AMIT 129: Lesson 1 Intro

Overview

Objectives

After completion of this lesson, students will:

  • Understand definitions of open pit and underground mine
  • Learn Mining methods
  • Learn Mining equipment’s
  • Understand Ground control
  • Recognize Mining hazard
  • Know Personal Protective Equipment

Vocabulary

Familiarize yourself with vocabulary introduced in this lesson.

Adit: An adit is a horizontal or nearly horizontal entrance to a mine.
Back: The back is the roof or overhead surface of an underground excavation.
Chute: A chute is a loading arrangement that utilizes gravity flow to move material from a higher level to a lower level.
Cone: A cone is a funnel-shaped excavation located at the top of a raise, and it is used to collect rock from the area above.
Crosscut: A crosscut is a horizontal or nearly horizontal underground opening that is driven to intersect an ore body. Dip: The dip is the angle at which an ore deposit is inclined from the horizontal.
Drawpoint: A drawpoint is a place where ore can be loaded and removed. A drawpoint is located beneath the stopping area, and gravity flow is used to transfer the ore to the loading place.
Drift: A drift is a horizontal or nearly horizontal underground opening.
Finger Raise: A finger raise is used for transferring ore. The usual arrangement is as a system of several raises that branch together to the same delivery point.
Footwall: The footwall is the wall or rock under the ore deposit (compare dip).
Grizzly: A grizzly is an arrangement that prevents oversize rock from entering an ore transfer system. A grizzly usually consists of a steel grating for coarse screening or scalping.
Hanging Wall: The hanging wall is the wall or rock above an ore deposit (compare dip).
Level: A level is a system of horizontal underground workings that are connected to the shaft. A level forms the basis for excavation of the ore above or below.
Manway: A manway is an underground opening that is intended for personnel access and communication. Ore: An ore is a mineral deposit that can be worked at a profit under existing economic conditions.
Orepass: An orepass is a vertical or inclined underground opening through which the ore is transferred.
Prospect: A. prospect is a mineral deposit for which the economic value has not yet been proven.

Reading

Surface mining is the predominant exploitation procedure worldwide. Almost all metallic ores (98%), about 97% of the nonmetallic ores and 61% of the coal in the Unites States are mined using surface methods. And most of these are mined by open pit or open cast methods.

In open pit mining, a mechanical extraction method, a thick deposit is generally mined in benches or steps, although thin deposits may require only a single bench or face. Open pit is usually employed to exploit a near-surface deposit or one that has a low stripping ratio.

Underground mining  is a method which divides into unsupported, supported and caving- are differentiated by the type of wall and roof supports, the configuration and size of production openings, and the direction in which mining operations progress. The unsupported methods of mining are used to extract mineral deposits that are roughly tabular (plus flat or steeply dipping) and are generally associated with strong ore and surrounding rock. Supported mining methods are often used in mines with weak rock structure. Caving methods are varied and versatile and involve caving the ore and/or the overlying rock.

Mining Method

Reaching the Ore Body Extracting         Ore Ground
Control
Haulage Processing Facilities
Shaft

Slope or inline

Outcrop or drift

Portal entries

Room and pillar

Stopes

Raises

Block caving

Timber

Rock bolts and split sets

Concrete and shotcrete

Rubber tired

Track

Grizzly and crusher

Mills

Mining Hazards and Accident Prevention

Unsafe Conditions Unsafe Acts
Ground hazards

Electrical hazards

Gas hazards

Explosive and fuel hazards

Taking risks in operating or maintaining equipment

Bending and lifting

Slips and falls

Mining Equipment and Their Functions

Equipment for reaching the ore body Equipment for extracting ore Equipment for ground control Equipment for haulage
Hoist

Boss buggy

Man trip

Walking

Stoper drill

Jack-leg drill

Jumbos

Muckers

Stoper drill

Jack-leg drill

Jumbo drill

Rock bolts and split sets

Timbers

LHD

Slusher

Muckers

Youngbuggies

Locomotives and ore cars

Company Safety Policy and Rule Book

  1. Management commitment to safety
  2. Safety rules

Ground Control – Underground Supports

  • Provide a safe workplace by supporting the roof and rib to prevent unintentional rock falls.
    Depending on:

    • geological conditions
    • mining methods
    • miners experience
  • Commonly used ground control methods:
    • Timbering
    • Rock/roof bolts
    • Split sets
    • Steel props
    • Concrete lining or shotcrete

Mine Hazards and Accident Prevention

Unsafe condition can cause accidents. These are condition not under the direct control of miners. However, good accident prevention procedures, such as workplace inspection and equipment maintenance, can minimize unsafe conditions. The following are common unsafe conditions.

  1. Ground hazards include falls or back or rib.
  2. Electrical hazards include faulty insulation, splices and grounding.
  3. Gas hazards include fumes from diesel-powered equipment, fires, batteries and blasting.
  4. Hazards will explosives and fuels are always present but are minimized through safe work practices. Transportation of explosives and diesel fuel require additional care.

Unsafe acts are usually the result of taking unnecessary risks and/or trying to take short cuts in proven safe work procedures. Your motivation to work safely will reduce the likelihood for accidents and injury by minimizing unsafe acts.

  1. Taking risks in operation or maintaining equipment means that it is only a matter of time before an accident occurs. Always drive safely. Use your seat belt. Do not give rides in buckets or other areas not intended for transportation.
  2. Much of a miner’s work involves bending and lifting. Always follow safe procedures by bending your knees and using them, rather than your back, to lift. If the load is too heavy or awkward get help. Avoid lifting while your body is twisted or turned. Remember to use tall enough ladders, reach safely, and avoid lifting heavy items overhead.
  3. Wet or oily surfaces, protruding objects, or inattention can cause slips and falls.

A Culture of Safety in a Mining Context

 

Lifting Heavy Objects

A diagram demonstrating how to lift properly
By Unknown or not provided – U.S. National Archives and Records Administration, Public Domain, https://commons.wikimedia.org/w/index.php?curid=17220893

 

  • If the load is too heavy, GET HELP.
  • When using a two-person carry, both carriers face in direction of travel.
  • When lifting in confined areas on hands and knees, lift object with one hand balance with the other.

OSHA Back Safety

 

Personal Protective Equipment

Personal protective equipment is equipment worn to minimize exposure to serious workplace injuries and illnesses. These injuries and illnesses may result from contact with chemical, radiological, physical, electrical, mechanical, or other workplace hazards.

Personal protective equipment is always required on a mine site. It is your responsibility to know how to use it properly, and to wear it whenever you are working.

Some PPE’s are common to all mines, while some may be site-specific for your mine. These include:

  •   safety glasses for protection from rocks, dust and other flying debris;
  •    hard hats;
  •    steel toed boots;
  •    hearing protection;
  •    respirators

PPE Chart

PPE Basics

PPE Overview from OSHAGeneral Respirator Safety from OSHA

 

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