[en] In mines in Katanga region of the Democratic Republic of Congo (DRC), cobalt is commonly recovered from oxy-hydroxide minerals (e.g. heterogenite, asbolane) using a sulfuric acid leach under reducing conditions. However, most of the leaching operations show yields of Co, below 80% so the current study focused on determining the reasons for the recovery shortfall. A range of samples were investigated comprising a detailed mineralogical characterization of five concentrate and leached samples from different mine plants in the Katanga region: namely Kalukuluku, Mutanda, Mabaya, Kamwali and Fungurume mines. The analyses were carried out prior to and after leaching treatments using a combination of chemical (ICP-AES) and mineralogical techniques (XRD, automated mineralogy, SEM-EDS and X-ray mapping). The results revealed that heterogenite and asbolane occur in samples both prior to and after leaching: this confirms the ineffective leaching of these minerals or/and the presence of Co-bearing refractory minerals and other phases inhibiting the diffusion of leachate. SEM-EDS and X-ray mapping of leached samples showed that both heterogenite and asbolane are commonly finely intergrown with clays and Fe-oxy-hydroxides (FOH). These outcomes are in agreement with automated mineralogy results for the Co deportment, showing that Co is mainly hosted in: (a) pure heterogenite particles, (b) heterogenite intergrown with other minerals, (c) fine-grain heterogenite (≤1µm) enclosed in clays, and (d) clays or/and FOH adsorbing Co in the structure. The Co recovery inefficiency is a result of the mineralogical complexity of the ores, making the current processing strategy sub-optimal. In
conclusion the two main reasons for the incomplete recovery are: firstly mineral liberation issues and secondly the presence of un-recoverable elemental Co within the structure of refractory phases
Arthur, W.R., Gino, C.B.-M., Adsorption of Cu, Pb, Zn Co, Ni, Ag by goethite and hematite: a control on metal mobilization from red beds into stratiform copper deposits. Econ. Geol. 88 (1993), 1226–1236.
Alexandre, J., Les cuirasses latéritiques et autres formations ferrugineuses tropicales. Exemple du Haut Katanga méridional: Annales du Musée Royal de l'Afrique Centrale. Sciences Géologiques, 107, 2002, 118.
Alvarez, M., Tufo, A.E., Zenobi, C., Ramos, C.P., Sileo, E.E., Chemical, Structural and hyperfine characterization of goethites with simultaneous incorporation of manganese, cobalt and aluminium ions. Chem. Geol. 414 (2015), 16–27.
Annels, A.E., The geotectonic environment of Zambian coppercobalt mineralization. J. Geol. Soc. Lond. 141 (1984), 279–289.
Annels, A.E., Ore genesis in the Zambian Copperbelt, with particular reference to the northern sector of the chambishi Basin. 36 Boyle, R.W., Brown, A.C., Jefferson, C.W., Jowett, E.C., Kirkham, R.V., (eds.) Sediment-hosted stratiform copper deposits, Spec. Pap. Geol. Assoc. Can., 1989, 427–452.
Bouzahzah, H., Benzaazoua, M., Mermillod-Blondin, R., Pirard, E., A novel procedure for polished section preparation for automated mineralogy avoiding internal particle settlement. 12th International Congress for Applied Mineralogy (ICAM). Istanbul (Turkey), 10–12 August 2015, 2015.
Burlet, C., Goethals, H., Vanbrabant, Y., Delafossite structure of heterogenite polytypes (HCoO 2 ) by Raman and infrared micro-spectroscopy. Spectrochim Acta, Part A: Mol. Biomol. Spectrosc. 159 (2016), 90–97.
Backes, E.A., Mclaren, R.G., Rate, A.W., Swift, R.S., Kinetics of cadmium and cobalt desorption from iron and manganese oxides. Soil Sci. Soc. Am. J. 59 (1993), 778–785.
Cahen, L., Snelling, N.J., Delhal, J., Vail, J.R., Bonhomme, M., Ledent, D., Geochronology and evolution of Africa. 1984, Clarendon, Oxford, 512.
Cailteux, J., Lithostratigraphy of the neoproterozoic shaba-type (Zaire) roan supergroup and metallogenesis of associated stratiform mineralization. 19 Kampunzu, A.B., Lubala, R.T., (eds.) Neoproterozoic Belts of Zambia. J. Afr. Earth Sci., 1994, Zaire and Namibia, 279–301.
Cailteux, J., Binda, P.L., Katekesha, W.M., Kampunzu, A.B., Intiomale, M.M., Kapenda, D., Kaunda, C., Ngongo, K., Tshiauka, T., Wendorff, M., Lithostratigraphical correlation of the neoproterozoic roan supergroup from Shaba (Zaire) and Zambia, in the central African copper–cobalt metallogenic province. 19 Kampunzu, A.B., Lubala, R.T., (eds.) Neoproterozoic Belts of Zambia J. Afr. Earth Sci., 1994, Zaire and Namibia, 265–278.
Cailteux, J.L.H., Kampunzu, A.B., Lerouge, C., Kaputo, A.K., Milesi, J.P., Genesis of sediment-hosted stratiform copper–cobalt deposits, central African copperbelt. J. Afr. Earth Sci. 42 (2005), 134–158.
Ceylan, H., Şahan, T., Gürkan, R., Kubilay, Ş., Removal of some heavy metal cations from aqueous solution by adsorbtion onto natural kaolin. Adsorpt. Sci. Technol. 23:7 (2005), 519–534.
Charalambos, P., Hayes, K., Distinguishing between interlayer and external sorption sites of clay minerals using X-ray absorption spectroscopy. Colloid. Surf. A. 107 (1996), 89–96.
Chen, C.C., Hayes, K.F., X-ray absorption spectroscopy investigation of aqueous Co(II) and Sr(II) sorption at clay-water interfaces. Geochim. Cosmochim. Acta 63:19–20 (1999), 3205–3215.
Cornell, R.M., Simultaneous incorporation of Mn, Ni and Co in the goethite (αFeOOH) structure. Clay Miner. 26 (1991), 427–430.
Cornell, R.M., Giovanoli, R., Effect of cobalt on the formation of crystalline iron oxides from ferrihydrite in alkaline media. Clays Clay Min. 37 (1989), 65–70.
Cornell, R.M., Schwertmann, U., Front Matter, in the iron oxides: structure, properties, reactions, occurences and uses. Second Edition, 2003, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, FRG.
De Putter, T., Mees, F., Decrée, S., Dewaele, S., Malachite, an indicator of major Pliocene Cu remobilization in a karstic environment (Katanga, Democratic Republic of Congo). Ore Geol. Rev. 38 (2010), 90–100.
Deliens, M., Les oxydes hydrates de cobalt du Shaba Méridional. Annales du Musée Royal de l'Afrique Centrale Sci. Géol., 76, 1974, 80.
Dewaele, S., Muchez, Ph., Vets, J., Fernandez-Alonzo, M., Tack, L., Multiphase origin of Co-Cu ore deposits in the western part of the Lufilian fold-and-thrust belt, Katanga (Democratic Republic of Congo). J. Afr. Earth Sci. 46:5 (2006), 397–474.
Decrée, S., Deloule, E., Ruffet, G., Dewaele, S., Mees, F., Marignac, C., Yans, J., De Putter, T., Geodynamic and climate controls in the formation of Mio-Pliocene world class oxidized cobalt and manganes ores in the Katanga province, DR Congo. Miner. Deposita. 45 (2010), 621–629.
Decrée, S., Pourret, O., Baele, J.M., Rare earth element fractionation in heterogenite (CoOOH): implication for cobalt oxidized ore in the Katanga Copperbelt (Democratic Republic of Congo). J. Geochem. Explor. 159 (2015), 290–301.
El Desouky, H.A., Muchez, P., Boyce, A.J., Schneider, J., Cailteux, J.L.H., Dewaele, S., von Quadt, A., Genesis of sediment-hosted stratiform copper–cobalt mineralization at Luiswishi and Kamoto, Katanga Copperbelt (Democratic Republic of Congo). Miner. Deposita. 45 (2010), 735–763.
Fay, I., Barton, M.D., Alteration and ore distribution in the Proterozoic mines series, Tenke-fungurume Cu-Co district Democratic Republic of Congo. Miner. Deposita 47 (2012), 501–519.
François, A., Stratigraphie, tectonique et minéralisations dans l'arc cuprifère du Shaba (république du Zaire). Bartholomé, P., (eds.) Gisements Stratiformes et Provinces Cuprifères, 1974, Société Géologique de Belgique, Liège, Belgium, 79–101.
Gauthier, G., Deliens, M., Cobalt minerals of the Katanga Crescent. Congo. Miner. Rec. 30:4 (1999), 255–273.
De Groot, G.J., Hoede, D., Validation of Dutch standard leaching tests using NEN-ISO 5725. Studies Environ. Sci. 60 (1994), 305–314.
Hanson, R.E., Wardlaw, M.S., Wilson, T.J., Mwale, G., U-Pb zircon ages from the Hook Granite Massif and Mwembeshi dislocation: constraints on Pan-African deformation, plutonism, and transcurrent shearing in central Zambia. Precambrian Res. 63 (1993), 189–209.
Hey, M.H., Cobaltic hydroxide in nature. Min. Mag., 33, 1962, 253.
Hitzman, M., Broughton, D., Selley, D., Woodhead, J., Wood, D., Bull, S., The Central African Copperbelt: Diverse stratigraphic, structural and temporal settings the world's largest sedimentary copper district. Econ. Geol. 16 (2012), 487–514.
Jackson, M.P.A., Warin, O.N., Woad, G.M., Hudec, M.R., Neoproterozoic allochthonous salt tectonics during the Lufilian orogeny in the Katangan Copperbelt, Central Africa. Geol. Soc. Am. Bull. 115 (2003), 314–330.
John, T., Schenk, V., Mezger, K., Tembo, F., Timing and PT evolution of whiteschist metamorphism in the Lufilian Arc- Zambezi Belt Orogen (Zambia); implications for the assembly of Gondwana. J. Geol. 112:1 (2004), 71–90.
Key, R.M., Liyungu, A.K., Njamu, F.M., Somwe, V., Banda, J., Mosley, P.N., Armstrong, R.A., The western arm of the Lufilian Arc inNWZambia and its potential for copper mineralization. J. Afr. Earth Sci. 33 (2001), 503–528.
Kampunzu, A.B., Cailteux, J.L.H., Tectonic evolution of the Lufilian arc (Central Africa Copper Belt) during Neoproterozoic pan-African orogenesis. Gondwana Res. 2 (1999), 401–421.
Kampunzu, A.B., Cailteux, J.L.H., Moine, B., Loris, H.N., Geochemical characterisation, provenance, source and depositional environment of ‘Roches Argilo-Talqueuses’ (RAT) and Mines Subgroups sedimentary rocks in the Neoproterozoic Katangan Belt (Congo): Lithostratigraphic implications. J. Afr. Earth Sci. 42 (2005), 119–133.
Kaur, N., Gräfe, M., Singh, B., Kennedy, B.J., Simultaneous incorporation of Cr, Zn, Cd, and Pb in the goethite structure. Clays Clay Miner. 57:2 (2009), 234–250.
Landers, M., Gilkes, R.J., Dehydroxylation and dissolution of nickeliferous goethite in New Caledonian lateritic Ni ore. Appl. Clay Sci. 35 (2007), 162–172.
Layton-Matthews, D., Hamilton, C., McClenaghan, M.B., Mineral chemistry: modern techniques and applications to exploration. Open File 7553 McClenaghan, M.B., Plouffe, A., Layton-Matthews, D., (eds.) Application of indicator mineral methods to mineral exploration, 2014, Geological Survey of Canada, 9–18.
Lefebvre, J.J., Depositional environment of copper-cobalt mineralization in the Katangan sediments of southeast Shaba, Zaire. Special Paper 36 Boyle, R.W., Brown, A.C., Jefferson, C.W., Jowett, E.C., Kirkham, R.V., (eds.) Sediment-hosted stratiform copper deposits, 1989, Geol. Assoc. Can., 401–426.
Manohar, D.M., Noeline, B.F., Anirudhan, T.S., Adsorption performance of Al-pillared bentonite clay for the removal of cobalt(II) from aqueous phase. App. Clay Sci. 31 (2006), 194–206.
Master, S., Rainaud, C., Armstrong, R.A., Phillips, D., Robb, L.J., Provenance ages of the neoproterozoic Katanga supergroup (Central African Copperbelt), with implications for basin evolution. J. Afr. Earth. Sci. 42 (2005), 41–60.
Mulaba-Bafubiandi, A., “The effects of process parameters on the acid leach ability and related impurities from heterogenite ore from Katanga (DRC), Copper, cobalt, nickel and zinc recovery conference” South African Institute of Mining and Metallurgy, 16–18 July 2001. 2001, Victoria Falls, Zimbabwe.
Mwema, M., Mpoyo, M., Kafumbila, K., Use of sulfur dioxide as reducing agent in cobalt leaching at Shituru hydrometallurgical plant. The Journal of Southern African Institute of Mining and Metallurgy, Johannesburg, 2002, 1–4.
Nalamo, J., Aqueous behaviour of cobalt in presence of copper, iron and sulfur dioxide with and without microwave processing. Master thesis, 2008, Faculty of Science, University of Johannesburg, RSA.
O'Connor, P.T., Kester, D.R., Adsorption of copper and cobalt from fresh and marine systems. Geochim. Cosmochim. Acta. 39:11 (1975), 1531–1543.
O'Connor, F., Cheung, W.H., Valix, M., Reduction roasting of limonite ores: effect of dehydroxylation. Int. J. Miner. Process. 80 (2006), 88–99.
Olanipekun, E.O., Kinetics of leaching laterite. Int. J. Miner. Process. 60 (2000), 219–221.
O'Day, P.A., Parks, G.A., Brown, G.E. Jr., Molecular structure and binding sites of cobalt(II) surface complexes on kaolinite from X-Ray absorption spectroscopy. Clays Clay Min. 42:3 (1994), 337–355.
Padmanabham, M., Comparative study of adsorption-desorption behaviour of copper(II), zinc(II), cobalt(II) and lead (II) at goethite-solution interface. Aust. J. Soil. Res. 21 (1983), 515–525.
Porada, H., Berhorst, V., Towards a new understanding of the Neoproterozoic-Early Palaeozoic Lufilian and northern Zambezi belts in Zambia and the Democratic Republic of Congo. J. Afr. Earth Sci. 30 (2000), 727–771.
Pourbaix M, 1963. Atlas d’équilibre électrochimique à 25 °C.
Rainaud, C., Master, S., Armstrong, R.A., Robb, L.J., A cryptic mesoarchaean terrane in the basement to the central African copperbelt. J. Geol. Soc. Lond. 160 (2003), 11–14.
Rainaud, C., Master, S., Armstrong, R.A., Phillips, D., Robb, L.J., Monazite dating and 40Ar–39Ar thermochronology of metamorphic events in the Central African Copperbelt during the Pan- African Lufilian Orogeny. J. Afr. Earth Sci. 42 (2005), 183–199.
Rose, A.W., Bianchi-Mosquera, G., Adsorption of Cu, Pb, Zn Co, Ni, Ag by goethite and hematite: a control on metal mobilization from red beds into stratiform copperdeposits. Econ. Geol. 88 (1993), 1226–1236.
Ruan, H.D., Frost, R.L., Kloprogge, J.T., Duong, L., Infrared spectroscopy of goethite dehydroxylation. II. Effect of aluminium substitution on the behaviour of hydroxyl units. Spectrochim. Acta, Part A 58 (2002), 479–491.
Sandmann, D., Method development in automated mineralogy. 2015, Ph.D. dissertation.
Senanayake, G., Childs, J., Akerstrom, B.D., Pugaev, D., Reductive acid leaching of laterite and metal oxides – a review with new data for Fe(Ni, Co)OOH and a limonitic ore. Hydrometallurgy 110 (2011), 13–32.
Seo, S.Y., Choi, W.S., Kim, M.J., Tran, T., Leaching of a Cu-Co ore from Congo using sulfuric acid – hydrogen peroxide leachants. 2013 Mining Metall. Sect. B-Metall. 49:1B (2012), 1–7.
Shaw, S., Geochemical and mineralogical impacts of sulfuric acid on argiles between pH 5.0 and -3.0, Thesis. 2008, University of Saskatchewan, Canada, 20–46.
B. Simons, S. Graham, 2016, Iron oxide analyses by Automated Mineralogy, http://www.petrolab.co.uk/.
Stuurman, S., Ndlovu, S., Sibanda, V., Comparing the extent of the dissolution of copper-cobalt ores from the DRC Region. Southern African Inst. Mining Metall. 114 (2014), 347–353.
Thompson, H.A., Parks, G.A., Brown, G.E. Jr., Dynamic interactions of dissolution, surface adsorption, and precipitation in aging cobalt(II)-clay-water system. Geochim. Cossmochim Acta. 63:11/12 (1999), 1767–1779.
Tshipeng, S.Y., Kaniki, A.T., Kime, M.B., (in press). Effects of the addition points of reducing agents on the extraction of copper and cobalt from oxidized copper-cobalt ores. J. Sust. Metall., 2017.
Valix, M., Cheung, W.H., Study of phase transformation of laterite ores at high temperature. Miner. Eng. 15 (2002), 607–612.
Van der Sloot, H., van der Wegen, G.J.L., Hoede, D., de Groot, G.J., Intercomparison of leaching tests for stabilized waste. Studies Environ. Sci. 60 (1994), 63–76.
Yavuz, Ö., Altunkaynak, Y., Güzel, F., Removal of copper, nickel, cobalt and manganese from aqueous solution by kaolinite. Water Res. 37 (2003), 948–952.
Youlton, B., Kinnaird, J.A., Gangue-reagent interactions during acid leaching of uranium. Miner. Eng. 52 (2013), 62–73.
USGS, 2016 Mineral Commodity Summaries 2017.
USGS, 2015 Minerals Yearbook, 2015.
Wang, Xiaodong, An investigation of the relationship between Western Australian nickel laterites leaching performance and their mineralogical properties. Ph.D. Curtin University, Faculty of sciences and engineering, Department of Imaging and Applied Physics, 2013.
