Liquidus Temperature of xNaF/AlF3-Al2O3-CaF2-MgF2-KF-y (LiAlO2/LiF) Molten Salts Energy System in Aluminum Electrolysis

The effect of LiAlO2 and combined effect of LiAlO2 and LiF on liquidus temperature of industrial electrolyte system were studied by thermal analysis method. The effect of cryolite molar ratio (CRt) on liquidus temperature of electrolytes which contained LiAlO2 was investigated as well. Furthermore, X-ray diffraction analysis revealed the effect of LiAlO2 on CRt. The results indicated that the liquidus temperature was decreased by 1.2 degrees C to 5.5 degrees C with every addition of 1 wt.% LiAlO2, and the LiAlO2 or its combination with LiF was more effective than LiF in decreasing the liquidus temperature at low level of lithium salt. With the increase of CRt, the liquidus temperature of electrolytes was firstly increased and then decreased, and the maximum value was located at CRt = 3.0. In the acid electrolytes, the addition of LiAlO2W led to the increase of the content of Al2O3 and LiNa2AlF6 and the value of CRt.