1796 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
strengthened the leaching process by mechanical activation,
and finally determined the optimal leaching conditions as
follows: 1.2 mol/L NaSCN, 4.0 mmol/L MnO2, pH=2.0,
liquid-solid ratio of 3:1 mL/g, leaching time of 6 h, rota-
tional rate of ball milling tank 150 rpm, and rotational rate
of ball milling tank 300 rpm, room temperature. Under the
optimal conditions, the extractions of gold and silver were
98.61% and 87.44%, and the leaching effect of gold and
silver was very satisfactory.
The gold and silver in the leach solution were recov-
ered by replacement precipitation, and the recoveries of
gold and silver were 96.21% and 90.46% under the condi-
tions of 1.0 g/L zinc powder, temperature 25 °C, 1.2 mol/L
NaSCN, replacement time of 10 min, and stirring rate of
300 rpm, which were satisfactory for the recovery of gold
and silver.
REFERENCES
Azizitorghabeh, A., et al., A review of thiocyanate gold
leaching—Chemistry, thermodynamics, kinetics and
processing. Minerals Engineering. 2021. 160.
Baláž, P. Dutková, E. Fine milling in applied mechano-
chemistry. Minerals Engineering. 2009, 22 (7–8),
681–694.
Dong, K. Xie, F. Wang, W. Chang, Y. Lu, D. Gu, X.
Chen, C. The detoxification and utilization of cya-
nide tailings: A critical review. Journal of Cleaner
Production. 2021, 302.
Hilson, G. Monhemius, A.J. Alternatives to cyanide in the
gold mining industry: what prospects for the future?
Journal of Cleaner Production. 2006, 14 (12–13),
1158–1167.
Johnson, C.A. The fate of cyanide in leach wastes at
gold mines: An environmental perspective. Applied
Geochemistry. 2015, 57, 194–205.
Li, J., et al., Thiocyanate hydrometallurgy for the recovery of
gold. Part IV: Solvent extraction of gold with Alamine
336. Hydrometallurgy. 2012. 113–114: p. 25–30.
Senanayake, G. Gold leaching in non-cyanide lixiviant sys-
tems: critical issues on fundamentals and applications.
Minerals Engineering. 2004, 17 (6), 785–801.
Senanayake, G. Gold leaching by thiosulphate solutions:
a critical review on copper(II)–thiosulphate–oxygen
interactions. Minerals Engineering. 2005, 18 (10),
995–1009.
Sitando, O. Senanayake, G. Dai, X. Nikoloski, A.N.
Breuer, P. A review of factors affecting gold leach-
ing in non-ammoniacal thiosulfate solutions includ-
ing degradation and in-situ generation of thiosulfate.
Hydrometallurgy. 2018, 178, 151–175.
Sitando, O. Dai, X. Senanayake, G. Nikoloski, A.N.
Breuer, P. A fundamental study of gold leaching in a
thiosulfate‑oxygen‑copper system in the presence of
activated carbon. Hydrometallurgy. 2020, 192.
USGS, Mineral Commodity Summaries, January 2023,
Gold. 2023, U.S. Geological Survey.
Wang, H.-j. Feng, Y.-l. Li, H.-r. Kang, J.-x. Simultaneous
extraction of gold and zinc from refractory carbo-
naceous gold ore by chlorination roasting process.
Transactions of Nonferrous Metals Society of China.
2020, 30 (4), 1111–1123.
Wang, J. Xie, F. Wang, W. Bai, Y. Fu, Y. Dreisinger, D.
Eco-friendly leaching of gold from a carbonaceous gold
concentrate in copper-citrate-thiosulfate solutions.
Hydrometallurgy. 2020, 191.
Xu, B. Yang, Y. Li, Q. Jiang, T. Liu, S. Li, G. The
development of an environmentally friendly leaching
process of a high C, As and Sb bearing sulfide gold con-
centrate. Minerals Engineering. 2016, 89, 138–147.
Zhang, L. Jiang, T. Guo, X.-y. Tian, Q.-h. Zhong, S.-p.
Dong, L. Qin, H. Liu, Z.-w. Makuza, B. Sustainable
processing of gold cyanide tailings: Reduction roasting,
mechanical activation, non-cyanide leaching, and mag-
netic separation. Hydrometallurgy. 2023, 217.
Zheng, S. Wang, Y.-y. Chai, L.-y. Research status and
prospect of gold leaching in alkaline thiourea solution.
Minerals Engineering. 2006, 19 (13), 1301–1306.
Table 5. Gold and silver recovery test results
Conditions
Gold
Precipitation, %
Silver
Precipitation, %
Zn, g/L 0.5 90.38 49.59
1.0 95.83 87.02
1.5 96.84 90.99
Temperature,
°C
25 94.83 90.30
55 88.54 76.63
85 74.71 63.28
SCN–, mol/L 0.14 97.16 91.70
0.42 98.11 91.14
0.70 96.21 90.46
Time, min 10 96.73 91.27
30 96.13 93.05
60 96.21 93.53
Stirring
rate, rpm
300 94.27 91.32
400 95.93 92.50
500 95.49 92.26
strengthened the leaching process by mechanical activation,
and finally determined the optimal leaching conditions as
follows: 1.2 mol/L NaSCN, 4.0 mmol/L MnO2, pH=2.0,
liquid-solid ratio of 3:1 mL/g, leaching time of 6 h, rota-
tional rate of ball milling tank 150 rpm, and rotational rate
of ball milling tank 300 rpm, room temperature. Under the
optimal conditions, the extractions of gold and silver were
98.61% and 87.44%, and the leaching effect of gold and
silver was very satisfactory.
The gold and silver in the leach solution were recov-
ered by replacement precipitation, and the recoveries of
gold and silver were 96.21% and 90.46% under the condi-
tions of 1.0 g/L zinc powder, temperature 25 °C, 1.2 mol/L
NaSCN, replacement time of 10 min, and stirring rate of
300 rpm, which were satisfactory for the recovery of gold
and silver.
REFERENCES
Azizitorghabeh, A., et al., A review of thiocyanate gold
leaching—Chemistry, thermodynamics, kinetics and
processing. Minerals Engineering. 2021. 160.
Baláž, P. Dutková, E. Fine milling in applied mechano-
chemistry. Minerals Engineering. 2009, 22 (7–8),
681–694.
Dong, K. Xie, F. Wang, W. Chang, Y. Lu, D. Gu, X.
Chen, C. The detoxification and utilization of cya-
nide tailings: A critical review. Journal of Cleaner
Production. 2021, 302.
Hilson, G. Monhemius, A.J. Alternatives to cyanide in the
gold mining industry: what prospects for the future?
Journal of Cleaner Production. 2006, 14 (12–13),
1158–1167.
Johnson, C.A. The fate of cyanide in leach wastes at
gold mines: An environmental perspective. Applied
Geochemistry. 2015, 57, 194–205.
Li, J., et al., Thiocyanate hydrometallurgy for the recovery of
gold. Part IV: Solvent extraction of gold with Alamine
336. Hydrometallurgy. 2012. 113–114: p. 25–30.
Senanayake, G. Gold leaching in non-cyanide lixiviant sys-
tems: critical issues on fundamentals and applications.
Minerals Engineering. 2004, 17 (6), 785–801.
Senanayake, G. Gold leaching by thiosulphate solutions:
a critical review on copper(II)–thiosulphate–oxygen
interactions. Minerals Engineering. 2005, 18 (10),
995–1009.
Sitando, O. Senanayake, G. Dai, X. Nikoloski, A.N.
Breuer, P. A review of factors affecting gold leach-
ing in non-ammoniacal thiosulfate solutions includ-
ing degradation and in-situ generation of thiosulfate.
Hydrometallurgy. 2018, 178, 151–175.
Sitando, O. Dai, X. Senanayake, G. Nikoloski, A.N.
Breuer, P. A fundamental study of gold leaching in a
thiosulfate‑oxygen‑copper system in the presence of
activated carbon. Hydrometallurgy. 2020, 192.
USGS, Mineral Commodity Summaries, January 2023,
Gold. 2023, U.S. Geological Survey.
Wang, H.-j. Feng, Y.-l. Li, H.-r. Kang, J.-x. Simultaneous
extraction of gold and zinc from refractory carbo-
naceous gold ore by chlorination roasting process.
Transactions of Nonferrous Metals Society of China.
2020, 30 (4), 1111–1123.
Wang, J. Xie, F. Wang, W. Bai, Y. Fu, Y. Dreisinger, D.
Eco-friendly leaching of gold from a carbonaceous gold
concentrate in copper-citrate-thiosulfate solutions.
Hydrometallurgy. 2020, 191.
Xu, B. Yang, Y. Li, Q. Jiang, T. Liu, S. Li, G. The
development of an environmentally friendly leaching
process of a high C, As and Sb bearing sulfide gold con-
centrate. Minerals Engineering. 2016, 89, 138–147.
Zhang, L. Jiang, T. Guo, X.-y. Tian, Q.-h. Zhong, S.-p.
Dong, L. Qin, H. Liu, Z.-w. Makuza, B. Sustainable
processing of gold cyanide tailings: Reduction roasting,
mechanical activation, non-cyanide leaching, and mag-
netic separation. Hydrometallurgy. 2023, 217.
Zheng, S. Wang, Y.-y. Chai, L.-y. Research status and
prospect of gold leaching in alkaline thiourea solution.
Minerals Engineering. 2006, 19 (13), 1301–1306.
Table 5. Gold and silver recovery test results
Conditions
Gold
Precipitation, %
Silver
Precipitation, %
Zn, g/L 0.5 90.38 49.59
1.0 95.83 87.02
1.5 96.84 90.99
Temperature,
°C
25 94.83 90.30
55 88.54 76.63
85 74.71 63.28
SCN–, mol/L 0.14 97.16 91.70
0.42 98.11 91.14
0.70 96.21 90.46
Time, min 10 96.73 91.27
30 96.13 93.05
60 96.21 93.53
Stirring
rate, rpm
300 94.27 91.32
400 95.93 92.50
500 95.49 92.26