Abstract
It was taken as typical steelmaking fluorine-containing slag systems with the remelting electroslag, continuous casting mould flux and refining slag. The volatilization behaviour of each slag system was analysed by thermogravimetric (TG) and mass spectrometry (MS) detection. The results showed that the remelting electroslag volatilized significantly above 1300°C and the volatiles were mainly CaF2, MgF2 with a small amount of SiF4 and AlF3; the continuous casting mould flux volatilization was divided into two stages, in the first stage (500°C∼800°C), CaF2 and Na2O reacted to form NaF, and in the second stage (greater than 1200°C), the CaF2 evaporation was highlighted; for CaF2-CaO-based refining slag, the volatilization was the most significant at the eutectic point 84% CaF2–16% CaO, and the volatility can be reduced by adding 5% SiO2. This research will be guiding significance for the composition and performance control of fluorine-containing slag and metallurgical environmental protection in the steelmaking process.
Highlights
The steelmaking process is a ‘slag-making’ process
In order to systematically analyse the slag volatilization behaviour in the steelmaking process, three typical steelmaking fluorine-containing slag systems were selected from Taiyuan Iron&Steel (Group) Co., Ltd, of which the annual production capacity is 0.3 million tons of steel ingots, including the remelting electroslag, the continuous casting mould flux and the traditional refining slag based on CaF2-CaO, shown in figure 1
(Note: the platinum crucible was used in the TG-mass spectrometry (MS) test and the graphite crucible was used in the tube furnace heating process.) — The components of roasted samples were analysed by X-ray fluorescence (XRF) for testing the above discussion on the volatilization characteristics of each slag system
Summary
The steelmaking process is a ‘slag-making’ process. The physico-chemical properties of slag are of significant effects on the melting temperature, chemical reactions, metal solidification and inclusions removal. The slag will volatilize at high temperature and eventually change the slag composition and metallurgical properties, if the slag contains fluoride or alkali metal oxide (Na2O, K2O) [2,3,4,5,6,7,8,9,10,11,12]. Three kinds of typical fluorine-containing slag systems for steelmaking process will be investigated and compared with the volatilization characteristics by thermogravimetric (TG), mass spectrometry (MS) and X-ray fluorescence (XRF) methods, which can directly reflect the volatilization characteristics of different steelmaking slag It can be practical and application value of slag composition and metallurgical performance control in steelmaking
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
