Hostname: page-component-77c89778f8-m8s7h Total loading time: 0 Render date: 2024-07-20T12:45:23.771Z Has data issue: false hasContentIssue false

The Dispersive Effect of Sodium Silicate on Kaolinite Particles in Process Water: Implications for Iron-Ore Processing

Published online by Cambridge University Press:  01 January 2024

Mark Ma*
Affiliation:
CSIRO Process Science and Engineering, Box 312, Clayton, Victoria, Australia 3168
*
* E-mail address of corresponding author: mark.ma@csiro.au

Abstract

Kaolinite is a common gangue mineral in iron ore and sodium silicate has been used widely as a dispersant of silicate gangue minerals including kaolinite in various iron-ore flotation methods over a wide range of pH. Its actual dispersive effect on kaolinite under iron-ore flotation conditions has received very limited attention, however. The presence of hydrolyzable metal cations in process water further complicates sodium silicate—kaolinite interactions. In the present study, the dispersive effect of sodium silicate on kaolinite particles in distilled water as well as in CaCl2 and MgCl2 solutions was investigated systematically through electrophoretic mobility and colloid-stability studies. The studies were based on controlled pH, which eliminated the dispersive effect of sodium silicate induced by increasingpulp pH, in order to simulate the conditions of iron-ore processing. With pH controlled at constant levels, sodium silicate dispersed kaolinite only when positively charged sites were present on kaolinite surfaces and the zeta potential of kaolinite was more negative than ~−30 mV. Over the pH range from 5 to 10.5, a significant dispersive effect of sodium silicate was only observed at pH 7. In process water, when Ca and Mgwere present, the strong coagulation of kaolinite particles caused by the hydrolyzable metal cations could not be dispersed effectively with sodium silicate.

Type
Article
Copyright
Copyright © The Clay Minerals Society 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Amorós, J.L. Beltrán, V. Sanz, V. and Jarque, J.C., 2010 Electrokinetic and rheological properties of highly concentrated kaolin dispersions: Influence of particle volume fraction and dispersant concentration Applied Clay Science 49 3343 10.1016/j.clay.2010.03.020.CrossRefGoogle Scholar
Andreola, F. Romagnoli, M. Castellini, E. Lusvardi, G. and Menabue, L., 2006 Role of the surface treatment in the deflocculation of kaolinite Journal of the American Ceramic Society 89 11071109 10.1111/j.1551-2916.2005.00814.x.CrossRefGoogle Scholar
Andreola, F. Castellini, E. Lusvardi, G. Menabue, L. and Romagnoli, M., 2007 Release of ions from kaolinite dispersed in deflocculant solutions Applied Clay Science 36 271278 10.1016/j.clay.2006.10.002.CrossRefGoogle Scholar
Aveston, J., 1965 Hydrolysis of sodium silicate: ultracentrifugation in chloride solutions Journal of Chemical Society 1965 44444448 10.1039/jr9650004444.CrossRefGoogle Scholar
Bass, J.L. and Turner, G.L., 1997 Anion distributions in sodium silicate solutions. characterization by 29SI NMR and infrared spectroscopies and vapor phase osmometry Journal of Physical Chemistry B 101 1063810644 10.1021/jp9715282.CrossRefGoogle Scholar
Diz, H.M.M. and Rand, B., 1989 The variable nature of the isoelectric point of the edge surface of kaolinite British Ceramic Transactions and Journal 88 162166.Google Scholar
Diz, H.M.M. and Rand, B., 1990 The mechanism of deflocculation of kaolinite by polyanions British Ceramic Transactions and Journal 89 7782.Google Scholar
Flegmann, A.W. Goodwin, J.W. and Ottewill, R.H., 1969 Rheological studies on kaolinite suspensions Proceedings of the British Ceramic Society 13 3145.Google Scholar
Gjaldbaek, J.K., 1925 Untersuchungen liber die Loslichkeit des magnesium hydroxyds Zeitschrift für Anorganische und Allgemeine Chemie 144 269288 10.1002/zaac.19251440127.CrossRefGoogle Scholar
Harman, R.W., 1928 Aqueous solutions of sodium silicates, part VIII General summary and theory of constitution. Sodium silicates as colloidal electrolytes. Journal of Physical Chemistry 32 4460.Google Scholar
Harris, R.K. and Newman, R.H., 1977 29Si NMR studies of aqueous silicate solutions Journal of the Chemical Society - Faraday Transactions 73 12041215 10.1039/f29777301204.CrossRefGoogle Scholar
Hast, N., 1956 A reaction between silica and some magnesium compounds at room temperature and at +37°C Arkivför Kemi 9 343360.Google Scholar
Herrington, T.M. Clarke, A.Q. and Watts, J.C., 1992 The surface charge of kaolin Colloids and Surfaces 68 161169 10.1016/0166-6622(92)80200-L.CrossRefGoogle Scholar
Ingri, N., 1959 Equilibrium studies of polyanions, IV. Silicate ions in NaCl medium Acta Chemica Scandinavica 13 758775 10.3891/acta.chem.scand.13-0758.CrossRefGoogle Scholar
Iwasaki, I. Smith, K.A. Lipp, R.J. Sato, H. and Somasundaran, P., 1980 Effect of calcium and magnesium ions on selective desliming and cationic flotation of quartz from iron ore Fine Particles Processing New York American Institute of Mechanical Engineers 10571082.Google Scholar
James, R.O. and Healy, T.W., 1972a Adsorption of hydrolyzable metal ions at the oxide-water interface, part III Journal of Colloid and Interface Science 40 6581 10.1016/0021-9797(72)90174-9.CrossRefGoogle Scholar
James, R.O. and Healy, T.W., 1972b Adsorption of hydrolyzable metal ions at the oxide-water interface, part I Journal of Colloid and Interface Science 40 4252 10.1016/0021-9797(72)90172-5.CrossRefGoogle Scholar
James, R.O. and Healy, T.W., 1972c Adsorption of hydrolyzable metal ions at the oxide-water interface, part II Journal of Colloid and Interface Science 40 5363 10.1016/0021-9797(72)90173-7.CrossRefGoogle Scholar
Johnson, S.B. Russell, A.S. and Scales, P.J., 1998 Volume fraction effects in shear rheology and electroacoustic studies of concentrated alumina and kaolin suspensions Colloids and Surfaces A 141 119130 10.1016/S0927-7757(98)00208-8.CrossRefGoogle Scholar
Johnson, S.B. Franks, G.V. Scales, P.J. Boger, D.V. and Healy, T.W., 2000 Surface chemistry-rheology relationships in concentrated mineral suspensions International Journal of Mineral Processing 58 267304 10.1016/S0301-7516(99)00041-1.CrossRefGoogle Scholar
Lagerström, G., 1959 Equilibrium studies of polyanions — the silicate ions in NaClO4 medium Acta Chemica Scandinavica 13 722736 10.3891/acta.chem.scand.13-0722.CrossRefGoogle Scholar
Leja, J., 1982 Surface Chemistry of Froth Flotation New York Plenum Press.Google Scholar
Ma, X., 2010 Role of hydrolyzable metal cations in starchkaolinite interactions International Journal of Mineral Processing 97 100103 10.1016/j.minpro.2010.09.003.CrossRefGoogle Scholar
Ma, X. and Bruckard, W., 2010 Effect of pH and ionic strength on starch-koalinite interactions International Journal of Mineral Processing 94 111114 10.1016/j.minpro.2010.01.004.CrossRefGoogle Scholar
Ma, X., 2011 Effect of a low-molecular-weight polyacrylic acid on the coagulation of kaolinite particles International Journal of Mineral Processing 99 1720 10.1016/j.minpro.2011.01.002.CrossRefGoogle Scholar
Manfredini, T. Pellacani, G.C. and Pozzi, P., 1987 Sodium silicates as deflocculating agents for clays Industrial Ceramics 7 8587.Google Scholar
Melton, I.E. and Rand, B., 1977 Particle interactions in aqueous kaolinite suspensions: II. Comparison of some laboratory and commercial kaolinite samples Journal of Colloid and Interface Science 60 321330 10.1016/0021-9797(77)90291-0.CrossRefGoogle Scholar
Miller, J.D. Nalaskowski, J. Abdul, B. and Du, H., 2007 Surface characteristics of kaolinite and other selected two layer silicate minerals Canadian Journal of Chemical Engineering 85 617624 10.1002/cjce.5450850508.CrossRefGoogle Scholar
Missanal, T. and Adell, A., 2000 On the applicability of DLVO theory to the prediction of clay colloids stability Journal of Colloid and Interface Science 230 150156 10.1006/jcis.2000.7003.CrossRefGoogle Scholar
Osswald, J. and Fehr, K.T., 2006 FTIR spectroscopic study on liquid silica solutions and nanoscale particle size determination Journal of Materials Science 41 13351339 10.1007/s10853-006-7327-8.CrossRefGoogle Scholar
Pushkarev, V.V., 1956 Adsorption of radioactive isotopes on ferric hydroxide Russian Journal of Inorganic Chemistry 1 176185.Google Scholar
Rand, B. and Melton, I.E., 1975 Isoelectric point of the edge surface of kaolinite Nature 257 214216 10.1038/257214a0.CrossRefGoogle Scholar
Rand, B. Diz, H.M.M. Li, J. and Inwang, I.B., 1988 Deflocculation of kaolinitic clay suspensions by sodium silicate Science of Ceramics 4 231236.Google Scholar
Rao, F. Ramirez-Acosta, F.J. Sanchez-Leija, R.J. Song, S. and Lopez-Valdivieso, A., 2011 Stability of kaolinite dispersions in the presence of sodium and aluminum ions Applied Clay Science 51 3842 10.1016/j.clay.2010.10.023.CrossRefGoogle Scholar
Rossington, K.R. Senapati, U. and Carty, M., 1998 A critical evaluation of dispersants for clay-based systems Ceramic Engineering and Science Proceedings 19 7787.Google Scholar
Sjöberg, S. Öhman, L.-O. and Ingri, N., 1985 Equilibrium and structural studies of silicon(IV) and aluminium(III) in aqueous solution 11. Polysilicate formation in alkaline aqueous solution. A combined potentiometric and 29Si NMR study. Acta Chemica Scandinavica 39 93107.Google Scholar
Smoluchowski, M., 1903 Contribution à la théorie de l’endosmose électrique et de quelques phénomènes corrélatifs Bulletin International de l’Academie des Sciences de Cracovie 1 182199.Google Scholar
Stumm, W. Huper, H. and Champlin, R.L., 1967 Formation of polysilicates as determined by coagulation effects Environmental Science & Technology 1 221227 10.1021/es60003a004.CrossRefGoogle Scholar
Svensson, I.L. Sjöberg, S. and Öhman, L., 1986 Polysilicate equilibria in concentrated sodium silicate solutions Journal of Chemistry Society - Faraday Transaction 82 36353646 10.1039/f19868203635.CrossRefGoogle Scholar
Weldes, H.H. and Lange, R.R., 1969 Properties of soluble silicates Industrial and Engineering Chemistry 61 2944 10.1021/ie50712a008.CrossRefGoogle Scholar
Williams, D.J.A. and Williams, K.P., 1978 Electrophoresis and zeta potential of kaolinite Journal of Colloid and Interface Science 65 7987 10.1016/0021-9797(78)90260-6.CrossRefGoogle Scholar
Yang, X. Roonasi, P. and Holmgren, A., 2008 A study of sodium silicate in aqueous solution and sorbed by synthetic magnetite using in situ ATR-FTIR spectroscopy Journal of Colloid and Interface Science 328 41–4 10.1016/j.jcis.2008.08.061.CrossRefGoogle ScholarPubMed
Zaman, A.A. Tsuchiya, R. and Moudgil, B.M., 2002 Adsorption of a low-molecular-weight polyacrylic acid on silica, alumina, and kaolin Journal of Colloid and Interface Science 256 7378 10.1006/jcis.2001.7941.CrossRefGoogle Scholar