Chair of Non-Ferrous Metals and Gold, National University of Science and Technology “MISiS”, Moscow, Russia:
A. P. Lysenko, Assistant Professor, e-mail: reikis@yandex.ru
A. Yu. Nalivayko, Leading Electronics Engineer, e-mail: nalivaiko@misis.ru

We investigated the key process of technology of obtaining of high-pure aluminium oxide. At the same time, we used the electrochemical method of aluminium oxidation. Investigation of electrolysis was carried out on laboratory unit for polarization measurements using potentiostate PARSTAT 4000, and on enlarged electrolyzer, included in experimental sample of the unit of obtaining of high-pure -oxide of aluminium. Aluminium with 99.99% (wt.) of the basic component was used as initial raw material. A range of electrochemical experiments (when polarization curves were constructed) was carried out for definition of optimal current density. Three sites with defined electrochemical processes were found on obtained polarization curves of anode dissolution of aluminium: formation of singleand trivalent ions of aluminium; anode passivation with formation of impermeable oxides; charges of water hygroxide-ions. For the purpose of definition of the mode of current feed, there was carried out the range of experiments, which basic purpose was the choice of minimal interval of the change of electrode polarity for provision of constant stress on bath. There was found the dependence of stresses on the time of the period of electrode polarity change. We defined the optimal parameters of the mode of current supply and current density. On the basis of the carried out investigations, there can be made a conclusion, that obtained optimal parameters of the process of electrolysis may be used during the scaling of high-pure aluminium oxide obtaining technology using the electrochemical method of aluminium oxidation.
This work was carried out with the financial support of the Ministry of Education and Science of the Russian Federation within the fulfillment of engagements (23 October 2014) No. 14.578.21.0072 (unique identifier of Agreement RFMEFI57814X0072).

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