396 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Feed Forward Control
Multi-elemental composition of process feed is visible to
process operators well before ore or concentrate enters a
process operation. A good understanding of ore and waste
mineralogy and the process sensitivity to changes in feed
quality allow process operators to adjust process settings to
optimize process efficiency. This may include the application
of geometallurgical data to correlate feed quality with process
performance outcomes. Elemental data can be utilized for
non-measurable parameters such as ore hardness and used
to control mill feed rate. Compositional variations may indi-
cate deleterious components which may require additional or
alternative processing steps. Mass flow as well as reagent dos-
ing (depressants or other flotation chemicals depending on
the parameter affected) can be controlled based on feed qual-
ity. Acid addition is proportioned to feed quality, particularly
acid-consuming gangue content in a leach feed (Balzan et al.
2016) or for phosphate rock composition variation in phos-
phoric acid reactor feed. Such reagent adjustments increase
process performance (recoveries) by a few percentage points
as normal process inefficiencies due to the absence of timely,
representative and precise data are avoided.
Changes in ore type detected through continuous mon-
itoring of run of mine ore enables plant operators to opti-
mize responses and ensure maximum process recovery for
each ore type. Patel (2014) discusses how changes in lead-
zinc ore feed quality to a dense medium separation plant
at Mount Isa Mines are measured to modify density cut
points. Matthews and Du Toit (2011) discuss the benefits
in measuring beneficiation feed to predict upgrade factors
for different iron ore types which are confirmed by utilizing
analyzers on the jig product streams and discard flows.
Metal Accounting and Ore Reconciliation
Representative and precise multi-elemental measurement
of primary crushed conveyed flows is ideal for feedback to
the mine for ore reconciliation to the mine schedule and
block model. It represents the actual ore quality supplied
from the mine to the process operation feed and has proven
to be the most effective way to determine the quality of
mined material at numerous mining operations.
Measurement data from PGNAA analysis is utilized
for metal accounting for process operations. Matthews and
Du Toit (2011) discuss the application of analyzer data for
elemental balance at the Khumani iron ore operations as
all relevant conveyed flows, including discard flows, contain
analyzers and belt weighers to quantify tonnages and grades.
GEOSCAN GOLD is able to measure elements as prox-
ies for gold if they are present over each thirty seconds of flow
and it can uniquely measure gold directly as an element in
primary crushed conveyed flows. Direct gold measurement
requires longer measurement times from five to ten minutes
in successful installations to date (Balzan et al. 2022). The
nature of the gold mineralization determines the suitability
of proxy elements. Gold measurement allows a previously
unattainable level of metal accounting to be performed.
Source: Anglo American
Figure 4. GEOSCAN analyzer used in a base metals bulk ore sorting plant for 30
seconds parcel diversion
Feed Forward Control
Multi-elemental composition of process feed is visible to
process operators well before ore or concentrate enters a
process operation. A good understanding of ore and waste
mineralogy and the process sensitivity to changes in feed
quality allow process operators to adjust process settings to
optimize process efficiency. This may include the application
of geometallurgical data to correlate feed quality with process
performance outcomes. Elemental data can be utilized for
non-measurable parameters such as ore hardness and used
to control mill feed rate. Compositional variations may indi-
cate deleterious components which may require additional or
alternative processing steps. Mass flow as well as reagent dos-
ing (depressants or other flotation chemicals depending on
the parameter affected) can be controlled based on feed qual-
ity. Acid addition is proportioned to feed quality, particularly
acid-consuming gangue content in a leach feed (Balzan et al.
2016) or for phosphate rock composition variation in phos-
phoric acid reactor feed. Such reagent adjustments increase
process performance (recoveries) by a few percentage points
as normal process inefficiencies due to the absence of timely,
representative and precise data are avoided.
Changes in ore type detected through continuous mon-
itoring of run of mine ore enables plant operators to opti-
mize responses and ensure maximum process recovery for
each ore type. Patel (2014) discusses how changes in lead-
zinc ore feed quality to a dense medium separation plant
at Mount Isa Mines are measured to modify density cut
points. Matthews and Du Toit (2011) discuss the benefits
in measuring beneficiation feed to predict upgrade factors
for different iron ore types which are confirmed by utilizing
analyzers on the jig product streams and discard flows.
Metal Accounting and Ore Reconciliation
Representative and precise multi-elemental measurement
of primary crushed conveyed flows is ideal for feedback to
the mine for ore reconciliation to the mine schedule and
block model. It represents the actual ore quality supplied
from the mine to the process operation feed and has proven
to be the most effective way to determine the quality of
mined material at numerous mining operations.
Measurement data from PGNAA analysis is utilized
for metal accounting for process operations. Matthews and
Du Toit (2011) discuss the application of analyzer data for
elemental balance at the Khumani iron ore operations as
all relevant conveyed flows, including discard flows, contain
analyzers and belt weighers to quantify tonnages and grades.
GEOSCAN GOLD is able to measure elements as prox-
ies for gold if they are present over each thirty seconds of flow
and it can uniquely measure gold directly as an element in
primary crushed conveyed flows. Direct gold measurement
requires longer measurement times from five to ten minutes
in successful installations to date (Balzan et al. 2022). The
nature of the gold mineralization determines the suitability
of proxy elements. Gold measurement allows a previously
unattainable level of metal accounting to be performed.
Source: Anglo American
Figure 4. GEOSCAN analyzer used in a base metals bulk ore sorting plant for 30
seconds parcel diversion
