1772 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
CONCLUSION
The effect of ultrasonic energy on the pretreatment and
leaching of the refractory gold ore was investigated. The
aim of present paper was to investigate the physical and
chemical effects of the ultrasound pretreatment on refrac-
tory gold tailings in order to come up with the mechanism
of ultrasound leaching in gold processing. It was found
that the ultrasound intensified leaching increased remark-
ably the leaching ratio of gold. Pyrite and silicate surface
were severely damaged into cracks and pores by ultrasound.
This proved that ultrasound could be an effective way to
expose gold from pyrite and silicate enclosure. The ultra-
sonic oxidation of pyrite was initiated by hydroxyl radical.
The increases of ultrasound treatment time can effectively
accelerate pyrite oxidation, which promote gold exposure
from pyrite enclosure. The oxidation of pyrite released a lot
of hydrogen ions, causing a decrease in pH.
ACKNOWLEDGMENTS
The authors wish to acknowledge the National Research
Foundation (NRF) of South Africa for their financial con-
tribution to the research. DRD Gold/Ergo plant, is grate-
fully acknowledged for the samples and reagents used in
this study as well as for the gold fire assays. Special thanks
to the Metals Extraction and Recovery Research Group
(MERG) for the teamwork.
REFERENCES
Adams, M.D. Gold Ore Processing: Project Development and
Operations, 2nd ed. Elsevier: Cambridge, MA, USA,
2016 pp. 57–94.
Adewuyi, Y.G. Sonochemistry: environmental science and
engineering applications, Ind. Eng. Chem. Res., Vol.
40, 2001, pp. 4681–4715.
Asakura, Y. Experimental Methods in Sonochemistry. In
Sonochemistry and the Acoustic Bubble Elsevier Inc.:
Amsterdam, The Netherlands, 2015, pp. 119–150.
Azizi, A. Petre, C.F. Olsen, C. Larachi, F. 2010.
Electrochemical behaviour of gold cyanidation in
the presence of a sulfide-rich industrial ore versus its
major constitutive sulfide minerals. Hydrometallurgy,
1013a4: 108–119.
C.T. Crowe, J.D. Schwarzkopf, M. Sommerfeld, and Y.
Tsuji, Multiphase Flows with Droplets and Particles,
Second. CRC Press, 2011.
Collasiol, A., Pozebon, D., &Maia, S.M. (2004). Ultrasound
assisted mercury extraction from soil and sediment.
Analytica Chimica Acta, 518 (1–2),157–164.
Das S, Mukhopadhyay AK, Datta S, Basu D. Bull. Mater.
Sci. 2008, 31, 943–956.
Edraki, M., Baumgartl, T., Manlapig, E., Bradshaw, D.,
Franks, D.M., Moran, C.J., 2014. Designing mine
tailings for better environmental, social and economic
outcomes: a review of alternative approaches. J. Clean.
Prod. 84, 411–420.
Fraser, K.S. Walton, R.H. Wells, J.A. Processing of refrac-
tory ores. Miner.Eng.1991, 4, pp. 1029–1041.
G. Cum, R. Gallo, A. Spadaro, and G. Galli, “Effect of
static pressure on the ultrasonic activation of chemical
reactions. Selective oxidation at benzylic carbon in the
liquid phase,” J. Chem. Soc. Perkin Trans. 2, vol. 0, no.
3, p. 375, Jan. 1988.
Hoffmann, M.R., Hua, I. and Höchemer, R., 1996.
Application of ultrasonic irradiation for the degrada-
tion of chemical contaminants in water. Ultrasonics
Sonochemistry, 3(3), pp.S163-S172.
I.H. and and M.R. Hoffmann, “Optimization of Ultrasonic
Irradiation as an Advanced Oxidation Technology,”
Environmental Science &Technology 1997,.
J. Zhu and S.N. Liu: ‘Status and research of leaching tech-
nology of gold ore that is difficult to be treated’, Min.
Eng., 2010, 8, pp. 35–37.
J.A. Barrera-Godinez, T.J. O’Keefe, J.L. Watson, Effect
of ultrasound on acidified brine leaching of double-
kiln treated EAF dust, Miner. Eng. 5 (10–12) (1992)
1365–1373.
J.-P. Franc and J.-M. Michel, Fundamentals of cavitation,
vol. 76. Springer, 2006.
John, J.J. Kuhn, S. Braeken, L. Van Gerven, T. Ultrasound
Assisted Liquid–Liquid Extraction with a Novel
Interval-Contact Reactor. Chem. Eng. Process. Process
Intensificaion. 2017, 113, pp. 35–41.
K.L. Narayana, K.M. Swamy, K.J. Sarveswara Rao and S.
Murty: Miner. Process. Extr. M., 1997, 16, 239.
K.M. Swamy, K. Sarveswara Rao, K.L. Narayana, J.S.
Murty and H.S. Ray: Miner. Process. Extr. M., 1995,
14, 179.
Karamanev, D. Margaritis, A. Chong, N. 2001. The
application of ore immobilization to the bioleaching
of refractory gold concentrate. International Journal of
Mineral Processing, 621‑4: 231–241.
Liu, Y., Jin, W., Zhao, Y., Zhang, G. and Zhang, W., 2017.
Enhanced catalytic degradation of methylene blue by
α-Fe2O3/graphene oxide via heterogeneous photo-
Fenton reactions. Applied Catalysis B: Environmental,
206, pp.642–652.
CONCLUSION
The effect of ultrasonic energy on the pretreatment and
leaching of the refractory gold ore was investigated. The
aim of present paper was to investigate the physical and
chemical effects of the ultrasound pretreatment on refrac-
tory gold tailings in order to come up with the mechanism
of ultrasound leaching in gold processing. It was found
that the ultrasound intensified leaching increased remark-
ably the leaching ratio of gold. Pyrite and silicate surface
were severely damaged into cracks and pores by ultrasound.
This proved that ultrasound could be an effective way to
expose gold from pyrite and silicate enclosure. The ultra-
sonic oxidation of pyrite was initiated by hydroxyl radical.
The increases of ultrasound treatment time can effectively
accelerate pyrite oxidation, which promote gold exposure
from pyrite enclosure. The oxidation of pyrite released a lot
of hydrogen ions, causing a decrease in pH.
ACKNOWLEDGMENTS
The authors wish to acknowledge the National Research
Foundation (NRF) of South Africa for their financial con-
tribution to the research. DRD Gold/Ergo plant, is grate-
fully acknowledged for the samples and reagents used in
this study as well as for the gold fire assays. Special thanks
to the Metals Extraction and Recovery Research Group
(MERG) for the teamwork.
REFERENCES
Adams, M.D. Gold Ore Processing: Project Development and
Operations, 2nd ed. Elsevier: Cambridge, MA, USA,
2016 pp. 57–94.
Adewuyi, Y.G. Sonochemistry: environmental science and
engineering applications, Ind. Eng. Chem. Res., Vol.
40, 2001, pp. 4681–4715.
Asakura, Y. Experimental Methods in Sonochemistry. In
Sonochemistry and the Acoustic Bubble Elsevier Inc.:
Amsterdam, The Netherlands, 2015, pp. 119–150.
Azizi, A. Petre, C.F. Olsen, C. Larachi, F. 2010.
Electrochemical behaviour of gold cyanidation in
the presence of a sulfide-rich industrial ore versus its
major constitutive sulfide minerals. Hydrometallurgy,
1013a4: 108–119.
C.T. Crowe, J.D. Schwarzkopf, M. Sommerfeld, and Y.
Tsuji, Multiphase Flows with Droplets and Particles,
Second. CRC Press, 2011.
Collasiol, A., Pozebon, D., &Maia, S.M. (2004). Ultrasound
assisted mercury extraction from soil and sediment.
Analytica Chimica Acta, 518 (1–2),157–164.
Das S, Mukhopadhyay AK, Datta S, Basu D. Bull. Mater.
Sci. 2008, 31, 943–956.
Edraki, M., Baumgartl, T., Manlapig, E., Bradshaw, D.,
Franks, D.M., Moran, C.J., 2014. Designing mine
tailings for better environmental, social and economic
outcomes: a review of alternative approaches. J. Clean.
Prod. 84, 411–420.
Fraser, K.S. Walton, R.H. Wells, J.A. Processing of refrac-
tory ores. Miner.Eng.1991, 4, pp. 1029–1041.
G. Cum, R. Gallo, A. Spadaro, and G. Galli, “Effect of
static pressure on the ultrasonic activation of chemical
reactions. Selective oxidation at benzylic carbon in the
liquid phase,” J. Chem. Soc. Perkin Trans. 2, vol. 0, no.
3, p. 375, Jan. 1988.
Hoffmann, M.R., Hua, I. and Höchemer, R., 1996.
Application of ultrasonic irradiation for the degrada-
tion of chemical contaminants in water. Ultrasonics
Sonochemistry, 3(3), pp.S163-S172.
I.H. and and M.R. Hoffmann, “Optimization of Ultrasonic
Irradiation as an Advanced Oxidation Technology,”
Environmental Science &Technology 1997,.
J. Zhu and S.N. Liu: ‘Status and research of leaching tech-
nology of gold ore that is difficult to be treated’, Min.
Eng., 2010, 8, pp. 35–37.
J.A. Barrera-Godinez, T.J. O’Keefe, J.L. Watson, Effect
of ultrasound on acidified brine leaching of double-
kiln treated EAF dust, Miner. Eng. 5 (10–12) (1992)
1365–1373.
J.-P. Franc and J.-M. Michel, Fundamentals of cavitation,
vol. 76. Springer, 2006.
John, J.J. Kuhn, S. Braeken, L. Van Gerven, T. Ultrasound
Assisted Liquid–Liquid Extraction with a Novel
Interval-Contact Reactor. Chem. Eng. Process. Process
Intensificaion. 2017, 113, pp. 35–41.
K.L. Narayana, K.M. Swamy, K.J. Sarveswara Rao and S.
Murty: Miner. Process. Extr. M., 1997, 16, 239.
K.M. Swamy, K. Sarveswara Rao, K.L. Narayana, J.S.
Murty and H.S. Ray: Miner. Process. Extr. M., 1995,
14, 179.
Karamanev, D. Margaritis, A. Chong, N. 2001. The
application of ore immobilization to the bioleaching
of refractory gold concentrate. International Journal of
Mineral Processing, 621‑4: 231–241.
Liu, Y., Jin, W., Zhao, Y., Zhang, G. and Zhang, W., 2017.
Enhanced catalytic degradation of methylene blue by
α-Fe2O3/graphene oxide via heterogeneous photo-
Fenton reactions. Applied Catalysis B: Environmental,
206, pp.642–652.