Effect of molten salt of potassium cryolite on inert anode

Effect of molten salt of potassium cryolite on inert anode

Potassium cryolite molten salt also corrodes inert anode and side lining materials seriously, so it is necessary to further find suitable inert anode and side lining materials. One of the problems of potassium cryolite electrolyte is low conductivity, resulting in a large ohmic drop. Although it can be compensated by adding LiF and other additives and reducing the pole distance,  However, the additive decreases the solubility of alumina and increases the primary crystal temperature while improving the conductivity, and the reduction of pole distance also depends on the industrial application of the wettable cathode.  

In addition, K+ is enriched at the cathode in the process of low temperature electrolysis, and the molecular ratio of electrolyte near the cathode increases, resulting in the phenomenon of cathode coating. In the electrolytic process with potassium cryolite as electrolyte, the common phenomenon is that the cell voltage is high and fluctuates greatly, and the current efficiency is low.  

Although the research on potassium cryolite electrolyte has been paid attention to to a certain extent, it is far from enough compared with the research on sodium cryolite. The physical and chemical properties of potassium cryolite have only been preliminary. the available data are few and incomplete, and there are also inconsistence in the data reported in literature.  Existing research is mainly focused on the conductivity and solubility of alumina and the physicochemical properties, such as crystal temperature and the physicochemical properties such as density, surface tension and viscosity research is very little, so you need to further the chemical and physical properties of potassium cryolite system research, moreover elpasolite thermodynamic data of electrolyte is relatively lack, not in-depth understanding on the structure of the molten salt,  All these aspects need further study.  

In addition to finding suitable inert anode materials, the industrial application of potassium cryolite electrolyte needs more research on electrolytic process and optimization process. In addition, the corrosion and infiltration of potassium salt on carbon cathode and wettable inert cathode is also one of the important conditions for its industrial application.