CHAPTERS

1) INTRODUCTION
2) OPENCAST MINING
3) UNDERGROUND MINING
4) EQUIPMENT PLANNING
5) PROJECT IMPLEMENTATION AND MONITORING
INTRODUCTION –SCOPE - REFERENCES
Lecture 1
 INTRODUCTION

PLAN: “Premeditated course of action.”

• Life of the mine:

1) Taylor’s formula..
T (years) = 0.20 R 0.25
where,
R= Mineable Reserves in tonnes.

So obviously annual production is Q=R/T=5R0.75

2)Modified Taylor’s rule:
T=0.165R0.25
IMPORTANCE OF PLANNING
 1)Jayanta Bhattacharya , “Principles of Mine Planning”-Allied
publishers ,Delhi 2003.
2) Hustrulid.W and Kucha.M , “Fundamendals of openpit planning and
design” ,1995.

REFERENCES:
3) SME handbooks,vol 1,2,3.
4)Hartman.H.L.,”Introductory to Mining Engineering”
TECHNICAL FACTORS IN MINE
PLANNING
Lecture 2
 TECHNICAL FACTORS IN MINE PLANNING

• Geological and mineralogy information

1. Size of the area to be mined(length ,width
,thickness)
2. Dip/plunge ,depth
3. Discontinuities
4. Variation of thickness and width within the
mineralised zone.
5. Boundaries between cut off and waste.
 TECHNICAL FACTORS IN MINE PLANNING

• Structural information(physical & chemical)

1. Depth
2. Structure features-both OB and mineral
3. Type of rock
4. Approximate strength
5. Porosity and permeability, swelling nature.
6. RQD
7. SILICEOUS CONTENT OF THE ORE
 TECHNICAL FACTORS IN MINE PLANNING

• Economic information
1. Tons of mineral reserve of various grades in all of the
mining zones, seams.(proven,probable,inferred)
2. Details of ownership, Royalties to be paid
3. Availability of water and its ownership on or near the
property.
4. The details of the surface ownership and surface
structure that be effected by subsidence.
5. The location of mining area in relation to ;any existing
roads railroads ,rivers; power , infrastructure and
available commercial supplies.
6. The local ,regional and national political situations.
 LIFE OF THE MINE
• Life of the mine:
1) Taylor’s formula..
T (years) = 0.20 R 0.25
where,
R= Mineable Reserves in tonnes.

So obviously annual production is Q=R/T=5R0.75

2)Modified Taylor’s rule:
T=0.165R0.25
METHODOLOGY OF MINE
PLANNING
Lecture 3
STEPS........

❑PRELIMINARY SENSITIVITY ASSESSMENT OF MINE AREA

❑PRELIMINARY MINE PLANNING ASSESSMENT

❑DETAILED SENSITIVITY ASSESSMENT

❑DETAILED MINE PLANING

❑MINING APPOROVAL APPLICATION

 Identify underground and surface
features e.g. cliffs, streams, homes,
and geology
Step : 1
PRELIMINARY SENSITIVITY Assess stakeholder sensitivity to
ASSESSMENT OF MINE legal constraints and mining
impacts
AREAS

Preliminary sensitivity assessment

of mine planning and surface
features

Develop alternative mine plans

Step : 2
PRELIMINARY MINE
PLANNING Preliminary assessment of
alternative mine plans
ASSESSMENT

Select preferred mine plans

 Infrastructure Natural features Private properties
Baseline assessment Baseline environmental Baseline assessment
and identify mine assessment and mine and identify mine
planning constraints planning constraints planning constraints

Step : 3 Update sensitivity

DETAILED assessment
SENSITIVITY
ASSESSMENT

Subsidence impact
assessment
 Detailed
assessment of
alternative mine
Step : 4 plans

DETAILED MINE PLANING

Select preferred
mine plan

Infrastructure Private properties

Natural features
Infrastructure Property
Subsidence
management plans subsidence
management plan
management plan

Prepare and submit

Step : 5 application to DMR

MINING APPOROVAL
APPLICATION
DMR’s subsidence
management plan
process
MINE PLANNING –SHORT
RANGE AND LONG RANGE
Lecture 4
 The planning process have been typically broken down into 3 categories

Short range planning Medium range planning Long term planning

• short range planning • Medium range • long term planning

where the day-to-day planning may extend which assesses the
planning process is from one month to overall profitability of a
involved. This time two years. It is here proposed mining
frame can typically that the conceptual pit operation. Here pits are
range from one day to designs are turned into designed with
one or two months detailed designs to be sufficient detail to
depending on the type given to the short provide the necessary
of operations and the range planners. information as to
tonnage of ores • The plan often deals whether a deposit is of
extracted. with the portion of the value to consider a
• Address the daily mine area. more detailed analysis.
problems and concerns • They are undertaken to The time frame is
with specific solutions. deal with a specific extended to life of the
• These are reality problem in the mine or mine.
operational plans ;they used in choosing a new
require a great amount piece of mining
of detail. equipment.
 LONG RANGE PLAN:
• Looks at providing mineral for a finite number of years and a specific size of power
(coal) or mineral beneficiation plant.

• 4 objectives of long range plans:

1) the plan must be feasible.
2) potential mining problems must be resolved
3)the plan must identify the major capital expenditures, equipment acquisition, lead
times required for implementation.
4)all reclamation and other mining related environmental questions must be
identified and answered.

• In general this plan is prepared for one or two the following reasons
1) consideration is being given to increase the number of units (size of power
plant/smelters).
2)the previous plan is outdated due to technological or economical changes.
INFLUENCES OF DIFFERENT GROUPS ON THE
PLANNING PROCESS
Data and Conceptual Long range Intermediate Short range
analysis range
group
Geology High Very high Very high Very high
Hydrogeology Low moderate moderate High
geotechnical moderate High High to Very high Very high
Financial analysis Moderate Very high Very high High
Environmental Low Moderate to high low Very high
science
Civil, mechanical Low Low to moderate High High
and electrical
engineering
Operation moderate high Very high Very high
research
Mining This is the group that pulls all the relevant data together.
engineering
MINE MODELLING-SIMULATION
AND SYSTEM APPROACH.
Lecture 5
ELEMENTS OF MINE MODEL
• Mine Modeling involves spatial location and interconnection of the basic
elements.
• Graphical modeling is designing by drawing like sketches, technical diagrams etc.
• Physical modeling is illustration of shape and structure either 2D or 3D on a
suitable scale.
• Physical models are used for conducting tests and measurements, Visual
illustration like seam depth, location and disturbances etc,
• Mathematical modeling involves simulation and optimization using mathematical
techniques.
• Analytical modeling is basically subset of mathematical modeling.
• Systems approach in mine planning conception, planning, design and engineering
of any interrelated elements so that objective is automatically optimized.
ELEMENTS OF MINE MODEL
MINE MODEL

model of mine surface model of mine

section underground section

development of the
development of the main
auxiliary mine surface development of deposit
mine surface sector
sector

connection between
main and auxiliary division of levels into
surface sectors and their levels
connections with system
environment

development of seam
 DESIGNED SYSTEM ‘THE MINE’. TRANSFORMATION OF INPUT AND
OUTPUT ELEMENTS ( system approach)
INPUT OUTPUT
ELEMENTS ELEMENTS

DEPOSIT
DESIGNED SALEABLE COAL

PERSONNEL
SYSTEM ECONOMICS
EFFECTS
MACHINERY "THE MINE" PREPARATION WASTE

ROCK
MATERIALS
CAPITAL WATER
EXPENDITURE ENERGY
SYSTEM USED AIR

FRESH AIR ENVIRONMENT

GASES

WATER LIQUID WASTE

INFORMATION
PRODUCTIVE AND NON-PRODUCTIVE SUBSYSTEM IN THE DESIGNED
SYSTEM “THE MINE”
Designed system
“THE MINE”

NON-
PRODUCTIVE PRODUCTIVE
SUBSYSTEM SUBSYSTEM

PRODUCTION
FROM FACES
COAL RESERVE IN
PRODUCTION SEAM EXTRACTIONOF
SEAMS GENERAL INDIVIDUAL

PRODUCTION FROM
PRODUCTION FIRST WORKING
FROM FACES ENERG
MANGEMENT OF
MACHINERY
MANAGEMENT
MINE
PRODUCTION HAULAGE OF
PRODUCTION
FIRST GOTTEN MATERIALS
WORKINGS TRANSPORTS
ADMINISTRATION

PRODUCTION ROCK
VERTICAL TRANSPORT
DEVELOPMENT OF PERSONNEL
WORKING
MINE
AUXILIARY SURFACE
MINE HOIST OF GOTTEN PRODUCTION FACILITIES
HORIZONTAL
TRANSPORT OF
PRODUCTION PERSONNEL

ROCK
ROCK VENTILATION
COMMUNICATIONS
COAL PREPARATION
AND DISPATCH ROCK
MINE DRAINAGE
PRODUCTION
DEVELOPMENT OF
ROCK SEAMS FOR
EXPLOITATION
 Estimation of
resources

Metallurgical Geotechnical
engineering engineering

Infrastructure
Mine plan
service

Budget &
evaluation

Mineable reserves
Proven + Probable
MINE PLAN
Mine plan
• Methods and layouts

Mine plan
• Equipment selection

Mine plan
• Extraction strategy

Mine plan
• Mine services

Mine plan
• Operational supplies

Mine plan
• Manpower and productivity

Mine plan
• Cost estimates

Mine plan
• Production plan

Mine plan
• schedules
SELECTION OF OC MINE CUTS
& SURFACE STRUCTURES
LECTURE 6
 FACTORS IN INFRASTRUCTURE PLANNING:

• Topography
• Existing infrastructure
• Future operations
• Ownership of the land
• Geology
• Surface ground water
• Communication available- roads,rail,telecommunication
• Power
• Location fir fighting station
• Dumping yard location
 TYPES OF INFRASTRUCTURES
• DISPERSE TYPE:
-Scattered infra-structure
- Mostly not preferred due its disadvantages like
# land
# transportation difficulties
# communication
• BLOCK TYPE:
structure are kept as close as possible.

( see figure 5.1 of the principles of mine planning , Jayant Bhattacharya)

LOCATION OF SURFACE STRUCTURES
• The starting point for design of the main mine surface area is the
siting of the mining plant, preliminary selection of the region or locality
being followed by the final decision on the exact location.

• In general, the siting of the mining plant is dictated by the position of

the deposit in the mine concession area.

• The ultimate location of both the main and auxiliary surface areas
depends on:
• Deposit mining and geological condition
• Ownership of the land
• Ground and surface condition
• Existing infrastructure
Contd..

• Before the detailed development plan for the main mine surface is
prepared, it is necessary to:

• Fix the siting and duties of the main shafts in relation to the model
of underground section

• Electric power, configuration of the land

• Fix the size of the particular facilities and installation and site the
individual facilities and installation in relation to the assumed main
production streams
• For this development plan the following principles must be observed:
• Mutual siting of building, facilities and installations
• Streams of coal, rock, materials, personnel, etc. should follow the routes established
• Distances between buildings should be big enough to comply with fire fighting
regulations
• Formation of barren rock dumps and spoil tips should be avoided
• Protection zones and green belts should be established.
• Regulations concerning protection of natural environment should be rigorously
observed.
EXAMINATION OF GEOLOGICAL AND DETERMINATION OF ORE
BODY,SELECTION OF SITE FOR BLOCKING,MINE DELINEATION

LECTURE 7
 GEOLOGY
The following points should be considered:

• Geology of the mineralized zone;

• Physical size and shape of the deposit;

• Quantitative data on grade and tons of material within pertinent cut-off limits;

• Mineralogical and metallurgical characteristics of the ore;

• Physical characteristics of the ore and waste; and

• Data on ground conditions, groundwater and other factors that affect mine design and operation.
 BLOCKING OF OREBODY/DELINEATION
• BLOCKING: “Delineating the ore body.”

For the convenience of mining operation ,sometimes the ore body is divided into blocks.

OTHER REASONS FOR BLOCKING:

1) Lease restrictions
2)Geological formations/faults
3) Grade variation
4) Operational Reasons – Very large block may not be mined as a single block. So in a single mine the block may be divided into
South block , North block .
Example : NLC has Mine 1,1A,2.
5) Depth
6) Safety Aspects
7)Natural/Environmental Restrictions
 MINE DESIGN AND
PLANNING OF LAYOUT
LECTURE 8
 PRINCIPLES OF MINE DESIGN
• Mine design techniques focus on three groups of problems
• Indicating most appropriate investment schemes and program of
exploitation.
• Optimization of basic parameters for new mine for map profit on
given investment outlay.
• Execution of technical design for implementation mine design
involves:
• Analyse feasibility of new design methods and justify choice of
suitable ones and their applications.
• Practical use of modeling techniques
 PRACTICAL USE OF MODELING TECHNIQUES..
• Graphical modeling – design by drawing –sketches, technical
drawings, diagrams(flow sheet) automated computer data
processing system.

• Physical design models- provide a clean objective of proposed

design – illustrate shape / structure: two dimentional or three
dimentional (block shapes – scaled down).

• Mathematical modeling – currently more frequently applied.

Simulation and optimization models are particularly important.
These models tend to elimination of the abstract and hence can
stimulate the true situation with considerable accuracy and also
the number of parameters to be optimized can be increases more
accurately for natural deposit conditions and provide for more
objective design decisions
DESIGNING OF OPEN PIT MINE
• Determination of pit outline in planning involves finding of pit slope angles, pit
bottom width, etc.

• Designing of open cast mine involves:

1. Height of benches with reference to its stability, strength and its

capability to withstand the forces, cleavages

2. Specific gravity, cohesive strength, internal frictional angle

3. Width of the benches

4. Slope of the benches, berm, face angle and bank width, final pit slope

5. Design of the haul roads

6. Planning for production, length of face, etc.

 LAYOUT SHOULD GIVE PROVISIONS FOR.....

• Vehicle movement and vehicle parks.

• Contractor’s compounds - temporary canteens ,offices ,site huts.
• Stores and workshops
• Site services – boiler house, electrical substation, sewage disposal
• Pit side facilities – lamp room, report centre , pit offices , rescue room
..etc
• Clean side facilities – pithead baths, medical centre , canteen ,mine
offices , time and wages offices.
 CLASSIFICATION OF SURFACE
LAYOUTS:
• 1) Dispersed Type
✓ The dispersed type contains a large number of facilities located over
a relatively large area.
✓ This is olden approach ,in those days space was not a constraint and
environmental, public reactions were minimum.
• 2) Block Type –TYPES: BELT FORM,ZONE FORM.
✓ Requires smaller site
✓ Better space utilization
✓ Easy transport
REFER : BHATTACHRYA PAGE:133.
 LAYOUTS
• Spiral layouts:
-for hilly deposits.
-Iron ore mines in hilly areas and steeply dipping deposits.
- gradient > 60*
PLANNING OF LAYOUTS
 FACTORS INFLUENCING THE LAYOUT OF MINE

• Stripping ratio

• Type of the machinery

• Local geology of the area – Gradient ,thickness ,depth

• Terrain – Hilly terrain / Flat terrain.

• Capital available- Example : NLC in Gujarat they have shovel dumper

system due to the shortage of capital available.
BENCH AND HAUL ROAD
DESIGN
LECTURE 10
 BENCH DESIGN
• Bench height is depend upon
i. Rock type
ii. Reach of the machine.

• Bench width should not be less than

➢ the bench height &

➢ also thrice the width of the dumper or
➢ twice the width of largest machine ply over the bench
➢ and 2m clearance.

• Bench slope should not be more than the angle of the repose of the material.
 HAUL ROAD DESIGN
• Should transfer travelling load to base
• Should seal off the water penetration
• Should have least friction
• Should produce least dust
• Layers of Haul Road:
• Wearing Surface: To resist abrasion (made up of asphalt or
concrete or crushed rock).
• Base: To resist shrinkage and swelling and should have high
stability and density to spread the load acting and distribute the
stresses.
• Sub base (optional): It is required for weak soils. Granular
material can be used for both base and sub base layers.
• Sub grade: Foundation layer which support all the load acting. If
the rock is strong, then the ground itself can be used as sub
grade layer.
Contd..
• Load acting on the Dumper tyres:
• 33 % on front tyres & 67 % on rear tyres

• Gradient:
• 1 in 14 for haul roads & 1 in 10 for ramps

• Super Elevation Rate:

E = (V2/(10 * R)) - F

Where, E – Super elevation rate (ft/ft) or (m/m)

V – Vehicle speed in (mph) or (kmph)
R – Curve radius in m
F – Friction factor (0.3 to 0.001)
Contd..
• Haul Road Signs

• Lighting

• Runaway Precautions

• Curve Design

• Drains and Culverts

• Road Edge Barriers

SLOPE STABILITY
LECTURE 11
SLOPE STABILITY
• Safety Factor:
F = S/Sm
where S = shear strength and Sm = mobilized shear resistance.

• F < 1: failure can take place, F > 1: safer slope, F=1: under
equilibrium.

• Types of Failures:
• Planar Failure
• Wedge Failure
• Circular Failure
• Toppling Failure
SLOPE STABILITY
STRESS VS SHEAR STRESS
GRAVITY LOADING - BASIC MECHANICS
WATER LOADING - BASIC MECHANICS
MAIN TYPES OF SLOPE FAILURE - TYPES OF
STEREOPLOTS
PRESENTATION OF STRUCTURAL
GEOLOGY INFORMATION
GEOMETRIC CONDITIONS FOR WEDGE FAILURE
BISHOP'S SIMPLIFIED METHOD OF SLICES FOR THE ANALYSIS
OF CIRCULAR FAILURE IN SLOPES CUT INTO MATTER
COMMON CLASSES OF TOPPLING FAILURES
FAILURE STAGES OF LARGE SCALE TOPPLING
FAILURE IN A SLOPE
INTERPRETATION OF SLOPE MOVEMENT
MONITORING DATA
ROCK SLOPE REINFORCEMENT
METHODS
TENSION LOADING - BASIC MECHANICS
ROCK SLOPE STABILIZATION MEASURES
Contd..
• Thumb rule: Slope angle should be always less than the angle of
repose.

• Critical height is the height at which the bank would fail for the given
design parameters of the pit slope.

• Critical Slope = 4C/P * tan (45° - (Φ/2))

• Slope Stable angle for:

• Soft rock (ex: clay) – 25 to 35°
• Limestone , Shale, Sandstone, Dolomite – 40 to 50°
• Weathered Igneous rock and Metamorphic rock – 50 to 60°
• Very hard Metamorphic rock and Igneous rock – 60 to 70°
CALENDAR
LECTURE 12
PLANNING
 CALENDAR PLANNING
• Calendar Plan is the Plan of various activities related to calendar
schedule.

a. Instantaneous excavation which indicates the following at any

instant:
❖ Production of Mineral per year
❖ Removal of Waste per year
❖ Stripping ratio per year

b. Cumulative excavation which indicates the following:

❖ Cumulative production of mineral upto that year
❖ Cumulative handling of waste upto that year
❖ Overall stripping ratio upto that year
❖ Stages upto which will be taken, upto that year
 OBJECTIVES & NEED OF CALENDAR PLANS

• Objectives of a Calendar Plan:

• To frame/set a definite Production Goals in space, with quantity
of material to be moved,
• To allow better economic evaluation than the phase average
period.

• Need of a Calendar Plan:

• In a calendar plan, a pictorial representation of stripping ratio
with respect to time is made with a view to optimizing the
extraction of mineral.
• In calculation of stripping work, the whole life span of the mine
is taken into consideration.
CALENDAR PLANNING
Contd..
c. Instantaneous and Cumulative Machinery Utilization – indicate Instantaneous and
cumulative utilization of machinery at various stages of mining.

d. Quality – indicates the quality of mineral acquired at various stages of mining work.

e. Development and dismantling of haul roads and ramps

f. Manpower Requirements.
Contd..
• The total life of the mine can broadly be divided into following four stages:
• 1. Construction Stage
• 2. Development Stage
• 3. Remunerative Stage
• 4. Slack Period.

• Overall planning of a mine is correlated to all phases of mining operations, which will
facilitate and ensure maximum utilization of heavy earth moving machinery(HEMM) and
other complementary equipment which will be a function of the total work load of waste
rock handling and mineral output within a particular time frame.

• The yearly productivity of the deployed equipment will indicate the complementary and
supplementary manpower required.
PRODUCTION SCHEDULING AND PLANNING
Lecture 13
Production planning:
 Optimum levels of production is to keep cost of production as
low as possible

 Operational Viability

 Sufficient exposure of minerals

 Keep the gap as little as possible between the ore and waste

 Minimize the pit slope

 Alternative production rate

 Proper equipment selection

 MINE SCHEDULING:
‘Mine Scheduling is a process of simulating the
extraction of deposit over time’
This process comprises of,
a) Defining the deposit as a group of mining
blocks and establishing attributes for these
blocks.
b) Establishing rates of removal for the minerals
in the mining blocks and the sequence in
which the blocks are to be removed.
c) Simulating this extraction sequence.
Cont.,
d) Reporting the results of the schedule.

Because of the spatial relationships between

mining blocks usually play an important role in
the feasibility of an extraction sequence, the
mining engineer can benefit from a graphical
representation of the schedule.
ECONOMIC PRODUCTIVITY
INDICES
LECTURE 14
 TECHNO – ECONOMIC ANALYSIS

• Performance monitoring / analysis

• Technical analysis includes:

• Production – achieving target – precession plant efficiency
• Productivity – OMS

• Machinery – machine utilization – machine availability –

machine efficiency
Contd..

• Manpower – skilled, semi-skilled, unskilled

• Safey – accidents per million hours or for thousand tonnes of

production or man lakh hours

• Energy –conservation, utilization

• Environment – green house gas emission – any bank loans –

10% of amount should be availed for environment
ECONOMIC ANALYSIS
 Economic analysis includes all of the above + capital and
operating costs

 Ex: Energy – cost/ tonne produced

 Safety – compensation and damage

 Production – cost / tonne ; NPV – techno economic indices

 Productivity – cost per labor of manpower

Contd..
 National Productivity Council : For measuring the performance of
different organizations

 Capital cost
 Ex: for a shovel – dumper : 50 crores for million tonnes per year
 For a BWE: 90 – 100 crores per million tonne production per year
 (Neyveli in Gujarat is not using BWE because of lack of capital funds)

 Operating cost
LOCATION OF UG ENTRIES
LECTURE 15
 LOCATION OF UG ENTRIES
 Type of/ mode of entry - Shaft, Decline, Adit

 Comparison of calculated construction costs, unit and

total costs

 Unit cost – cost / ton

 Total cost - construction, maintenance, cost of haulage

 Objective: to meet the production requirement

 SITE CONSTRAINTS
 Shaft Location – presence of water bodies, forest area etc.
 Geological Disturbances, Hydrological Disturbances, Topography etc.,
 HFL
 Loss of Mineral in Shaft Pillar

 Infrastructure ( in remote areas) – power and materials

 Purpose of Shaft – production / ventilation / waste pumping

 Haulage/ Transport – dispatch

 Energy availability

 Sand stowing – location of same

Contd..
• Algorithms to select shaft / decline: Zian’s method,
Vez’s method – Analytical method (Refer Jayantha
Bhattacharya)
Optimization of mine
parameters
LECTURE 16
 Optimization of mine parameters (Size of panel, length of face,
location of levels, level intervals)

 Optimization is a mathematical operation involving the

parameters that influence the objective which can be
minimization or maximization.
 Production - In terms of Economics, Safety and
Environment – graph
 Panel Size –
 For coal mines – Production * Incubation Period
 For metal mines – No Incubation Period but production is a problem
Contd..
 Level Interval – Graph
 Dimensions of galleries –
 Larger galleries can give lots of advantages but safety problems are also high.
 Regulations /rules .
 Face- Length of Longwall Face
 Let the production / day / shift for 6 hour shift be 330 tonnes
 Length of Longwall Face = 330/(γ*Area of panel)
Where
γ=
Area of Panel = Panel length * thickness
Panel length is dictated by the Incubation Period
LONGWALL FACE LENGTH

The chosen length determines:

• Rate at which advances/
repeats
• Tonnage recoverable from
panel
• AFC length
• Number of supports required.
• Capital cost of face equipment
 ADVANTAGES OF LONG FACE

• Output/ shearer greater.

• Greater cutting time as less time loss at face end measurement.
• Reduced devi seqts fewer faces per panel
• Reduced mix of gate side packs.
• Fewer face moves, reduced interruptions to production
• Reduced construction work are crossings in, doors, conveyor
installation.
• Important vent effects, lesser leakage points.
ADVANTAGES OF SHORTER FACES
• Lower capital requirements/ face
• Higher speed of face, better strata control,
consistent production
• Light loading on AFC promote reliability, avoids
unplanned stoppages
• Less equipments involved in face transfers.
• More development work.
• COAL INDIA has standardized on 150m length
faces.
OPTIMIZATION OF MINE PARAMETERS
DESIGN OF PROTECTIVE AND SHAFT PILLAR
Lecture 17
 SHAFT PILLAR
Consider, D=depth of the shaft in m,
T=Thickness of seam in m,
R=Radius of shaft pillar in m.
(1) DRON’S rule:
Area of shaft pillar = area to be supported + D/6 on all sides
(2) FOSTER’S rule:
R=3√Dt
(3) WADIN’S rule:
For shaft upto 100m depth, size should not be less than 36.5m×36.5m.
There after for every 36.5m depth, increase size by9m.
Cont.,
(4) MINING ENGINEERS rule:
For shallow shafts the minimum radius for shaft pillar is 18m.
For deeper shaft,
√Dt
R=18.3+ 32.8
(5) DONAHUE’s formula for inclined seams:
If D= Depth of shaft, X= angle of dip of coal seam,
Then y = D Sinx Cosx
S= Margin of safety, usually equal to 5% to10% of the depth,
Then width of the pillar on rise side = S+ D/7+ 2y/3
Then width of the pillar on Dip side = S+ D/7 – v/3
Then width of the pillar along strike = S+ D/7
SHAFT PILLAR PROTECTION

• Rapid Mining
• Stowing
• Harmonic Extraction
• Partial Extraction
SELECTION OF METHOD OF
EXTRACTION
Lecture 19
 FACTORS IN SELECTION
• Spatial characteristics of deposit
• Size(dimensions, especially height or thickness)
• Shape (tabular, lenticular, massive, irregular)
• Altitude(inclination or dip)
• Depth (mean and extreme values, stripping ration)
• Geologic and hydrologic conditions
• Mineralogy and petrography (sulfides vs. oxides)
• Chemical composition (primary, by-product minerals)
• Deposit structure (folds, faults, discontinuities, intrusions)
• Planes of weakness (joints, fractures, cleavage in mineral, cleats in coal)
• Uniformity, alteration weathering (zones, boundaries)
• Groundwater and hydrology (occurrence, flow rate, water table)
• Geotechnical(soil and rock mechanics ) properties
• Elastic properties (strength, modulus of elasticity, Poisson’s ratio. Etc.)
• Plastic or viscoelastic behavior (flow, creep
• State of stress (original, modified by mining)
• Consolidation, companion, and competence (ability of opening to stand
unsupported)
• Other physical properties (specific gravity, voids, porosity, permeability, moisture
content)
• Economic considerations
• Reserves (tonnages and grades_
• Production rate( output per unit time)
• Mine life ( operating period for development and exploitation)
• Productivity (output per unit of labor and time)
• Comparative mining costs of suitable methods.
• Technological factors
• Mine recovery
• Dilution( amount of waster produced with ore
• Flexibility of method with changing conditions
• Selectivity of method to distinguish ore and waster.
• Concentration or dispersion of workings
• Capital, labor and mechanization intensities
• Environmental concerns
• Ground control to maintain integrity of openings
• Subsidence, or caving effects on the surface.
• Atmospheric control (ventilation, quality control, heat and humidity control)
• Work force(recruitment, training, health and safety, living, community conditions)
Type of ore body Dip Strength of ore Strength of walls Possible Method
of Mining
Thin bodies Flat Strong Strong Room and pillar,
Casual pillar Open
slopes

Weak or Strong Weak Top slicing, Longwall

Thick bodies Flat Strong Strong Sub-level stoping
room and pillar
cut and fill

Weak or Strong Weak Sub level caving

Top slicing

Weak Strong Square set,

Cut and fill
Sub level stoping
Narrow Veins Steep Weak or Strong Weak or Strong Reusing in open
slopes or sculled
slopes
Thick veins Steep Strong Strong Open stopes
sub-level stoping
shrinkage slopes
Cut and fill method
Steep Weak Cut and fill stope
square –set stope
top slicing
sub-level caving
Weak Strong Open casual pillar
square-set slope
top slicing
Sub-level caving
Weak Weak Square-set stopes
top-slicing ,sub-
level caving
Massive Strong Strong Shrinkage stope
Sub-level stoping
Cut and fill stope
Weak Weak or strong Square-set stope
Top –slicing
Sub-Level caving
Block caving
Man Power Management
LECTURE 20
• List of life Time certificates
• List of statutory certificates
• List of statutory and life time certificates
• Details of employees – Due date prior 3 months
• License and PME information details
• List of employees for selected period whose license, statutory
certificates are for renewal
• List of employees for selected period who did not attend PME
• List of employees who did not attend PME in their service.
• Strikes

• All strike details

• For selected month

• For selected period

• Cause wise analysis of strike

• Legal/Illegal wise Strike Details

• Partial/Total wise Strike Details

• Designation

• Total number of lockouts

• Month wise/Year wise

• Charge Sheet

• Standing Order number wise Charge Sheet

• Standing Order number wise Status Report

• All charge Sheet details

• Enquiry

• Submitted /not submitted wise enquiry report

• Enquiry details based on Duration

• All enquiries Details

• Warning Letters/Charge Sheet Information Details

PLANNING ON WATER
MANAGEMENT
Lecture 21
 Planning on Water Management
1. Expected inflow assessment
Open cast relates to exposed area to rain (catchment area vis-a vis
mine area), Underground excess inflow due to rain on S/F,
underground water generation, water from water bearing
strata/aquifer.
2.Plan to prevent ingress to mine
Open cast S/F drains, channels, guide run off –underground mine
subsidence areas to be protected, S/F drains, consolidation where
feasible – such as cracks/ fissures – prevent run off access to mine
workings outlets above HFL away from water bodies.
3. Plan for sump capacity
➢ Open cast –heaviest showers in the past- required pumping capacity
and sump volume without affecting operations. Underground
maximum inflow in the monsoon seasons- all sources.
➢Number / location of sumps- special sumps- in particular if water is to
be stored for future use by mine in dry season – like spraying/
quenching / colony requirements.
➢Pump capacity – dead / live – type of pumping operation –
concentrated spread out all sifts/ night shift.
4.Pumping Plans
• Pit bottom main sump – open cast sump – single /supplicate drainages in
stone may be required – storage capacity 24 hours /2 days/ as required.
• Cardinal Principle – collect water where it is generated, do not allow or
take to lower levels- use maximum of gravity flows to reduce pumping cost.
• Ample size of delivery lines reduce open cost all points at crucial points to
be duplicated with separate (duplicate) delivery to meet any emergency.
• Layout of pump room and foundations, pump fitting and switch gear-
pump and pipe joints – ventilation/ lighting / communication to pump
room.
• Choice of face / intermediate pumps – centrifugal (various types) turbine /
MONO / submersible types/piston type, etc
TECHNO ECONOMIC
INDICES
LECTURE - 23
 BASIC TECHNO ECONOMIC INDICES

INDICES UNIT
Mine Production (net) t/day
Average construction time to produce first coal years
Average construction time to reach target production years
Construction time for an extraction level years
Numbers of extraction levels in the mine years
Production from one level t/day
Production from one face t/day
Production per loading point t/day
Intensity of extraction t/km²
Overall productivity t
(OMS)
Index of mechanization of coal getting %
VENTILATION PLANNING
Lecture - 24
 VENTILATION PLANNING
• AIR QUANTITY & VELOCITY:
• Deals with effects of
• Methane and other gases
• Heat
• Dust
Cont’d
• VENTILATION PLANNING:
• Prepare mine working plans
• Project at each life stages of mine the proposed extent
of mine workings – U/G roadways, working districts,
drifts, dev.headings, raise/winze, substations, pump
houses, loco garage, first aid rooms, haulage rooms,
miners stations etc…
• Link all these to period of major change – drifts,
horizons, stopes, depillaring, etc…
• Random interval can also be selected – 5 yrs interval
upto 25 years.
Cont’d
• VOLUME FLOW:

• Quantity of air required at different places estimates based on

methane emission, volume of production, no of persons
working U/G / man shift, wet bulb temp, dust SPM

• Calculate the resultant velocities on each roadway to ensure this

flow & reqd velocity at working places – not too high / nor too
low, adequate to control dust also.

• Allow for all leakages, S/P at airlock, pit bottom dons, intake to
return – which increase with extended working and WG.
Estimate VEQ % overall air to air at face. 50% VEQ is good
ventilation standard
 Cont’d

• MINE RESISTANCE:

• Calculate roadway resistance as per formulae and then series / parallel for all
circuits – nodal point resistances.

• Evaluate total resistance. Chart variation in mine resistance through mine life.
 Cont’d

• VENTILATION PRESSURE:

• Small pressure only observed at face – balance due to rest. all along roadways
/ shafts etc…
 Cont’d

• VENTILATION NETWORK:

• Identify nodes, branches, tabulate for all the stage of life plans. Allow for
leakages

• system resistance and equivalent orifice can be calculated.

VENTILATION:
 Cont’d

• STATUTORY REQUIREMENT:
• Heat and Humidity

• Wet bulb temp – 30.5º C

• Velocity not less than 1 m/s

• No deployment of mess when wet bulb temp is over 33.5º C

 Cont’d

• Dust is controlled best with velocity 1.5 to 2 m/s. Gas dilution – keep
methane below 0.5% at face. Virgin rock temp to be considered.

• Indian Coal Fields:

• Geothermic gradient 1º C per 36m depth commencing at 18m depth
27.2º C constant VRT at 100m = 27.2 + (100 – 18) / 36 = 29.42º C
 Cont’d

• CONTROL OF DUST AND GASES:

• Explosion and Fire hazard

• Health risk

• Nuisance value – irritation of skin, eyes, ears, nose – machine relays, bearings
circuitry, Visibility – dust cloud.
 Cont’d

• Primary cause:
• Mechanical breakage and disintegration during mining operations, also
release & dispersion of dust present – slip planes
• Degradation and agitation of material during transport – respirable dust, is
that aims airborne ( less than 10 micron in diameter ).
MINE SUPPORT PLANNING
LECTURE 24
• Supports in UG in mines are designed to support the load coming from the “IMMEDIATE ROOF” only.(not
the total load above it).

• So supports have to be designed to carry the load from pressure arc, not the total load above excavation.

• CAVABILITY: its the most important factor in designing the supports.

• CMRI: CAVABILITY INDEX=I=t0.6(∂*m)n

Where , t=thickness of the strong bed
∂=compressive strength
m=parameter of massiveness=(RQD+10)/100
n=factor depend on RQD=1.1-1.3.
 ESTIMATION OF SUPPORT
REQUIRMENT FOR LONGWALL
FACE
 NCB METHOD
FORMULAS:
1) SUPPORT LOAD /UNIT AREA = P= (VLM)/(K-1)
Where,
V= average density in t/m3
L= Longwall face length in m
M= average face length in m
K= bulking factor

2)HEIGHT OF IMMEDIATE ROOF=IR=T/(K-1)

where,
T= thickness of extraction.
K= Bulking factor.

3) TOTAL LOAD ACTING

Load = Density *Height of immediate roof*(Length of the face + Gate roadway width on both sides)*span
 EXAMPLE
FOR GIVEN DATA OF :
Density of coal = 1.2 t/m3,Bulking factor = 1.2,Length of the face = 120 m ,
Width of gate roadways=4+4= 8 m, Span = 8 m. Extraction height/thickness=3m.
Calculation:
Assuming the width of the support is = 1.5 m
immediate roof height = t/(k-1)=3/(1.2-1)=15
• Load = Density *Height of immediate roof*(Length of the face + Gate roadway
width on both sides)*span
=1.2*15*(120+8)*8 = 18432 t

• NUMBER OF SUPPORTS REQUIRED =Total face length/width of support

=128/1.5= 85
• LOAD ON EACH SUPPORT = Load acting/No.of supports
=18432/85 = 217 t
• To have a factor of safety above one ,
the load bearing capacity of each support is taken as 250 t.

THUMB RULE:

Loading acting at a particular depth(d) = 0.025*d.

If strata is inclined =0.025*d*cos(angle)

MINE RECLAMATION
PLANNING
LECTURE 26
 Mine Reclamation
• “Land reclamation is the treatment of the land
,creating conditions for putting the land to its pre-
mining use or other useful working.”

• A reclamation area both aesthetically attractive as well

as useful is more desirable.

• The reclamation process serves a binding agreement

between the management and the government
agencies.

• However there may be some changes in the over all

life of the project –usually techniques and
methodology.
 Reclamation plan purpose

• Provide detailed guideline for reclamation process and fulfill all the
statutory requirements.

• Plans for the use during entire operational period and subsequent to
the cessation of exploration, mining and possessive activities.

• Reclamation planning should provide direction and standards to assist

on monitoring and compliance evaluations.
 Reclamation plan content

• A logical sequence of steps for the completing the reclamation

purpose

• The specifics of how the reclamation standards will be achieved.

• As the estimation of the specific costs of reclamation

• Sufficient information for development of the basis of the inspection.

 Reclamation standards

• Waste management
• All undesirable materials(all toxic sub soil contaminated soil , fluids
process residue, refuse)shall be isolated \recovered\buried or
appropriate disposal
A)Area protected from future contamination from mining activities.
B)No contamination materials remaining near S\F
C)Remove \isolate ]bury inappropriate manner all the toxic substance
D)Adopt acceptable waste disposal practices
 Reclamation standards

• Subsurface
To be properly sterilized, holes in U\G working property plugged and
sub surface integrity ensured

• Site stability
Reclaimed area should be stable and should not exhibit—large rills or
gullies, soil movement, slope instability.
 Reclamation planning steps…..

• Make an inventory of the pre-mining conditions.

• Evaluate and decide the post-mining requirements of the region with
due considerations of needs and desires of the affected group.
• Analyze alternative mining and reclamation schemes best of the
objective.
• Develop an acceptable mining, reclamation and land use scheme that
is most suitable under technical, social and economic conditions.
 Information requirements
Natural land use factor
• Topography
• Climate
• Altitude
• Exposure
• Hydrology
Surface hydrology
Ground water hydrology
• Geology
• Soils
Agricultural character
Engineering character
• Terrestrial ecology
• Aquatis ecology
 Information requirments
Cultural factors
➢Location
➢Accessibility
➢Size and shape of the site
➢Surrounding land use
➢Land ownership
➢Type, intensity and value of use
➢Population characteristics
 Process of Reclamation

TECHNICAL RECLAMATION
This includes back filling of the excavations, spreading of the
subsoil and top soil, grading of the backfilling and waste dump .
BIOLOGICAL RECLAMATION
• Restore the fertility and biological productivity of the disturbed lands
• This phase takes 3 to 5 years
• During this favorable spices are grown which depend on the climate
depth and nature of the topsoil and subsoil, local type of farming etc.
BIOLOGICAL RECLAMATION
BIOLOGICAL RECLAMATION
TECHNICAL RECLAMATION
PLANNING OF SELECTION OF
EQUIPMENT
LECTURE 27
 Planning and selection of equipment

The process involved are

• Selection of the apt technology
• Selection of the primary equipment
• Selection of the individual equipment
• Sizing of the equipment
• Selection of the supplier.
 Factors influencing selection of equipment

• Type of the deposit

• Size of the equipment
• Location of the deposit
• Production parameters
• Project life
• Capital availability
• Performance factors
• Geo technical considerations
• Ergonomics and saftey
 Accessible for surface mining

Non
stratified
stratified

Massive
horizontal inclined Vertical vein
stock\pipe
Thick Thin Gentle Gentle
inclinati inclina Steep narrow wide irregular
ob ob inclina
on < tion >
Thick Thin angle angle tion
seam seam of of
repose repose
Outsid Outsid
Backfilling Backfilling e Outside dump e
around direct dump dump
pit carting

Near fixed obratio Increasing ob ratio Increasing ob ratio

near fixed depth increasing depth increasing depth vertical
lateral advance cutoff lateral &vertical advance lateral advance
due to surface advance to dip cutoff required for a saftey cutoff
variation
CAPACITY PLANNING AND
UTILIZATION
LECTURE 28
 PROBLEM
STATEMENT

Economics Condition Activities Equipment Public policy

Equipment
Guidelines Selection Evaluation
type
Operational
Encumbared
space
Geometric Equipment
Selection
design size
Evaluation

Limits and
failures

Performence
analysis

Suitable tests Completion

checks

Reselect or
alternative
EQUIPMENT FOR DRILLING
AND BLASTING
LECTURE 29
 Factors in drill performance

• Operating variables (drill, rod, bit and fluid)

(a) Drill power, blow energy and frequency, rotary, speed, thrust
and rod design;
(b) Fluid properties and flow rate.

• Drillhole factors (hole size, length, and inclination)

Hole diameters,
in surface 6 – 18 in. (150-450mm)
in underground 1.5-7 in. (40-175 mm)
Contd…
• Rock factors
• Properties of the rock,
• Geological conditions
• State of stress acting on the drill hole.

• Service factors
• Labour and supervision,
• Power supply
• Jobsite,
• Weather
Drill performance parameters
There are four parameters are measured or
estimated most frequently:
➢Process energy and power consumption

➢Penetration rate

➢Bit wear (life)

➢Cost(ownership + operating = overall)

DRILL SELECTION
• Determine and specify the conditions under the conditions under
which the machine will be used,
• such as the job - related factors (lobor, site, weather, etc...), with
safety the ultimate consideration.
• State the objectives for the rock breakage
• tonnage, fragmentation, throw, vibrations
• Based on blasting requirements, design the drill hole pattern for
surface mining or drill round if underground (hole size and depth,
inclination, burden, spacing, etc...)
Contd…
• Determine the drillability factors, and, for the kind of rock anticipated
identify the drilling method candidates that appear feasible
• Specify the operating variables for each system under consideration
including drill, rod, bit, and circulation fluid factors.
• Estimate the performance parameters, including machine availability
and costs, and compare.
• Cost /meter.
• Consider the power source and select specifications.
Selection also includes….
• Machines capability (pulldown, rotary torque, etc.) must exceed formation
penetration requirements.
• Maximum hole size capability increases with machine size.
• Larger machines are more rugged and can generally drill in harder
formations.
• A machine that can handle drill pipe long enough to permit single pass
drilling can significantly improve productivity.
• The production rate is dependent both on the actual penentration rate
and on the time required for pipe changes and machine repositioning.
• Electric drives have the lowest operating cost, the longest service life and
the best track record for reliability.
• Electric drives require an in-pit power distribution system.
• Three levels of pit and area mobility are available; low speed crawlers
(electric machines), medium speed crawlers (diesel machines) and
roadable high speed carriers (wheel mounted units)
• Dust control requirements are dictated by regulations.
• Optional equipment such as powered cable reels, automatic
lubrication, automated controls. Etc., can increase the efficiency of
the drilling operations.
• Long term productivity is dependent on the ruggedness, reliability
and maintainability of the design.
Drill selection
• Type of drill
• Type of bit
• Size of bit
• Power source
• Drillability (rate of penetration)
• Blasting factor
• Drilling factor
EQUIPMENT FOR
EXCAVATION
Lecture 30
CONTINUOUS MINERS – AN
UNIVERSAL CHOICE.

• Irrespective of the site, Continuous miners are the

first choice.

-For OC mine: compressive strength

of rock - up to 80 MPa it can be used.

-For UG mine: Protodyaknov index

>2.
 SELECTION

• Idealized output
• Operating factors
- working time
- operating conditions
- rock fragmentation

• Cost of the equipment- both installation and maintenance cost.

• Availability of spares - local or foreign manufacture.
SELECTION OF EXCAVATOR

1.Idealized output
Measure Soil Rock
(Tonnes/m3) (Tonnes/m3)
Bank (solid) 1.8 2.4

Loose (broken) 1.5 1.5

2.OPERATING FACTORS
2A.WORKING TIME
AVAILABILITY ACTUAL TIME
Favourable 55 min/hr , 7 hr/shift
Average 50
Unfavourable 40
2B.OPERATING CONDITIONS
CONDITIONS CORRECTIONS
Favourable 80% Average
70%
Unfavourable 60%
Contd…
• 2C.ROCK FRAGMENTATION

FRAGMENTATION TABLE OUTPUT

• Well blasted (easy) Larger figure

• Average (average) Average value
• Poorly blasted (hard) Smaller figure
ESTIMATING PARAMETERS FOR SURFACE
EXCAVATORS
Type of Capacity Estimate wt. Est. Power Est. Life Est. Price
excavator m3 Kg/m3 kW/m3 hr $/m3

Rubber tired 19 – 40 1,700 14 12,000 9,500

scraper

Front end 2.7 - 2.3 7,100 51 12,000 36,000

loader

Hydraulic 3 - 23 17,800 70 30,000 85,000

excavator

Electric power 4.6 – 57 32,000 40 75,000 144,000

shovel

Walking 6.9 – 138 68,000 99 100,000 275,000

dragline

Bucket wheel 0.1 - 4 - - 30,000 -

excavator
EQUIPMENT FOR HAULAGE
AND TRANSPORT
Lecture 31
• In OC mines around 55-60% of the mining cost goes
to Transportation.

• In UG mines around 30% of the mining cost goes to

Transportation.

• If distance is less than 500m then trucks are

preferable than conveyors.

• Conveyors are advantageous in longer distance.

• In NLC , Conveyor length = 14.5km(Second largest

conveyor in Asia).
 EQUIPMENT SELECTION

oSelection of primary equipment

oSelection of individual equipment

oSizing
o
oSelection of supplier
 FACTORS AFFECTING FOR THIS SELECTION
• Type of deposit
• Size of deposit
• Length
• Width
• Depth
• Location of deposit
• Production parameter
• Project life
• Capital available
• Performance factors
PRIMARY FACTORS ARE...
• DISTANCE

• GRADIENT/TERRAIN NATURE(FLAT/UNDULATION/SLOPE)

• TONNAGE

• CAPITAL AVAILABLE

• MATERIAL SIZE AND CHARACTERISTICS.

NOTE:
Average Standard working hour in a year by the HEMM in the surface mining operation.
With one shift operation/ day 1200 hrs
With two shift operation/ day 2000 hrs
With three shift operation/ day 2500 hrs
Life of the HEMM depends upon the system of good maintenance, proper handling and
working in the normal environmental condition.
Contd…
 PRODUCTIVITY AND AVAILABILITY NORMS FOR
HEAVY EARTH MOVING MACHINERY (HEMM)

1.Type of material to be excavated

S.no Rock type compressive category of Boundary
Strength rock values of
(kg/cm2) Compaction
factor*
1 Alluvium and up to 55 I 0.80
Soil
2 Soft shales 55 – 125 II 0.77
fireclay, etc..
3 Shales and soft 125 – 250 III 0.74
sandstone
4 Weathered and 250 – 1025 IV 0.71
hard sandstone
5 Granite and More than 1025 V 0.68
metamorphic
rocks
2. Dragline bucket cycle time, 90 degree swing angle.
Cat – I material 0.91 minutes
Cat – II material 1.04 minutes
Cat – III material 1.17 minutes
Cat – IV material 1.29 minutes
3. Dragline bucket cycle time, 100 degree swing angle.
Cat – I material 1.27 minutes
Cat – II material 1.41 minutes
Cat – III material 1.54 minutes
Cat – IV material 1.67 minutes
Contd…
4. Dragline bucket fill factor for 32m3 and 4m3 buckets.
Category of material
fill factor
(for 32m3 bucket) (for 4m3 bucket)
Cat – I 1.05 0.95
Cat – II 1.02 0.92
Cat – III 0.98 0.88
Cat - IV 0.95 0.85

Fill factor for sizes in between will be proportionate to above. Use of dragline in cat – 5 material is not
recommended.
Contd…
5.(a) electric rope shovel bucket cycle time:
Category of material (time in minutes)
(1800 swing angle) (900 swing angle)
Cat – I 0.55 0.44 Cat – II
0.50 0.47
Cat – III 0.61 0.50
Cat - IV 0.64 0.53
Cat – V 0.67 0.56
Contd…
(b) Hydraulic Shovel Bucket cycle time:
Category of material (time in minutes)
(1800 swing angle) (900 swing angle)

Cat – I 0.49 0.42 Cat – II

0.51 0.44
Cat – III 0.53 0.46
Cat - IV 0.55 0.48
Cat – V 0.57 0.50
Contd…
6. Time for spotting the dumper for shovel loading, 0.5 minutes for 35 t dumper and 0.6
minute for 120 t dumper. For all bottom – discharge dumpers it is taken as 0.6 minutes.

7. Time at dumper yard for dumper waiting, spotting and unloading -2.9 minutes for 35t
dumpers and 3.4 minutes for 120 t dumper.

8. Average dumper speed depends on type of dumper (electric wheel drive or

mechanical drive ) and the distance of haul. For 2 km lead, it is 22 and 20 km/hr
respectively, for 4 km lead, the figures are 27 and 25 km/hr respectively
Contd…
9. Availability of dumpers

Type 2 shift operation 3 shift operation

Mechanical 87% 67%
Electrical 89% 72%

In practice, it is found that practical availability figures for indigenous

dumpers is much below the above norms.
• 10.Annual output norms for commonly used draglines
and shovels on 3 shifts a day and 300 days a year
basis.

Assuming
50% OB : CAT – III
Draglines size Swing angle 5O% OB : CAT – IV
Annual output in
million cubic metre
10/70 900 1.30

1200 1.18

20/90 900 2.72

1200 2.46

24/96 900 3.31

1200 3.00
Contd…
Assuming

50% OB : CAT – III

Shovel size
5O% OB : CAT – IV
(Rope shovel) Dumper size
Annual output in million
cubic metre
4.6 cu m 35 t RD 0.79 (RD)

5.0 cu m 35 t RD 0.86

10.0 cu m 85 t RD 1.80

10.0 cu m 120 t RD 1.89

PERFORMANCE MONITORING
OF MINING EQUIPMENTS

Lecture 31
Monitoring parameters...
Availability
• Availability = --------------------------------------------

Available hours + downtime

Where available hours = Rostered hours – (downtime+ lost time)

if per day 2 hours is downtime.available hours is 22 hours , then availability is 22/24 =

.91*100=91%.
Utilized hours
• Utilization of availability = ---------------------------

Available hours

Where utilized hours = available hours – equipment idle hours.

In the above stated 22 hours of available time,if 20 hours are utilised the, utilisation of availability
is 20/22=.90*100=90%.
 Utilized hours
• Utilization = -----------------------------------------
Rostered hours – lost time

Utilized hours
• MTBF = -------------------------
Failure frequency

Where MTBF is Mean Time Between Failures that describes reliability of the equipment.
Example: if in a month 630 hours the equipment is utilized and 2 times it met a breakdown then MTBT is 630/2=315 hours.

Repair hours
• MTTR = -----------------------------
Failure frequency

Where MTTR is Mean Time To Repair that describes the maintainability of equipment and maintenance efficiency of the
organization.

Example: if the equipment fails 3 times and 5 hours ,2 hours,8 hours takes to repair it respectively , then
MTTR=(5+2+8)/3=5 hours.
So at average it takes 5 hours to repair if it fails.