Subject of 6th Semester BS Mining Engineering.

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(Balochistan University of Information Technology,
Engineering & Management Science, Quetta)
(Features of Mine-Machines)
SUBMITTED TO: Engg. Fawad-ul-Hassan
SUBMITTED BY: Ghulam Mehdi
SUBJECT: Mine Power ,Drainage & Material Handling
CMS ID: 23101
DEPT: BS Mining Engg. 6th
, (Fall-12)
DATE: 11-05- 2015
……………………Buitems,Quetta……………………………

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Features of Machines
Continuous Operation:
The machines combine the breakage and handling functions, cutting, drilling and blasting are
eliminated, and extraction and loading are performed in a single function (excavation).
Cyclic Operation:
The machines performed the two principal operations loading and haulage, with hoisting an
optional third when essentially vertical transport is required.
Conveyor System:
Surface/Underground Equipment
Continuous Operation
The most common conveyor systems of haulage are the belt conveyors, but there are also scraper
chain conveyors and cable belt conveyors.
Portable Stacking Conveyor
Belt Conveyor:
Modern belts are made of a number of materials, including cotton, canvas, leather, neoprene,

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nylon, polyester, polyurethane, urethane, PVC, rubber, silicone and steel.
A belt conveyor consists of two pulleys located at either end of the machine, and a continuous
belt that rotates on them. The powered pulleys move the belt and any material on it, forward.
There are mounted carrying idlers and return idlers. In order to achieve a tough shape to
accommodate more and more fragmented material, the carrying idlers mounted on the sides are
fixed at 20-30 degree to the horizontal. A driving unit installed at its one ends having a motor,
gears, driving drum and other fittings to start, stop, or run the belt. At the other end a take-up
pulley is fitted to provide necessary tension to the system. At the discharge end a belt cleaner
cleans any adhered material.
The belt conveyor classified into three types, based on mobility from one place to another.
 Stationary
 Mobile
 Portable
The belt conveyor also classified into three types, based on their path.
 Horizontal
 Inclined
 Combination of Horizontal & Inclined
Cable Belt Conveyors:
In this type of conveyor system the belt is relieved from the tractive force which is transferred to
the ropes, which are attached at both sides of the belt all along its length. A cable belt conveyor
system consists of:
 Two endless ropes, which are supported on the rollers & pass over the drum or pulleys at
both ends.
 Spring steel strips embedded in the body of the belt. To these strips are mounted the steel
shoes which grip the ropes.
 The belt conveyor itself, which could be of a single ply construction.
It is the cheap quality belt with less number of piles. It could be of longer length. The only
problem is the complicated construction at both ends of this installation.
Scraper Chain Conveyors:
These types of conveyors have been designed to withstand rigorous mining conditions
particularly at a working face, which is always advanced ahead. These conveyors can negotiate
gradients of more than 18 degree. These conveyors are easily extendible without dismantling but
their length is limited & usually not more than 200m. A scraper chain conveyor consists of the

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troughs, endless chain, sprocket wheel, drive head having motors, gears, tensioning devices and
other parts.
Chains are the important part of the scraper chain conveyors. Chains should be of high breaking
strength and longer life. Also their design should be such that damaged links can be easily
replaced
Conveyors are used in a wide variety of industries including industrial, mining and automotive.
The technology has even been adapted into moving sidewalks and escalators.
Advantages:
 Continuous operation
 High production
 Low operating cost
Disadvantages:
 Capital cost
 Material size
Truck:
Surface/Underground Equipment
Continuous Operation
A truck is a vehicle used for carrying materials or for towing other vehicles and trailers. Trucks
can be used for a variety of purposes, both industrial and commercial. In addition to transporting
materials great distances, they can also haul and tow large objects not feasibly towed by a car,
such as farm equipment, cattle, supplies, trailers, recreational boats, and homes.
Features:
The features of a truck can vary from type to type. The typical truck, commercial or industrial,
contains only two passenger seats.
Trucks, particularly heavy-duty trucks, have a series of clutches, gears, and pedals to help
facilitate a smooth drive. Trucks without a synchronizer to accompany the transmission use
double clutching for each shift to help change gears. Double clutching can help the driver operate
the engine and control the transmission power so the revolutions are synchronized, allowing for a
smooth shift to be achieved.
The internal configuration of a heavy-duty truck calls for a manual transmission without
synchronizers to cut down on the bulk and weight that the synchronizers add. It is not
uncommon, however, to see synchronizers used in conjunction with some large truck

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transmissions.
Advantages:
 Handles coarse materials
 Flexible and maneuverable
 Considerable speed 30 to 45 mph
 Diesel powered
 Good traction with maximum load applied
Disadvantages:
 Requires good haul roads
 High operating cost
 Slow by bad weather
Bucket Wheel Excavator (BWE)

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Surface Equipment
Continuous Operation:
The bucket wheel excavator (BWE) is a machine that digs and excavates dirt continuously with
the help of buckets, chutes, and a conveyor apparatus. BWEs are used for cross-pit mining and
large construction projects.
BWEs Advancements including mounting them on crawler and wheeler bases to allow them to
move forward for continuous excavation developed through time. The power and complexity of
BWEs mean that they can take as much as five years to build but in return they are capable
of mining more than 313,908 cubic yards (240,000 m3) of earth per day.
BWEs are typically some of the largest machines on earth, weighing as much as 11,000 tons and
standing hundreds of feet tall.
Features:
The first BWEs were powered by steam and mounted on railway tracks. Traditionally, the
buckets would empty dirt into carts that could be driven on the railroads. Eventually they became
electric and were driven with hydraulics and oil engines.
In their early days, BWEs consisted of booms that were raised and lowered by cables pulled by
men. Eventually, manpower was replaced by winches that raised the cables of the excavator.
To excavate materials continuously, the BWE uses a rotating wheel that is positioned at the rear
of the boom. The wheel consists of backets, also known as buckets. It can have any number of
buckets, depending on the project and model. The rotating wheel penetrates the face while the
boom swings from both sides and the bucket collects the dirt. As the material falls onto the
conveyor belts, it is transported to further conveyors until it reaches a discharge point. The
conveyors used are usually connected so they can be dismantled when the BWE needs to be
transported.
Advantages
 Continuous operation; no swinging necessary.
 Long discharge range.
 Can be operated on a highwall bench or on the coal seam.
 Can easily handle spoil with poor stacking characteristic and poor stability.
 Can extend range of shovel or dragline when operated in tandem.
 Can facilitate land reclamation as it dumps surface material back on top of the spoil pile.

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(Diagrammatic BWE Sketch)
Disadvantages
 Will not dig hard materials.
 Some surface preparation required.
 Lower availability.
 Large maintenance crew required.
 High capital cost compared with output.
 Can be susceptible to spoil slides and flooding.
 Can cause coal damage with resulting lower coal recovery.
 Poor mobility.
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