2016 Volume 56 Issue 4 Pages 594-601
In order to clarify the viscosity of FeO–SiO2–V2O3–TiO2–Cr2O3 system as the main components of vanadium slag with varied Cr2O3 and TiO2 contents, the viscosity and structure characteristics of the slag were investigated by the rotating cylinder method and Raman spectroscopy, respectively. The results showed that the viscosity was decreased to 3.5 Pa·s at temperature above 1534 K for the FeO–SiO2–V2O3 system, and the polymerization degree of this system was low due to the main structure of silicate as monomer. Meanwhile, V3+ mainly existed in the form of V–O–V as a chain structure in FeO–SiO2–V2O3 system, which slightly enhanced the polymerization degree of the slag. With the introduction of 6 mass% Cr2O3 into FeO–SiO2–V2O3 system, the viscosity increased rapidly and was decreased to 3.5 Pa·s until temperature higher than 1767 K, and the polymerization degree of the slag was enhanced drastically due to the formation of Q2 and Cr–O–Cr band in a chain structure as well as the formation of Q3 species in a sheet structure. Furthermore, part of the chromium existed in the form of the high melting point of spinel (FeCr2O4). With the introduction of 13 mass% TiO2 into the FeO–SiO2–V2O3–Cr2O3 system, the viscosity decreased and was of 3.5 Pa·s at 1624 K, and the polymerization degree of the slag became weak due to the formation of discrete Si–O–Ti and Ti–O–Ti inhibiting the formation of sheet structure and hampering the crystallization of FeCr2O4 in molten slag, which was advantageous to decrease the viscosity of FeO–SiO2–V2O3–Cr2O3–TiO2 system.
