Vol. 337 No. 2 (2026)
DOI https://doi.org/10.18799/24131830/2026/2/5316
Effect of various factors on anode current density in electrolytic production of fluorine
Relevance. Currently, the main industrial method for producing fluorine is the electrolysis of hydrogen fluoride from potassium hydrofluoride melts. For this purpose, medium-temperature (up to 105°C) electrolyzers with an electrolyte of the composition KF∙2HF (potassium trifluoride) are most often used, designed for a current of up to 40 kA, in which the fundamental elements are a louvered steel cathode and a coke anode in the form of a rectangular parallelepiped. In this case, coke plates produced by JSC Donkarb Grafit (Chelyabinsk), which are the only suppliers in Russia, are used as anodes. Aim. Experimental studies of changes in anode current density (i) depending on the height of coke anode plates (h), electrolysis process voltage (U), interelectrode distance (anode–cathode, b) and the ratio (k) of the electrolyte volume in the electrolyzer (V, cm3) to the working area of the anode plate (S, cm2). Methods. Experimental studies, physicochemical and chemical methods of analysis. Object. Experimental setups for medium-temperature electrolytic production of fluorine. Results. The authors have studied the effect of the anode plate height (h) from 1 to 12 cm, the electrolysis process voltage (U) from 5 to 7.5 V, the interelectrode distance (b) from 1 to 4.5 cm and the ratio of the electrolyte volume in the electrolyzer to the working area of the coke anode plates (k) from 29 to 512 cm on the anode current density (i, A/cm2). It was established that the anode current density decreases sharply with an increase in the anode height from 1 to 5 cm, then it decreases much more slowly; the anode current density decreases with an increase in the interelectrode distance at all voltages of the electrolysis, and with its increase this dependence grows; the anode current density increases linearly with a growth in the voltage of the electrolysis, and this dependence becomes more noticeable with a decrease in the working height of the anode; the anode current density increases linearly with a growth in the ratio k, it becomes more significant with an increase in the voltage of electrolysis. Recommendations are given for further production tests of the electrolytic fluorine production.
Keywords:
fluorine, medium-temperature electrolysis, coke (coal) plates, plate height, plate area, electrolyte volume, current density
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