Thermodynamic Modeling and Experimental Studies of Bayerite Precipitation from Aluminate Solution: Temperature and pH Effect

Document Type: Research Article

Authors

1 Department of Mineral Processing, Faculty of Mining Engineering, Sahand University of Technology, Tabriz, I.R. IRAN

2 Amirkabir Branch, Iranian Academic Center for Education, Culture, and Research (ACECR), Tehran, I.R. IRAN

Abstract

Bayerite is one of the phases of aluminum hydroxide which is precipitated by the carbonation of aluminate solutions obtained from sintered nepheline syenite leaching. In this study, the conditions for the bayerite formation were predicted by thermodynamic modeling of the carbonation process and the Bromley- Zemaitis model was used for this purpose. Carbonation experiments were carried out at pH 11 and the temperature range of 50- 90 °C based on the data obtained from thermodynamic modeling results. XRD analysis of products showed that bayerite was the predominant phase at all temperatures. SEM and LDS analysis indicated that the bayerite precipitates had uniform morphology and bimodal particle size distribution with mean particle size of 4.6 μm at 50 °C to 12.9 μm at 90 °C. It was found that the d50 increased slowly at the precipitation temperature ranging from 80 to 90 °C, from 12.6 to 12.9 μm and the effect of temperature was on the shape of particles. XRF analysis of the products indicated that the amount of Al2O3 and SiO2 in the bayerites decrease by increasing the temperature. According to the thermodynamic modeling data and experimental results, the temperature of 80 °C and pH 11 were determined as optimal conditions for bayerite precipitation.  

Keywords

Main Subjects


[2] Panov A., Vinogradov S., Engalychev S., Evolutional Development of Alkaline Aluminosilicates Processing Technology, Light. Met., 9-16 (2017).

[3] Karamalidis A.K., Dzombak D.A., “Surface Complexation Modeling: Gibbsite”, John Wiley & Sons(JWS), (2011).

[4] Schoen R., Roberson C.E., Structures of Aluminum Hydroxide and Geochemical Implications, Am. Mineral., 55(1970).

[5] Lee M-y., Parkinson G.M., Smith P.G., Lincoln F.J., Reyhani M.M., Characterization of Aluminum Trihydroxide Crystals Precipitated from Caustic Solutions, J. Am. Chem. Soc.( ACS), (1997).

[6] Wefers K., Misra C., Oxides and Hydroxides of Aluminum, Alcoa Technical Paper No. 19, Alcoa Laboratories, (1987).

[7] Misra C., “Industrial Alumina Chemicals”, Am. Chem. Soc.(AC S), (1986).

[8] Li Y., Zhang Y., Yang C., Zhang Y., Precipitating Sandy Aluminium Hydroxide from Sodium Aluminate Solution by the Neutralization of Sodium Bicarbonate, Hydrometallurgy, 98(1): 52-57 (2009).

[9] Czajkowski A., Noworyta A., Krótki M., Studies and Modelling of the Process of Decomposition of Aluminate Solutions by Carbonation, Hydrometallurgy, 7(3): 253-261 (1981).

[10] Zhou Q., Peng D., Peng Z., Liu G., Li X., Agglomeration of Gibbsite Particles from Carbonation Process of Sodium Aluminate Solution, Hydrometallurgy, 99(3): 163-169 (2009).

[11] Klimenko A.A., Shapovalov V.V., Kolesnik T.V., Shapovalova T.V., Osovska A.A., The Question of the Mechanism of Allocation Aluminum Hydroxide from Solutions of Sodium Aluminate, J. Sci. Donetsk. Inter. Tech. Uni., 14-21 (2013), [in Russian].

[12] You S., Li Y., Zhang Y., Yang C., Zhang Y., Synthesis of Uniformly Spherical Bayerite from a Sodium Aluminate Solution Reacted with Sodium Bicarbonate, Ind. Eng. Chem. Res., 52(36): 12710-12716 (2013).

[13] Yeboah I., Addai E. K., Acquah F., Tulashie S. K., A Comparative Study of the Super Cooling and Carbonization Processes of the Gibbsitic Ghanaian Bauxite, Int. J. Eng. Sci. Inno. Tech., (2014).

[14] Hunter K.A., “Acid-base Chemistry of Aquatic Systems”, Dunedin, New Zealand: University of Otago, (1998).

[15] Carroll J.J., Mather A.E., The System Carbon Dioxide-Water and the Krichevsky-Kasarnovsky Equation, J. Solution Chem., 21(7): 607-621 (1992).

[16] Pahlevanzadeh H., Mohseni Ahooei A., Estimation of UNIQUAC-NRF Model Parameters for NH3-CO2-H2O System, Iran. J. Chem. Chem. Eng. (IJCCE), 24(1) 21-26 (2005).

[17] Bromley L.A., Thermodynamic Properties of Strong Electrolytes in Aqueous Solutions, AIChE Journal, 19(2) 313-320 (1973).

[18] Linz D., Rafal M., Berthold J., “Introduction to OLI Electrolytes”, OLI Systems Inc., 1-21(2003).

[20] Zemaitis J.F., Clark D.M., Rafal M., Scrivner N.C., “Handbook of Aqueous Electrolyte Thermodynamics: Theory & Application”, John Wiley & Sons (JWS), (2010).