Methane Dangers for Mining Operations Safety
Posted on 05/06/08 @ 8:04am by Max Griffin
Methane is formed by the decomposition of organic matter. Methane gases can be extremely dangerous in all tunnels and mines.
It’s important to know what kinds of effects it can have on you. Since it is lighter than air, methane tends to rise to the roof of a mine or tunnel. It injures and kills in two different ways: It asphyxiates (suffocates) you when there is too much of it in the air (by crowding out the oxygen you need to breathe). Methane explodes when ignited by a flame or even a spark.
The following is a list of the best work practices to use when Methane is present.
Control Measures:
Ventilation must be adequate. This is the single most effective way of controlling tunnel and mine gases. Respirators must be used whenever levels of hazardous particles or gases are high. After blasting, the blasting area may not be reentered until gases have reached safe levels. This means the air must be tested after every blast.
1) Do not smoke when working underground where methane may be present.Mining
2) Methane monitors must be installed on all continuous underground workers and longwall face equipment.
3) When methane concentrations within 12 inches of the back, face, or rib exceed 1.0%, all equipment must be shut down and work stopped until the gas is diminished.
4) When methane concentrations go above 1.5%, all underground workers in the area must be withdrawn.
5) When welding is done, methane tests must be made just before, and continuously throughout the activity.
6) If the main fan stops at a tunnel or mine where a single main fan is used, or if all fans stop where multiple main fans are used, all persons must be withdrawn from the affected part of the tunnel or mine. If methane concentrations go above 1%, everyone must be withdrawn. If a fan goes off for more than 15 minutes, methane tests must be made.
7) Doors must be plainly marked to indicate whether they should be closed or open for ventilation control.
8) Preshift examinations of all working areas must be made within 3 hours before any workers enter the tunnel or mine.
9) Every tunnel or mine should have multiple escape ways and an evacuation plan, and underground workers should be trained for emergencies. Self-Iron Minegenerating oxygen devices should be provided in all underground areas. Self-rescuers should be inspected and maintained, and every undergroundworker should be trained to use them. Scrap timber and other combustible waste materials should be removed immediately from the area. Series ventilation systems should not be used, because they tend to spread toxic gases throughout the underground area. MSHA-approved methane monitors must be installed on: electric face cutting equipment, continuous miners, longwall face equipment, and loading machines. The monitor shouldbe as close to the working face as possible, and should be set to give an automatic warning whenever the methane level reaches 1.0% (or lower if MSHA says) and to turn off the equipment automatically when the monitor doesn't’t work properly, or when the methane level reaches 2.0% (or lower if MSHA says). Check your methane monitor frequently.
10) The operator must follow a written maintenance program. It must be checked for accuracy at least once a month.
11) Sometimes the methane monitors are by-passed by wiring around it so they don’t work. The monitors may be a nuisance, and they sometimes malfunction, but the risks are so high (even a spark can ignite an explosion) that monitors are worth using.
12) Operators working underground must survey gas, mist, dust, and fumes as often as necessary to determine the adequacyMining of controlmeasures. MSHA does not have a set policy, but you should not go for more than a week without a survey. Where special conditions exist—like changes or breakdowns in the ventilation system, or there are a high number of machines being used in one area—the air should be tested more often. Read all MSDS that are applicable.
13) MSHA requires that only methane testing equipment, which it has examined and approved, be used in the mines. Several different methane detectors (methanometers) are approved which measure the amount of methane present.
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