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Doing Things Differently: Addressing the Comminution
Energy Challenge
Andrew Batchelor, Sam Kingman
The University of Nottingham
David Craig, Herman Purutyan
Jenike &Johanson
Richard Bearman
Bear Rock Solutions
ABSTRACT: As ore bodies age and grades decline, increasingly higher embodied energy input is required for
comminution to maintain production, which increases costs and the carbon footprint of these operations. A
step-change in energy reduction is required to meet the future demand of these processes. Indeed, several miners
have made zero carbon commitments for the coming decades. Following haul trucks, comminution represents
the highest percentage of CO2 emissions and a step change in the efficiency of comminution is required to
significantly reduce overall mine -site emissions. In our work we present the state of the art in microwave
processing of ores, an electrical technology which, after decades of development, now has the potential to be
a key part of the step changes needed to deliver the zero-carbon outcomes required by the mining industry.
The technology is now at the stage where commercial deployment can be considered, and we review routes to
maximise the commercial and carbon reduction benefit of this technology. In particular, we consider the impact
of induced fractures on conventional grinding/flotation circuits, on the performance of leach systems and on new
flowsheets with the potential to deliver a paradigm shift in carbon emissions from mineral processing circuits.
INTRODUCTION
Crushing and grinding rocks uses significant energy with
an average of 25% (but up to 50% in some areas) of the
total energy in mineral processing operations used for par-
ticle size reduction (Engeco 2021). As ore bodies age and
grades decline, more ore must be processed with increas-
ingly higher embodied energy input required for commi-
nution to maintain valuable commodity production, which
increases costs and the carbon footprint of these opera-
tions. In conjunction with incremental optimisation of
comminution processes, a step-change in energy reduction
is required to meet the future demand of these processes
while reducing greenhouse gas emissions.
Microwave-induced fracture of metalliferous ores
employs rapid and selective heating of certain mineral
phases within the ore matrix. Microwave-heating phases
commonly found in ores include copper, nickel, lead
and iron sulphides, iron and titaniferous iron oxides and
hydrated clays. In contrast, common rock-forming gangue
minerals such as quartz, feldspars and micas do not heat
well in microwaves. When the mineral phases heat up, they
expand, and the differential thermal expansion of heating
Doing Things Differently: Addressing the Comminution
Energy Challenge
Andrew Batchelor, Sam Kingman
The University of Nottingham
David Craig, Herman Purutyan
Jenike &Johanson
Richard Bearman
Bear Rock Solutions
ABSTRACT: As ore bodies age and grades decline, increasingly higher embodied energy input is required for
comminution to maintain production, which increases costs and the carbon footprint of these operations. A
step-change in energy reduction is required to meet the future demand of these processes. Indeed, several miners
have made zero carbon commitments for the coming decades. Following haul trucks, comminution represents
the highest percentage of CO2 emissions and a step change in the efficiency of comminution is required to
significantly reduce overall mine -site emissions. In our work we present the state of the art in microwave
processing of ores, an electrical technology which, after decades of development, now has the potential to be
a key part of the step changes needed to deliver the zero-carbon outcomes required by the mining industry.
The technology is now at the stage where commercial deployment can be considered, and we review routes to
maximise the commercial and carbon reduction benefit of this technology. In particular, we consider the impact
of induced fractures on conventional grinding/flotation circuits, on the performance of leach systems and on new
flowsheets with the potential to deliver a paradigm shift in carbon emissions from mineral processing circuits.
INTRODUCTION
Crushing and grinding rocks uses significant energy with
an average of 25% (but up to 50% in some areas) of the
total energy in mineral processing operations used for par-
ticle size reduction (Engeco 2021). As ore bodies age and
grades decline, more ore must be processed with increas-
ingly higher embodied energy input required for commi-
nution to maintain valuable commodity production, which
increases costs and the carbon footprint of these opera-
tions. In conjunction with incremental optimisation of
comminution processes, a step-change in energy reduction
is required to meet the future demand of these processes
while reducing greenhouse gas emissions.
Microwave-induced fracture of metalliferous ores
employs rapid and selective heating of certain mineral
phases within the ore matrix. Microwave-heating phases
commonly found in ores include copper, nickel, lead
and iron sulphides, iron and titaniferous iron oxides and
hydrated clays. In contrast, common rock-forming gangue
minerals such as quartz, feldspars and micas do not heat
well in microwaves. When the mineral phases heat up, they
expand, and the differential thermal expansion of heating