Mining_Methods_UnderGround_Mining - Mining and Blasting

Refill of waste
Rill mining in progress.
garPenBerg, Sweden
Cut off slot
approximately 17 m-long, holes are
blasted into the void. Three rows having
a total of 24 holes are blasted simultaneously.
After mucking out each blast,
new waste is discharged into the stope
forming a 45 degrees rill down into the
drawpoint. As the waste material will
stay quite stable at 45 degrees rill angle,
the risk of ore dilution is negligible.
Output limitations
The total mine output is restricted to
the 1.2-1.3 Mt/y hoisting capacity
Drill pattern for cut off slot.
Waste
Rill mining in progress
Blasted ore
available, with a limited amount of
truck ore haulage to surface possible.
And, although flotation capacity has
been improved, concentrator throughput
is now limited to the same sort of
tonnage by grinding mill capacity.
Assuming demand for Garpenberg concentrates
increases in the near term, it
will be necessary for New Boliden to
decide whether to increase hoisting
capacity.
Developing the now-available reserves
for higher long-term production using ad-
ditional hoisting and processing capacity
might double the amount of investment
initially planned.
new drilling technology
Atlas Copco has supplied drilling equip-
ment to Boliden’s underground mines
for many years. Recently, the company
has worked particularly closely with
Garpenberg on the development of
computer-based technology for more
precise drilling and blasting to enhance
productivity and reduce ore dilution and
operating costs.
50 underground mining methods
1.8 m
8 holes in each fan Ø 70 mm
3 fans in one blast
45°
One fan
Max
2 m
70°
Approx. 15 m
Approx. 15 m