A Study of the Alumina Distribution in the Lab-Scale Cell during Aluminum Electrolysis
Authors: Olga Tkacheva, Pavel Arkhipov, Alexey Rudenko, Yurii Zaikov
The aluminum electrolysis process in the conventional cryolite-alumina electrolyte with cryolite ratio of 2.7 was carried out at an initial temperature of 970 °C and the anode current density of 0.5 A/cm2 in a 15A lab-scale cell in order to study the formation of the side ledge during electrolysis and the alumina distribution between electrolyte and side ledge. The alumina contained 35.97% α-phase and 64.03% γ-phase with the particles size in the range of 10-120 μm. The cryolite ratio and the alumina concentration were determined in molten electrolyte during electrolysis and in frozen bath after electrolysis. The side ledge in the electrolysis cell was formed only by the 13th hour of electrolysis. With a slight temperature decrease a significant increase in the side ledge thickness was observed. The basic components of the side ledge obtained by the XRD phase analysis were Na3AlF6, Na5Al3F14, Al2O3, and NaF.5CaF2.AlF3. As in the industrial cell, the increased alumina concentration in the side ledge formed on the cell walls and at the ledge-electrolyte-aluminum three-phase boundary during aluminum electrolysis in the lab cell was found (FTP No 05.604.21.0239, IN RFMEFI60419X0239).
Keywords: Alumina, alumina distribution, aluminum electrolyzer, cryolite-alumina electrolyte, side ledge.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.3607878Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 564
 A.Tabereaux, “A Prebake Cell Technology: A Global Review” JOM, 2000, vol.52, No. 2, pp. 22-28.
 M. Meijer, “New logistic concept for 400 and 500 kA smelters”, Light metals, 2010, pp. 343–348.
 L. Dingxiong, B. Yungang, Q. Junman, A. Zijin, “New progress on application of NEIU400kA family high energy efficiency aluminium reduction pot "HEEP" technology”, Light metals, 2011, pp. 443–452.
 P. Thibeault, H. Mezin, O. Martin, “Rio Tinto AP44 cell technology developement at ALMA smelter”, Light metals, 2016, pp. 295–300.
 M. Reverdy, S. Hussain, Q. Galadari, J.-L. Faudou, A. Al Zarouni, N. Ahli, I. Al Ali, Sh. Al Shehhi, B. Malladeb, M. Abdulla, and V. Nair, “The successful implementation of DUBAL DX+ technology at EMAL”, Light metals, 2016, pp. 307–311.
 R.G. Haverkamp, and B.J. Welch “Modelling the dissolution of alumina powder in cryolite”, Chemical engineering and processing, 1998, vol. 37, pp. 177-187.
 V. Dassylva-Raymond, “Modeling the behavior of alumina agglomerate”, Light Metals, 2014, pp. 603–607.