PROCESSES OF ELECTROSTATIC SEPARATION AND FLOTATION IN THE BENEFICIATION OF ILMENITE ORES FROM VIETNAM AND CHEMICAL PROCESSING OF THE OBTAINED CONCENTRATES

• Published in: Izvestiâ Tomskogo politehničeskogo universiteta. Inžiniring georesursov Vol. 333; no. 2; pp. 38 - 52
• Main Authors: Vladimir A. Karelin, Son H. Le, Nadezhda V. Karelina, Huong Le Thi Mai
• Format: Journal Article
• Language: Russian
• Published: Tomsk Polytechnic University 01.02.2022
• Subjects: beneficiation by electrostatic separation and flotation; electrolysis in low-melting eutectic of alkali metal and titanium fluorides; granulometric and chemical compositions of titanium powder; ilmenite ore and concentrate from vietnam
• ISSN: 2500-1019; 2413-1830
• DOI: 10.18799/24131830/2022/2/3495

The relevance of the study is determined by the creation of a fundamentally new method for the synthesis of titanium powders of high purity from ilmenite ores of Vietnam deposits, containing a mixture of ilmenite with rutile in the heavy fraction. This is one of the priority areas for the integrated development of deposits of rare and rare earth elements in Vietnam. The main aim: selection of conditions, methods and sequence of technological operations for the beneficiation of Vietnamese ilmenite ores and their subsequent chemical processing to obtain high-purity titanium. Objects: ilmenite ore of the Ha Tinh deposit (Vietnam) with a high content of oxides of titanium, iron, zirconium and a low content of silicon, aluminum, rare earth elements, vanadium, as well as ilmenite concentrate obtained as a result of enrichment of the original ilmenite ore. Methods: in the beneficiation process – electrostatic separation, flotation, the use of collectors, activators and depressants added to flotation reagents; in the electrolytic synthesis of titanium – the use of a low-melting eutectic of fluoride salts of alkali metals with the addition of titanium tetrafluoride; selection of the conditions for starting the electrolyzer, cathode current density, current and voltage for the deposition of titanium on the cathode; investigation of the optimal conditions for the release of titanium powder at low temperatures using anhydrous hydrogen fluoride. Results. The prospects of using the methods of electrostatic separation and flotation in the dressing of Vietnamese ilmenite ores of the Ha Tinh deposit are shown. An ilmenite concentrate with a titanium dioxide content of more than 50 % was obtained. The advantages of using the method of direct fluorination of an ilmenite concentrate with gaseous fluorine are substantiated, which makes it possible to ensure both the completeness of the decomposition of the solid phase and to separate the fluorides of titanium, niobium, vanadium and silicon that pass into the gas phase from those remaining in the condensed state – fluorides of iron, zirconium, hafnium and cerium. This allows you to optimize the number of stages in the subsequent processing of titanium tetrafluoride and the synthesis of metallic titanium. In titanium electrolysis, the authors have substantiated the use of composition of the eutectic of fluoride salts of alkali metals LiF (0,465 M)-NaF (0,115 M)-KF (0,42 M), which has a minimum melting point (454 °C) and the range of changes in the concentration of K2TiF6 (25–30 %). In this case, the values of current density and current efficiency approach the maximum values of 3,5–4,0 A/cm2 and 60–65 %, respectively. The content of impurities in titanium powder does not exceed 0,135 %, which meets the requirements for the manufacture of products from compact titanium.