SAFETY IN MINE

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SAFETY IN MINE

• Ba-Lan Ho

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Introduction

• Safety in mine ? many aspect (ie. Safety in Blast
  operations, safety at work place, safety of Belt
  Conveyor, Heat and Fires hazard, etc.
• Concern more about electrical hazards in this
  topic.
• Electricity is a form of energy and ready convert
  to heat.

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EFFECT OF ELECTRICITY

• The harmful effect of electricity on the human
  body has been classified as follows
• Electric shock, ie. The harm done to the human
  body as whole.
• Electric trauma, ie. Local external lesion in the
  form of mechanical rupture of tissue, danger to
  bones burns metallization of the skin.

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ELECTRIC SHOCK HAZARDS

• May result in ignition sources underground (ie.
  Overloaded or over heated cables or machinery or
  expose contact, slip ring, etc.)
• Statistic shows, 5.2 of electric shock in
  opencast pits.
• In some pit, reaches 20 25 of all fatal cases.

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SAFETY VOLTAGE OF CONTACT

• Result of numerous investigation, a current of
  50mA can be dangerous (causing loss of
  consciousness).
• Effect of 0.1A current or greater maybe fatal.
• Most dangerous frequency lie between 40-60 cycles
  per second.
• Voltage higher than 40V I hazardous to man
• A voltage of 65V maybe fatal.
• Where the floor is a good conductor of
  electricity, max safe voltage is 12V.

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PROTECTION FROM ELECTRIC SHOCK

• Cable or portable electrical equipment must be
  protected or remove to a safe place in a blast
  operation.
• Overhead power line should be switch off.
• Trailing and flexible cable must be inspect
  before each shift.
• Vehicles shall not be driven over electric power
  cables unless such cables are proteced from
  mechanical injury.

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Conclusion

• The risk is well known
• Still many accidents occur every year, due to the
  ignorance and slackness.
• Lead to some fatal in some cases.

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References

• J.Strang. P.Mackenzie-Wood, 1985. A Manual On
  Mines Rescue, Safety And Gas Detection. Austcue
  Publishers, Australia.
• N.Melnikov, M.Chenokov, 1969. Safety In Opencast
  Mining. Mir publisher, Moscow.
• Onlinelthttp//www.dir.ca.gov/Title8/7181.htmlgt