Shen, Y.; Chong, J.; Huang, Z.; Tian, J.; Zhang, W.; Tang, X.; Ding, W.; Du, X. Viscosity and Structure of a CaO-SiO2-FeO-MgO System during a Modified Process from Nickel Slag by CaO. Materials2019, 12, 2562.
Shen, Y.; Chong, J.; Huang, Z.; Tian, J.; Zhang, W.; Tang, X.; Ding, W.; Du, X. Viscosity and Structure of a CaO-SiO2-FeO-MgO System during a Modified Process from Nickel Slag by CaO. Materials 2019, 12, 2562.
Shen, Y.; Chong, J.; Huang, Z.; Tian, J.; Zhang, W.; Tang, X.; Ding, W.; Du, X. Viscosity and Structure of a CaO-SiO2-FeO-MgO System during a Modified Process from Nickel Slag by CaO. Materials2019, 12, 2562.
Shen, Y.; Chong, J.; Huang, Z.; Tian, J.; Zhang, W.; Tang, X.; Ding, W.; Du, X. Viscosity and Structure of a CaO-SiO2-FeO-MgO System during a Modified Process from Nickel Slag by CaO. Materials 2019, 12, 2562.
Abstract
There is a high iron content in the nickel slag that mainly exists in fayalite phase. Basic Oxide can destroy the stable structure of fayalite which is beneficial to the treatment and comprehensive utilization of nickel slag. The reseach was based on the composition of the raw nickel slag, taking CaO-SiO2-FeO-MgO system as the object and CaO as a modifier. The effect of basicity on the melting characteristics, viscosity and structure of CaO-SiO2-FeO-MgO system was studied. The relationship between the viscosity and structure of CaO-SiO2-FeO-MgO system was also explored. The results show as follows. (1) When the basicity is 0.38~0.90, the phase of primary crystal is olivine at argon atmosphere, while it is monoxide at the basicity of 0.90~1.50. The liquidus temperature, softening temperature, hemispherical temperature, and flow temperature all reach the lowest value at the basicity of 0.90. (2) With the increase of basicity, critical viscosity temperature of CaO-SiO2-FeO-MgO system decreases first and then increases. Critical viscosity temperature is the lowest at the basicity of 0.90, which is 1263 ℃. (3) When the slag system is heterogeneous, the viscosity of the molten slag increase rapidity because of the type and quantity of solid phase precipitated from CaO-SiO2-FeO-MgO system. And critical viscosity temperature of the slag system is also significantly affected. (4) When the slag system is in a homogeneous liquid phase, the molar fraction of O0 decreases with the increase of basicity and the mole fraction of O- and O2- increases continuously at the basicity of 0.38~1.50. The silicate network structure is gradually depolymerized into simple monomers, resulting in the degree of polymerization is reduced and the viscosity is reduced, too.
Chemistry and Materials Science, Metals, Alloys and Metallurgy
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