Mechanization and Automation in Mining |
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Because
of the high proportion of wages in the cost of production,
mechanization is more necessary in mining than in almost any
other industry. On the other side, because of the difficult
conditions the mineral mined underground must be obtained,
the scope for mechanization of the actual production process
is limited. |
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Mechanization
is providing human operators with machinery to assist them
with the physical requirements of work. It can also refer
to the use of machines to replace manual labor or animals.
A step beyond mechanization is automation. The use of hand
powered tools is not an example of mechanization. |
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The
term is most often used in industry. The addition of powered
machine tools, such as the steam powered lathe dramatically
reduced the amount of time needed to carry out various tasks,
and improves productivity. Today very little construction
of any sort is carried out with hand tools. Among the earliest
developments in mine mechanization was the introduction of
locomotives to replace manual or pony haulage. In present-day
mining the operation of loading the mine cars, placing them
in the cage at the winding shaft, discharging the cars at
the surface, etc., are all performed automatically. |
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Underground
haulage in mine cars and the like has in part been replaced
by continuous conveying systems of various kinds such as belt
conveyors, steel-apron conveyors, chain conveyors, etc., which
can handle up to 600 or 700 tons of material per hour in the
horizontal direction and at gradients up to about 12 degrees.
Co-ordination of the various mechanical handling appliances
is ensured by control centers operating with automatic interlocking
optical and acoustic signaling systems in conjunction with
measuring and monitoring equipment, overall control being
assisted by remote indication of measured quantities, electronic
data processing by computers, and a variety of other up-to-date
aids. |
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Underground
drilling is now performed by large crawler-mounted power drills
equipped with high-alloy-steel or tungsten carbide tipped
tools. These tools have swivel mountings and hydraulic feed
mechanisms. They can drill blastholes at rates of up to 30m
(100ft) per minute. Blasting techniques too have been improved
in recent years and are safer and more efficient.
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Coal
cutters are used to get most of the coal mined by longwall
or other systems in Britain. A typical machine for longwall
work has a jib provided with a cutting chain fitted with tungsten
carbide-tipped cutter picks. The machine, which makes an approximately
5ft. deep horizontal cut, rest on the floor and hauls itself
along by winding a wire rope on a drum. |
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Loaders
and cutter-loading machines of American design were introduced
into Britain chiefly during and after the Second World War.
The majority of loaders employed in present-day mining are
of two main types: (1) shovels which pick up and empty in
sequence (2) gathering machines with integral conveyors in
continuous motion. Shovel-type mobile loaders have been developed
since about 1925 and are now widely used in certain types
of mining e.g., ironstone mining. |
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Mechanization
has also been applied to the construction of the supports
for underground workings. For e.g. a special type of anchor
bolt for roof lagging is secured in a drilled hole by means
of a screw thread and nut which expands the two halves of
a tapered split bushing, so that the bolt is gripped firmly
in the hole (Fig.4). A more elaborate and important device
is the fully mechanized remote controlled hydraulic chock
(Fig.5), which is used to provide temporary support in situations
where stability is very important, more particularly at the
working face. |
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Automation plays an increasingly
important role in the global economy and in daily experience.
Engineers strive to combine automated devices with mathematical
and organizational tools to create complex systems for a rapidly
expanding range of applications and human activities. |
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Many
roles for humans in industrial processes presently lie beyond
the scope of automation. Human-level pattern recognition,
language recognition, and language production ability are
well beyond the capabilities of modern mechanical and computer
systems. Tasks requiring subjective assessment or synthesis
of complex sensory data, such as scents and sounds, as well
as high-level tasks such as strategic planning, currently
require human expertise. In many cases, the use of humans
is more cost-effective than mechanical approaches even where
automation of industrial tasks is possible. |
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