In situ Ca-F cluster formation during crystallisation of mold fluxes

Mold fluxes are used as sort of ‘lubricants’ for molten steel, and are prepared as mixtures of calcite, flurite, some SiO2, and some Na: these mixtures are tailored to melt at certain temperature, providing a molten layer that works as a lubricant. These melts, at lower T, start to crystallise, forming a mineral called cuspidine and some other Ca-silicates. The very beginning of the process is the most interesting part, because what happens (likely the formation of Ca-F clusters) changes radically the rheological properties of the material, and therefore its ability to function as a lubricant. The idea behind this proposal is to first start the structure of these amorphous materials ex-situ, and then to study the onset of crystallisation from melt, looking for Ca-F clusters, which, if present and depending on their size, changes considerably the rheological properties of the material.