394 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
APPLICATIONS AND BENEFITS
Conveyed material is measured at full production flows
and unbiased measurement data provided to enable qual-
ity control. A PGNAA analyzer is typically installed on a
conveyed flow after primary crushing but can be used in
IPCC (In-Pit Crushing and Conveying), on product flows
from the process, and in downstream process flows at the
smelter or in scrap handling. Measurement data is used for
multiple concurrent purposes and may involve instanta-
neous responses to material quality or in determining an
average quality over a longer timeframe, depending on the
intended use of the data and the benefits sought.
Ore Blending
Elemental measurement in ore blending applications may
be over larger parcels and measurement times of five min-
utes have been used and sometimes composited to 30
minutes averages. This provides a smoothed average com-
position compared to higher ore variations seen in shorter
increments. Benefits resulting from multi-elemental data
used to improve ore blending in process feed include:
• Control of copper metal content in leach circuit feed
to prevent overloading and copper losses to discard
(Arena and McTiernan 2011)
• Control of additives such as pyrite to copper carbon-
ate ore in a leach feed process (Balzan et al. 2016)
• Improvements in metal recoveries of up to 10%
through more consistent process feed quality
(Goodall 2021)
Blending is common in coal and iron ore operations to
ensure average shipment quality is near the required speci-
fication and to enable adjustment through blend changes
if quality varies from the target. Blending can be used on
product material such as mineral concentrates to control
composition prior to loading onto a train or ship. Blending
is used in the iron making process in additive control prior
to blast furnaces where sinter basicity is determined from
measurements of multiple elements and limestone dosing
adjusted to a target ratio. High performance GEOSCAN
has been particularly beneficial in this application as it
measures elements such as aluminum and magnesium that
low specification systems are unable to measure effectively
(Balzan 2022). The technology is also suitable for blend-
ing scrap materials to smelters to produce more consistent
metal product quality and to ensure contaminant levels are
controlled, e.g., copper content in steel. It has process qual-
ity control applications in many recycling applications such
as e-waste, black mass from batteries, and various other
metals.
Bulk Sensing for Diversion
Shorter measurement times indicate higher quality variabil-
ity in heterogeneous flows and therefore enable more selec-
tivity in bulk sorting conveyed flow increments. Shorter
measurement times are only more beneficial if accompa-
nied by high measurement precisions (Kurth 2022 and
Scott et al. 2020). Technologies that do not provide repre-
sentative measurements over very short increments usually
increase the amount of misallocated material. This high-
lights the need to customize the measurement solution to
the application.
Iron Ore
Elements measured routinely in iron ore include iron, alu-
minum, silicon, manganese, titanium, phosphorus, potas-
sium, sodium, calcium and magnesium as needed. A very
successful application of bulk sensing in iron ore has been
the diversion of product quality material to avoid unneces-
sary processing. At Assmang Khumani operations in South
Africa iron ore quality on overland conveyors between two
mines and the beneficiation plant is measured and diverted
as needed (Matthews and Du Toit 2011). Approximately
one third of annual mine product is direct shipping qual-
ity and diverted to bypass the jig plant saving US $5M/yr
in processing costs. Processing emissions of approximately
8 kg of CO2 per ton are saved for this material, or 40,000 t
CO2 e/yr in addition to the processing cost saving. The
original plant design was developed to include analyzers for
the bypass application so a smaller plant was built with the
same planned output capacity at a lower capital cost than
for a plant design excluding analyzers.
Copper
Copper responds very well to measurement by high speci-
fication PGNAA and precisions of 0.02% Cu are achieved
for 30 second measurement increments at sites such as New
Afton in British Columbia (Nadolski et al. 2018). Some
ore types, such as porphyry copper, were considered rela-
tively homogeneous and potential for upgrading through
bulk sorting was believed to be limited. The basis for these
assumptions has been grade data from large orebody blocks
of many hundreds or thousands of tons having little grade
variability. However, measured parcels are typically tens of
tons and much higher variability is seen than that predicted
from block models. Bulk ore sorting has been successfully
applied to mines extracting porphyry copper ores. Copper
ore grade variability occurs at different scales, and this can
be utilized for bulk ore sorting to increase ore grade and
quality consistency in plant feed (Figures 2 and 3).
APPLICATIONS AND BENEFITS
Conveyed material is measured at full production flows
and unbiased measurement data provided to enable qual-
ity control. A PGNAA analyzer is typically installed on a
conveyed flow after primary crushing but can be used in
IPCC (In-Pit Crushing and Conveying), on product flows
from the process, and in downstream process flows at the
smelter or in scrap handling. Measurement data is used for
multiple concurrent purposes and may involve instanta-
neous responses to material quality or in determining an
average quality over a longer timeframe, depending on the
intended use of the data and the benefits sought.
Ore Blending
Elemental measurement in ore blending applications may
be over larger parcels and measurement times of five min-
utes have been used and sometimes composited to 30
minutes averages. This provides a smoothed average com-
position compared to higher ore variations seen in shorter
increments. Benefits resulting from multi-elemental data
used to improve ore blending in process feed include:
• Control of copper metal content in leach circuit feed
to prevent overloading and copper losses to discard
(Arena and McTiernan 2011)
• Control of additives such as pyrite to copper carbon-
ate ore in a leach feed process (Balzan et al. 2016)
• Improvements in metal recoveries of up to 10%
through more consistent process feed quality
(Goodall 2021)
Blending is common in coal and iron ore operations to
ensure average shipment quality is near the required speci-
fication and to enable adjustment through blend changes
if quality varies from the target. Blending can be used on
product material such as mineral concentrates to control
composition prior to loading onto a train or ship. Blending
is used in the iron making process in additive control prior
to blast furnaces where sinter basicity is determined from
measurements of multiple elements and limestone dosing
adjusted to a target ratio. High performance GEOSCAN
has been particularly beneficial in this application as it
measures elements such as aluminum and magnesium that
low specification systems are unable to measure effectively
(Balzan 2022). The technology is also suitable for blend-
ing scrap materials to smelters to produce more consistent
metal product quality and to ensure contaminant levels are
controlled, e.g., copper content in steel. It has process qual-
ity control applications in many recycling applications such
as e-waste, black mass from batteries, and various other
metals.
Bulk Sensing for Diversion
Shorter measurement times indicate higher quality variabil-
ity in heterogeneous flows and therefore enable more selec-
tivity in bulk sorting conveyed flow increments. Shorter
measurement times are only more beneficial if accompa-
nied by high measurement precisions (Kurth 2022 and
Scott et al. 2020). Technologies that do not provide repre-
sentative measurements over very short increments usually
increase the amount of misallocated material. This high-
lights the need to customize the measurement solution to
the application.
Iron Ore
Elements measured routinely in iron ore include iron, alu-
minum, silicon, manganese, titanium, phosphorus, potas-
sium, sodium, calcium and magnesium as needed. A very
successful application of bulk sensing in iron ore has been
the diversion of product quality material to avoid unneces-
sary processing. At Assmang Khumani operations in South
Africa iron ore quality on overland conveyors between two
mines and the beneficiation plant is measured and diverted
as needed (Matthews and Du Toit 2011). Approximately
one third of annual mine product is direct shipping qual-
ity and diverted to bypass the jig plant saving US $5M/yr
in processing costs. Processing emissions of approximately
8 kg of CO2 per ton are saved for this material, or 40,000 t
CO2 e/yr in addition to the processing cost saving. The
original plant design was developed to include analyzers for
the bypass application so a smaller plant was built with the
same planned output capacity at a lower capital cost than
for a plant design excluding analyzers.
Copper
Copper responds very well to measurement by high speci-
fication PGNAA and precisions of 0.02% Cu are achieved
for 30 second measurement increments at sites such as New
Afton in British Columbia (Nadolski et al. 2018). Some
ore types, such as porphyry copper, were considered rela-
tively homogeneous and potential for upgrading through
bulk sorting was believed to be limited. The basis for these
assumptions has been grade data from large orebody blocks
of many hundreds or thousands of tons having little grade
variability. However, measured parcels are typically tens of
tons and much higher variability is seen than that predicted
from block models. Bulk ore sorting has been successfully
applied to mines extracting porphyry copper ores. Copper
ore grade variability occurs at different scales, and this can
be utilized for bulk ore sorting to increase ore grade and
quality consistency in plant feed (Figures 2 and 3).