1. I
Abstract
This research investigates the contribution of the spatial arrangement of hydrophobic
mineral grains at particles surface towards their flotation response and its implications for
forecasting flotation response. The approach taken was to estimate this grain textural
characteristic from particle sections and to identify how it affected the overall rougher and
scavenger copper mineral flotation recovery from two industrial copper flotation circuits.
For the second circuit, the overall rougher flotation kinetic parameters for the copper
mineral were also evaluated.
The first contribution of this work is the demonstration that a novel textural indicator is
relevant to understanding the contribution of exposed mineral grain texture on the flotation
process. It is the first mineral grain textural indicator that considers both the size of the
grains and the degree to which they are dispersed at the particle surface. When the
indicator was applied to particle sections from flotation feed, concentrate and tail samples
from two industrial copper flotation circuits, it was shown, for the first time, with confidence
that while particle size and perimeter composition affect particle flotation response the
spatial arrangement of the copper mineral grains at the particle surface plays a key role.
For the iron-oxide-copper-gold ore, copper mineral grains in complex texture classes
produced statistically higher overall rougher recoveries for the 0-20% perimeter
composition class. Chalcopyrite grains in complex texture classes in the copper porphyry
ore produced higher overall rougher and scavenger recoveries for the 20-40% perimeter
composition class. For the 0-20% perimeter composition class, statistically meaningful
differences were observed for the +106 m size class. It was shown that the higher
overall recoveries for the complex texture classes, in this case, were due to increases in
the overall rougher rate of flotation, the proportions of recoverable chalcopyrite in the feed
or both. For both ores, the largest proportions of copper mineral within complex perimeter
texture classes were within coarse particles and complex textures were less common
when particle perimeters comprised more than 40% of the copper minerals. This
demonstrated that in order to study the impact of this textural characteristic for the two
ores it must be done within well-defined particle size and perimeter composition classes,
an important outcome that has not been reported in the current literature.
The second contribution is a three-step method for evaluating the flotation response of
copper minerals within different grain texture classes namely; particle perimeter texture

2. II
estimation, determining coefficients of variation in the mass proportions of the target
mineral within perimeter texture-composition classes and mass reconciliation and recovery
calculations. Another key contribution is in applying the bootstrap resampling technique to
estimate these coefficients. This demonstrated the sensitivity of seemingly feasible
perimeter texture-composition classes to the grade of the copper minerals in a sample and
a notable finding was that the feed size classes for both ores were adequate for
determining the final perimeter texture-composition classes for assessments.
A third contribution is a demonstration that an empirical equation incorporating the
textural complexity of exposed copper mineral grains can be used to more accurately
predict the flotation response of copper minerals in complex texture classes. It applies the
flotation response (overall rougher recovery, overall rougher rate of flotation) versus
perimeter composition relationships of copper minerals with simple exposed grain textures
and adjusts the effective perimeter composition for copper minerals with complex exposed
grain textures.
The final aspect of this research proposes a novel particle-based flotation simulation
approach that enables the distribution of particle compositions within streams to be
predicted. A final contribution, therefore, is a demonstration that the existing particle-
surface composition model is not adequate for predicting the rougher and scavenger
flotation response of chalcopyrite in the copper porphyry ore. Chalcopyrite showed
substantial flotation in low-grade particles which needed to be incorporated albeit through
an empirical function per size class. Using this particle-based approach it is further
demonstrated that accurately identifying the proportion of each particle composition class
that is recoverable at the particle level is important. Although this aspect was previously
highlighted for laboratory flotation data there is little in the published works that addresses
this on an industrial scale at the particle level, and existing particle-based simulations
assume that 100% of each composition class is recoverable during flotation. As with the
overall rougher flotation rate constant, this parameter did not follow a linear trend with
perimeter composition for chalcopyrite and trends were different for different size classes.
It was, however, important to quantify to enable accurate particle-based simulations.
This thesis therefore presents new knowledge on the contribution of exposed copper
mineral grain texture on flotation response, an important feature to consider for further
research and property-based modelling. It also presents a novel, particle-based flotation

3. III
simulation approach which is important for incorporating this new textural feature into
future simulations and as a platform for linking other processes with flotation at the particle
level.