3814 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
that for the type of material, the moisture content has a
potential influence on decreasing of Bond work index not
significantly greater than F. Both variables, however, have
positive effect on decreasing the Wi index and thus, poten-
tial energy savings in downstream crushing and grinding
stages in technological circuit. However, it should be fair
to say that this model is convergent to operational reality
only to some extent (within a certain range of F and M).
Further increasing the pressing force in HPGR results in
relatively lower and lower fineness, and also lower reduc-
tions in Wi. For moisture, in turn, situation is different
because its excessive content a has usually negative techno-
logical impact. Too high a water content in the feed mate-
rial affects throughput as a result of the material slip on rolls
and insufficient comminution.
The main reason for producing this model is to use it
for simulation in future analyses. The Bond procedure is
a time-consuming method, and a properly designed and
validated model can help in the estimation of Wi values in
accepted range of variability.
The yield model analyses the potential effect of opera-
tional pressing force and moisture content on fine genera-
tion below 0.1 mm (g–0.1) in HPGR products. It results
from processing technology and beneficiation which is
based on flotation operations. The model of the fine rela-
tionship between the yield and pressing force and moisture
can be expressed through equation (4). The method of mul-
tiple regression was also used for its determination.
..25M 6 52 0.99F 0
.1 0 c =-++
-(4)
where: F is expressed in [kN], moisture, M is expressed in
[%]and γ–0.1 is expressed in percentages. Both indepen-
dent variables F and M are statistically significant on the
confidence level (1 – α) =0.95. The impact of the pressing
force is higher than the impact of the moisture in this case.
Equation (4) shows that increasing F by 1 kN results in
increasing of fines below 100 µm in the HPGR product by
0.99 percent. For moisture, in turn, a similar changes in
yield (0.25%) can be observed. The accuracy of this model
is high, also, the coefficient of R 2 equals 0.92.
The practical benefits resulting from the application
of HPGR in technological circuits are usually apparent in
downstream grinding operations, mostly through lower
energy consumption and improvement of upgrading indi-
ces in the beneficiation operations. But these advantages
result directly from more intense breakage in the HPGR
device and thus a higher degree of liberation. The main
findings of the paper show that both the operational pres-
sure in HPGR and the moisture content of the material
influence the technological and economic benefits of device
operation. For the type of the material the values of Bond
working index were reduced together with an increase in
the pressing force and moisture content. Within the ana-
lysed changeability range of these two parameters, their
functional relationship between the Bond Wi index has a
shape close to hyperbolic. In the case of the finest particle
size fraction, operational pressing force has a greater impact
than the moisture, as can be seen from model (4), while its
accuracy is 92%.
Practical implementation of calculated models may
help to achieve better technological results measured mostly
through the level of useful mineral recovery. However,
recovery is closely connected with the level of degree of lib-
eration and this, in turn, is in a close relationship with the
breakage intensity of the feed material. The models may
help in more precise prediction and control of the particle
size composition of the product. It should be noted that
these models were calculated for the range of regular opera-
tional conditions and cannot be extended beyond them in
the presented form. For example, insufficient operational
pressure in HPGR results in very low comminution inten-
sity, while too much moisture affects the throughput and
breakage as a result of slip, among other things, and models
presented in the paper do not show that. The main aim of
the paper was, rather, to determine the impact of the ana-
lysed parameters within operational conditions of HPGR,
to make a practical implementation from achieved results
of investigations. In order to determine such relationships
for other types of materials, specific tests are required, but
the shape of the functional forms of model should be simi-
lar to some extent, but values of coefficients should differ.
ACKNOWLEDGMENTS
The article is an effect of the realisation of project
101091885 “A Holistic Digital Mine 4.0 Ecosystem”
(acronym mine.io), financed through the European
Health and Digital Executive Agency within the frame-
work of HORIZON Innovation Actions, action:
HORIZON-CL4-2022-RESILIENCE-01-06.
REFERENCES
Abouzeid, A.Z., Fuerstenau, D.W. 2009. Grinding of
mineral mixtures in high-pressure grinding rolls.
International Journal of Mineral Processing. 93(1):59–65.
Altun, O., Benzer, H.,Dundar, H., Aydogan, N.A. 2011.
Comparison of open and closed circuit HPGR appli-
cation on dry griding circuit performance. Minerals
Engineering. 24(3–4):267–275.
that for the type of material, the moisture content has a
potential influence on decreasing of Bond work index not
significantly greater than F. Both variables, however, have
positive effect on decreasing the Wi index and thus, poten-
tial energy savings in downstream crushing and grinding
stages in technological circuit. However, it should be fair
to say that this model is convergent to operational reality
only to some extent (within a certain range of F and M).
Further increasing the pressing force in HPGR results in
relatively lower and lower fineness, and also lower reduc-
tions in Wi. For moisture, in turn, situation is different
because its excessive content a has usually negative techno-
logical impact. Too high a water content in the feed mate-
rial affects throughput as a result of the material slip on rolls
and insufficient comminution.
The main reason for producing this model is to use it
for simulation in future analyses. The Bond procedure is
a time-consuming method, and a properly designed and
validated model can help in the estimation of Wi values in
accepted range of variability.
The yield model analyses the potential effect of opera-
tional pressing force and moisture content on fine genera-
tion below 0.1 mm (g–0.1) in HPGR products. It results
from processing technology and beneficiation which is
based on flotation operations. The model of the fine rela-
tionship between the yield and pressing force and moisture
can be expressed through equation (4). The method of mul-
tiple regression was also used for its determination.
..25M 6 52 0.99F 0
.1 0 c =-++
-(4)
where: F is expressed in [kN], moisture, M is expressed in
[%]and γ–0.1 is expressed in percentages. Both indepen-
dent variables F and M are statistically significant on the
confidence level (1 – α) =0.95. The impact of the pressing
force is higher than the impact of the moisture in this case.
Equation (4) shows that increasing F by 1 kN results in
increasing of fines below 100 µm in the HPGR product by
0.99 percent. For moisture, in turn, a similar changes in
yield (0.25%) can be observed. The accuracy of this model
is high, also, the coefficient of R 2 equals 0.92.
The practical benefits resulting from the application
of HPGR in technological circuits are usually apparent in
downstream grinding operations, mostly through lower
energy consumption and improvement of upgrading indi-
ces in the beneficiation operations. But these advantages
result directly from more intense breakage in the HPGR
device and thus a higher degree of liberation. The main
findings of the paper show that both the operational pres-
sure in HPGR and the moisture content of the material
influence the technological and economic benefits of device
operation. For the type of the material the values of Bond
working index were reduced together with an increase in
the pressing force and moisture content. Within the ana-
lysed changeability range of these two parameters, their
functional relationship between the Bond Wi index has a
shape close to hyperbolic. In the case of the finest particle
size fraction, operational pressing force has a greater impact
than the moisture, as can be seen from model (4), while its
accuracy is 92%.
Practical implementation of calculated models may
help to achieve better technological results measured mostly
through the level of useful mineral recovery. However,
recovery is closely connected with the level of degree of lib-
eration and this, in turn, is in a close relationship with the
breakage intensity of the feed material. The models may
help in more precise prediction and control of the particle
size composition of the product. It should be noted that
these models were calculated for the range of regular opera-
tional conditions and cannot be extended beyond them in
the presented form. For example, insufficient operational
pressure in HPGR results in very low comminution inten-
sity, while too much moisture affects the throughput and
breakage as a result of slip, among other things, and models
presented in the paper do not show that. The main aim of
the paper was, rather, to determine the impact of the ana-
lysed parameters within operational conditions of HPGR,
to make a practical implementation from achieved results
of investigations. In order to determine such relationships
for other types of materials, specific tests are required, but
the shape of the functional forms of model should be simi-
lar to some extent, but values of coefficients should differ.
ACKNOWLEDGMENTS
The article is an effect of the realisation of project
101091885 “A Holistic Digital Mine 4.0 Ecosystem”
(acronym mine.io), financed through the European
Health and Digital Executive Agency within the frame-
work of HORIZON Innovation Actions, action:
HORIZON-CL4-2022-RESILIENCE-01-06.
REFERENCES
Abouzeid, A.Z., Fuerstenau, D.W. 2009. Grinding of
mineral mixtures in high-pressure grinding rolls.
International Journal of Mineral Processing. 93(1):59–65.
Altun, O., Benzer, H.,Dundar, H., Aydogan, N.A. 2011.
Comparison of open and closed circuit HPGR appli-
cation on dry griding circuit performance. Minerals
Engineering. 24(3–4):267–275.