1512 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
(Hower et al., 1992 McIntyre &Plitt, 1980 Mucsi, 2008
Mucsi et al., 2019). The errors obtained in this study are
very close to those achieved through commercially avail-
able simplified tests, between 2.3% and 16% (Aminpro,
2023 M. Bueno et al., 2021 Kojovic, 2016 Kojovic et
al., 2019 Matus et al., 2020 SGS, 2023). Still, the mass
needed to perform the test is significantly smaller, requiring
only 30 cm3. Considering that 30–50% of the sample pre-
pared for the Bond test is usually retained in 0.600 mm, the
test will require approximately 100 g of sample to obtain
30 cm3 or 40 g to 60 g for each test, depending on the ore
bulk density. The mass requirement varies from 220 g to
1,200 g of material from the reviewed commercial tests.
It is important to highlight that the proposed method’s
error is lower than the one reported in the literature for
the BBMWI test, where differences up to 10% between the
higher and the lower values for the same sample are reported
(Angove &Dunne, 1997 Bailey et al., 2009 Heiskari et al.,
2018 Kaya et al., 2002 Mosher &Tague, 2001 Weier &
Chenje, 2018). That said, it is important to point out that
the proposed test uses a very small sample, so care should be
taken with the sampling protocol. Also, the test is carried
out in only one cycle, so it is not sensitive to selective com-
minution, accumulation, and recirculating mass fractions
with higher competency for multi-component ores (Bueno
et al., 2013 Hesse et al., 2017). For example, in the case of
highly heterogeneous ores, this could be a source of error
in the proposed method, which does not account for the
increase in the proportion of harder material recirculating
back to the mill in the traditional Bond test. The result for
high clay, fibrous, or mica samples should also be evaluated,
as this is potentially critical for upscaling (Chandramohan
et al., 2015 Tavares et al., 2012). There are no statements
about mineralogical variability that might give some evi-
dence that this issue is less severe in the proposed test. The
correlations presented here are suggested to be validated
and/or adjusted for different ores and mines.
CONCLUSIONS
A new method to predict the BBMWI using a Hardgrove
mill was proposed. In this case, using a torque measure-
ment system was essential, as the energy consumption
varies with the sample characteristics. Accordingly, using
size-specific energy resulted in significantly smaller predic-
tion errors than the standard Hardgrove test for predict-
ing the BBMWI. The proposed test allows predicting the
BBMWI using 30 cm3 of sample in the –3.35+0.600 mm
size fraction. The results indicate that the BBMWI was
estimated with less than 7% deviation from the measured
value. Because of the ease of execution, low mass and time
required, the proposed method could be a valuable tool for
obtaining grindability data for geometallurgical studies as
well as in the initial stages of a mineral project.
ACKNOWLEDGMENTS
This work was supported by CNPq (Brazilian Technological
and Scientific Development Council) for a productiv-
ity grant under process #313411/2019 and post-doc-
toral training under process #200298/2022-4, Sao Paulo
Research Foundation (Fapesp) for the BPE grant under pro-
cess #2021/11923-9, the Thematic Project under process
#2019/11866-5 and the research project #2023/13203-9.
REFERENCES
A.J. Lynch. (1977). Mineral crushing and grinding cir-
cuits: Their simulation, optimization, design and control
(Elsevier Scientific Publishing Company, Org.).
Administration, U. S. E. I. (2009). Energy Information
Administration. https://www.eia.gov/outlooks/archive
/ieo09/pdf/0484(2009).pdf.
Agus, F., &Waters, P. L. (1972). Predicting the grind-
ability of coal/shale mixtures. Fuel, 51(1), 38–43. doi:
10.1016/0016-2361(72)90035-X.
Amelunxen, P., Torres, F., Panduro, L., &Berríos, P. (2016).
Una nueva prueba de bajo costo para complementar la
prueba Bond estándar para la caracterización geomet-
alúrgica. 3rd International Seminar on Geometallurgy.
Aminpro. (2023). Innovation. http://aminpro.com/en
/servicios/innovation/.
Angove, J. E., &Dunne, R. C. (1997). A review of standard
physical ore property determinations. World Gold’97
Conference, 139–144.
ASTM D409. (2002). Standard Test Method for
Grindability of Coal by the Hardgrove-Machine
Method 1. Em ASTM International (Vol. 05). doi:
10.1520/D0409.
Austin, L. G., Shah, J., Wang, J., Gallagher, E., &Luckie,
P. T. (1981). An analysis of ball-and-race milling. Part
I. The Hardgrove mill. Powder Technology, 29(2), 263–
275. doi: 10.1016/0032-5910(81)87029-5.
Bailey, C., Lane, G., Morrell, S., &Staples, P. (2009). What
can go wrong in comminution circuit design? Tenth
Mill Operators’ Conference, 143–149.
Ballantyne, G. R., Peukert, W., &Powell, M. S. (2015).
Size specific energy (SSE) -Energy required to
generate minus 75 micron material. International
Journal of Mineral Processing, 136, 2–6. doi: 10.1016
/j.minpro.2014.09.010.
(Hower et al., 1992 McIntyre &Plitt, 1980 Mucsi, 2008
Mucsi et al., 2019). The errors obtained in this study are
very close to those achieved through commercially avail-
able simplified tests, between 2.3% and 16% (Aminpro,
2023 M. Bueno et al., 2021 Kojovic, 2016 Kojovic et
al., 2019 Matus et al., 2020 SGS, 2023). Still, the mass
needed to perform the test is significantly smaller, requiring
only 30 cm3. Considering that 30–50% of the sample pre-
pared for the Bond test is usually retained in 0.600 mm, the
test will require approximately 100 g of sample to obtain
30 cm3 or 40 g to 60 g for each test, depending on the ore
bulk density. The mass requirement varies from 220 g to
1,200 g of material from the reviewed commercial tests.
It is important to highlight that the proposed method’s
error is lower than the one reported in the literature for
the BBMWI test, where differences up to 10% between the
higher and the lower values for the same sample are reported
(Angove &Dunne, 1997 Bailey et al., 2009 Heiskari et al.,
2018 Kaya et al., 2002 Mosher &Tague, 2001 Weier &
Chenje, 2018). That said, it is important to point out that
the proposed test uses a very small sample, so care should be
taken with the sampling protocol. Also, the test is carried
out in only one cycle, so it is not sensitive to selective com-
minution, accumulation, and recirculating mass fractions
with higher competency for multi-component ores (Bueno
et al., 2013 Hesse et al., 2017). For example, in the case of
highly heterogeneous ores, this could be a source of error
in the proposed method, which does not account for the
increase in the proportion of harder material recirculating
back to the mill in the traditional Bond test. The result for
high clay, fibrous, or mica samples should also be evaluated,
as this is potentially critical for upscaling (Chandramohan
et al., 2015 Tavares et al., 2012). There are no statements
about mineralogical variability that might give some evi-
dence that this issue is less severe in the proposed test. The
correlations presented here are suggested to be validated
and/or adjusted for different ores and mines.
CONCLUSIONS
A new method to predict the BBMWI using a Hardgrove
mill was proposed. In this case, using a torque measure-
ment system was essential, as the energy consumption
varies with the sample characteristics. Accordingly, using
size-specific energy resulted in significantly smaller predic-
tion errors than the standard Hardgrove test for predict-
ing the BBMWI. The proposed test allows predicting the
BBMWI using 30 cm3 of sample in the –3.35+0.600 mm
size fraction. The results indicate that the BBMWI was
estimated with less than 7% deviation from the measured
value. Because of the ease of execution, low mass and time
required, the proposed method could be a valuable tool for
obtaining grindability data for geometallurgical studies as
well as in the initial stages of a mineral project.
ACKNOWLEDGMENTS
This work was supported by CNPq (Brazilian Technological
and Scientific Development Council) for a productiv-
ity grant under process #313411/2019 and post-doc-
toral training under process #200298/2022-4, Sao Paulo
Research Foundation (Fapesp) for the BPE grant under pro-
cess #2021/11923-9, the Thematic Project under process
#2019/11866-5 and the research project #2023/13203-9.
REFERENCES
A.J. Lynch. (1977). Mineral crushing and grinding cir-
cuits: Their simulation, optimization, design and control
(Elsevier Scientific Publishing Company, Org.).
Administration, U. S. E. I. (2009). Energy Information
Administration. https://www.eia.gov/outlooks/archive
/ieo09/pdf/0484(2009).pdf.
Agus, F., &Waters, P. L. (1972). Predicting the grind-
ability of coal/shale mixtures. Fuel, 51(1), 38–43. doi:
10.1016/0016-2361(72)90035-X.
Amelunxen, P., Torres, F., Panduro, L., &Berríos, P. (2016).
Una nueva prueba de bajo costo para complementar la
prueba Bond estándar para la caracterización geomet-
alúrgica. 3rd International Seminar on Geometallurgy.
Aminpro. (2023). Innovation. http://aminpro.com/en
/servicios/innovation/.
Angove, J. E., &Dunne, R. C. (1997). A review of standard
physical ore property determinations. World Gold’97
Conference, 139–144.
ASTM D409. (2002). Standard Test Method for
Grindability of Coal by the Hardgrove-Machine
Method 1. Em ASTM International (Vol. 05). doi:
10.1520/D0409.
Austin, L. G., Shah, J., Wang, J., Gallagher, E., &Luckie,
P. T. (1981). An analysis of ball-and-race milling. Part
I. The Hardgrove mill. Powder Technology, 29(2), 263–
275. doi: 10.1016/0032-5910(81)87029-5.
Bailey, C., Lane, G., Morrell, S., &Staples, P. (2009). What
can go wrong in comminution circuit design? Tenth
Mill Operators’ Conference, 143–149.
Ballantyne, G. R., Peukert, W., &Powell, M. S. (2015).
Size specific energy (SSE) -Energy required to
generate minus 75 micron material. International
Journal of Mineral Processing, 136, 2–6. doi: 10.1016
/j.minpro.2014.09.010.