Mining_Methods_UnderGround_Mining - Mining and Blasting

nanJing, CHina
Wagner service truck doing the rounds of the mine.
thickness of 292.50 m and a minimum
thickness of 2.56 m, giving an average
thickness of 134 m. The deposit is esti-
mated to contain reserves of 260 million t
of predominantly Fe 3 O 4 iron ore.
The mine entrance is located 37 m
above sea level (ASL), where the first
phase of development got underway in
1975, and the ore is currently mined at
-243 m ASL.
Idealized long section of mine.
Southwest
ventilation
1# Main shaft 2# Main shaft
+31.50 m +37 m
–447 m
development
Phase One of the Meishan development
plan comprised shaft development, underground
stoping and sub-level caving.
There are six shafts, three for hoisting
(main, secondary and southwest), and
three for ventilation (south, southeast
and west). The main ramp, built in
2000, is connected at its lower end to
RAMP
Southeast
ventilation
+47 m
–186 m
–198 m
the horizontal mining area at the -198
m level. The mining process consists
of development drifting, rock drilling
for stoping, back-stoping and recovery,
transportation, and ore hoisting, in which
Meishan has pioneered the introduction
of mechanization.
In this respect, the mine has been
working hand in hand with Atlas Copco.
It installed its first Atlas Copco Simba
H252 drill rig in April, 1993, and now
operates 11 Atlas Copco rigs. Of these,
three Simba H252, one Simba H254
and two Simba H1354 rigs are used for
production drilling, while four Boomer
281 and one Rocket Boomer 281 are
used in development. In addition, two
Scooptram ST1020 loaders are employed
on production.
The Simba rigs drill 76 mm blast
holes, while the Boomer rigs drill 76 mm
cut holes and 48 mm blast holes. All
drifting and medium-to-long hole dril-
ling is carried out by Atlas Copco drilling
rigs. This equipment has been instrumental
in enabling Meishan to continuously
improve its productivity and
efficiency, year on year.
For example, from 1995 to present,
the number of workers employed in drif-
ting has been successively reduced from
more than 500 to 160, and the number
of miners has also diminished significantly.
During the same period, productivity
has been substantially increased
(see table).
Meishan is in operation approximately
300 days/year, and drifting and mining
teams comprise two men per drill
North
ventilation
–198 m
–213 m
–228 m
–243 m
Shaft for
personnel hoist
116 underground mining methods
–258 m
–330 m