Open AccessEffect of Aluminium Fluoride on the Structure and Properties of Cryolite Alumina Molten Salt System
Author(s) -
Guocai Tian,
Yongzhi Wang
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1637/1/012093
Subject(s) - cryolite , aluminium , fluoride , molten salt , chemistry , fluorine , inorganic chemistry , ion , ionic bonding , salt (chemistry) , diffusion , viscosity , materials science , thermodynamics , organic chemistry , composite material , physics
The influence of aluminium fluoride AlF 3 on the structure and properties of cryolite-Al 2 O 3 melts are studied by molecular dynamics simulations at 1283 K and 0.1 MPa. The structure property such as radial distribution functions and coordination numbers, and the physical-chemical property such as density, conductivities, diffusion coefficients, and viscosities of the systems are obtained. It is shown that with the increase of aluminium fluoride content, fluorine ions in (Na 3 AlF 6 +4%Al 2 O 3 ) 1- w (AlF 3 ) w molten salt system will replace the position of oxygen in alumina to form aluminium oxy-fluoride ion group, while aluminium ion group will form larger aluminium composite ion group through the connection of oxygen bridge and fluorine bridge. The formation of these ionic groups results in the decrease of the diffusion coefficient of anion and anion, the increase of viscosity and the decrease of conductivity in (Na 3 AlF 6 +4%Al 2 O 3 ) 1- w (AlF 3 ) w , molten salt system.