Institut za rudarstvo i metalurgiju Bor

Start-minute maximum intensity of
daily rainfall for the period of 50 years in
the period of 30 minutes is 4.12 mm / min,
and medium intensity rainfall in the period
of 8 hours, authoritative for the calculation
of normal flow caused by atmospheric
precipitation is 0.08 mm / min.
Maximum daily amount of surface water
caused by atmospheric precipitation,
which is released into the open pit is
14 000 m 3 . The amount of atmospheric
water caused by rainfall that reaches the
prospect of normal inflows is 735 m 3 .
Maximum inflow of ground water is
estimated at 500 l/s. Normal influx of
ground water is 40 l/s.
Maximum daily inflow of underground
water is during the extreme rainfalls and is
43 200 m 3 . Normal daily inflow of underground
water is 3 450 m 3 .
Total maximum inflow into the pit of
surface and ground water is considered as
the relevant for dimensioning the pumping
plant at the open pit, amounts to 57 200 m 3 .
SYSTEM FOR WATER PUMPING
At the open pit “Potrlica“ , two types
of pump, manufactured by “Jastrebac”
from Niš are in operation:
• Pipe pumps BP 300 – 1 engine
power 132 kW, and
• Centrifugal pumps VPN 251 – 3 engine
power 475 kW.
System for water pumping is the following
[2]:
• The temporary water sump is located
at the lowest bench of open pit with
2 pumps, type
• BP 300 – 1. Water is pumped from
bench level K+632 m, pipeline
length is 50 m.
• The water from auxiliary water sump
is pumped into the main water sump
at level K+643 m, where 4 pumps,
type BP 300 – 1, are located.
• From the main water sump, the water
is pumped through pipeline, length
160 m to the level K+656 m where 4
pumps, type VPN 251 – 3, are installed.
The pumps BP – 300 – 1 and
VPN 251 – 3 are directly connected
with pipeline.
• From the level of K +656 m, the water
is pumped to the water sump at
level +758 K m, by pipeline of 970
m length.
One section of pumps for water pumping
from the main water sump to the settling
tank are connected by a serial BP 300-
1 pump and VPN 251 – 3 pump. Such four
section are in operation at the open pit.
Figures 1 and show the line diagram of
drainage system and spatial position of
pump facilities, and Figure 3 shows the
operation diagram of one section.
Operation points of pumps at auxiliary
and section on the main water sump are
given in Table 2.
No 1,2010. 99
MINING ENGINEERING