A research and test system for the carbon anode plate preparation technology was established to optimize the physical and chemical indicators of carbon anode plates, such as bulk density, resistivity, and compressive strength, and improve the operating cycle. In this study, a carbon plate was prepared via a combination of high-temperature molding and freeze drying using a formulation with asphalt content much lower than the industry standard. The experimental results show that the density of the carbon plate is increased by 0.02-0.04 g/cm 3 by improving the drying method. The carbon plate prepared in the laboratory has a bulk density of 1.814 g/cm 3 , resistivity of 29.8 μΩ•m, and compressive strength of 89.27 MPa. The bulk density, room-temperature resistivity, compressive strength, graphitization, and other key indices of the carbon plates made in the laboratory and those procured from a factory in Shanxi, Datong, were tested. Additionally, the specimens were analyzed using thermogravimetry-differential scanning calorimetry, scanning electron microscopy, and X-ray fluorescence. The laboratory-made carbon plates were superior to the factory specimens in terms of all the indicators tested. The process in this study improves the performance of the carbon anode plate and is used to provide technical support for electrolytic fluorine production in enterprises. The carbon plates prepared in the laboratory fully meet the process requirements of a medium-temperature electrolytic fluorine production line, which indicates the possibility of its use in the stable production of fluorine gas.

The kinetics of the forward extraction of aluminum ion had been investigated using Lewis cells. The influences of the aluminum concentration, temperature, and interfacial area were studied. The extracted species was demonstrated to be AlL 3 •(HL) 3 by stoichiometry studies and the mechanism of the extraction was explained. The results indicated that the extraction process was under mixed-control by the extraction reaction at the interface and the diffusion of the resultant in the organic phase. The activation energy was calculated to be 23.26 kJ/mol and was concordant with the mixed-control regime. Further analysis suggested that the reaction orders with respect to aluminum and extractant were 1 and 2, respectively, and the extraction rate constant was 10 −4.526 L 2 •g −2 •s −1 . The total rate of the extraction reaction for AlL 3 •(HL) 3 was given based on kinetic steps.

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The reaction mechanism and kinetics of Sinco-430 cation exchange resin removing Mg 2+ from wet-process phosphoric acid (WPA) were studied. Fourier transform infrared and X-ray photoelectron spectroscopy analyses revealed that the main functional group of the resin that combined with Mg 2+ ions was -SO 3 H. To investigate the most suitable conditions for Mg 2+ removal, the operating parameters that could affect Mg 2+ removal were studied. The results demonstrated that under optimal conditions (T = 50 C, solid to liquid mass ratio = 0.3, and P 2 O 5 content = 20 wt.%) the reaction reached equilibrium in 8 min and Mg 2+ removal rate reached 59.09%. The kinetic model and activation energy of the reaction were second-order and 19.11 kJ/mol according to kinetic analysis, respectively. The diffusion model of Mg 2+ removal was determined as pore diffusion according to the comparison of three different diffusion models. H 3 PO 4 was recovered using deionized water and Mg 2+ was removed from the loading resin with 20 wt.% H 2 SO 4 . In addition, after eight loading/regeneration cycles, the Mg 2+ removal ability of the Sinco-430 resin remained the same. The Mg 2+ removal rate in a fixed-bed reactor was 98.83%, higher than that obtained in a continuous stirred-tank reactor.

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