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Acidic Dissolution of Magnetite: Experimental Study on the Effects of Acid Concentration and Temperature

Published online by Cambridge University Press:  01 January 2024

Riina Salmimies*
Affiliation:
LUT Chemistry, Lappeenranta University of Technology, P.O. Box 20, FI-53851 Lappeenranta, Finland
Marju Mannila
Affiliation:
LUT Chemistry, Lappeenranta University of Technology, P.O. Box 20, FI-53851 Lappeenranta, Finland
Juha Kallas
Affiliation:
LUT Chemistry, Lappeenranta University of Technology, P.O. Box 20, FI-53851 Lappeenranta, Finland
Antti Häkkinen
Affiliation:
LUT Chemistry, Lappeenranta University of Technology, P.O. Box 20, FI-53851 Lappeenranta, Finland
*
* E-mail address of corresponding author: [email protected]
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Abstract

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Magnetite (Fe3O4) is a key economically valuable component in iron ore and is extracted by dissolution processes, but among the Fe (oxyhydr)oxides its solubility behavior is one of the least understood. The objective of this study was to improve understanding of magnetite dissolution mechanisms leading to thermodynamic equilibrium by comparing the dissolution of two solid samples, one synthetic and one industrial, using oxalic, sulfuric, and nitric acids at varying concentrations and temperatures. Of the three solid-liquid systems investigated, only the system consisting of magnetite and oxalic acid reached an equilibrium state within the duration of an individual experiment (6 h). In this system, increasing the acid concentration resulted in a significant increase in the equilibrium concentration of dissolved Fe. When dissolving synthetic and industrial magnetite, increasing the temperature not only increased the rate of reaction but also affected the concentration of dissolved Fe. Significant effects were observed when increasing the temperature from 15 to 35°C, but only slight differences were seen on further increases in temperature. Observations regarding the equilibrium state of the sulfuric and nitric acid systems could not be made because equilibrium was not reached. The most important individual observation regarding the equilibrium state of the nitric- and sulfuric-acid systems seems to be that in future studies a much longer reaction time is necessary, due to slow kinetics of the dissolution mechanism. A proton-based mechanism has been hypothesized as the one governing the dissolution of magnetite by these two acids, but only the dissolution of the industrial sample yielded results that were similar for these two acids and consistent with that hypothesis.

Type
Article
Copyright
Copyright © The Clay Minerals Society 2011

References

Arslan, V. and Bayat, O., 2009 Removal of Fe from kaolin by chemical leaching and bioleaching Clays and Clay Minerals 57 787794 10.1346/CCMN.2009.05706011.CrossRefGoogle Scholar
Banwart, S. Davies, S. and Stumm, W., 1989 The role of oxalate in accelerating the reductive dissolution of hematite (α-Fe2O3) by ascorbate Colloids and Surfaces 39 303309 10.1016/0166-6622(89)80281-1.CrossRefGoogle Scholar
Blesa, M.A. Magaz, G. Salfity, J.A. and Weisz, A.D., 1987 Mechanism of dissolution of magnetite by oxalic acidferrous iron solutions Inorganic Chemistry 26 37133717 10.1021/ic00269a019.CrossRefGoogle Scholar
Brown, W.E. Dollimore, D. Galwey, A.K., Bamford, C.H. and Tipper, C.F., 1980 Reactions in the solid state Comprehensive Chemical Kinetics 41109.Google Scholar
Bruyere, V.I.E. and Blesa, M.A., 1985 Acidic and reductive dissolution of magnetite in aqueous sulphuric acid. Site-binding model and experimental results Journal of Electroanalytical Chemistry 182 141156 10.1016/0368-1874(85)85447-2.CrossRefGoogle Scholar
Chiarizia, R. and Horwitz, E., 1991 New formulations for iron oxides dissolution Hydrometallurgy 27 339360 10.1016/0304-386X(91)90058-T.CrossRefGoogle Scholar
Cornell, R M and Schindler, R W, 1987 Photochemical dissolution of goethite in acid/oxalate solution Clays and Clay Minerals 35 347352 10.1346/CCMN.1987.0350504.CrossRefGoogle Scholar
Demirkiran, N. and Künkül, A., 2007 Dissolution kinetics of ulexite in perchloric acid solutions International Journal of Mineral Processing 83 7680 10.1016/j.minpro.2007.04.007.CrossRefGoogle Scholar
Handbook of Chemistry and Physics (1998) Physical and Optical Properties of Minerals. pp. 4140 (Haynes, W. M., editor). CRC Press Inc., Boca Raton, Florida, USA.Google Scholar
Hemingway, B.S., 1990 Thermodynamic properties for bunsenite, NiO, magnetite, Fe3O4, and hematite, Fe2O3, with comments on selected oxygen buffer reactions American Mineralogist 75 781790.Google Scholar
Houben, G.J., 2003 Iron oxide incrustations in wells Part 2: Chemical dissolution and modeling. Applied Geochemistry 18 941954.Google Scholar
Langmuir, D. Whittemore, D.O., Gould, R.F., 1971 Variations in the stability of precipitated ferric oxyhydroxides. Nonequilibrium Systems in Natural Water Chemistry 209234 10.1021/ba-1971-0106.ch008.CrossRefGoogle Scholar
Lee, S.O. Tran, T. Jung, B.H. Kim, S.J. and Kim, M.J., 2007 Dissolution of iron oxide using oxalic acid Hydrometallurgy 87 9199 10.1016/j.hydromet.2007.02.005.CrossRefGoogle Scholar
Mandal, S. and Banerjee, P., 2004 Iron leaching from China clay with oxalic acid: Effect of different physicochemical parameters International Journal of Mineral Processing 74 263270 10.1016/j.minpro.2004.01.004.CrossRefGoogle Scholar
Panias, D. Taxiarchou, M. Paspaliaris, I. and Kontopoulos, A., 1996 Mechanism of dissolution of iron oxides in aqueous oxalic acid solutions Hydrometallurgy 42 257265 10.1016/0304-386X(95)00104-O.CrossRefGoogle Scholar
Raschman, P. and Fedorocková, A., 2004 Study of inhibiting effect of acid concentration on the dissolution rate of magnesium oxide during the leaching of dead-burned magnesite Hydrometallurgy 71 403412 10.1016/S0304-386X(03)00114-2.CrossRefGoogle Scholar
Reichard, P.U. Kretzschmar, R. and Kraemer, S.M., 2007 Rate laws of steady-state and non-steady-state ligandcontrolled dissolution of goethite Colloids and Surfaces A: Physicochemical and Engineering Aspects 306 2228 10.1016/j.colsurfa.2007.03.001.CrossRefGoogle Scholar
Sidhu, P. Gilkes, R. Cornell, R. Posner, A. and Quirk, J., 1981 Dissolution of iron oxides and oxyhydroxides in hydrochloric and perchloric acids Clays and Clay Minerals 29 269276 10.1346/CCMN.1981.0290404.CrossRefGoogle Scholar
Stumm, W. Furrer, G. Wieland, E. Zinder, B., Drever, J.I., 1985 The effects of complex-forming ligands on the dissolution of oxides and aluminosilicates The Chemistry of Weathering 5574 10.1007/978-94-009-5333-8_4.CrossRefGoogle Scholar
Sweeton, F.H. and Baes, C.F., 1970 The solubility of magnetite and hydrolysis of ferrous ion in aqueous solutions at elevated temperatures The Journal of Chemical Thermodynamics 2 479500 10.1016/0021-9614(70)90098-4.CrossRefGoogle Scholar
Tinke, A.P. Vanhoutte, K D M ^R and Verheyen, S W ^H, 2005 A new approach in the prediction of the dissolution behaviorof suspended particles by means of theirp article size distribution. Journal of Pharmaceutical and Biomedical Analysis 39 900907 10.1016/j.jpba.2005.05.014.CrossRefGoogle Scholar
Veglió, F. Passariello, B. Barbaro, M P ^P and Marabini, A., 1998 Drum leaching tests in iron removal from quartz using oxalic acid and sulphuric acid International Journal of Mineral Processing 54 183200 10.1016/S0301-7516(98)00014-3.CrossRefGoogle Scholar
Zinder, B. Furrer, G. and Stumm, W., 1986 The coordination chemistry of weathering: II Dissolution of Fe(III) oxides. Geochimica et Cosmochimica Acta 50 18611869 10.1016/0016-7037(86)90244-9.CrossRefGoogle Scholar