Abstract: The equilibrium solubilities of the ternary system YCl3-CdCl2-H2O, the quaternary system YCl3-CdCl2-HCl(~8.8%)-H2O were determined at 25 ℃ and the phase diagrams were constructed. The results show that the ternary system was complicated with six equilibrim solid phases CdCl2·2.5H2O, CdCl2·H2O, 8CdCl2·YCl3·15H2O (8∶1 type), 4CdCl2·YCl3·13H2O(4∶1 type), 5CdCl2·2YCl3·26H2O (5∶2 type) and YCl3·6H2O. The quaternary system was also complicated with four equilibrim solid phase CdCl2·H2O, 4CdCl2·YCl3·13H2O (4∶1 type), 5CdCl2·2YCl3·26H2O(5∶2 type) and YCl3·6H2O. Among the three new compounds 8CdCl2·YCl3·15H2O, 4CdCl2·YCl3·13H2O and 5CdCl2·2YCl3·26H2O, 8CdCl2·YCl3·15H2O was a kind of metastable compound only in ternary system, and it was changed into 4CdCl2·YCl3·13H2O with time. Both 4∶1 type and 5∶2 type existed in ternary and quaternary system, but they were also congruently soluble compounds in quaternary system. They have been prepared from the system and have been characterized by XRD, TC-DTG and DSC. |