A OPEN PIT MINING AÇIK OCAK MADENCİLİĞİ

economical. As described before, the
location of an in pit crusher should have the
following conditions:
1. It should be within an optimum distance
from each working face.
This will reduces the total distance
between the crusher and the working faces,
so, the system will require less number of
trucks in the faces. Hence the capital and
operational cost of truck fleet reduces. The
optimum distance from each working face
should consider the total amount of material
that must be mined from each working face
according to the mine production plan. This
item brings the IPC location to the center of
gravity of working faces.
2. The location of the crusher must be fixed
at least for a period of one year.
The optimum location of an IPC must be
fixed for a period of time. Because working
faces are dynamic and the pit shape changes
through time, therefore, in determining a
location for an IPC, the mine plan and
working schedule should be taken into
account. A suitable location would be the
one which is not inside the mine working
area at least for a period of one year. If this
point is not considered then the number of
times that the crushing facilities is removed
and reinstalled will increase. With respect to
the fact that removing and reinstalling of the
crusher unit requires time and it is costly,
these operations could disturb the mine
production schedule. This problem is more
considerable in semi mobile operations. In
case of mobile operations, mine production
will not stop because of crushing facilities
reinstallation.
Based on the above discussion, one
should identify the possible locations for the
IPC taking into account that these locations
will not be mined during the next year. Then
these locations are assumed as the potential
hub nodes. Finally applying and solving the
single hub location problem, one could
optimize the location of the in pit crusher.
These steps are given in Figure 7.
Here comes a simplified example to show
the application of single hub problem in
determining the IPC location. Suppose that
the geometry of the pit as equal to the one
given in figure 8. The unit operation in this
example is supposed to be semi mobile
operation. This type of operation requires a
number of shovels, trucks and an in pit
crushing and conveying unit. Suppose that
there are 3 working faces in a mine and they
must be mined according to the mine annual
plan. Each working face has a known
amount of material to be mined according to
the mine schedule. This fact causes the hub
location to be near the larger working faces
which contains considerable amount of ore
(or waste) compared to the other faces.
Figure 7. Steps required to find an optimum
location for the in pit crusher
Figure 8. Shape of a hypothetical open pit
and its working faces
In Figure 8, C1 and C2 represent the
candidate crusher locations and working
faces are represented by F1, F2, and F3.
Considering the mine plan, there are 2 sites
which are not inside the working area of the
mine (C1 and C2 in Fig. 8). One could take
the advantage of decision making techniques
to select and rank the candidate location of
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