5
The introduction of Advanced Analytics Measurements
(FLEN, LDL, IA, FTA, IOT, and JbJc) allows for online
utilization of the power curves every rotation of the mill.
This advancement opens new possibilities by clearly iden-
tifying and graphically displaying, in real-time, when the
mill is in an empty condition, optimal impact condition,
overfilled, or overloaded, as indicated in Figure 4.
As the adage goes, “we can’t manage what we can’t mea-
sure.” This is particularly true in grinding: we can’t con-
trol what we can’t measure, and we can’t optimize what we
can’t control. Therefore, to optimize grinding, we need to
control it, and for this we need to measure several impor-
tant and relevant variables that drive the grinding actions
inside the mill. The introduction of Advanced Analytics
Measurements (AAM) provides an opportunity to measure
what’s going on inside the mill, thereby enabling better
control on the milling process. When combined with tra-
ditional power curves, it is possible to achieve true opti-
mal operation in real-time, despite challenges such as a low
stockpile, a high or low-ball charge, coarse/fine ore, hard/
soft ore, new versus worn liners and upstream &down-
stream limitations related to other circuits e.g., flotation
capacity, leaching, etc. This new combination of vibration
derived variables clearly identifies in real-time whether a
mill is empty/underfilled, overfilled/overloaded, or operat-
ing in an optimum manner.
INDUSTRIAL APPLICATIONS
The following plant results illustrate how Advanced
Analytics Measurements (AAM) have been applied to SAG,
AG and BM operation including topics such as liner dam-
age, liner wear, pegging detection and Jb/Jc ratios.
Liner Damage Level versus Vibration Profile
Liner damage in grinding mills is inevitable due to con-
stant impact and abrasion from grinding media and ore.
However, it can be effectively controlled through proper
measurements and monitoring, particularly under chal-
lenging conditions such as running the mill empty due to
ore limitations.
In these situations, grinding media directly impacts
the liners without the cushioning effect of ore, accelerat-
ing wear and potentially causing liner and grinding media
fractures. Real-time measurement systems can monitor mill
dynamics, detect irregularities, and identify early signs of
excessive liner damage. By proactively adjusting operating
parameters, it is possible to minimize liner damage, extend
lifespan, and maintain consistent grinding efficiency.
The following example illustrates this concept using a
22-foot ball mill with variable speed. Figure 5 (left) shows
six weeks of recorded LDL values. In the red zone, LDL is
high in the yellow zone, LDL is low and in the white zone,
LDL is within acceptable limits.
The vibration profile for each zone is displayed on the
right-hand side of the graphic:
In the red zone, the Impact Angle (orange triangle) is
much higher than the Toe Angle (cyan triangle), indicating
high vibration caused by grinding media impacting the mill
shell or colliding with other grinding media.
Figure 5. Liner Damage Level vs Vibration Profile -22 ft Ball Mill
The introduction of Advanced Analytics Measurements
(FLEN, LDL, IA, FTA, IOT, and JbJc) allows for online
utilization of the power curves every rotation of the mill.
This advancement opens new possibilities by clearly iden-
tifying and graphically displaying, in real-time, when the
mill is in an empty condition, optimal impact condition,
overfilled, or overloaded, as indicated in Figure 4.
As the adage goes, “we can’t manage what we can’t mea-
sure.” This is particularly true in grinding: we can’t con-
trol what we can’t measure, and we can’t optimize what we
can’t control. Therefore, to optimize grinding, we need to
control it, and for this we need to measure several impor-
tant and relevant variables that drive the grinding actions
inside the mill. The introduction of Advanced Analytics
Measurements (AAM) provides an opportunity to measure
what’s going on inside the mill, thereby enabling better
control on the milling process. When combined with tra-
ditional power curves, it is possible to achieve true opti-
mal operation in real-time, despite challenges such as a low
stockpile, a high or low-ball charge, coarse/fine ore, hard/
soft ore, new versus worn liners and upstream &down-
stream limitations related to other circuits e.g., flotation
capacity, leaching, etc. This new combination of vibration
derived variables clearly identifies in real-time whether a
mill is empty/underfilled, overfilled/overloaded, or operat-
ing in an optimum manner.
INDUSTRIAL APPLICATIONS
The following plant results illustrate how Advanced
Analytics Measurements (AAM) have been applied to SAG,
AG and BM operation including topics such as liner dam-
age, liner wear, pegging detection and Jb/Jc ratios.
Liner Damage Level versus Vibration Profile
Liner damage in grinding mills is inevitable due to con-
stant impact and abrasion from grinding media and ore.
However, it can be effectively controlled through proper
measurements and monitoring, particularly under chal-
lenging conditions such as running the mill empty due to
ore limitations.
In these situations, grinding media directly impacts
the liners without the cushioning effect of ore, accelerat-
ing wear and potentially causing liner and grinding media
fractures. Real-time measurement systems can monitor mill
dynamics, detect irregularities, and identify early signs of
excessive liner damage. By proactively adjusting operating
parameters, it is possible to minimize liner damage, extend
lifespan, and maintain consistent grinding efficiency.
The following example illustrates this concept using a
22-foot ball mill with variable speed. Figure 5 (left) shows
six weeks of recorded LDL values. In the red zone, LDL is
high in the yellow zone, LDL is low and in the white zone,
LDL is within acceptable limits.
The vibration profile for each zone is displayed on the
right-hand side of the graphic:
In the red zone, the Impact Angle (orange triangle) is
much higher than the Toe Angle (cyan triangle), indicating
high vibration caused by grinding media impacting the mill
shell or colliding with other grinding media.
Figure 5. Liner Damage Level vs Vibration Profile -22 ft Ball Mill