The Determination of the Liquid Immiscibility Boundaries of the Lithium-Sodium and Thallium-Selenium Systems by the Liquid Density Method

Abstract

The immiscibility boundaries and monotectic temperatures of the lithium-sodium and thallium-selenium systems were determined by techniques using density-temperature and density-composition isotherms. The immiscibility boundary of the lithium-sodium system was found to extend from 10.5 to 96 weight percent sodium at the monotectic temperature, 170°±1°C. The critical solution (consolute) temperature was found to be 306°±1°C. The thallium-rich immiscibility region of the thallium-selenium system has a consolute temperature of 750°±1°C and a monotectic isothermal of 380°±1°C extending over the composition range 0.1–32.9 atom percent selenium. The second immiscibility region in this system was found to have a consolute temperature of 454° ± 1°C and a monotectic isothermal of 201° ± 1°C. The latter extends between the composition limits 77–99.9 atom percent selenium.