This document discusses various methods for transporting coal after excavation from mines. It describes surface mining and underground mining extraction techniques. Several transportation methods are then outlined, including railroad trains, coal slurry pipelines, barge transport, highway trucks, and conveyor belts. Key details are provided about how each method functions as well as their advantages and disadvantages for moving coal efficiently over long distances.

1. Submitted to:
Mam Sumaira kanwal
Submitted by
Navira Younas
Roll no# 22
25/June/2015

2. Coal:
Coal is heterogeneous,
sedimentary organic rock. It
originates from plant material,
under elevated pressure and
temperature for a long period of
time.

3.  Generally Coal is extracted by two mining methods:
1. Surface mining
2. Underground mining
Surface mining:
If coal seam is near to the surface,
then it can extracted by surface mining methods.
Underground mining:
While if coal seam is
under considerable depth, then it is extracted by
underground mining methods.
 After excavation of coal, transportation of coal
from mine to plant is necessary for usage of coal.

4.  Seam height
 Reserve tonnage
 Desired daily production
 Number of shifts worked per day
 General shape of property
 Seam contours
 Character of roof and floor
 Average seam rejects
 Daily tonnage of mine rock handled
 Type of mining equipment
 Mining plan and general projections
 Maximum length of main haulage

5. Air pollution
Water pollution
Solid wastes
Noise level
Safety hazard
Traffic hazards
Direct environmental impacts:
Direct environmental impacts
can occur at the mine, where the coal transferred, transported or
loaded.
Indirect environmental impacts:
Indirect environmental
impacts from coal transportation largely results from the
combustion of fuel for the transportation itself.

6. Following equipments are used for
transportation of coal:
1. Railroad trains
2. Coal slurry pipelines
3. Barge transport
4. Highway trucks
5. Conveyers belt

7. The two types of train configuration used for transportation
of coal
 General freight train
 Designated unit train coal
 General freight train:
A general freight train carries numerous types
of cars, some of which can be coal carrying hopper cars. General
freight trains typically handle from 1500 to 6000 net tons. Typical
haul distance for coal being moved by general train is 100 to 500
miles.
 Designated unit train:
The specifically designated unit coal only
handles coal from a single origin to a single destination so that it much
faster and cheaper than the general trains for coal movement. Unit

9.  In a coal slurry pipeline, the coal must first be ground to a uniform size of
100%-14 mesh with not more than 20%-325 mesh by successive crushing
and pulverization. The coal is then distributed in the liquid phase by
agitation and mixing and passed through the pipeline to the end use point.
Coal slurry pipeline can make use of water, methanol, crude oil, or other
liquid transport medium. The coal is separated from liquid phase at the
destination for subsequent use in combustion. The liquid may then
disposed of by reuse or as fuel, discharge to receiving waters or returned
to the point where the coal is added the pipeline.
The major variables affecting slurry pipelines
 Pipe diameter
 Pipeline length
 Slurry velocity
 Solids concentration.
 Slurry pipelines can ranges up to 48 inches in diameter and
can have length ranging from 100 to 1200 miles. Solids flow velocity is
about five feet per second.

10.  Slurry pipelines have following advantages:
 It can be able to move large amounts of coal over long distances.
 Efficient cost with minimum potential for en-route environmental disruption.
 Operating costs for labor is low.
Disadvantages:
Two major disadvantages of slurry pipelines are:
 Water requirements.
 Low degree of operational flexibility.
A source of water is required in the amount of 220 to 270 gallons per ton of coal moved
for a one-way, once through slurry pipeline.
Water consumption can be reduced to between 50 to 75 gallons per ton of
coal if a two-way recirculating slurry pipeline is employed. It can also be reduced by using
methanol and crude oil as a transport medium.
The major operational problem is operational flexibility because of the critical transport
velocity.

12.  Coal is normally moved in open hopper barges which range in
capacity from 1,000 to 3,000 net tons, with average of
1,500 net tons. Ten to s barges are normally located in
series. A typical shipment will contain up to 30,000 net tons
of coal moving in 10 barges at an average speed of 6 miles
per hour.
 Fuel requirements for barge movement:
Fuel
requirements for barge movement of coal can be low as 300
to 500 Btu per net ton-mile for downstream movement of
large barges, or as high as 800 to 1100 Btu per net ton-mile
for upstream movement or coastal movement in small
barges. The potentially significant environmental impacts of
waterways movement of coal are dust loses during loading,
unloading or transport, oil losses from fuel systems of barges,
and the emissions from towboat fuel combustion.

14.  There are two type of trucks used in surface mining:
 Off high way
 Regular
 Off high way:
Off high way trucks are used for haulage because of their
inbuilt ability for continuous uninterrupted operation.
They are of two types:
1. The bottom dump
2. The rear dump trucks
 The bottom dump trucks will handle aggregate and unconsolidated
materials and dump while in motion. The gradient for their efficient
operation is 4%. They are primarily used for coal haulage.
 The rear dump trucks are of three types:
i. Small to medium two axel trucks: good for small pits.
ii. Large two axle trucks: can handle large loads and negotiate steep
gradients.
iii. Large size three axle trucks.

15. Trucks do suffer from several disadvantages
relative to other transportation methods:
 Highest unit energy consumption
requirements.
 Highest net operating cost.
 Greater external damage to highway.

17. Conveyors enable continuous transport of overburden or coal. They are the coal economic means of
transport in coal seams with more than 10-12° inclination for working in deep pits 250 m or
more where truck transport will become uneconomic. The belt conveyors can be worked up to a
gradient of 1 in 3 and thus lead distance is shortened. Besides, belt conveyor are not affected by
rain whereas haul roads are deteriorated in rains.
 Advantages :
 Conveyor haulage is less sensitive to inflanationary pressures and to fuel shortage.
 Conveyor haulage is much less labor intensive.
 Conveyor haulage is environmentally preferable, because it is much quieter and has fewer
particulate emissions.
 Lower unit cost may extend the economic pit life.
 Operation is less sensitive to inclement weather.
 Conveyor is more reliable. They can achieve an availability of 90-95%.
 Disadvantages:
 The initial cost of conveyor is high.
 It is location inflexible, which making a truck haul still necessary.
 Coal dust losses during loading, unloading and transport have adverse environment impact.

18. There are many types of belt conveyors used:
1. Cross pit conveyor
2. High angle conveyor
3. Shift able spoils conveyor
 Cross pit conveyor:
It can result in lower capital and transportation costs. Loading of
cross pit conveyor can be done by dragline, face shovel, bucket wheel.
 High angle conveyors:
 High angle conveyors can build with belt widths of up to 3m to carry up to 9000 t of
material/hour, provide a lift of over 300 m with steel cord belt and angle of slopes of
up to 60°. The major advantages of high angle conveyors are:
 More efficient use of energy.
 More efficient for elevating material to great heights.
 Less labor intensives.
 Shift able spoils conveyors:
It conveys the overburden material from the
collecting conveyors to the mobile tripper car and is located on the edge of the backed
filled benches. The shift able conveyors are stationary.

20. As an alternative
solid fuel movement, energy in coal can be sent
indirectly to the point of end use via electrical
transmission. Transmission of electricity can
occur as either alternating or direct current, but
in US it is transmitted by high voltage alternating
current. Electricity is normally transmitted at
138,000 volts near load centers, but is usually
transmitted at either 345 kV or 765 kV over
extended distances.

22.  The greatest single environmental problem from
coal transportation is coal dust entertainment.
Adding water to coal can significantly reduce
dust entertainment; the critical dusting moisture
content varies with the type of coal. The use of
covered hopper cars is not practical for coal
transport because of loading difficulties.
Chemical additives as well as crude oil or
kerosene can also be added to coal, but may also
undesirable pollutants.