Document Type : Original Research Paper

Authors

1 Mining Engineering Department, University of Engineering & Technology, Lahore, Pakistan

2 Reko Diq Mining Company (Private) Limited, Balochistan, Pakistan

3 Graduate School of International Resource Sciences, Akita University, 1-1 Tegata-Gakuenmachi, Akita 010-8502, Japan

10.22044/jme.2026.17521.3482

Abstract

Low-grade copper–gold porphyry ores present significant processing challenges due to poor mineral dissemination and high gangue content. In this study, a representative ore sample from the Saindak Copper–Gold Project, Pakistan, with an average copper grade of 0.4 wt%, was investigated to optimize flotation parameters for improved copper recovery. Mineralogical characterization using XRD, XRF, SEM–EDS, and ICP-OES confirmed chalcopyrite as the primary copper-bearing mineral finely disseminated within silicate gangue and iron sulfides. A series of batch flotation experiments were conducted by systematically varying particle size, slurry pH, collector dosage, and flotation time. The results showed that optimal conditions (particle size <75 μm, pH 12, and 1-min flotation time) enabled selective chalcopyrite recovery. Optimal flotation performance was achieved at pH 12 with a collector dosage of 5 g/t and a flotation time of 1 min, yielding a copper recovery of approximately 93% and a concentrate grade of 23 wt% under multistage flotation conditions. Flotation kinetics analysis indicated that the first-order kinetic model provided the best fit to the experimental data. The findings demonstrate that efficient copper upgrading from low-grade Saindak ore can be achieved with minimal collector consumption, offering a potentially cost-effective and sustainable processing strategy for similar porphyry copper deposits.

Keywords

Main Subjects

[1]. M. Bilal et al., “The Challenges and Prospects of Recovering Fine Copper Sulfides from Tailings Using Different Flotation Techniques: A Review,” 2022.
[2]. C. B. Tabelin et al., “Copper and critical metals production from porphyry ores and E-wastes: A review of resource availability, processing/recycling challenges, socio-environmental aspects, and sustainability issues,” Resour. Conserv. Recycl., vol. 170, p. 105610, 2021.
[3]. M. Bilal et al., “Carrier Flotation Using Coarse Pyrite for Improving the Recovery of Finely Ground Chalcopyrite: Development of Post-Process of Carrier Flotation to Separate Finely Ground Chalcopyrite Particles from Coarse Pyrite Particles,” 2023.
[4]. Y. Dong and H. Lin, “Influences of flotation reagents on bioleaching of chalcopyrite by Acidthiobacillus ferrooxidans,” Miner. Eng., vol. 32, pp. 27–29, May 2012.
[5]. L. Lin, L. Xianjun, Q. Jun, and L. Peng, “The Study on the Flotation of Tailings of Molybdenum Minerals for the Reclamation of Iron,” Procedia Environ. Sci., vol. 12, pp. 453–458, Jan. 2012.
[6]. I. Park, “Advances in Selective Flotation and Leaching Process in Metallurgy,” 2022. doi: 10.3390/met12010144.
[7]. I. Park et al., “Beneficiation of Low-Grade Rare Earth Ore from Khalzan Buregtei Deposit (Mongolia) by Magnetic Separation,” 2021.
[8]. M. E. Schlesinger, K. C. Sole, W. G. Davenport, and G. R. F. Alvear Flores, “Chapter 1 - Overview,” M. E. Schlesinger, K. C. Sole, W. G. Davenport, and G. R. F. B. T.-E. M. of C. (Sixth E. Alvear Flores, Eds., Elsevier, 2022, pp. 1–18.
[9]. G. F. de Lima, C. de Oliveira, H. A. de Abreu, and H. A. Duarte, “Water Adsorption on the Reconstructed (001) Chalcopyrite Surfaces,” J. Phys. Chem. C, vol. 115, no. 21, pp. 10709–10717, Jun. 2011.
[10]. I. Park, S. Hong, S. Jeon, M. Ito, and N. Hiroyoshi, “A Review of Recent Advances in Depression Techniques for Flotation Separation of Cu–Mo Sulfides in Porphyry Copper Deposits,” 2020.
[11]. Y. Peng and T. Bhambhani, “Preface to the MME Special Focus Issue on Managing Gangue Minerals,” Mining, Metall. Explor., vol. 38, no. 2, pp. 669–671, 2021.
[12]. J. Chen, W. Chimonyo, and Y. Peng, “Flotation behaviour in reflux flotation cell – A critical review,” Miner. Eng., vol. 181, p. 107519, 2022.
[13]. C. F. De Gontijo, D. Fornasiero, and J. Ralston, “The limits of fine and coarse particle flotation,” Can. J. Chem. Eng., vol. 85, no. 5, pp. 739–747, Oct. 2007, doi: 10.1002/CJCE.5450850519;WGROUP:STRING:PUBLICATION.
[14]. M. Bilal et al., “Heterogenous carrier flotation technique for recovering finely ground chalcopyrite particles using coarse pyrite particles as a carrier,” Miner. Eng., vol. 180, p. 107518, Apr. 2022.
[15]. J. Ran, X. Qiu, Z. Hu, Q. Liu, B. Song, and Y. Yao, “Effects of particle size on flotation performance in the separation of copper, gold and lead,” Powder Technol., vol. 344, pp. 654–664, 2019.
[16]. A. Azizi, “Influence of collector dosage and pulp chemistry on copper flotation,” Geosystem Eng., vol. 17, no. 6, pp. 311–316, Nov. 2014.
[17]. A. Asghar, H. Ahmad, and F. Behnam, “Investigating the first-order flotation kinetics models for Sarcheshmeh copper sulfide ore,” Int. J. Min. Sci. Technol., vol. 25, no. 5, pp. 849–854, 2015.
[18]. A. Azizi, “Optimization of Rougher Flotation Parameters of the Sarcheshmeh Copper Ore Using a Statistical Technique,” J. Dispers. Sci. Technol., vol. 36, no. 8, pp. 1066–1072, Aug. 2015.
[19]. V. Hornn et al., “Kinetic Analysis for Agglomeration-Flotation of Finely Ground Chalcopyrite: Comparison of First Order Kinetic Model and Experimental Results,” Mater. Trans., vol. 61, no. 10, pp. 1940–1948, 2020.
[20]. A. Bahrami, Y. Ghorbani, M. R. Hosseini, F. Kazemi, M. Abdollahi, and A. Danesh, “Combined Effect of Operating Parameters on Separation Efficiency and Kinetics of Copper Flotation,” Mining, Metall. Explor., vol. 36, no. 2, pp. 409–421, 2019.
[21]. C. Owusu, D. Fornasiero, J. Addai-Mensah, and M. Zanin, “Influence of pulp aeration on the flotation of chalcopyrite with xanthate in chalcopyrite/pyrite mixtures,” Int. J. Miner. Process., vol. 134, pp. 50–57, 2015.
[22]. X. Huang, K. Huang, Y. Jia, S. Wang, Z. Cao, and H. Zhong, “Investigating the selectivity of a xanthate derivative for the flotation separation of chalcopyrite from pyrite,” Chem. Eng. Sci., vol. 205, pp. 220–229, 2019.
[23]. L. Bai, J. Liu, Y. Han, K. Jiang, and W. Zhao, “Effects of Xanthate on Flotation Kinetics of Chalcopyrite and Talc,” 2018.
[24]. X. Zheng and P. Manton, “A potential application of collectorless flotation in a copper/gold operation,” Miner. Eng., vol. 23, no. 11, pp. 895–902, 2010.
[25]. A. Yang, Z. Li, H. Park, and L. Wang, “Collectorless flotation of ultrafine and coarse chalcopyrite particles in an ultrasonic piezoelectric tube,” Miner. Eng., vol. 237, p. 109959, 2026.
[26]. R. H. Yoon, “Collectorless flotation of chalcopyrite and sphalerite ores by using sodium sulfide,” Int. J. Miner. Process., vol. 8, no. 1, pp. 31–48, 1981.
[27]. B. Gayratov et al., “Copper Recovery from Copper Sulfide Ore by Combined Method of Collectorless Flotation and Additive Roasting Followed by Acid Leaching,” 2025.
[28]. J. Hong et al., “Magmatic Evolution at the Saindak Cu-Au Deposit: Implications for the Formation of Giant Porphyry Deposits,” 2025. doi: 10.3390/min15080768.
[29]. B. Yang, X. Tong, Z. Deng, and X. Lv, “The Adsorption of Cu Species onto Pyrite Surface and Its Effect on Pyrite Flotation,” J. Chem., vol. 2016, no. 1, p. 4627929, Jan. 2016, doi: https://doi.org/10.1155/2016/4627929.
[30]. R. Li Jie Lee and Y. Peng, “Assessing the depression of high-concentration pyrite in copper flotation by high pH,” Miner. Eng., vol. 209, p. 108651, 2024, doi: https://doi.org/10.1016/j.mineng.2024.108651.
[31]. X. Bu, X. Wang, S. Zhou, B. Li, H. Zhan, and G. Xie, “Discrimination of Six Flotation Kinetic Models Used in the Conventional Flotation and Carrier Flotation of −74 μm Coal Fines,” ACS Omega, vol. 5, no. 23, pp. 13813–13821, Jun. 2020, doi: 10.1021/acsomega.0c01116.