XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 121
Beyond mechanical methods, there has also been an
uptick in non-mechanical methods, including Microwave,
Electric Pulsed Discharge, High Impact Breakage, Water
Jet, Laser, Ultrasonics and Cryogenics.
Of the non-mechanical methods, the most advanced
in terms of continuous operation at industrial rates is the
SHOT (Selective Heating Ore Treatment) equipment
developed at the University of Nottingham and currently
offered through Jenike and Johanson. The method relies
on minerals absorbing varying levels of microwave energy
and as a result leading to differential expansion and inter-
granular stress and fracture. Although, not a full commer-
cial offering, the equipment can be supplied for continuous
demonstration at operational sites at a capacity in excess
of 300tph. Details of the move to this larger scale can be
found in Batchelor et al., (2017). (2024) and Buttress et al.
(2017).
Electric Pulse Disintegration (EPD), or High Voltage
Pulse (HVP) technology using the induced stress break-
age method relies on an electric field being generated in
a particle, which causes fracture once a limiting value is
reached. EPD is under development by a number of orga-
nizations, including the JKMRC (Lay et al., 2023), SelFrag
((Bru et al., 2020), i.Pulse (Frescaline &Avrillaud, 2021)
and Conti-E-Pulse (Lieberwirth et al., 2019). but although
small scale tests of continuous units have been reported,
there are not any applications at-scale known to the author.
As with any system, the measurement of key param-
eters and process control are essential to extract optimum
performance. In flowsheets where the focus is applying
energy as effectively as possible, it is crucial to understand
the properties and mineralogy of both ore and waste and
how this varies from the initial presentation at the mining
scale through to how material types distribute into the vari-
ous streams within a beneficiation plant. Only by under-
standing the composition and reaction of materials within
a specific stream to various types of comminution, precon-
centration and beneficiation, can it be hoped to design the
most effective flowsheet and therefore minimize energy for
maximized recovery.
In terms of comminution, measurement applies to
strength, abrasivity, mineral content and machine oper-
ating parameters. Real-time, or in-line strength measure-
ment, has been investigated over time, but the author is
not aware of any current commercial deployments. Most
of the developments in the general area have concentrated
on rapid measurement, or use of smaller samples, either
for more comprehensive orebody evaluation or mapping
of areas for specific purposes. Amongst these are ROHM,
Minpraxis, HIT and SMC Test. Through incorporation
into simulation packages, the individual stream strength
composition can then be determined and this will inform
decisions on equipment selection.
Process control, in a traditional sense, is well under-
stood and does not require any additional commentary, but
the emergence of the new generation of Machine Learning
and AI is having a major impact. The impact is not just on
the direct control, but on the ability to analyze data as part
of the control system and even in the gathering of equip-
ment operating metrics. In this sense, there is the ability
to interrogate equipment to the point that each unit can
become an on-line measurement instrument. For commi-
nution circuits, this can mean on-line strength measure-
ment could be made available.
The recent prevalence of AI based methods does not,
however, come without issues. Not surprisingly, AI models
fitted to historical data, do not provide a comprehensive
picture, rather, they need to be augmented by physics based
models. In a majority of cases, the critical data required to
feed a successful AI deployment, does not even exist and if
it does, the unreliability of the data can de-rail any efforts.
Numerous researchers and providers have started to
suggest novel comminution circuits, variously named
future flowsheets, hybrid circuits, custom processing etc.
Amongst some of the initiatives from process equipment
vendors are:
• FLS: MissionZero Mine
• Metso: Planet Positive
• Weir: Transformative Flowsheets.
WHAT ARE THE SPEED-HUMPS?
In the journey towards a future state for comminution, the
industry faces a range of speed-humps, that can slow prog-
ress or disrupt the narrative for improvement.
Such hurdles can appear even before the initial concept
study level. At a business level, there are a range of factors
which can act against innovation, with some of the most
widely noted factors listed below:
• Organizational attitudes and structure
• Scale and economics
• Embedded momentum (existing and proven equip-
ment, circuits, design)
• Risk
• Uncertainty of performance (lack of track record)
• Lack of system thinking
• Production pressures
• Unwillingness to trade-off short-term detrimental
effects versus longer term value.
Beyond mechanical methods, there has also been an
uptick in non-mechanical methods, including Microwave,
Electric Pulsed Discharge, High Impact Breakage, Water
Jet, Laser, Ultrasonics and Cryogenics.
Of the non-mechanical methods, the most advanced
in terms of continuous operation at industrial rates is the
SHOT (Selective Heating Ore Treatment) equipment
developed at the University of Nottingham and currently
offered through Jenike and Johanson. The method relies
on minerals absorbing varying levels of microwave energy
and as a result leading to differential expansion and inter-
granular stress and fracture. Although, not a full commer-
cial offering, the equipment can be supplied for continuous
demonstration at operational sites at a capacity in excess
of 300tph. Details of the move to this larger scale can be
found in Batchelor et al., (2017). (2024) and Buttress et al.
(2017).
Electric Pulse Disintegration (EPD), or High Voltage
Pulse (HVP) technology using the induced stress break-
age method relies on an electric field being generated in
a particle, which causes fracture once a limiting value is
reached. EPD is under development by a number of orga-
nizations, including the JKMRC (Lay et al., 2023), SelFrag
((Bru et al., 2020), i.Pulse (Frescaline &Avrillaud, 2021)
and Conti-E-Pulse (Lieberwirth et al., 2019). but although
small scale tests of continuous units have been reported,
there are not any applications at-scale known to the author.
As with any system, the measurement of key param-
eters and process control are essential to extract optimum
performance. In flowsheets where the focus is applying
energy as effectively as possible, it is crucial to understand
the properties and mineralogy of both ore and waste and
how this varies from the initial presentation at the mining
scale through to how material types distribute into the vari-
ous streams within a beneficiation plant. Only by under-
standing the composition and reaction of materials within
a specific stream to various types of comminution, precon-
centration and beneficiation, can it be hoped to design the
most effective flowsheet and therefore minimize energy for
maximized recovery.
In terms of comminution, measurement applies to
strength, abrasivity, mineral content and machine oper-
ating parameters. Real-time, or in-line strength measure-
ment, has been investigated over time, but the author is
not aware of any current commercial deployments. Most
of the developments in the general area have concentrated
on rapid measurement, or use of smaller samples, either
for more comprehensive orebody evaluation or mapping
of areas for specific purposes. Amongst these are ROHM,
Minpraxis, HIT and SMC Test. Through incorporation
into simulation packages, the individual stream strength
composition can then be determined and this will inform
decisions on equipment selection.
Process control, in a traditional sense, is well under-
stood and does not require any additional commentary, but
the emergence of the new generation of Machine Learning
and AI is having a major impact. The impact is not just on
the direct control, but on the ability to analyze data as part
of the control system and even in the gathering of equip-
ment operating metrics. In this sense, there is the ability
to interrogate equipment to the point that each unit can
become an on-line measurement instrument. For commi-
nution circuits, this can mean on-line strength measure-
ment could be made available.
The recent prevalence of AI based methods does not,
however, come without issues. Not surprisingly, AI models
fitted to historical data, do not provide a comprehensive
picture, rather, they need to be augmented by physics based
models. In a majority of cases, the critical data required to
feed a successful AI deployment, does not even exist and if
it does, the unreliability of the data can de-rail any efforts.
Numerous researchers and providers have started to
suggest novel comminution circuits, variously named
future flowsheets, hybrid circuits, custom processing etc.
Amongst some of the initiatives from process equipment
vendors are:
• FLS: MissionZero Mine
• Metso: Planet Positive
• Weir: Transformative Flowsheets.
WHAT ARE THE SPEED-HUMPS?
In the journey towards a future state for comminution, the
industry faces a range of speed-humps, that can slow prog-
ress or disrupt the narrative for improvement.
Such hurdles can appear even before the initial concept
study level. At a business level, there are a range of factors
which can act against innovation, with some of the most
widely noted factors listed below:
• Organizational attitudes and structure
• Scale and economics
• Embedded momentum (existing and proven equip-
ment, circuits, design)
• Risk
• Uncertainty of performance (lack of track record)
• Lack of system thinking
• Production pressures
• Unwillingness to trade-off short-term detrimental
effects versus longer term value.