A miscibility gap in LiF-BeF₂ and LiF-BeF₂-ThF₄

Abstract

LiF BeF₂ and LiF BeF₂ ThF₄ are key systems for Molten Salt Reactor fuel. The liquid phase of these systems has been assessed using Redlich Kister polynomials. The result shows a miscibility gap on the BeF₂-rich side. This has never been proven experimentally. Nevertheless, evidence for a two liquids region is given by the fact that such a region exists in the analogous MgO SiO₂ system. Also the ternary system LiF BeF₂ ZrF₄ contains such a miscibility gap in the BeF₂ corner.