Gold extraction from oxide gold ores through glycine leaching

Ahmet Turan; Mehmet Baris Daryal; Mehmet Hakan Morcali; Umay Cinarli Yavas

doi:10.3989/revmetalm.e266.1647

Authors

Ahmet Turan Yeditepe University https://orcid.org/0000-0002-7578-1089
Mehmet Baris Daryal Gama Composite Engineering & Products https://orcid.org/0000-0003-0166-6472
Mehmet Hakan Morcali Gaziantep University https://orcid.org/0000-0002-5021-4459
Umay Cinarli Yavas Yeditepe University https://orcid.org/0000-0001-5374-8352

DOI:

https://doi.org/10.3989/revmetalm.e266.1647

Keywords:

Glycine Leaching, Oxide Gold Ore, Extraction, Gold, Silver, Cyanide Free Process

Abstract

The use of glycine, a non-toxic and simple amino acid, has gained attention for gold extraction because of its selective dissolution of precious metals. This study explores gold extraction from oxide gold ore using non-analytical grade glycine at concentrations of 1-3 M and reaction times ranging from 4 to 60 hours. The pH was maintained at 11-12, with the reactor temperature set at 60 °C, a stirring speed of 350 rpm, and an air flow rate of 1 L·min^-1. The ore's particle size averaged 70.7 μm. The highest gold extraction (81.41%) occurred at 3 M glycine after 48 hours. Silver extraction was moderate, reaching 44.50%, while iron solubility was low at 7.71%. The results show that increased reaction time and glycine concentration enhance gold dissolution from oxide ore. This glycine-based process offers a more environmentally friendly and sustainable approach for selective extraction of gold and silver from oxide ores or oxidized waste containing precious metals.

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References

Altinkaya, P., Wang, Z., Korolev, I., Hamuyuni, J., Haapalainen, M., Kolehmainen, E., Yliniemi, K., Lundström, M. (2020). Leaching and recovery of gold from ore in cyanide-free glycine media. Min. Eng. 158, 106610. https://doi.org/10.1016/j.mineng.2020.106610

Aylmore, M.G. (2016). Chapter 17 - Alternative lixiviants to cyanide for leaching gold ores, Gold ore processing. Adams (Ed.) Elsevier, Amsterdam, Netherlands, pp. 447-484. https://doi.org/10.1016/B978-0-444-63658-4.00027-X

Balmumcu (2025). Merck 104201.0100 glycine gr for analysis 100 g. https://www.balmumcukimya.com/glycine-gr-for-analysis-100g. [accessed 25 July 2025].

Barani, K., Dehghani, M., Azadi, M.R., Karrech, A. (2021). Leaching of a polymetal gold ore and reducing cyanide consumption using cyanide-glycine solutions. Min. Eng. 163, 106802. https://doi.org/10.1016/j.mineng.2021.106802

Bioradlab (2025). Glisin glycine farma grade 100 gr. https://www.n11.com/urun/glisin-glycine-farma-grade-100-gr-2653024. [accessed 25 July 2025].

Breuer, P.L., Jeffrey, M.I. (2003). The reduction of copper (II) and the oxidation of thiosulfate and oxysulfur anions in gold leaching solutions. Hydrometallurgy 70 (1), 163-173. https://doi.org/10.1016/S0304-386X(03)00078-1

Cao, P., Zhang, S., Zheng, Y., He, H., Lai, S., Wang, X., Tan, B. (2020). Differences of cyanide leaching between calcine and dust from refractory gold concentrates. Trans. Nonferrous Met. Soc. China. 30 (7), 1964-1979. https://doi.org/10.1016/S1003-6326(20)65354-7

Carvill, J. (1993). Mechanical Engineer's Data Handbook: 3-Thermodynamics and heat transfer. Oxford, England, pp.102-145. https://doi.org/10.1016/B978-0-7506-1014-8.50008-8

Chamber of Geological Engineers (2022). Gold production by cyanidation and waste utilization. https://www.jmo.org.tr/resimler/ekler/a9d8bf5b7a4b35f_ek.pdf?dergi=HABER%20B%DCLTEN%DD. [accessed August 2025].

Clesceri, L.S., Greenberg, A.E., Aeton, A.D. (1999). Standard methods for the examination of water and wastewater. 20th ed. American Water Works Association, Colorado, USA.

Dehghanpoor, M.H., Zivdar, M., Torabi, M. (2016). Extraction of copper and gold from anode slime of Sarcheshmeh Copper Complex. J. S. Afr. Inst. Min. Metall. 116 (12), 1153-1157. https://doi.org/10.17159/2411-9717/2016/v116n12a9

Fleming, C.A., McMullen, J., Thomas, K.G., Wells, J.A. (2003). Recent advances in the development of an alternative to the cyanidation process: Thiosulfate leaching and resin in pulp. Min. Metall. Explor. 20, 1-9. https://doi.org/10.1007/BF03403107

Freitas, J., Horta, D. (2023). Impacts of cyanide in gold mining and cyanide removal methodologies in liquid waste from gold processing. Rev. Metal. 59 (3), e247. https://doi.org/10.3989/revmetalm.247

Godigamuwa, K., Okibe, N. (2023). Gold leaching from printed circuit boards using a novel synergistic effect of glycine and thiosulfate. Minerals 13 (10), 1270. https://doi.org/10.3390/min13101270

Harris, D.C. (1990). The mineralogy of gold and its relevance to gold recoveries. Mineral. Deposita 25 (Suppl. 1), S3-S7. https://doi.org/10.1007/BF00205243

Hedjazi, F., Monhemius, A.J. (2018). Industrial application of ammonia-assisted cyanide leaching for copper-gold ores. Miner. Eng. 126, 123-129. https://doi.org/10.1016/j.mineng.2018.07.005

Khezri, M., Rezai, B., Akbar, A., Molaeinasab, M., Wilson, B.P., Lundström, M. (2020). Glycine leaching of sarcheshmeh chalcopyrite concentrate at high pulp densities in a stirred tank reactor. Miner. Eng. 157, 106555. https://doi.org/10.1016/j.mineng.2020.106555

Khezri, M., Rezai, B., Abdollahzadeh, A.A., Wilson, B.P., Mehdi Molaeinasab, Lundström, M. (2021). Investigation into the effect of mechanical activation on the leaching of chalcopyrite in a glycine medium. Hydrometallurgy 203, 105492. https://doi.org/10.1016/j.hydromet.2020.105492

Kim, G.H., Kim, K., Lee, E., An, T., Choi, W., Lim, G., Shin, J.H. (2018). Recent progress on microelectrodes in neural interfaces. Materials 11 (10), 1995. https://doi.org/10.3390/ma11101995 PMid:30332782 PMCid:PMC6213370

Kursun, I., Ercelik, G., Eskibalci, F., Terzi, M., Ozdemir, O., Sezen, R. (2019). Sülfürlü altın cevheri flotasyonunda alternatif kollektörlerin araştırılması. Turkey 26th International Mining Congress and Exhibition, Antalya, pp. 999-1009.

Li, H., Deng, Z., Oraby, E., Eksteen, J. (2023). Amino acids as lixiviants for metals extraction from natural and secondary resources with emphasis on glycine: A literature review. Hydrometallurgy 216, 106008. https://doi.org/10.1016/j.hydromet.2022.106008

Oraby, E.A., Eksteen, J.J. (2015). The leaching of gold, silver and their alloys in alkaline glycine-peroxide solutions and their adsorption on carbon. Hydrometallurgy 152, 199-203. https://doi.org/10.1016/j.hydromet.2014.12.015

Oraby, E.A., Eksteen, J.J., Karrech, A., Attar, M. (2019). Gold extraction from paleochannel ores using an aerated alkaline glycine lixiviant for consideration in heap and in-situ leaching applications. Miner. Eng. 138, 112-118. https://doi.org/10.1016/j.mineng.2019.04.023

Oraby, E.A., Eksteen, J.J., O'Connor, G.M. (2020). Gold leaching from oxide ores in alkaline glycine solutions in the presence of permanganate. Hydrometallurgy 198, 105527. https://doi.org/10.1016/j.hydromet.2020.105527

Salehian, M., Mohammadian, A., Vaezzadeh, M., Saeidi, M. (2017). Influence of size on the melting temperature of metallic nanoparticle. Int. J. Nanosci. Nanotechnol. 13 (1), 91-95. https://www.ijnnonline.net/article_24537.html.

Sayın, E.Z., Batar, T., Kaya, E., Tufan, B. (2010). Reduced cyanide use with alternative gold production method combination of gravity and leach methods. Ekoloji. 19, 65-71. https://doi.org/10.5053/ekoloji.2010.7710

Tapfuma, A., Akdogan, G., Tadie, M. (2024). Investigation of glycine leaching for gold extraction from Witwatersrand gold mine tailings with permanganate pre-treatment. J. S. Afr. Inst. Min. Metall. 124 (4), 219-229. https://doi.org/10.17159/2411-9717/2967/2024

Turan, A., Yucel, O. (2011). The effect of iron and oxidizing flux addition on the fire assay of low grade pyritic refractory gold ores. J. Min. Metall. B 47 (2), 219-227. https://doi.org/10.2298/JMMB110127007T

Ulusoy, U., Girgin, İ. (1998). Refrakter cevherlerden siyanürleme dışı altın üretim yöntemleri. Madencilik 37, 23-33.

Vaughan, J.P. (2004). The process mineralogy of gold: The classification of ore types. JOM 56, 46-48. https://doi.org/10.1007/s11837-004-0092-8

Wang, J., Wang, R., Pan, Y., Liu, F., Xu, Z. (2022). Thermodynamic analysis of gold leaching by copper-glycine-thiosulfate solutions using Eh-pH and species distribution diagrams. Miner. Eng. 179, 107438. https://doi.org/10.1016/j.mineng.2022.107438

Wu, J., Ahn, J., Lee, J. (2021). Gold deportment and leaching study from a pressure oxidation residue of chalcopyrite concentrate. Hydrometallurgy 201, 105583. https://doi.org/10.1016/j.hydromet.2021.105583

Yan, B., Stadtmüller, B., Haag, N., Jakobs, S., Seidel, J., Jungkenn, D., Mathias, S., Cinchetti, M., Aeschlimann, M., Felser, C. (2015). Topological states on the gold surface. Nat. Commun. 6, 10167. https://doi.org/10.1038/ncomms10167 PMid:26658826 PMCid:PMC4682159

Yannopoulos, J.C. (1991). Physical and Chemical Properties of Gold. In: The Extractive Metallurgy of Gold. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-8425-0