5
Vertical Cave Progression (dY)
Vertical cave progression relative to each PB4 drift are mea-
sured every quarter and compared to the height of draw
(HOD) differences. Ratio of vertical changes (dY) to HOD
expansion (dHOD) is called cave-growth ratio. Looking at
the skewness of the distribution curve, the median (2nd
quartile) is then used for the data (Figure 6). Statistical
analysis shows that 1 m of HOD pulling is equal to 0.69m
vertical fractured/ yielded zone growth.
Horizontal Cave Progression (dX)
Similar approach is made to the X-lateral progression
of cave as well (Figure 7). A non-significant horizontal
advancement is seen from the data, where 0.01m of lateral
progression happen when 1m HOD drawing produced.
Based on the data mentioned above, it is apparent that
material drawing in PB1 and 2 have affected more to the
vertical than to the horizontal progression.
Figure 6. PB1-2 Vertical Cave Propagation Ratio
Figure 7. PB1-2 Horizontal Cave Propagation Ratio
Draw Strategies at Production Block#2
The cave progression correlation with draw strategies allows
the prediction of time remaining for the PB2 (2590/L) cave
to grow until it reaches the minimum 50 m thickness of
the lower wedge pillar at PB4 (2815/L). The total length of
HOD that we are allowed to pull till the minimum pillar
is around 250m (where 1m HOD equals to 0.69m vertical
cave progression). Through various draw scenarios per day
from 3 to 20 buckets per shift, the mine is allowed to be
pulled ranging from a max 9.8 years and drops to 1.5 years
only (Figure 8).
As the development at PB4 and production at PB2
advance at the same time, this prediction permits the abil-
ity to safely develop new drifts while achieving targeted
metal or reserves recovery from the southern perimeter
draw points.
Vertical Cave Progression (dY)
Vertical cave progression relative to each PB4 drift are mea-
sured every quarter and compared to the height of draw
(HOD) differences. Ratio of vertical changes (dY) to HOD
expansion (dHOD) is called cave-growth ratio. Looking at
the skewness of the distribution curve, the median (2nd
quartile) is then used for the data (Figure 6). Statistical
analysis shows that 1 m of HOD pulling is equal to 0.69m
vertical fractured/ yielded zone growth.
Horizontal Cave Progression (dX)
Similar approach is made to the X-lateral progression
of cave as well (Figure 7). A non-significant horizontal
advancement is seen from the data, where 0.01m of lateral
progression happen when 1m HOD drawing produced.
Based on the data mentioned above, it is apparent that
material drawing in PB1 and 2 have affected more to the
vertical than to the horizontal progression.
Figure 6. PB1-2 Vertical Cave Propagation Ratio
Figure 7. PB1-2 Horizontal Cave Propagation Ratio
Draw Strategies at Production Block#2
The cave progression correlation with draw strategies allows
the prediction of time remaining for the PB2 (2590/L) cave
to grow until it reaches the minimum 50 m thickness of
the lower wedge pillar at PB4 (2815/L). The total length of
HOD that we are allowed to pull till the minimum pillar
is around 250m (where 1m HOD equals to 0.69m vertical
cave progression). Through various draw scenarios per day
from 3 to 20 buckets per shift, the mine is allowed to be
pulled ranging from a max 9.8 years and drops to 1.5 years
only (Figure 8).
As the development at PB4 and production at PB2
advance at the same time, this prediction permits the abil-
ity to safely develop new drifts while achieving targeted
metal or reserves recovery from the southern perimeter
draw points.