Exploration and Resources in Section 1.2.3
Engineering
The 2010 engineering program is designed to assess a range of options to optimize the project
scale, including: trade-off studies of major project components; metallurgical studies to determine
the optimal conventional processing systems and designs; and evaluations of the major
infrastructure elements to identify the optimum alternatives and designs for these project
components.
During the third quarter, the scope of work for the 2011 work program was developed.
Metallurgy
The next round of metallurgical testwork started at the beginning of the quarter, and commenced
with the preparation of 104 new variability samples from untested 2008 Pebble West metallurgical
drill core.
Additional comminution tests were conducted to expand the grinding parameter database for
future modeling purposes. In total, slightly more than 140 tests of various types were completed on
samples from untested 2008 metallurgical drill core.
A total of 236 additional variability composites from the Pebble East and Pebble West areas were
submitted for mineralogy studies using scanning electron techniques. The purpose of this work
was to assist in the development of the geometallurgical model, and to group the metallurgical
variability samples into their respective domain types.
Copper speciation data was incorporated into the block model as previous metallurgical work
found copper speciation to be an important variable in the predictive recovery equations for
copper, gold and molybdenum.
Flotation optimization testwork was conducted on previously tested variability samples that
displayed lower than expected molybdenum recoveries. Samples representing a range of
molybdenum head grades and clay content were selected. The optimisation work shows improved
molybdenum recovery with increased reagent dosage.
Flotation batch and locked-cycle testwork began on samples from untested portions in the Pebble
East area. Seven new samples were tested during the period. Data collected from this work will be
used to update the predictive recovery equations for copper, gold and molybdenum. Initial results
are similar to previous flotation testwork for Pebble East. Additional samples will be tested in the
fourth quarter.
Viscosity testwork was also completed which examined the behavior of pulps with varying clay and
solids content. The purpose of this work was to assist in the verification of the maximum
volumetric throughput limit for semi-autogenous grinding. Results of this work will be available
during the next reporting period.
Four two-tonne test composites were prepared from the present inventory of Pebble East and West
metallurgical variability samples for continuous flotation testwork. The composites were prepared
to represent the four major geometallurgical domain types in the deposit. The purpose of this work
is to provide a product for future testwork, to evaluate the potential of gravity recovery within the
regrind circuit, and to confirm the laboratory-scale recoveries from locked-cycle tests. Work
conducted in September focused on commissioning the continuous flotation plant. A 10-tonne
commissioning sample, consisting of grinding reject material from Pebble West, was used for this
purpose. The actual testwork commenced toward the end of the quarter. Results from the domain
samples will be available during the next reporting period.
The investment strategies/thoughts expressed here are my opinions alone. E-E stands for non Encrypted-English.
