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Fire safety in mining

Over the past few years, Johannesburg has been an excellent, yet terrible example of what happens when fire safety regulations are ignored due to incompetence and/or corruption. Fires have always been a threat, but taking absolutely no responsibility for fire-proofing buildings will eventually result in the fires that make the news – at the very least.

In the mining industry, it goes without saying that fire safety is critical, and mine executives are not able to shrug their shoulders and move on. When one looks closely at mines, fire risks start with people wearing battery-operated lamps and expands to include fuel and explosive stores and transportation, gas risks (either flammable or poisonous) and mobile machinery.Vehicles, and other equipment can also create fire risks when used so extensively in harsh environments. Processing plants with more heavy machinery using chemicals of varying degrees of flammability – not to mention the storage of these chemicals, are another potential fire risk. One can continue almost endlessly to add conveyor belts, energy generation and storage equipment, and other operational systems that seem to be fires waiting to happen.

To complicate matters further, different fires may require different extinguishing mechanisms. For example, water will not be a good option if your lithium battery racks catch fire. Government fire services are unreliable, so mines need their own teams with the right equipment, training and knowledge to deal with fires. Although automated detection and suppression systems are always preferable, they are not always possible in a mining environment. Adding the regulatory environment to the list simply makes things even more complex.

SMART Security Solutions asked FS Systems for some insight into the fire safety risks and solutions that pertain to mining. As a kick-off point, we ask Clinton Hodgson, Head of the Industrial Fire & Life Safety Division at FS Systems International, to highlight some of the primary challenges prevalent in this field. He lists the following as a starting point:

• Infrastructure limitations: Many mining operations in Africa are in remote areas with limited access to infrastructure such as roads, water, and electricity. This can hinder the availability and effectiveness of fire suppression systems and emergency response mechanisms.

• Resource and supply chain constraints: Limited access to suitable resources may restrict the implementation of comprehensive fire safety measures, including the purchase and maintenance of firefighting equipment, training programmes for personnel, and the development of evacuation plans.

• Regulatory compliance: Compliance with fire safety regulations and standards may be inconsistent or lacking enforcement in some African countries. This can result in a lax approach to fire prevention and safety practices within mining operations.

• Environmental conditions: Harsh environmental conditions, such as extreme temperatures, drought, and dust, can increase the risk of fire outbreaks in mining areas. Dust particles generated during mining activities can also pose a significant fire hazard if not properly managed.

• Training and awareness: The lack of adequate training and awareness among mine workers regarding fire prevention, evacuation procedures, and the proper use of firefighting equipment can exacerbate the risks associated with fires in mining operations.

• Security concerns: In certain regions of Africa, security concerns related to theft, vandalism, and civil unrest can compromise fire safety measures and emergency response capabilities within mining operations.

• Ageing infrastructure: In some cases, mining infrastructure in Africa may be outdated or poorly maintained, increasing the likelihood of equipment malfunction and fire incidents.

Underground fire risks

Going underground, the confined spaces people operate in can be a literal tinderbox; limited escape routes and fresh air circulation are the norm, as well as the dangers of smoke and toxic gases produced by or producing fires. The limited space also complicates firefighting efforts and rescue operations. If you are caught on the wrong side of the airflow in a tunnel, things can quickly get out of hand no matter how fast you can run.

While there are a number of solutions for these underground risks, Hodgson notes that the best form of fire protection is to make sure that processes and procedures are in place to limit the chances of a fire even starting. There are a few steps mines can take in this pursuit:

• Effective housekeeping: Storing flammable materials separately from sources of ignition.

• Electrical engineering: Underground electrical reticulation and energised systems should be ‘over-engineered’ in such a manner that equipment and cabling have safety tolerance levels exceeding similar systems used in above-ground scenarios.

• Enhanced maintenance: Keeping mechanical and hydraulic systems and vehicles in top condition.

• Toxic and flammable gas detection: Appropriate detection instruments suitably integrated into evacuation and air handling systems should be deployed at strategic locations. Mobile detection instruments should be used to carry out checks at various points.

• Enhanced training: Ensuring that first responders are adequately trained and equipped to deal with emergency situations.

Should a fire start, effective, fast response fire detection systems with reporting to a centralised control room will ensure that first responders are notified to attend to the problem without delay.

Prevention and automation

The nature of mining operations means that there are flammable materials located and it is important for supervisors and managers to ensure the environment remains in a ‘fire-safe’ condition. Of course, this will not remove all danger, and systems, therefore need to be put in place to monitor for smoke and fire, and, where possible, raise the alarm and release suppression agents when detected. Naturally, they also need to raise the alarm immediately, allowing a central control station to dispatch the right personnel to manage the situation and make sure no people are in harm’s way.

“Where a high risk of fire is present, suitable fire detection and automatic fire suppression systems should be fitted where feasible and appropriate, which could include optical flame detection and linear heat detection systems combined with a water, foam or chemical agent suppression systems,” notes Hodgson. “All signals and events should be monitored remotely by the emergency response team so that first responders can be dispatched as soon as possible.”

A pragmatic approach to fire prevention is required in workshops where hot works are done and where flame-retardant clothing and other materials are used in the workshop. Combustible materials should be stored outside of the hot works zone. Suitable protective guards should be fitted to machines to limit the spread of hot sparks and slag, and properly serviced portable firefighting appliances should be located nearby. Detailed risk assessments should be carried out when hot works are required in the field. In areas of high risk, cold cutting and joining solutions can be considered.

For conveyor belts, he says a combination of linear heat fire detection and distributed acoustic sensing systems should be fitted. “These systems detect more than just fire – they can provide warnings to the system operator in the event of vibration changes caused by failing idler bearings and drive motors. The failing components cause heat and are often the main causes of ignition in conveyor belt fires.”

When it comes to the risks stemming from gas, Hodgson says there are several noxious and flammable gas detection systems on the market available from various OEMs. The detection instruments can be integrated into fire detection systems, SCADA systems, or they can be utilised as stand-alone warning devices.

Services and solutions from FS Systems

Asked about the fire safety solutions FS Systems provides to mines in Africa, Hodgson explains, “The FS Group designs and installs mining-specific fire protection systems that provide early warning and minimise the damage caused by fires, keeping people and assets safe and reducing downtime. We custom design fire protection and life safety solutions that work in extremely harsh environments and provide the earliest warning possible of fire.

“Our enterprise access control, video surveillance and workforce automation solutions are tailored to a mining-specific environment and are integrated to secure all mining operations, ensuring a comprehensive safety and security approach.”

He provides examples of projects completed by FS Systems:

• Fire detection and gas suppression for critical electrical infrastructure at a West African gold mine: The mine required an early warning fire detection system connected to an automatic clean agent fire suppression system. Operating the system had to be simple and easy enough for an untrained person to understand, whilst still providing high-quality protection. The equipment needed to be robust enough to deal with the harsh weather conditions in West Africa and be easy to maintain. The extinguishing gas could not cause damage to the equipment in the protected space or be hazardous to people who may be in the area should the system discharge.

The solution was developed in four weeks and deployed in eight weeks. An ASD early warning smoke detection system combined with a conventional gas control panel to which optical smoke detectors are connected in double knock configuration, was identified as a suitable detection solution for each protected area. A pre-engineered FM200 gas suppression system with electrical actuation was identified as a suitable fire extinguishing system. A bespoke integration pack was developed and deployed for the customer to interface all systems into their on-site PLC system. Furthermore, a linear heat detection cable was fitted to all cable ladders underneath the structures to provide warning of possible fires in cable tunnels that may approach the protected spaces.

Find out more at www.securitysa.com/*fs1 (links to https://www.fsi-systems.com/post/fire-detection-and-gas-suppression-for-critical-electrical-infrastructure-at-a-west-africa-gold-mine).

• Water deluge system for underground magazines: Keeping explosives underground in close proximity to operations poses a serious risk to the safety of miners. The FS Group has developed and installed a fully functional, quick-response, electronically actuated water deluge system for an underground explosives magazine. The system is designed so that all sprinklers in the area will discharge water in the event of a confirmed fire event, resulting in complete saturation of the entire area.

By installing Industry leading flame and heat detection equipment configured in double knock operation, the system will provide the highest fire detection sensitivity capabilities providing maximum immunity against false alarms.

Furthermore, the deluge system is connected via fibre optic components into the site wide fire detection network, allowing full offsite monitoring at the mine’s security and safety control room. Further integration into the mine’s data collection systems is possible through software-level integration using the fire control systems’ onboard MODBUS over IP capabilities.

Find out more at www.securitysa.com/*fs2 (links to https://www.fsi-systems.com/post/water-deluge-fire-suppression-system-for-an-underground-explosives-magazine).

• Integrated fire protection for Modular E-Houses: FS Systems installed numerous Modular E-Houses to a mining client in Ghana. It installed the latest fire detection and gas suppression technologies in these electrical rooms (E-Houses) with custom integrations into the mining fire control network. Modular E-Houses are prefabricated transportable substations, designed to house critical power equipment. Naturally, fire can cause extensive damage to the critical electrical components within an E-House, so early warning smoke detection and immediate shut down of interconnected systems is needed to protect against the risk of irreversible damage and downtime.

Find out more at www.securitysa.com/*fs3 (links to https://www.fsi-systems.com/post/integrated-fire-protection-for-modular-e-houses).

For more information, contact FS-Systems, [email protected], www.fs-systems.co.za

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