Improving safety at MICO
The use of an automated system to actively monitor the location of personnel underground and Emergency Refuge Bay (ERB) capacities has significantly improved safety at Mount Isa Copper Operations.
In the case of an emergency event, ERBs are available for personnel to evacuate to if the atmosphere becomes contaminated and unsafe to breathe. An unwanted event such as a fire, explosion, release of toxic gases, or entrapment – cutting off fresh air supply to a work area – could result in workers having to retreat to an ERB as a safe place of refuge.
ERBs are a portable sealed environment which contain drinking water supply, multiple breathable air supply sources, and communication channels to the surface.
The capacity of an ERB ranges from four people in low populated work areas up to 32 people which are used in higher populated work areas. When in use, personnel can remain in the ERB until they’re rescued or given the all clear.
MICO has a total ERB capacity that is well in excess of the number of employees underground at any one time, however the number of workers in a specific area could exceed the capacity of nearby ERBs. This situation would place workers at an elevated risk of ERB oversubscription.
In 2018, Senior Continuous Improvement Engineer, Zondani Mtawale and Communications Supervisor, Geoff Ramsay developed a system to ensure that the available active ERB capacity was sufficient for the number of personnel working in any part of the mine at any one time. This was the result of findings from a safety audit conducted by external auditors.
Firstly, the mine was divided into 26 zones each with designated ERBs.
Secondly, Wi-Fi tracking tags were installed in each ERB to monitor their position underground and status. These new tags combined with existing Wi-Fi tracking of personnel via cap lamps allowed immediate comparisons between the number employees underground at the time with nearby ERB capacity.
A program called MineDash monitors the movement of personnel and equipment in real-time and allows zone capacities to be automatically updated.
A procedure and Trigger Action Response Plan (TARP) for managing situations where the number of personnel exceeded available active ERB capacity was then implemented along with a guideline for MICO Control Centre operators which trained them in the use of the system.
Zondani says that this innovation has already proven its worth, with the past year’s operations already benefiting from the use of the system.
“We are pleased with the response from the global auditors, with them reporting that they have not seen such a concept and considered it leading global industry practice.”
MICO Control Centre operators monitor the MineDash ERB Dashboard every hour to check for any oversubscriptions. In case of any oversubscription, the operators follow the TARP.
The system testing process of the automated monitoring was rigorous, with research and development commencing over two years before it was introduced to MICO Control Centre in January 2021.
“During the initial testing phase, ERB statuses were manually updated in MineDash. This was not sustainable due to availability of personnel on a 24-hour basis. With the implementation of this program, we have real-time monitoring and no longer have this issue.”
“It’s made our mine safer. We’ve got confidence that sufficient capacity of ERBs is always available to keep all personnel safe in each zone.”
“If an ERB becomes out of order in a zone, and we cannot redeploy personnel or repair the ERB within one hour, we will shut down that part of the mine. Due to the vigilance of the MICO Control Centre operators and the underground supervisors, we have not had to shut down an area as a result of over subscription since implementing this program,” Zondani says.
In response to this initiative, the MICO management team have encouraged Zondani and Geoff to produce a submission to this year’s Queensland Mining Safety Conference.