Advances in the preparation and application of fluoride molten salts

Fluoride molten salt has many advantages,such as high temperature stability,high thermal conductivity,large heat capacity,wide electrochemical window,low saturated vapor pressure and small neutron absorption cross section. It is an important functional material which has found widespread applications. The typical preparation and purification methods of fluoride molten salt,including vacuum dehydration,fluorination using ammonium fluoride,H2-HF purification,electrochemical purification and reduction with metals,are introduced in detail. The mechanism and technical characteristics are analyzed for the different methods that are used to remove impure ions in molten salt. At the same time,the applications and progress of fluoride molten salts in nuclear energy,metallurgy,functional materials preparation,advanced energy storage medium,surface treatment technology,electronic chemicals,fine chemicals and molten salt battery materials are reviewed. The fluoride molten salts are mainly used as the nuclear reactor coolant,molten salt electrolyte,high temperature energy storage material and reaction medium. The existing problems in this area are also discussed. It is important to study and clarify the preparation and purification mechanism of fluoride molten salt,to explore the existence form and impurity migration nature in the process of fluoride purification,and to develop a new method for the purification of the molten salt to reduce its corrosion and cost. © 2018, Chemical Industry Press. All right reserved.