3968 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
CAHM and MonoRoll are part of a new generation of
equipment designed to maximize the transfer of commi-
nution energy into particle fracture. In both machines, as
depicted in Figure 1, an inner hammer roll rotates within a
concentric, but offset anvil shell. As drums rotate together,
particles are caught and drawn into a decreasing gap
between the roll surfaces. The largest particles are broken
first because broken fragments are released from the mill as
soon as they are produced ensuring an unconfined breakage
environment.
The CAHM prototype resembles a horizontal slice
from a gyratory crusher turned on its side. Undersized par-
ticles (including feed particles) exit immediately through
slots in the anvil. In contrast, the MonoRoll is similar to a
ball mill where the grinding media has been replaced with a
single hammer roll rotating inside the anvil shell, as shown
in Figure 2. Particles enter one end of the mill and are pro-
gressively guided or swept along the mill. Ore particles pass
under the hammer multiple times, undergoing multiple
stages of unconfined compressive fracture, before exiting
the other end of the machine.
Both machines benefit from a longer comminution arc,
slower compression rate, and greater nip angle capture zone
as the rock is broken between converging concave surfaces
(Nordell et al., 2016), contrasting the converging convex
surfaces of the HPGR.
CAHM and MonoRoll represent significant advance-
ments in the field of comminution. They offer the poten-
tial for substantial energy savings, operational efficiencies
through circuit simplification, and reduced costs with the
elimination of grinding media when compared to com-
mon, conventional comminution circuits.
Discrete Element Method (DEM) modeling using
Ansys’ Rocky DEM software was the primary design tool
for both CAHM and MonoRoll. This high-fidelity model-
ing approach simulates the complex interactions between
individual particles and predicts individual particle break-
age. It enabled design optimization for maximum energy
efficiency and operational effectiveness.
In this paper, we present the design and optimization
of the CAHM technology in two prototype machines based
on DEM simulations. HPGR simulations are presented as
benchmark comparisons. All three pieces of equipment
-the CAHM, MonoRoll, and HPGR—have been physi-
cally tested at pilot scale and the results from these tests are
Figure 1. Concept drawing of the CAHM design principles
Figure 2. MonoRoll concept model with ore feeding on left-
hand side and discharging on right-hand side
CAHM and MonoRoll are part of a new generation of
equipment designed to maximize the transfer of commi-
nution energy into particle fracture. In both machines, as
depicted in Figure 1, an inner hammer roll rotates within a
concentric, but offset anvil shell. As drums rotate together,
particles are caught and drawn into a decreasing gap
between the roll surfaces. The largest particles are broken
first because broken fragments are released from the mill as
soon as they are produced ensuring an unconfined breakage
environment.
The CAHM prototype resembles a horizontal slice
from a gyratory crusher turned on its side. Undersized par-
ticles (including feed particles) exit immediately through
slots in the anvil. In contrast, the MonoRoll is similar to a
ball mill where the grinding media has been replaced with a
single hammer roll rotating inside the anvil shell, as shown
in Figure 2. Particles enter one end of the mill and are pro-
gressively guided or swept along the mill. Ore particles pass
under the hammer multiple times, undergoing multiple
stages of unconfined compressive fracture, before exiting
the other end of the machine.
Both machines benefit from a longer comminution arc,
slower compression rate, and greater nip angle capture zone
as the rock is broken between converging concave surfaces
(Nordell et al., 2016), contrasting the converging convex
surfaces of the HPGR.
CAHM and MonoRoll represent significant advance-
ments in the field of comminution. They offer the poten-
tial for substantial energy savings, operational efficiencies
through circuit simplification, and reduced costs with the
elimination of grinding media when compared to com-
mon, conventional comminution circuits.
Discrete Element Method (DEM) modeling using
Ansys’ Rocky DEM software was the primary design tool
for both CAHM and MonoRoll. This high-fidelity model-
ing approach simulates the complex interactions between
individual particles and predicts individual particle break-
age. It enabled design optimization for maximum energy
efficiency and operational effectiveness.
In this paper, we present the design and optimization
of the CAHM technology in two prototype machines based
on DEM simulations. HPGR simulations are presented as
benchmark comparisons. All three pieces of equipment
-the CAHM, MonoRoll, and HPGR—have been physi-
cally tested at pilot scale and the results from these tests are
Figure 1. Concept drawing of the CAHM design principles
Figure 2. MonoRoll concept model with ore feeding on left-
hand side and discharging on right-hand side