Fluorination of rutile, electrochemical reduction of titanium fluoride to titanium, and its separation from the electrolyte salts melt
| Parent link: | Journal of Chemical Technology and Metallurgy Vol. 55, № 5.— 2020.— [P. 1111-1119] |
|---|---|
| Corporate Author: | |
| Other Authors: | , , , , |
| Summary: | Title screen The present communication substantiates the need to develop a new technology of processing titanium-containing concentrates. This technology uses three main processes: fluorination of rutile with elemental fluorine, an electrolytic reduction of the obtained titanium tetrafluoride in a low-melting eutectic melt of fluoride salts of alkali metals (LiFKF-NaF) and washing-off of the synthesized titanium powder from the molten electrolyte salts. The studies performed using ASTRA software show that the process of fluorination of rutile concentrates hasno thermodynamic limitations. The time dependences of the change of the rutile fluorination degree are given in the temperature range of 580 K - 830 K. The mathematical processing of the experimental results shows that the process is limited by diffusion factors – the approach of the fluorinating agent to the surface of the solid material. The electrolytic production of titanium powders is carried out using fluoride melts with titanium tetrafluoride as a consumable reagent. TiF4 concentration in the eutectic of fluoride salts of alkali metals is 7.75 % (3 % in respectto Ti). Since the electrolytic potential of titanium extraction is much less than that of the fluoride salt, the process of titanium reduction proceeds with a high efficiency. The yield of titanium in terms of current efficiency (?t, %) is at least 93 % at a cathode current density of 0.4 A/cm2. It practically does not change with a further increase of thecurrent density. The washing-off of the titanium-containing cathode deposit is carried out with anhydrous HF as well. The benefitsof HF washing are shown in the paper. The impurities content of the titanium powder obtained by the fluoride method is lower than that of the titanium sponge synthesized by the Kroll process. This is due to the impurities’ dissolution in anhydrous HF during the process of the washing-off. |
| Published: |
2020
|
| Subjects: | |
| Online Access: | https://dl.uctm.edu/journal/node/j2020-5/24_19-90_p1111-1119.pdf |
| Format: | Electronic Book Chapter |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=662997 |