65
Table 2. Illustrates the drilling pattern that gives the level of confidence in resource classification.
Drillhole spacing (m)
Grade (v1)
Thickness (v2)
Resource
Measured
100 × 200
100 × 200
Classification
Indicated
100 × 400
100 × 400
Figure 6. Mean of the accuracy around the mean within a 90% CI from the five scenarios rescaled into
quarter and annual basis – Thickness (v2).
3 CONCLUSION
Considering that the value of mining companies, the investments and benefits to shareholders revolve around millions of dollars, it is critical to quantify the level of confidence on
resources estimation and classification to have a reliable estimation of the mining assets. As
the drillholes represent a sample of the reality to be understood, and the level of geological
knowledge impacts on the mineral resources estimation and classification, there is a genuine
need for companies to assess the pattern of drillholes that are suitable for a robust economic
evaluation of an operating mine or mineral exploration project.
In this paper, an approach integrating drilling spacing simulation techniques with the
resource classification proposed by Verly et al. (2014) is described and its applications
explored. The approach is based on conditional simulations, which take into account the
spatial variability of the studied variables, and the uncertainty analysis associated with each
drilling mesh and production volume is computed for resource classification.
With the proposed approach, it is possible for the mining companies to estimate the risk
attached to a range of drilling patterns, even during the early stage exploration program, in
order to create a systematic drilling campaign considering the risks and the impact on the
mineral resources classification of each drilling pattern. The results of the combined method
is a guideline for the companies to support their decision making for additional drilling campaigns, thus reducing geological uncertainty and converting the resources into measured or
indicated.
25.0%
20.0%
~
0
"' 15.0%
'=!
> u
~ 10.0%
u
u
<(
5.0%
0.0%
100x100m
100x150m
Thickness (v2)
100x200m
100x250m
100x300m
100x400m
Drill hole Spacing (m)
-
Yea r -
Quarter
Table 2. Illustrates the drilling pattern that gives the level of confidence in resource classification.
Drillhole spacing (m)
Grade (v1)
Thickness (v2)
Resource
Measured
100 × 200
100 × 200
Classification
Indicated
100 × 400
100 × 400
Figure 6. Mean of the accuracy around the mean within a 90% CI from the five scenarios rescaled into
quarter and annual basis – Thickness (v2).
3 CONCLUSION
Considering that the value of mining companies, the investments and benefits to shareholders revolve around millions of dollars, it is critical to quantify the level of confidence on
resources estimation and classification to have a reliable estimation of the mining assets. As
the drillholes represent a sample of the reality to be understood, and the level of geological
knowledge impacts on the mineral resources estimation and classification, there is a genuine
need for companies to assess the pattern of drillholes that are suitable for a robust economic
evaluation of an operating mine or mineral exploration project.
In this paper, an approach integrating drilling spacing simulation techniques with the
resource classification proposed by Verly et al. (2014) is described and its applications
explored. The approach is based on conditional simulations, which take into account the
spatial variability of the studied variables, and the uncertainty analysis associated with each
drilling mesh and production volume is computed for resource classification.
With the proposed approach, it is possible for the mining companies to estimate the risk
attached to a range of drilling patterns, even during the early stage exploration program, in
order to create a systematic drilling campaign considering the risks and the impact on the
mineral resources classification of each drilling pattern. The results of the combined method
is a guideline for the companies to support their decision making for additional drilling campaigns, thus reducing geological uncertainty and converting the resources into measured or
indicated.
25.0%
20.0%
~
0
"' 15.0%
'=!
> u
~ 10.0%
u
u
<(
5.0%
0.0%
100x100m
100x150m
Thickness (v2)
100x200m
100x250m
100x300m
100x400m
Drill hole Spacing (m)
-
Yea r -
Quarter