National University of Science and Technology “MISiS”, Moscow, Russia:

C. V. Makhov, Senior Researcher
V. I. Moskvitin, Professor, e-mail: vmoskvitin@mail.ru
D. A. Popov, Engineer (Chair of Non-ferrous Metals and Gold)

This article shows the research results of kinetics of aluminothermic process, carried out on derivatograph in real laboratory conditions. Researches were carried out by thermogravimetric method in dynamic mode in air atmosphere on derivatograph NETZCH STA 409 PC/PG. DTA curves and thermograms are the curves of salt melts and aluminothermic processes, translated by time and sample heat temperature. Gradual heating of samples leads to gradual exothermal and endothermal processes, connected with salts and aluminium smelting and their interaction. Zirconium extraction in ligature is changed, depending on temperature and time of aluminothermy process. The obtained data correspond with results of thermodynamic assessment of process, which concludes that during the salt melt temperature decreasing, the ratio of reaction of zirconium reduction from this melt should be decreased, and, at the same time, zirconium extraction should grow. During the researches, coarseness of TiAl₃ intermetallides' grains in ligature was not higher than 15 μm. This article gives the results of research of influence of potassium chloride content on the temperature of salt system smelting and zirconium extraction in ligature. Holding time in experiments was 10 minutes, which showed that potassium chloride decreases the melting temperature of salt mixture and increases its fluidity. At the same time, zirconium extraction in ligature is increased. Method of obtaining of ligature, consisting of zirconium and 5–10% of aluminium, was tested in plant conditions on induction furnace IST-0.4 (ИСТ-0.4). Six smeltings with the temperature of 850 ^оC were carried out with holding time of 30 minutes. Extraction of zirconium in ligature reached 96%.

1. Moskvitin V. I., Popov D. A., Makhov S. V. Termodinamicheskie osnovy alyuminotermicheskogo vosstanovleniya tsirkoniya iz ZrO₂ v khloridno-ftoridnykh solevykh rasplavakh (Thermodynamic basis of aluminothermic reduction of zirconium from ZrO₂ in chloride-fluoride salt melts). Tsvetnye Metally = Non-ferrous metals. 2012. No. 4. pp. 43–46.
2. Denisov V. M., Pinigin V. V., Antonova L. T. et al. Alyuminiy i ego splavy v zhidkom sostoyanii (Aluminium and its alloys in liquid state). Ekaterinburg : Ural Branch of Russian Academy of Sciences, 2005. 266 p.
3. TU 95 2782–2001. Dioksid tsirkoniya (Technical requirements 95 2782–2001. Zirconium dioxide). (in Russian).
4. GOST R 53777–2010. Ligatury alyuminievye. Tekhnicheskie usloviya (State Standard R 53777–2010. Aluminium ligatures. Technical requirements). (in Russian).
5. Makhov S. V., Moskvitin V. I., Popov D. A. Sposob polucheniya ligatury alyuminiy-tsirkoniy (varianty) (Method of obtaining of aluminium-zirconium ligature (methods)). Patent RF, 2482209 С1. Published: March 20, 2013.
6. Makhov S. V., Moskvitin V. I., Popov D. A. A method for producing an aluminium-titanium master alloy (variants). Patent WO2013141744 (A1). Published: September 26, 2013.