MINE RESCUE & SAFETY
Futureproofing the workforce
The mine rescue and safety space never stands still , with the onset of automation and electrification underground bringing with them an evolving set of demands and challenges that need to be confronted , Dan Gleeson reports
The Strata Emergency Refuge Chamber Modular is a cost-effective unit that can be modified over time to meet any changing needs of the project , site and size of the workforce , according to the company
The long-term vision for underground mining imagines electric equipment of all types managed autonomously , with robots carrying out maintenance , grade control , scaling , rock bolting and various other tasks remotely or autonomously without the need to bring the workforce below ground .
While this is the end goal , the steps for realising this vision come with much uncertainty . The interaction of staffed and autonomous load and haul equipment , for instance , has still not been seen in the same zone on a commercial basis . At the same time , maintenance staff continue to travel underground to service fullyautonomous LHDs and the like . Geologists navigate ramps or shafts regularly to get to the most active stopes for grade control procedures .
These examples are but a fraction of the processes taking place at mine sites today that indicate how much further the industry has to go to achieve this vision .
Revising refuge expectations
Refuge chambers are a common site at underground mines , offering the safety net that personnel , mine managers and executives require to operate these assets .
Many of the adaptations to these structures that have come about in the past few decades have related to clean air capacity , connectivity , environmental monitoring and mobility . The last facet has been important for mine plans that require significant moves over short time horizons .
The solutions on the market have been decked out to deal with all these requests , with the highest specification chambers now equipped with connectivity and clean air to allow more than 10 people to comfortably reside in these chambers for around 36 hours . Looking at the example set by one of the world ’ s leading miners , it is possible that the accelerated introduction of battery-electric machines will lead to the required oxygen supply levels being standardised at such levels across the board .
During a presentation in Skellefteå , Sweden , in late August for the Future Tech Days event hosted by ABB , Boliden and Epiroc , Jonas Ranggård , Manager of Boliden Mines Electrification Program , shared the company ’ s experiences of working with battery-electric vehicles .
He outlined the safety benefits the company envisaged with the increased uptake of BEVs at its underground mines – saying these machines were less likely to catch fire than the dieselpowered equivalent . He did acknowledge that the only avenue for putting out battery fires that Boliden had proved was full immersion of the battery in water .
Such procedures , plus the fact that battery fires typically burn for longer with less intensity , has been a contributing factor in Boliden ensuring all its new refuge chambers are equipped with 36 hours of oxygen . This is a significant increase on the eight-hour capacity the company previously required .
“ We would have increased the capacity regardless as eight hours was deemed suboptimal , but we feel that this increased level is the most concrete action to cope with battery fires ( as they burn less intensely but for longer ),” Ranggård told IM .
Strata Worldwide is looking to increase the flexibility associated with emergency refug e chambers with its latest solution for mining companies and tunnelling contractors .
The Strata Emergency Refuge Chamber Modular ( ERCM ) is designed with a series of attachable sections that can be assembled preor-post-delivery , which can help overcome possible handling and shaft size restrictions .
The ERCM modular design provides expanding options that allow operators to order chambers to their existing requirements and add more capacity later . The result is a cost-effective unit that can be modified over time to meet any changing needs of the project , site and size of the workforce , according to Strata .
Dave Maust , General Manager of Refuge Chambers at Strata Worldwide , said : “ A significant benefit of this new , lightweight modular design and subsequent manufacturing economies is that the chamber provides greater flexibility and price competitiveness for the customer . Although some premium accessories available on Strata ’ s traditional ERCX chamber may not be available on the ERCM , the uniform , modular design enables Strata to inventory the modules , which allows for a quicker production turnaround and shorter lead times for the assembled chamber .”
Each segment is bolted together at the Strata facility , or on location to create a secure , air-tight seal that matches the high functionality and quality standards of Strata ’ s traditional singleunit refuge chambers , the company explains . Flexible in size , the ERCM can range from 12- person occupancy up to 36 people by increasing the number of seating segments used .
“ Every Strata refuge chamber is designed with built-in flexibility to meet local and industryspecific requirements ,” the company added .
Strata designers have years of experience working closely with customers to understand
44 International Mining | OCTOBER 2024