Underground mine design is something that has slowly morphed over the past 30 years. As more mechanised mining techniques have become the industry norm, the scale at which we mine underground has increased. This has been driven by key several factors, including new equipment capability, safety requirements, and increasing labour/supply costs requiring better production rates.
Twin boom jumbo development drills and larger capacity loaders, coupled with a fleet of increased capacity trucks has allowed expectations of what a mine can produce to increase. This coupled with a focus on safety legislation in systems such as ventilation and secondary means of egress (escapeway networks), has also sculpted a new design manual for the mechanised age.
We still see artisanal mining taking place across the world, and in some instances within sections of predominately mechanised mines. However, this is generally a subsidiary production front to add to the bottom line, with a generally low dilution and cost base. The use of hand drilling techniques such as airlegging, which was once commonplace in the 1980s, has now become a rare feature at many modern mines. However, this can be seen across the Australian landscape, at specific mines, such as Red5’s Darlot Operations in Western Australia.
This dying art form, despite many people’s protests, must be one of the most uncontrolled working environments of the modern industrial era. With many businesses turning their back on a process that was once the industry norm.
If we consider the design changes seen since the 1980s due to this ongoing mechanisation there are multiple areas that have seen radical change:
- Mining drive profile size – as the ability to remove more blasted ore has increased so have drive sizes, with many modern mines now utilising 5.0mW x 5.0mH profiles as a minimum.
- Geotechnical improvements – the expectation that supported ground be at the least bolted and meshed, has altered mining cycle times, whilst improving safety outcomes.
- Electrical infrastructure – the delivery of power to multiple mining areas for the drilling fleet has meant a sharp upturn in electrical infrastructure and its importance for effective mining.
- Ventilation systems – as diesel fleets and underground blasts have become larger, the requirement to remove these potentially harmful fumes from the working environment has also increased. This has resulted in many underground mining projects employing ventilation officers, whose primary task is related to continual ventilation delivery.
This change has been incrementally slow and the shifting standards that underpin this design revolution did not occur overnight. With the ongoing talk of a “digital mining” environment, we should start to see designs change within both brown and greenfield projects, as they look to unlock the potential of advancing systems.
So with this in mind, what could we expect to see the change in underground mine design in the next 20 years as the new digital wave starts to deliver more automation to underground mines:
- Design for automation – mining levels are often built for the multiple tasks and interactions that need to occur for mass excavation of ore. However, increasing automation of tasks that once required many human inputswill allow for radical redesigns. The industry is already seeing automated load and haul, with truck loading bays being utilised to keep human-driven trucks separated from tele-remote loaders.
- Charging Bays for batteries – with the adoption of battery electric likely to gather strong pace in the next decade, there will be a requirement for safe charging and battery swap areas within mining projects.
- Ventilation re-think – less fumes from diesel fleets and fewer people in the underground environment means that ventilation requirements can be revisited.
- Lighting and Collision Avoidance requirement – as machines transition quieter electric motors, interactions will need to be managed with improved lighting and/or collision avoidance systems.
With the increasing digital transition seen within the underground environment, it is time for a holistic overhaul of many parts of the traditional cycle. Increasing automation of all tasks, from cable bolt installation to geological data entry, will mean that technical mining staff will have additional time to complete alternative duties, such as analysis of data.
Mine design will be just one facet of the wider mining sphere that will need to adapt as we ride the digital wave to Mining 4.0. Concepts, trials and pilot tests could be communicated through the industry from forward-facing consortia like NEXGEN SIMS, educating and empowering the future of the industry.
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