Journal of Sustainable Metallurgy

, Volume 4, Issue 4, pp 470–484 | Cite as

Comparative Study of Simultaneous Removal Performance of Silica and Solid Colloidal Particles from Chalcopyrite Bioleachate Solution by Washing and Coagulation Methods

  • David Lukumu BampoleEmail author
  • Antoine F. Mulaba-Bafubiandi
Research Article


Most of the surface reserves of copper minerals are oxidized while underground mining leads to rich silica–chalcopyrite–pyrite ore. Based on the challenges of the twenty-first century, the (bio)-hydrometallurgy processing is suggested as an alternative route to replace conventional techniques. However, the search for a sustainable metallurgy and/or more effective method to decrease impurities for efficient solvent extraction led to a comparative study of the removal performances of silica and solid colloidal particles from bioleachate solution by comparing the techniques using Shellsol set #2325 and Magnafloc set #1597, respectively. Three ratios (thinner/aqueous) or/and (coagulant /aqueous) of 1/2, 1, and 3/2 were assessed, along with the disengagement time and the required absorbed dose of Magnafloc 1597. The search for the alternative route also sought to ensure that the requirements in terms of concentration values at solvent extraction stage did not exceed 500 and 75 ppm, respectively. Findings show that the diluent/wash method is less efficient in terms of the removal performances of silica and solid colloidal particles from the bioleachate solution, but the phase disengagement time was similar, being comparatively around 150 s. The results of Magnafloc 1597 coagulation tests show removal performances of silica and colloidal particles from the bioleachate solution to be greater than 300 ppm, with a volume ratio of 1/1 for recovery rates of 68 and 58%, respectively, for SiO2 and colloidal solids in suspension. In comparison, the employment of Shellsol 2325 achieved silica removal efficiencies of 20.92 and 40%, respectively, of SiO2 and colloidal fine particles in suspension. A decreased phase separation time in aqueous continuity from 245 to 148 s has been recorded with a ratio of 1/1 (thinner or coagulant/aqueous). On the other hand, coagulant concentration of 300 ppm was retained. Hence, it could be assumed that the coagulation showed better results than the washing method.


Silica Solid colloidal particles Bioleachate solution Greener environment Sustainable metallurgy 



Solvent extraction


Pregnant leach solution


Phase disengagement time


Total solids in suspension


Revolution per minute

Rdt or Rec

Yield of the operation


Aqueous continuity


Continuity in aqueous phase


Organic continuity


Continuity in organic phase



The first author wishes to extend his gratitude not only to the University of Johannesburg (UJ), South Africa, for providing the means and facilities for this research—but also to the Mineral Processing &Technology Research Centre and the Metallurgy Department.

Compliance with Ethical Standards

Conflict of interest

All the authors declare that there are no conflict of interests to disclose in this study.


  1. 1.
    Rahman SM, Spalding-Fecher R, Haites E, Kirkman GA (2018) The levelized costs of electricity generation by the CDM power projects. Energy 148:235–246CrossRefGoogle Scholar
  2. 2.
    Chang SH, Wahab AAA, Som AM (2016) Optimization of Cu (II) ion extraction and stripping through liquid membrane by response surface methodology. In: Proceedings of the international multi conference of engineers and computer scientistsGoogle Scholar
  3. 3.
    Sengupta B, Bhakhar MS, Sengupta R (2007) Extraction of copper from ammoniacal solutions into emulsion liquid membranes using LIX 84I. Hydrometallurgy 89:311–318CrossRefGoogle Scholar
  4. 4.
    Bergh LG, Yianatos JB (2001) Current status and limitations of copper SX/EW plants control. Miner Eng 14(9):975–985CrossRefGoogle Scholar
  5. 5.
    Erdogan S, Merdivan M, Hamamci C, Akba O (2004) Baysal A polymer supported humic acid for separation and preconcentration of thorium(IV). Anal Lett 37:2565CrossRefGoogle Scholar
  6. 6.
    Pereira AS, Ferreira G, Caetano L, Castro RSD, Santos A, Padilha PM (2010) Castro GR 4-Amine-2-mercaptopyrimidine modified silica gel applied in Cd(II) and Pb (II) extraction from an aqueous medium. Pol J Chem Technol 12:7–11CrossRefGoogle Scholar
  7. 7.
    Chen Y, Baygents JC, Farrell J (2017) Evaluating electrocoagulation and chemical coagulation for removing dissolved silica from high efficiency reverse osmosis (HERO) concentrate solutions. J Water Process Eng 16:50–55CrossRefGoogle Scholar
  8. 8.
    Zhang L, Hessel V, Peng J, Wang Q, Zhang L (2017) Co and Ni extraction and separation in segmented micro-flow using a coiled flow inverter. Chem Eng J 307:1–8CrossRefGoogle Scholar
  9. 9.
    Readett DJ, Miller GM (1995) The impact of silica on solvent extraction: Girilambone Copper Company case study. Santiago, Chile, 26–29 November, 1995Google Scholar
  10. 10.
    Virnig MJ, Olafson SM, Kordosky GA, Wolfe GA (2007) Crud formation: field studies and fundamental studies. In: Riveros PA, Dixon DG, Dreisinger DB, Collins MJ (eds) Copper, Toronto, Canada, 26–29 August 2007. Canadian Institute of Mining Metallurgy and Petroleum, Montreal, pp 291–303Google Scholar
  11. 11.
    Ritcey GM (1982) Crud in uranium solvent extraction. In: Proceedings of the 14th international mineral processing congress, October 17–23 Toronto, CanadaGoogle Scholar
  12. 12.
    Brown CW (2015) Physical property–performance relationships of commercial diluents in African copper solvent extraction conditions. In: Proceedings of the copper cobalt Africa conference. Southern African Institute of Mining and Metallurgy, Johannesburg, pp. 269–280Google Scholar
  13. 13.
    Robinson T (2007) Innovations in solvent extraction. In: Riveros A, Dixon DG, Dreisinger DB, Collins MJ (eds) Copper, Toronto, Canada, 26–29 August 2007. Canadian Institute of Mining Metallurgy and Petroleum, MontrealGoogle Scholar
  14. 14.
    Talik E, Wojtyniak M et al (2017) Unique properties of silver and copper silica-based nanocomposites as antimicrobial agents. RSC Adv 7:28092–28104CrossRefGoogle Scholar
  15. 15.
    Bahadur NM, Furusawa T, Sato M, Kurayama F, Siddiquey IA, Suzuki N (2011) Fast and facile synthesis of silica coated silver nanoparticles by microwave irradiation. J Colloid Interface Sci 355:312–320CrossRefGoogle Scholar
  16. 16.
    Marsh RM, Norris PR (1983) The isolation of some thermophilic autotrophic, iron- and sulphur-oxidising bacteria. FEMS Microbiol Lett 17:311–315CrossRefGoogle Scholar
  17. 17.
    Zhang X, Feng X, Tao J, Ma L, Xiao Y, Liang Y, Liu X (2016) Yin H Comparative genomics of the extreme Acidithiobacillus thiooxidans reveals intraspecific divergence and niche adaptation. Int J Mol Sci 17:1355CrossRefGoogle Scholar
  18. 18.
    Peacey J, Guo XJ, Robles E (2004) Copper hydrometallurgy—current status, preliminary economics, future direction and position versus smelting. Trans Nonferr Metals Soc China 14(3):560–568Google Scholar
  19. 19.
    Rami M, Guizard C (2010) Study of the stability of Zirconia Yttriee. Colloidal dispersions for the manufacture of fine grain ceramics. Ph.D. Thesis, University of Toulouse, Genie of Processes and Environment, Toulouse (in French)Google Scholar
  20. 20.
    Cai Y, Tan F, Qiao X, Wang W, Chen J, Qiu X (2016) Room-temperature synthesis of silica supported silver nanoparticles in basic ethanol solution and their antibacterial activity. RSC Adv 6:18407–18412CrossRefGoogle Scholar
  21. 21.
    Bampole DL, Patricia L, Lukumu, ME (2017) Effect of substrates during the adaptation of indigenous bacteria in bioleaching of sulphide ores. In: ASRJETS, 2013, vol 32Google Scholar
  22. 22.
    Nayak S, Singh K (2007) Instrumental characterization of clay by XRF, XRD and FTIR. J Bull Mater Sci 30:235–238CrossRefGoogle Scholar
  23. 23.
    James OM, Adekola F, Odebumni E, Adekeye JID (2008) Benefication and characterization of a bentonite from North-eastern Nigerian. J N C Acad Sci 124:154–158Google Scholar
  24. 24.
    Aouali Z, Kebir M, Adel M, Adjdir M, Bengueddach A, Sassi M (2018) Preparation and antibacterial activity of silver nanoparticles intercalated kenyaite materials. Mater Res Express 5:8Google Scholar
  25. 25.
    Patel AR, Rodriguez Y, Lesaffer A (2014) Dewettinck K High internal phase emulsion gels (HIPE-gels) prepared using food-grade components. RSC Adv 4:18136–18140CrossRefGoogle Scholar
  26. 26.
    Cole P, Bednarski T, Thomas L, Muteba D, Banza G, Soderstrom M (2015) Understanding aqueous-in-organic entrainment in copper solvent extraction, copper cobalt Africa. In: Association with the 8th base metal conference, South African Institute of Mining & Metallurgy, Marshalltown, South AfricaGoogle Scholar
  27. 27.
    Gorrepati EA, Wongthahan P, Raha S, Fogler HS (2010) Silica precipitation in acidic solutions: mechanism, pH effect, and salt effect. Langmuir 26:10467–10474CrossRefGoogle Scholar
  28. 28.
    Lok RTBM (1983) Silicoaluminophosphate molecular sieves: another new class of microporous crystalline inorganic solids. Zeolites 3:282CrossRefGoogle Scholar
  29. 29.
    Binnemans K, Jones PT (2017) Solvometallurgy: an emerging branch of extractive metallurgy. J Sustain Metall 3:570–600CrossRefGoogle Scholar
  30. 30.
    Iler RK (1955) The colloid chemistry of silica and silicates. Cornell University Press, New York, pp 194–195Google Scholar
  31. 31.
    Dreisinger DB, Littlejohn P (2007) Technical review: copper solvent extraction. In: Hydrometallurgy. MTRL 557Google Scholar
  32. 32.
    Matthew IG, Elsner D (1977) The hydrometallurgical treatment of zinc silicate ores. Metall Trans B 8B:73–83CrossRefGoogle Scholar
  33. 33.
    Jiang XL, Zhang LJ, Bai Y, Liu Y (2017) Bi-stage time evolution of nano-morphology on inductively coupled plasma etched fused silica surface caused by surface morphological transformation. Appl Surf Sci 409:163–165CrossRefGoogle Scholar
  34. 34.
    Miller WS (2009) Understanding ion-exchange resins for water treatment systems. GE Water Process Technol, FairfieldGoogle Scholar
  35. 35.
    Pless JD, Philips ML, Voigt JA, Moore D, Axness M, Krumhansl JL, Nenoff TM (2018) Desalination of brackish waters using ion-exchange media. Ind Eng Chem Res 45:4752–4856CrossRefGoogle Scholar
  36. 36.
    White MJ, Masbate JL Jr, Gare SG (2010) Reverse osmosis pre-treatment of high silica waters, GE power & water, vol. TP1058EN. Water & Process TechnologiesGoogle Scholar
  37. 37.
    Harith ZT, Yusoff FM, Mohamed MS, Din MSM, Ariff AB (2009) Effect of different flocculants on the flocculation performance microalgae, Chaetoceros calcitrans, cells. Afr J Biotechnol 8:5971–5978CrossRefGoogle Scholar
  38. 38.
    Latour I, Miranda R, Blanco A (2013) Silica removal from newsprint mill effluents with aluminum salts. Chem Eng J 230:522–531CrossRefGoogle Scholar
  39. 39.
    Latour I, Miranda R, Blanco A (2014) “Silica removal in industrial effluents with high silica and low hardness. Environ Sci Pollut R 21:9832–9842CrossRefGoogle Scholar
  40. 40.
    Samadi MT, Saghi MH, Rahmani A, Hasanvand J, Rahimi S, Shirzad M (2010) Hamadan landfill leachate treatment by coagulation-flocculation process. Iran J Environ Health Sci Eng 7(3):253–258Google Scholar
  41. 41.
    Bryan D, Logan V, Bret M (2018) Coagulation of colloidal silica from uranium leach solutions for improved solvent extraction. In: Proceedings of the international symposium on uranium raw material for the nuclear fuel cycle: exploration, mining, production, supply and demand, economics and environmental issues (URAM-2018), Canada, June 2018Google Scholar
  42. 42.
    Danks AE, Hall SR, Schnepp Z (2016) The evolution of ‘sol–gel’ chemistry as a technique for materials synthesis. Mater Horiz 3:91–112CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society 2018

Authors and Affiliations

  • David Lukumu Bampole
    • 1
    • 2
    Email author
  • Antoine F. Mulaba-Bafubiandi
    • 1
  1. 1.Mineral Processing & Technology Research Centre, Department of Metallurgy, Faculty of Engineering and the Built EnvironmentUniversity of JohannesburgJohannesburgSouth Africa
  2. 2.Department of Industrial Chemistry, Faculty of PolytechnicUniversité de LikasiLikasiDemocratic Republic of the Congo

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