Sep 27, 2018 - Fire detection and prevention in underground coal mines ... Abstract. Underground fires are known for their catastrophic impact when they occur. ...... It ionises these gases through its circuit and create a current which can .... P. S. Kurt Konolige, âA Low-Cost Laser Distance Sensor,â ROBOTICS, USA, 2008.
University of Johannesburg Department of Mining Engineering
Module name
MINING TECHNICAL SERVICES IVB
Module code
MTLB411 Fire detection and prevention in underground coal mines
Student name
MABASO ST
Student number
201412088
Due date
27 SEPTEMBER 2018
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Abstract Underground fires are known for their catastrophic impact when they occur. Dating back from the very first underground fire to be recorded there had been an edge to be able to detect underground fire which were taking place and preventative means to be put in place to suppress such fire. With progressive research that taking place old instrument were further improved giving rise to the new innovated system used to detect fire. These instruments are being developed and continuously improved. In this report I will be discussing fire detection system that are widely used in South African coal mines but I will not be limited to South African coal industry I will also look at the international standards.
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Table of Contents 1.
Introduction .......................................................................................................................................... 7
2.
Research methodology ......................................................................................................................... 7
3.
Objectives.............................................................................................................................................. 7
4.
Scope of study ....................................................................................................................................... 7
5.
History of underground fire .................................................................................................................. 8
6.
Formation of underground fire ............................................................................................................. 8 6.1.
7.
Three factors of fire ...................................................................................................................... 9
6.1.1.
Fuel ........................................................................................................................................ 9
6.1.2.
Oxygen ................................................................................................................................ 10
6.1.3.
Heat source ......................................................................................................................... 10
Four stages of fire ............................................................................................................................... 10 7.1.
Stage one: incipient .................................................................................................................... 10
7.2.
Stage two: growth ....................................................................................................................... 10
7.3.
Stage three: fully developed ....................................................................................................... 10
7.4.
Stage four: decay ........................................................................................................................ 10
8.
Risk assessment .................................................................................................................................. 11
9.
Causes of underground fire ................................................................................................................ 12 9.1.
Methane...................................................................................................................................... 12
9.2.
Explosives .................................................................................................................................... 12
9.3.
Spontaneous combustion ........................................................................................................... 13
9.4.
Oxy-acetylene cutting/welding ................................................................................................... 14
9.5.
Mobile equipment ...................................................................................................................... 14
9.6.
Electrical equipment ................................................................................................................... 15
10.
Monitoring system .......................................................................................................................... 15
10.1. 11.
Gas detecting instruments ...................................................................................................... 15
Fire detecting .................................................................................................................................. 15
11.1.
Fire alarm system .................................................................................................................... 15
11.2.
Smoke detector ....................................................................................................................... 15
11.3.
Sperosens ................................................................................................................................ 15
12.
Fire preventing ................................................................................................................................ 15
12.1.
Methane .................................................................................................................................. 15 3
12.2.
Electrical equipment ............................................................................................................... 16
12.3.
Oxy-acetylene ......................................................................................................................... 17
12.4.
Mobile equipment .................................................................................................................. 17
13.
Latest technology to detect fire ...................................................................................................... 18
13.1.
Fire optic linear heat detection system .................................................................................. 18
13.2.
Very early detection apparatus............................................................................................... 18
13.3.
Flame ionisation and temperature detectors ......................................................................... 18
13.4.
Thermal imaging camera ........................................................................................................ 19
13.5.
Laser sensor ............................................................................................................................ 19
14.
Emergency preparedness ............................................................................................................... 20
14.1.
Evacuation ............................................................................................................................... 20
14.2.
Extinguishing fire ..................................................................................................................... 20
15.
Legal framework ............................................................................................................................. 21
15.1.
South African legislation ......................................................................................................... 21
15.2.
International legislation .......................................................................................................... 22
16.
Conclusion ....................................................................................................................................... 22
17.
Recommendations .......................................................................................................................... 22
18.
Bibliography .................................................................................................................................... 23
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Table of figures Figure 1: formation of fire ........................................................................................................................... 8 Figure 2: The stages of fire . ........................................................................................................................ 11 Figure 3: Coal sample taken from underground coal mine showing evidence of spontaneous combustion .................................................................................................................................................................... 13 Figure 4: Flame proof electrical equipment................................................................................................ 16 Figure 5: flame proof LHD ........................................................................................................................... 18 Figure 6: thermal imaging showing temperature in underground ............................................................. 19 Figure 7: fire extinguishers.......................................................................................................................... 21 Figure 8: protective gears worn by proto team during rescue mission ...................................................... 21
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Table of tables Table 1: classification of fuels ...................................................................................................................... 9
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1. Introduction Underground coal fire are one of the most destructive hazard in such a manner that when they take place they result in unbearable aftermath effect. When they have occurred they can result into great magnitude loss of life and major injuries to the survivors, the greater loss of valuable property, equipment that is damaged and could not be repaired, loss of infrastructure and the increased cost and loss of revenue. Underground coal mine have a lot of fuel sources such as the lubricants used on the machines, spray paints used to mark the face, flammable gas inherited from the coal seam and the packaging materials. The source of spark can be from the faulty trailing cables, faulty flameproof equipment, and friction lighter that is not permitted to be used underground, negligence during the use of cutting torch and welding equipment. Oxygen is introduced as ventilating air underground [1]. In this report I will discuss in details the causes of underground fires, preventative measures that are put in place and the detection system that are used.
2. Research methodology To compile this report I gather the information from all the published academic journals, research bodies which includes SAIMM, ECSA, SACMA, Department of Mineral and Resources website, Chamber of Mines website and other sources which includes internet and magazines. The information gather was carefully read, reviewed, analysed and recorded to factor out the required information.
3. Objectives
The objective of this study is to know the history of underground fire. To get a better enlighten of the causes of underground fire. To know and understand the function of fire detection system and how are they used. To find the way to prevent underground fire. To have enlighten of the emergency preparedness in case of fire.
4. Scope of study This report will focus on causes of underground fires, the impact they bring about. It will further discuss the instruments used to detect fire and the latest technology that is being employed by mines now in South Africa.
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5. History of underground fire There had been a lot of fatality cases in South African mining industry which the cause was underground fires. I will highlight few cases that resulted in loss of life in the past.
13 May 1993 at Middlebult Colliery situated near Secunda, Mpumalanga, 53 people lost their lives due the coal dust explosion caused by the methane gas coming in contact with a heat source which in turn caused a major fire that triggered coal dust explosion [2]. 16 September 1986 at Kinross mine in Evander, Mpumalanga, 177 people lost their lives. The cause of death was fire which was caused by an acetylene tank that sparked flames which and ended up finding way into underground tunnel which burnt the cables releasing a deadly fumes that cokes miners in the sections and leading to their death [2]. 12 September 1944 at Hlobane coal mine near Vryheid, 57 people lost their lives due to coal dust explosion triggered by underground fire. The fire was caused by high quantity of methane which came into contact with heat source and resulted into a fire [2].
6. Formation of underground fire
Figure 1: formation of fire [3]
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6.1.
Three factors of fire
For fire to occur there should be at least 3 factors are to be balanced in the correct quantity and be of correct quality or requirements, these factors are as follow…
6.1.1. Fuel For fire to occur and burn the must be fuel that is present. Fuel can be any combustible material which can be in gaseous form, solid form or liquid form. For solid and liquid form type they must be vaporized in order to burn. In an underground environment fuel is found in abundant amount [4]. The fuel can be classified according to their types, this will help us with the understanding of the risk associated with that particular fuel during fire. Having an in-depth understanding will enable us to predict the nature of the environment if that particular fuel had been the source of fire. Knowing the toxicity, flammability, combustibility, and explosiveness of the fire can be applied to be properly prepaid with tools to extinguish the fire and the necessary apparatus should we want to task the rescue team during the fire [5]. The following table shows the classification of the fuel source Classification of the fuel Grouped according to flammability or combustibility A
Ordinary combustibles ( they include but not limited to wood, rubber and ventilating ducts)
B
Flammable liquids ( these includes diesel, hydraulic fluid and lubrication oil)
C
Flammable gases ( these are the main contributors they include methane, acetylene and spray paints)
D
Combustible metals
E
Equipment that are used in an underground environment ( includes energized switch gears, and the cables)
Table 1: classification of fuels [5]
The properties of each of the material displayed in the table above are shown the spreadsheet known as material safety data sheet, which every manufacturer and supplier must disclose the mine which they supply since the knowledge of every material going underground must be known. Technical information must be provided as well for reason such as planning and safety purposes.
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6.1.2. Oxygen For the fire to occur the oxygen level must at least be at 16 percent in the surrounding environment where there is fuel potential to cause fire. In an underground environment oxygen level is not the problem since it get introduced as ventilating air [4].
6.1.3. Heat source The must be enough heat source that is applied to actually raise the fuel temperature to its igniting temperature so to start combustion and potentially continue the combustion process. In an underground environment the heat source could be poor blasting that results in flames, faulty flameproof equipment, faulty trailing cables, hot surface of equipment and intention spark caused by prohibited articles such as lighter or match sticks [4].
7. Four stages of fire Any fire undergoes four stages which has different characteristics from the previous stage.
7.1.
Stage one: incipient
Incipient is the first stage when the fire occurs. It is a result of chemical reaction when oxygen, fuel source and heat source combine and result in a fire. The layer of hot gases increase in volume and start to be clearly defined. This stage is also known as ignition and usually it is a small fire that goes out on its own, and this is the most crucial stage because that is when you can actually detect the fire and put in fire suppression system to extinguish the fire from progressing [6].
7.2.
Stage two: growth
In this stage the fire structure load and start to be well defined, oxygen is used as a fuel for the fire. The fire is usually limited to the source of ignition. The temperature of the flame may be as high as 540 degrees Celsius, where the upper region as go as far as 700 degrees Celsius. The growth of the fire can be influence by the availability of sufficient oxygen and fuel source [7].
7.3.
Stage three: fully developed
Fully developed stage is when the growth stage has reach its maximum, and when all the combustible material have reached their ignition temperature. The only limitation in this stage is the availability of oxygen to fuel up the fire. This stage is regarded as the hottest stage of the fire [7].
7.4.
Stage four: decay
The decay stage is known to be the longest phase of the fire, should the fire continue the smoke and gases could potentially reach the temperature of over 1000 degrees Celsius. It is associated with the decrease in oxygen and the decrease of combustible material mostly being the fuel source which significantly put an end to a fire [7].
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Figure 2: The stages of fire [6].
8. Risk assessment Conducting a fire risk assessment, we will gather information, analyse, interpret and finally come up with the tool that will equip us to identify and assess all the contributors to have a potential risk of fire. The tool will help to inform us about the areas where it is likely for the fire to occur and which proactive steps we should put in place to curb the occurrence of the risk or propagation of the risk [3]. In the assessment of risk, the priority is to identify the presence and amount of fuel source, the potential ignition source and its likelihood to start the fire and other significant contributors which can be type and magnitude to impact the risk [3]. The risk will be assessed on basis of the probability of the risk to occur and the resulting outcomes should the risk occur. One of the most important things to be considered is the risk drivers to the fire event, which should be assessed in greater details [3]. In most of the risk assessment that failed previously, there was an important aspect which is the human resource that was not considered, making sure that everyone working underground do understand the procedures that are applicable to ensure the successful prevention of the fire risk. Employees should be empowered with knowledge through training to know what to do and where to go in an event of fire. Employees should know all the contributors that are capable of causing fire and if that is achieve then most of the human error would be minimized and consequently having a reliable risk assessment tool. In the risk assessment evaluation of the emergency preparedness such as the instruments that can detect, give warning, and extinguish fire in the area where there could be a potential of risk of fire are available. Risk assessment to be effective it must be review periodically. This should be done on basis where there is something new introduced or it changes the nature of operation. The change could be the environment, the mining layout, change of procedure such as underground welding, a change to ventilation system of mine or of the panel, the change of equipment used that can affect or influence the risk of having fire underground [3].
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9. Causes of underground fire 9.1.
Methane
Methane is a gas that is liberated as a result of mining through virgin ground. It is liberated in three ways, namely Gradual exudation which is the slow seeping of escaping gas and is easily diffused by good ventilation. Blowers which are jets of gas released generally through slips and faults, the gas is blown out under pressure and is only diffused by large quantities of air. Outburst which occur when large quantities of gas under pressure are released from the coal by bursting forth [8]. For methane to cause a fire it must be exposed to an ignition source which includes but not limited to
Use of smoking articles Spark from cutting picks Electrical equipment Lightning strikes Static electricity Blown out shorts
Methane combustibility ranges that must be avoided at all time, if not they may result in fire
Up to 5 % methane burns but does not support combustion From 5% to 15% it explodes At 10% the mixture reaches its greatest potential explosive intensity
It is very important that we know other areas other than the coal face where methane could be expected, so that we put preventative measures.
An area after blasting After there was a massive fall of ground Whenever we encounter underground water When we are approaching dyke, fault and slips When the coal face has been put to idle in more than 6 hours When there are problem with ventilation, if it stop or reverse
9.2.
Explosives
Blown out shots are the major cause coal underground fire, they occur when the shot hole is over charged with explosives or when is not properly tamped. Blown out shots cause an immediate fire in the face then ignite methane in the environment resulting in a major fire. Fire can erupt whenever the explosives are mismanaged, for instance when they are not carried in their designated carrying box such that cartridges and detonators are put in the same box that might cause an accident which would result in a fire. During charging when the charging instruments do not meet the required standards (steel charging stick), this might cause an early detonation of explosives resulting in a fire.
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9.3.
Spontaneous combustion
In the recent study it shows that about 75% of fires in coal mines are as a result of spontaneous combustion. When coal interact with oxygen from the ambient air and liberate heat, and such heat is not disperse rather it is allowed to accumulate in the rate that it causes self-heating of the coal consequently may lead to fire. Every cause of spontaneous combustion however small, if it’s not dealt in accordance it might end up causing even huge disasters such as methane explosion which will result in a fire and continue to become coal dust explosion. There are some the common working practises that actually facilitate the formation of spontaneous combustion, such as working near the abandoned opencast mine, working along the outcrop of the coal seam and the very usually one where coal is left behind (in the goaf area) during pillar extraction (stooping) [9]. The following factors form substantive argument for spontaneous combustion [9].
Proximity of intake and return airway Coal seam that is thick Long exposer of coal into the open atmosphere Coal that is left in the goaf If there was a fire before
Figure 3: Coal sample taken from underground coal mine showing evidence of spontaneous combustion [10]
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9.4.
Oxy-acetylene cutting/welding
Coal mining has long moved from convectional mining to mechanise mining. Mechanised mining is characterised by the use of mining machinery. Mining machinery tend to be on break down from time to time, which requires maintenance. Maintenance might be schedules or just random depending on the urgent requirement of the machine. In maintenance the boiler makers make use of Oxy-acetylene gas for cutting steel on the machine and for welding. The correct proportion of oxygen and oxy-acetylene gas produce hottest flame [11]. Oxy-acetylene gas is rated as one of the most unstable gas making it one of the dangerous fuel that are taken underground. Oxy-acetylene at this purest form when it reaches the pressure that exceeds 15 psi it decomposes and should it exceed the pressure of 30psi it will explode without with any source of spark [11]. When using the oxy-acetylene there are standard that are often overlooked or neglected then result in outbreak of fire. [11].
Inappropriate way to test for flammable gases in and around the area where cutting or welding is to take place. The tendency of not conducting a continuous test for flammable gas during cutting and welding. Lack of ventilation Not following the predetermined procedure during the process of cutting or welding. Having employees who are not well trained to do the actual pf cutting and welding and have no supervisors to oversee the entire process. Poor preparation of tools that are to be used in the welding and cutting.
9.5.
Mobile equipment
Mobile equipment are mostly used in coal mines since it is a mechanised mining. The use of mining equipment that are powered by diesel engine is something that is done on daily bases. The danger that comes with diesel powered engine is that should it be faulty it stands a risk of causing a fire. The diesel powered engine equipment that are used includes but not limited to LHD, Scoop, Tractor, water tank truck and scraper. The major issue with underground diesel powered equipment is flame proof. Should the flame proof be faulty, the equipment is prone to cause fire. There are other issues that can also cause fire, they include but not limited to [3].
Backfiring on the exhaust system Using incorrect standard when refuelling, resulting in fuel spillage into the machine which can cause fire later. Oil leak that pose a chance of catching fire Oil pipes that are close to hot surfaces Electrical components that are positions near the hot surfaces
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Excessive lubrication onto the moving part that have a potential of heating up and case a fire.
9.6.
Electrical equipment
Electrical equipment are treated with precaution than any other equipment underground since they are regarded as one of the most catastrophic equipment if mismanaged. The underground substation are more prone to cause underground fire when are overloaded. Substation is the source of electricity to every underground equipment that is power by electricity which include continuous miner, roof bolter, shuttle car, ventilation fans and general lighting.
10.
Monitoring system
10.1. Gas detecting instruments Miners are exposed in the most unfriendly environment, to curb unforeseen risk of fire and explosion it is utmost important for mine worker to continuously monitor the environment in which they are working for toxic gases and flammable gas.
11.
Fire detecting
11.1. Fire alarm system Fire alarm is an instrument that is designed to detect fire should it occur. It is mostly installed at the feeder breaker and all the transfer point, when it detect fire it automatically cut power to the conveyor belt. Then the miner will be alerted about the problem giving the team enough time to extinguish the fire or to evacuate the area into designated safe place
11.2. Smoke detector Is an automatic device designed to detect the presence of fire and gives warning as an audible sound or visual light. They are position in a scattered area where there is likelihood of fire. This help the team to be prepared to deal with the risk of fire.
11.3. Sperosens The sperosens is installed in the cutter drum of the continuous miner (CM). It is calibrated early beginning of the shift to trip the cutter drum of CM whenever it detect the presence of methane while cutting. They can calibrate the sperosens to trip at desired percentage but that is determined by the management responsible for engineering of machinery. It is mostly set to trip the CM when it detect methane that reaches 1% in concentration. It is an effective tool because it works on preventing the accident from occurring.
12.
Fire preventing
12.1. Methane Methane is one of the gases that can cause a deadly result. When methane is ignited it can further ignite dust resulting in coal dust explosion. There are laws that are put in place to deal with occurrence of
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methane. Should an operator detect methane in the face while operating the machine, he must seize the task, pull the machine out of the face and cut the power to the machine and report to the miner. The miner shall then install scope brattices or install a ducting into the face and ventilate out all the gas detected on the face. Before the work can continue the miner must get an approval from the shift boss to cut the face. Under no circumstance should it be allowed that the gas reach the concentration of 1%. The ventilation on the last through road must be at least 1m/s in a continuous miner section and it must be 1.2m/s in a blasting section.
12.2. Electrical equipment Electrical equipment pose a significant risk of fire should they be defective and not only that they the cables when they are burning can release one of the most poisonous gases which are far too dangerous. In a good working practice cable are to be taken care of at all times not just to cut cost but to prevent the risk that comes with them. Cable are to be inspected at least 3 times during the shift. Cables are to be suspended into the roof using hook provided by the employer, the shortcuts and using incorrect tools such as using a wire to suspend cable are to be stopped. To ensure that the electrical equipment are safely used, they will be fitted with pilot circuit which its main function is that when the control switch on the electric equipment is not activated there will be no current through the cable. It also provides pilot protection, should the plug be pulled out under load, the contact in the electric equipment panel is broken causing the switch to trip out. This feature will help the electric equipment from failing and causing fires [8]. All the electrical equipment must be flameproof. When the equipment start to arch flames inside or should an explosion occur inside the flame proofed equipment the fire should not spread outside causing a disaster but it should be contained inside [8].
Figure 4: Flame proof electrical equipment
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12.3. Oxy-acetylene Oxy-acetylene gas is a dangerous substance to work with therefore it is important to follow the procedure laid down to prevent the occurrence of fire. In the procedure it clearly states that it is important to do a full risk assessment of the environment where you are about to use the oxy-acetylene gas. The material to be worked on should be well prepared such that the surfaces are not having oil or any combustible material. Negligence can be cause of fire hence it need to be handled and operated by a trained person who was found competent with this regards. When cutting or welding using oxy-acetylene fire extinguisher are a primary need. Cutting wood and plastics should be avoided at all times. The following precautions needs to be followed at all times when using oxy-acetylene. At all times must ensure good housekeeping in the working space, ensure that substances like spray paints are not in the vicinity of working space. At all times the competent person must ensure that their clothing does not contain any fuel such as diesel, grease and oil. When cutting or welding any electrical equipment must ensure that the power to the equipment is isolated. Any material that is going to welded or cut must ensure that they are free from any fuel that might cause fire [11].
12.4. Mobile equipment Mobile equipment are supposed to be flameproof especially those that will be working in a hazardous area. They must ensure that all the components that might pose a risk of fire are maintained all the time. For instance it must be ensured that all the pipes are not leaking oil and lubrication is well place. The engine will maintained and does not cause back firing in its exhaust system. Extra care is put in at the filling station that diesel is not being over filled, such that the fuel chamber experience the problem of high pressure and result in explosion consequently fuel is not being poured onto the machine which might later catch fire. Every mobile machinery must be fitted with a fire extinguisher that would always be in the machine. It must be accessible and readily available at all time, it must be maintained at all time. When it no longer meet the standards it better for the equipment not to be used.
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Figure 5: flame proof LHD
13.
Latest technology to detect fire
13.1. Fire optic linear heat detection system Fibre optic linear heat detection system is made to be a robust system that can be operated in very harsh environment without giving false alarm and false results, it is mostly installed in linear operating system like the conveyor belt and in the tunnels. This system is able to pick up even slight change in temperature and can still survive a temperature above 1000 degrees Celsius [12].
13.2. Very early detection apparatus Very early detection apparatus is a warning system that is responsible for giving warning when there is a fire. Its operation system is sophisticated in a manner that it sucks the air using a laser chamber in the system from the operating environment. It is calibrated to compare the quality of air in the environment, should it detect a percentage of smoke that is predetermined it’s going to give a visual and audible warning. It has an ability of operating in the harsh environment. It is mostly used in Australian mines and has recently been introduced in the South African mines [13].
13.3. Flame ionisation and temperature detectors Since hydrocarbons are the other significant contributor to fires, Flame ionisation is a special type of technology developed it has the ability to detect the presence of hydrocarbons gases in the environment. It ionises these gases through its circuit and create a current which can actually determine the amount of hydrocarbons in the environment [13]. Temperature detector it is used to detect the increase in temperature of the flammable gas available in the environment. If there is any increase detected then the warning is given off.
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13.4. Thermal imaging camera Thermal imaging is widely used in coal mines that are mostly prone to spontaneous combustion. The system has few components but the most important is the infrared camera and the software that is operated from the control room. The camera works all day all taking photos in areas which are mostly suspected to have likely hood of fire, it continuously check any increase in temperature. If the temperature has reach the level which is deemed as an indicator, measures are taken to extinguish that fire [14]
Figure 6: thermal imaging showing temperature in underground [14]
13.5. Laser sensor Laser sensor it is used underground mines for detecting fire. It working principle is that of latest technology where it uses laser sensor to detect the early smoke particles in the environment during the event of the fire, it will give out the signal to as alarm and also send the data to the control room. Laser sensor has the same working principle as the photoelectric detector, the difference is that the laser sensor is more sensitive than the photoelectric detector. This comes after the analysis of the two equipment was done and the result shows that, the laser sensor uses a laser were the photoelectric detector uses a LED [15]. Laser sensor have the following benefit when compared to the photoelectric detector.
It is more favourable because of its low cost It has high accuracy It is more sensitivity It has a reliable stability and versatility
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14.
Emergency preparedness
When fire detecting devices gave a clear visual warning or audible warning that there is a fire, the safety procedure is to evacuate the area in case of huge fire or to extinguish the fire if it is not too much.
14.1. Evacuation When evacuating during the emergency the most common issue is toxic fumes, smokes and dust that is decreases the visual of the employees from escaping. It is important that the employees know the escape route from the section to the refuge bay. The escape route should be free from mud, stagnant water and objects that might obscure the route or cause problem for the workers during emergency. Lifeline must be installed in all the escape route and it must be made sure that it arrives at the refuge bay. The refuge bays must be placed at predetermined interval distance from each other and at a reason distance from the section, and it must always be kept at good working conditions that support life. Miners are supposed to practise emergency escape drill every month so that they are always familiar with the procedure. The new person to the section supposed to be shown the emergency escape on the first day. The rescue pack procedure is supposed to be demonstrated at determined period to retrain all the underground mine workers.
14.2. Extinguishing fire Extinguishing fire is a task that is done collectively as a team provided it is not a life threatening case of fire. Along the belt route there are fire hydrants which are supposed to be used in case of fire outbreak. Fire extinguishers are the first line of defence when the fire start and its still small. Every eunderground worker should be trained to use a fire extinguisher. In a section they should have certain number of extinshers they must be determined by the manager, it must be ensured that the expiry is alsways inspected and that they are maintained from time to time to meet there standard and to ensure that they don’t cake over time. Therefor fire extinguishers should be found at all designated places such as
In all the equipment especially the ones that are diesel powered engine. At every area that is designated as the storage for flammable materials. At every last through road At waiting place. At switch gear At everyplace where there is a likelihood of catching fire
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Figure 7: fire extinguishers
Figure 8: protective gears worn by proto team during rescue mission
15.
Legal framework
15.1. South African legislation The South African mining industry is governed by the mining legislation which is being updated on term basis with the approval of the minister of Mineral and resource. The mine health and safety act applies to all the mining operations in South Africa, the act stipulates the conditions in which the mines are supposed to be managed. The mining regulations gives the guidelines of how the risk assessment should be conducted. The regulations further informs on the effectiveness of putting on the measures that will prevent initiation and outbreak of fire, secondly detect if there is fire outbreak and thirdly combat the fire outbreak Mine health and safety act section 9 provides guideline for preparing and implementing a code of practice for safe operation to detect, monitor and extinguish fire which might affect the safety of employees and non-mine employees. It might be a request from the chief inspector of mines and failing to provide it is taken as bridge of law and has penalties. Mine Health and Safety Act Regulation 8.9(3) The Act requires the mine owner to ensure measures which are also reasonable are in place to prevent anyone from being subjected to dangerous gases, heat or smoke generated from installation of the conveyor which can catch fire, such measures should also be able detect fire occurrence or combat it.
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15.2. International legislation The following law has been extracted exactly as it is from the source, i haven’t change anything with a fear that I will change the meaning and intended purpose.
The Mines Miscellaneous Health and Safety Provisions Regulations 1995, Regulation 4 states that employers are required to show document regarding health and safety and it must be evident that risk assessment at which workers are exposed to risks while at work have been conducted in line with the Management of Health and Safety at Work Regulations 1999, Regulation 3. It must be noted that regulation 4(2) (a) together with regulation 4(5) (a) of the 1995 Regulations dictate that the protection plan regarding or incorporating fire together with explosion must be available inside the document of the health and safety of workers in the mines [1].
16.
Conclusion
Fire detection and prevention is the most crucial part of planning for underground mining operation, to prevent catastrophic event from taking place. Emergency preparedness is an important requirement that every employee should be skilled in order to save their lives and of their fellow colleagues in case of fire. Depending on the rescues can endanger them even further should they rescue team delay or be unable to access the workings. Fire can claim all the mine assets, the lives of the workers and leaving severe injuries to the survivors in a little space of time. It is therefore of high importance that a fire be detected early so that it can be extinguished while it is still in its first stage known as incipient. Underground employee’s needs to be properly trained on how to use the firefighting equipment. It is the responsibility of the employer to provide all the necessary equipment and make sure that they are in good working condition and are readily accessible at all time. It is the responsibility of the Department of Mineral and Resources to ensure that all the mines abide to the laws that have put in place by the government to ensure that no lives are lost in the mines, where there were laws to prevent the same accident from happening.
17.
Recommendations
The escape route should always be clear of obstruction such as stockpiles, water and old structures that are dumped there. Escape routes must always be equipped with necessary infrastructure such the lifeline Refuge bays must be at reasonable distance from the section The fire detectors must be continuously maintained so that they don’t give false alarm which will make the workers complacent even when the thread is real. Firefighting equipment must be positioned in a visible and accessible area, where they will be accessible at any time when needed. They must be maintained and kept at good working condition. The mine must have a proto team that could be accessed at any time when required.
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18.
Bibliography
[1] H. a. s. i. department of mineral and resources, “Guideline for madantory compilation code of practice for prevention of fires at mine,” Johannesburg, september 2016. [2] M. Phala, “The Daily Vox,” 29 02 2016. [Online]. Available: www.thedailyvox.co.za. [Accessed 4 09 2018]. [3] Department of Mines and Petroleum, “Prevention of fires in underground mines — guideline,” Resources Safety, Department of Mines and Petroleum, Australia, 2013. [4] RRC International, “principle of fire and explosion,” 2006. [5] C. J. Voelkert, “Fire and fire extinguishment a brief guide to fire chemistry extinguishment theory for fire equipment service technicians,” Insitute of fire technology, 2009. [6] A. Ali, “HSE Professionals,” 17 october 2014. [Online]. Available: www.hseprofessionals.co.za. [Accessed 9 spetember 2018]. [7] boeing consultant, “fire basics,” 17 october 2008. [Online]. Available: www.boeingconsult.com. [Accessed 9 septemeber 2018]. [8] CTC, National certificate in coal mining operations, witbank : MQA, 2012. [9] R. V. K. Singh, “spontaneous heating and fire in coal mines,” science direct , jharkhand, 2013. [10] O. Moroeng, “spontaneous combustion in south african context,” university of Pretoria, pretoria, 2015. [11] W. MONAGHAN, “Reducing the fire and explosion hazards of flame-cutting and welding in undergroound coal mines,” NIOSH, johannesburg, 2010. [12] G. Koffmane, “More than Just Fire Detection: Fibre Optic Linear Heat Detection (DTS) enables Fire Monitoring in Road- and Rail-Tunnels,” AP Sensing GmbH, germany, 2010. [13] U. D. o. E. W. a. Assessment, “Early Warning Systems,” Early Warning Systems: A State of the Art Analysis and Future Directions, Nairobi, 2012. [14] D. C. OLDROYD, “FEASIBILITY STUDY OF THERMAL IMAGING EQUIPMENT TO IDENTIFY POTENTIAL ROCKFALLS,” samrec, johannesburg, November 2. [15] J. A. N. D. C. F. a. P. S. Kurt Konolige, “A Low-Cost Laser Distance Sensor,” ROBOTICS, USA, 2008.
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