Influence of alumina on mineralogy and environmental properties of zinc-copper smelting slags

Abstract

An iron-silicate slag, from a zinc-copper smelting process, and mixtures of this slag with 5wt%, 10wt%, and 15wt% alumina addition were re-melted, semi-rapidly solidified, and characterized using scanning electron microscopy equipped with energy dispersive spectroscopy, and X-ray diffraction. The FactSage™6.2 thermodynamic package was applied to compare the stable phases at equilibrium conditions with experimental characterization. A standard European leaching test was also carried out for all samples to investigate the changes in leaching behaviour because of the addition of alumina. Results show that the commonly reported phases for slags from copper and zinc production processes (olivine, pyroxene, and spinel) are the major constituents of the current samples. A correlation can be seen between mineralogical characteristics and leaching behaviours. The sample with 10wt% alumina addition, which contains high amounts of spinels and lower amounts of the other soluble phases, shows the lowest leachabilities for most of the elements.

Keywords

slags / characterization / mineralogy / alumina / leaching / solidification

References

[1] Petkovic G, Engelsen CJ, Håφya A, Breedveld G. Environmental impact from the use of recycled materials in road construction: method for decision-making in Norway. Resour. Conserv. Recycl., 2004, 42, 249.

[2] Parsons MB, Bird DK, Einaudi MT, Alpers CN. Geochemical and mineralogical controls on trace element release from the Penn Mine base-metal slag dump, California. Appl. Geochem., 2001, 16, 1567.

[3] Shanmuganathan P, Lakshmipathiraj P, Srikanth S, Nachiappan AL, Sumathy A. Toxicity characterization and long-term stability studies on copper slag from the ISASMELT process. Resour. Conserv. Recycl., 2008, 52, 601.

[4] Tossavainen M, Forssberg E. The potential leachability from natural road construction materials. Sci. Total Environ., 1999, 239, 31.

[5] Roth L, Eklund M. Environmental evaluation of reuse of by-products as road construction materials in Sweden. Waste Manage., 2003, 23, 107.

[6] Tossavainen M, Engströ F, Menad N, Yang Q. Stability of modified steel slags. European Slag Conference in Oulu, 2005

[7] Puziewicz J, Zainoun K, Bril H. Primary phases in pyrometallurgical slags from a zinc-smelting waste dump, Świętochłowice, Upper Silesia, Poland. Can. Mineral., 2007, 45, 1189.

[8] Ettler V, Legendre O, Bodénan F, Touray JC. Primary phases and natural weathering of old lead-zinc pyrometallurgical slag from Pribram, Czech Republic. Can. Mineral., 2001, 39, 873.

[9] Piatak NM, Seal RR II. Mineralogy and the release of trace elements from slag from the Hegeler zinc smelter, Illinois (USA). Appl. Geochem., 2010, 25, 302.

[10] Kierczak J, Néel C, Puziewicz J, Bril H. The mineralogy and weathering of slag produced by the smelting of lateritic Ni ores, Szklary, Southwestern Poland. Can. Mineral., 2009, 47, 557.

[11] Manasse A, Mellini M. Chemical and textural characterization of medieval slags from the Massa Marittima smelting sites (Tuscany, Italy). J. Cult. Heritage, 2002, 3, 187.

[12] Deng T, Ling YH. Chemical and mineralogical characterizations of a copper converter slag. Rare Met., 2002, 21, 175.

[13] Navarro A, Cardellach E, Mendoza JL, Corbella M, Domènech LM. Metal mobilization from base-metal smelting slag dumps in Sierra Almagrera (Almer’la, Spain). Appl. Geochem., 2008, 23, 895.

[14] Kucha H, Martens A, Ottenburgs R, Vos WD, Viaene W. Primary minerals of Zn-Pb mining and metallurgical dumps and their environmental behavior at Plombières, Belgium. Environ. Geol., 1996, 27, 1.

[15] Ettler V, Johan Z, Kř’lbek B, Šebek O, Mihaljevič M. Mineralogy and environmental stability of slags from the Tsumeb smelter, Namibia. Appl. Geochem., 2009, 24, 1.

[16] Gbor PK, Mokri V, Jia CQ. Characterization of smelter slags. J. Environ. Sci. Heal. A, 2000, 35, 147.

[17] M. Borell, Slag: a resource in the sustainable society, [in] Proceedings of Securing the future: International Conference on Mining and the Environmental, Metals and Energy Recovery, Skellefte 2005, p. 1.

[18] He FX. A Novel Method for Metal Recovery from Zinc Fuming Slags, 2000, Vancouver, The University of British Columbia, 9.

[19] Bale CW, Béisle E, Chartrand P, Decterov SA, Eriksson G, Hack K, Jung IH, Kang YB, Melançon J, Pelton AD, Robelin C, Petersen S. FactSage thermodynamical software and databases-recent developments. CALPHAD, 2009, 33, 295.

[20] BS EN. Characterisation of Waste-Leaching-Compliance Test for Leaching of Granular Waste Materials and Sludges: Part 2. One Stage Batch Test at a Liquid to Solid Ratio of 10 L/kg for Materials with Particle Size below 4 mm (without or with Size Reduction), 2002

[21] Kün M, Behmenburg M, Capodilupo M, Romera MQ. Decreasing the Scorification of Chrome, 2000, Luxembourg, European Commission, 1018.

[22] Tüen F, Bailey NT. Recovery of metal values from copper smelter slags by roasting with pyrite. Hydrometallurgy, 1990, 25, 317.

[23] Nickel EH. The definition of a mineral. Can. Mineral., 1995, 33, 689.

[24] van der Sloot HA, Hoede D, Cresswell DJF, Barton JR. Leaching behaviour of synthetic aggregates. Waste Manage, 2001, 21, 221.

[25] Beverskog B, Puigdomench I. Revised pourbaix diagrams for zinc at 25-300°C. Corros. Sci., 1997, 39, 107.

[26] Piatak NM, Seal RR II Hammarstrom JM. Mineralogical and geochemical controls on the release of trace elements from slag produced by base- and preciousmetal smelting at abandoned mine sites. Appl. Geochem., 2004, 19, 1039.

[27] Wells AF. Structural Inorganic Chemistry, 1984 5th Ed. Oxford, Oxford University Press

[28] Mills KC. The influence of structure on the physicochemical properties of slags. ISIJ Int., 1993, 33, 148.

[29] Sridhar S, Mills KC, Afrange ODC, Lörz HP, Carli R. Break temperatures of mould fluxes and their relevance to continuous casting. Ironmaking Steelmaking, 2000, 27, 238.

[30] Mostaghel S, Samuelsson C, Björkman B. Influence of alumina on iron-silicate slag properties. European Metallurgical Conference (EMC 2011), 2011 291.

[31] Levin EM, Robbins CR, McMurdie HF. Phase Diagrams for Ceramics, 1964, Columbus, The American Ceramic Society

[32] Jak E, Zhao B, Hayes P. Phase equilibria in the system FeO-Fe₂O₃-Al₂O₃-CaO-SiO₂ with applications to non-ferrous smelting slags. Trans. Inst. Min. Metall. C, 2008, 117, 147.

[33] Zhang SW, Rezaie HR, Sarpoolaky H, Lee WE. Alumina dissolution into silicate slag. J.Am. Ceram. Soc., 2000, 83, 897.

[34] Stefánsson A. Dissolution of primary minerals of basalt in natural waters: I. Calculation of mineral solubilities from 0°C to 350°C. Chem. Geol., 2001, 172, 225.

[35] Gislason SR, Arnórsson S. Dissolution of primary basaltic minerals in natural waters: saturation state and kinetics. Chem. Geol., 1993, 105, 117.

[36] Ojha SN. Metastable phase formation during solidification of undercooled melt. Mater. Sci. Eng. A, 2001, 304–306, 114.