Geoscience Reference
In-Depth Information
Table 13.
1
Material type classifications as of December 1999, Ujina
Material Type
Dispatch Code
Destination
Description
High-grade sulfide
SAL
Stock 1
TCu >= 2.0%
Medium-grade sulfide
SME
Stock 2
1.0% =< TCu < 2.0%
Low-grade sulfide
SBA
Stock 5
0.8% =< TCu < 1.0%
Marginal-grade sulfide
SMR
Stock 4
0.4% =< TCu < 0.8%
Sub-marginal grade sulfide
SSM
Stock 6
0.2% =< TCu < 0.4%
SAS
Stock 3
As > 100 ppm y
TCu >= 1.0%
High As sulfide
High-grade Oxides
OXA
Stock 10
TCu >= 1.0%
Medium-grade Oxides
OXM
Stock 12
0.6% =< TCu < 1.0%
Low-grade Oxides
OXB
Stock 11
0.3% =< TCu < 0.6%
Low-Oxi
OXL
Stock 30
TCu >= 0.2%, with clays and
Fe oxides
MIX
Stock 13
Mixed, TCu > 0.7%
Mixed
Waste Rock Types
IGS, IGC, RIO, SUE, PLR,
OTR
Waste dumps
Waste, TCu < 0.2%
Fig. 13.7
Blast holes, color- and
shape coded by destination, and
grade control panels based on
ID
3
interpolation. Blast hole
spacing is approximately 8 × 8 m,
and the area is 250 m per side.
Blast holes and panel hatching
represents Stocks 1 through 6 in
Table
13.1
to illustrate the performance of different grade control meth-
ods, even in deposits with relatively low variability.
Figure
13.7
shows a small area of Bench 4270 with the
Total Copper (TCu) blast hole grades and selection panels as
defined by ID
3
, which was the method used by the operation.
Figure
13.8
shows the same area with panels as defined by
the BEI method. And finally, Fig.
13.9
shows the comparison
of the panels defined based on these two methods. In this
area only sulfide material was present, corresponding to des-
tinations (Stocks) 1 through 6 in Table
13.1
. These figures
demonstrate that, locally, the differences among the different
grade control methods can be significant.
The comparison among the four methods tested was made
against a reference model corresponding approximately to
