Effects of Basicity and MgO in Slag on the Behaviors of Smelting Vanadium Titanomagnetite in the Direct Reduction-Electric Furnace Process

Abstract

Abstract:The effects of basicity and MgO content on reduction behavior and separation of iron and slag during smelting vanadium titanomagnetite by electric furnace were investigated. The reduction behaviors affect the separation of iron and slag in the direct reduction-electric furnace process. The recovery rates of Fe, V, and Ti grades in iron were analyzed to determine the effects of basicity and MgO content on the reduction of iron oxides, vanadium oxides, and titanium oxides. The chemical compositions of vanadium-bearing iron and main phases of titanium slag were detected by XRF and XRD, respectively. The results show that the higher level of basicity is beneficial to the reduction of iron oxides and vanadium oxides, and titanium content dropped in molten iron with the increasing basicity. As the content of MgO increased, the recovery rate of Fe increased slightly but the recovery rate of V increased considerably. The grades of Ti in molten iron were at a low level without significant change when MgO content was below 11%, but increased as MgO content increased to 12.75%. The optimum conditions for smelting vanadium titanomagnetite were about 11.38% content of MgO and quaternary basicity was about 1.10. The product, vanadium-bearing iron, can be applied in the converter steelmaking process, and titanium slag containing 50.34% TiO 2 can be used by the acid leaching method.

Effect of Lime on Stability of Chromium in Stainless Steel Slag

“…For the purposes of dephosphorization and desulfurization, a certain amount of lime must be added to the molten slag [10]. The basicity of slag (the mass ratio of basic components to acidic components) increases with lime fusing, which causes a variation of elemental distributions in various phases [11][12][13]. However, there are discrepancies in the literature regarding the influence of the basicity of slag on the chromium migration behavior in the SSS.…”

Effect of MgO in Sinter and Primary‐Slag on Smelting Mechanism of Chromium‐Bearing Vanadium Titanomagnetite

“…Gao et al studied that the addition of MgO decreases the slag viscosity because MgO decreases the viscous flow of the slag. Jiang et al researched that the addition of MgO to increase quaternary basicity decreases the viscosity of titanium slag and promotes the optimal separation of iron and slag.…”

“…Inexpensive and substantial dolomite can be used to increase the MgO content of CVTM. The little‐studied effects of MgO on the smelting mechanism of high‐Cr V–Ti magnetite have been researched with different methods . Nevertheless, the influences of primary‐slag structure and properties on the smelting properties of CVTM is rarely reported.…”

Slag Chemistry and Behavior of Nickel and Tin in Black Copper Smelting with Alumina and Magnesia-Containing Slags

“…Additionally, copper slags usually contain about 1 to 10 wt% of CaO and MgO, designedly or otherwise [10]. The presence of these oxides in the molten slag changes slag basicity and affects the physical properties, viscosity, and melting temperature of the slags [12]. Therefore, it enhances the stabilities of solid primary phases.…”