframes.
“Some of these systems require significantly different design parameters than those applied for conventional methods,” Shaw told Australian Resources & Investment. “Also, typically these technologies are economically more advantageous when evaluated over longer timeframes. Projects with short remaining mine lives often cannot justify transitioning to the new systems.”
Shaw gives the example of electrification of mining projects and the development of renewable energy sources to power them – a hot topic in the resources sector.
Electrifying a mine might involve in-pit crushing and conveying (IPCC) systems; ex-pit conveying; trolley-assisted truck haulage technologies; ore sorting; material handling systems, just to name a few. Autonomous mining technologies, which might already be used at the operation, are another advancement that can synergise well with electrification initiatives.
“It all gets back to planning,” Shaw said. “Even if a company isn’t incorporating electrification or renewable technologies immediately, to future-proof projects they must understand how these technologies would work and apply the associated parameters within their initial mine plans to set the project up for success in the future.”
This is not only an issue for new projects. Shaw said mining companies should consider how established projects can incorporate renewable technologies or how these technologies could be used to aid mine closures.
A mining company, for example, could consider if the design of an open-pit mine will allow for the pit to be progressively backfilled and rehabilitated, or repurposed into a pumped-hydro storage (water battery) facility when the mine eventually closes. These potential options require non-conventional thinking, and early iterative planning.
“Mining companies that don’t do this type of planning are missing opportunities,” Shaw said. “We are still seeing a lot of ‘low-hanging fruit’ across the industry. By implementing best practice mining processes, companies can make projects more efficient and have a more positive effect on the surrounding environment.’
Shaw said some mining companies might not realise the potential benefits of incorporating ESG thinking into pit-shell selection, pit staging, life-of-mine scheduling, progressive mine closure and other aspects of mine design.
Benefits include reducing overburden removal requirements or using overburden for other aspects of mines, such as pit backfilling, tailing storage facilities or infrastructure foundations.
Appropriate application of fundamental mine planning principles can complement ESG aspects. For example, less economic material being sent to waste dumps, less sub-economic material being processed, and less unnecessary rehandling of materials, all result in less energy used.
Ensuring mine design can incorporate renewable technologies is also about risk management. Miners that lag on ESG performance could find it harder to attract investors or face a higher cost of capital.
“No mining company wants to be in a position where it has to quickly incorporate renewables technologies to lower carbon emissions at their project – only to realise that it is too costly to do so, or that the current mine setting does not enable this transition,” he said.
Shaw worked on a study for an IPCC and trolley-assisted truck-haulage system at a large open-pit mine in South East Asia, but there were issues. The trolley system was viable, but the IPCC was unviable due to remaining mine life and tonnage issues.
“We evaluated an IPCC solution for a project when the mine was around 70 per cent of the way through its life,” Shaw said. “Had an IPCC system been evaluated at the start of the project, it might have been justified. The point is: companies need to do this planning early in the design process.”
