Overview of the role of fluorine in the mold fluxes.

Fluoride is one of components of the traditional mold flux, but it causes environmental pollution. With the increasing requirement of environmental protection on the metallurgical industry, it is a trend to develop low fluorine or fluorine-free mold fluxes in the future. In recent years, many scholars have researched some low fluorine or fluorine-free mold fluxes. However, because the action mechanism of fluorine in mold flux is not completely clear, the performance of mold fluxes composed of fluorine-substituting components has not reached the effect of fluorine-containing mold fluxes. In view of this, this paper summarizes the effects of fluorine in protective slag from macro and micro aspects: in the study of the macro properties of mold flux, it is generally believed that a certain amount of fluorine plays an important role in adjusting the melting temperature, viscosity and surface tension of mold flux, but its adjusting mechanism is not clear; in terms of microstructure, the structural behavior of fluorine in mold flux is very complicated due to the influence of alkalinity, other components and fluorine content. The microstructure of slag determines the properties of slag. Therefore, the complexity of the structural behavior of fluorine leads to the complexity of the transformation mechanism of the physical properties of mold flux, which makes it impossible to control the properties of mold flux fundamentally and increases the difficulty in selecting the alternative component of fluorine in the process of developing low fluorine or fluorine-free mold flux. Therefore, it is necessary to further study the influence mechanism of fluorine on the structure of mold flux. [ABSTRACT FROM AUTHOR]