XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 405
In the absence of a high degree of predictability and
stability of sorter response, sorting needs to deliver a sig-
nificant change in the project economics to justify the risk.
On this basis, the use of ore sorting as an integral part of
the flowsheet is often difficult to justify in terms of invest-
ment return.
To address some of the hurdles identified, the main
suggestions are as follows:
• Engagement with preconcentration vendors at the
outset
• Early definition of sample mass requirements and
timing of testwork to integrate with the study
• Experienced structural geology expertise required
early in the study, at a greater level than may be con-
sidered ‘normal’ for early phase studies such as at a
Pre-Feasibility level
• Engage mining design, planning and scheduling
personnel and ensure capability exists to incorporate
preconcentration into designs and therefore defini-
tion of project value
• Mine planners must preserve heterogeneity at all
costs, avoid pre-crusher stockpiles in the design and
moves away from a mind-set that works to blend out
heterogeneity to achieve the greatest possible homo-
geneity in mill feed
• Design of preconcentration installation must be an
integral part of the plant and excess materials han-
dling needs to avoided
• Buffer stocks to be used between the mine, sorting
and downstream process plants, sized to absorb a
range of heterogeneity and sorter response and
• Operating envelope for process plant must be suffi-
cient to absorb any fluctuations in preconcentration
performance, without driving capital cost to exces-
sive levels.
These aspects are not insurmountable as is testified by the
number of modern preconcentration installations, includ-
ing a wide range of particle sorter applications in smaller
operations, but also large, multi-unit particle sorting
(Pilbara Minerals—International Mining, 2023, Ma’aden
Umm Wu’al—Mining Technology, 2023), size based
upgrading (Minera San Cristobel—Adair et al. 2019) and
bulk sorting (FQM Kanshansi mine—NextOre, 2022).
What is missing, are examples of total precision mining
and selective processing applications, whereby the orebody
value and resource utilization, for a given operation, has
been demonstrably improved across the life of mine.
To the best of the authors knowledge, such a case does
not exist, but if preconcentration is to deliver on the often-
cited promise of changing the face of the industry, these
total system implementations are pivotal to success.
CONCLUSIONS
Over recent years, the original concerns relating to precon-
centration have been tackled to varying degrees of success.
What remains are a range of soft and hard constraints
that will dictate if, how and where preconcentration can
make the biggest impact. The heart of the matter is pre-
concentration is a geologically reliant process, which makes
evaluation more difficult to assess to the required level of
certainty, compared to other metallurgically based pro-
cesses. Coupled to this is the orebody variability and how
sorting response can vary to the detriment of project value.
Table 2. Aspects of preconcentration in Greenfield and Brownfield situations
Bulk Sorting Particle Sorting
• Complex to gather geological domain samples for sorter
amenability testing.
• Scale and availability of material for bulk testing.
• Will have a significant influence on mill flowsheet.
• Business case definition is challenging due to deployment
and orebody variability.
• Sensor testing possible from diamond core drilling and
possibly geotechnical programs (if in ore).
• Need to understand structural geology at fine resolution.
• Low capacity &high cost of sorting may require a subset of
the mill feed stream as sorter feedstock
• If mature deposit, good opportunity to understand geology
&heterogeneity.
• Likely to be able to source bulk sample for pilot scale
testwork.
• Little ability to influence existing mill design.
• Can impact performance of existing mill circuits.
• Sunk capital may mean the status quo remains the highest
value option.
• Abundant material for sensor amenability testing.
• Existing understanding of structural geology.
• Difficult to insert into flowsheet without additional buffers.
• Waste handling requirements add cost.
• Impacts on mining rate.
Greenfield
Brownfield
In the absence of a high degree of predictability and
stability of sorter response, sorting needs to deliver a sig-
nificant change in the project economics to justify the risk.
On this basis, the use of ore sorting as an integral part of
the flowsheet is often difficult to justify in terms of invest-
ment return.
To address some of the hurdles identified, the main
suggestions are as follows:
• Engagement with preconcentration vendors at the
outset
• Early definition of sample mass requirements and
timing of testwork to integrate with the study
• Experienced structural geology expertise required
early in the study, at a greater level than may be con-
sidered ‘normal’ for early phase studies such as at a
Pre-Feasibility level
• Engage mining design, planning and scheduling
personnel and ensure capability exists to incorporate
preconcentration into designs and therefore defini-
tion of project value
• Mine planners must preserve heterogeneity at all
costs, avoid pre-crusher stockpiles in the design and
moves away from a mind-set that works to blend out
heterogeneity to achieve the greatest possible homo-
geneity in mill feed
• Design of preconcentration installation must be an
integral part of the plant and excess materials han-
dling needs to avoided
• Buffer stocks to be used between the mine, sorting
and downstream process plants, sized to absorb a
range of heterogeneity and sorter response and
• Operating envelope for process plant must be suffi-
cient to absorb any fluctuations in preconcentration
performance, without driving capital cost to exces-
sive levels.
These aspects are not insurmountable as is testified by the
number of modern preconcentration installations, includ-
ing a wide range of particle sorter applications in smaller
operations, but also large, multi-unit particle sorting
(Pilbara Minerals—International Mining, 2023, Ma’aden
Umm Wu’al—Mining Technology, 2023), size based
upgrading (Minera San Cristobel—Adair et al. 2019) and
bulk sorting (FQM Kanshansi mine—NextOre, 2022).
What is missing, are examples of total precision mining
and selective processing applications, whereby the orebody
value and resource utilization, for a given operation, has
been demonstrably improved across the life of mine.
To the best of the authors knowledge, such a case does
not exist, but if preconcentration is to deliver on the often-
cited promise of changing the face of the industry, these
total system implementations are pivotal to success.
CONCLUSIONS
Over recent years, the original concerns relating to precon-
centration have been tackled to varying degrees of success.
What remains are a range of soft and hard constraints
that will dictate if, how and where preconcentration can
make the biggest impact. The heart of the matter is pre-
concentration is a geologically reliant process, which makes
evaluation more difficult to assess to the required level of
certainty, compared to other metallurgically based pro-
cesses. Coupled to this is the orebody variability and how
sorting response can vary to the detriment of project value.
Table 2. Aspects of preconcentration in Greenfield and Brownfield situations
Bulk Sorting Particle Sorting
• Complex to gather geological domain samples for sorter
amenability testing.
• Scale and availability of material for bulk testing.
• Will have a significant influence on mill flowsheet.
• Business case definition is challenging due to deployment
and orebody variability.
• Sensor testing possible from diamond core drilling and
possibly geotechnical programs (if in ore).
• Need to understand structural geology at fine resolution.
• Low capacity &high cost of sorting may require a subset of
the mill feed stream as sorter feedstock
• If mature deposit, good opportunity to understand geology
&heterogeneity.
• Likely to be able to source bulk sample for pilot scale
testwork.
• Little ability to influence existing mill design.
• Can impact performance of existing mill circuits.
• Sunk capital may mean the status quo remains the highest
value option.
• Abundant material for sensor amenability testing.
• Existing understanding of structural geology.
• Difficult to insert into flowsheet without additional buffers.
• Waste handling requirements add cost.
• Impacts on mining rate.
Greenfield
Brownfield