Experimental Study On Thickening Mechanism Of Blast Furnace Slag Bearing Titanium

Panzhihua-Xichang Region in China is abundant in vanadium titanomagnetiteresource, the iron resource in which is extracted mainly by blast furnace smelting. Inview of making the most of the vanadium titanomagnetite resource and improving theeconomic competitiveness, increasing the proportion of vanadium titanomagnetite inraw materials for blast furnace would be imperative. However, the percentage of TiO2would inevitably increase consequently, which could deteriorate the slag properties,especially the viscosity, according to the experiences of blast furnace smelting. With thedevelopment of BF smelting technology, reviewing the previous achievements andresearching on the rheological property of BF slag bearing titanium would providereference for practice.The paper involving laboratory-scale experimental researches on low-temperaturesimulation and high-temperature measuring of the viscosity of BF slag bearing titanium,as well as the reduction of BF slag bearing titanium, on the basis of reviewing theprevious achievements about the rheological properties of BF slag in domestic andabroad, the specific information of which is as following:(1) In the low-temperature simulation experiment, the glycerol-PPS suspensionwas adopted to simulate the molten slag-Ti(C, N) solid-liquid system, and therheological property of the glycerol-PPS suspension was measured with the BrookfieldViscometer to investigated the influence of volume fraction and particle size of soliddispersion phase on viscosity of suspension. The results are as follows: the glycerol-PPSsuspension showed Binham behavior; the apparent viscosity of the suspension increasedwith the increase of the volume fraction and the decrease of the particle size of the solidparticle; the exponential type viscosity model best described the relation between theviscosity of suspension and the volume fraction of solid particles; variance analysisshowed that both the effects of volume fraction and particle size of PPS were significant,and the effect of volume fraction was more significant than that of particle size.(2) The viscosity evolution of BF slag bearing titanium was measured by rotationalcylinder method under high-temperature reduction condition. As demonstrated by theexperimental results, the TiO2content、reduction time and the basicity (CaO/SiO2)played significant role in the slag viscosity; the slag viscosity increased with theincrease of TiO2content and reduction time; after90mins’ and120mins’ reduction, the slag viscosity increased with the increase of basicity (CaO/SiO2) firstly and maximizedat (CaO/SiO2)=1.11, however, it decreased afterwards.(3) With respect to the experimental research on the reduction of the BF slagbearing titanium, the tube furnace was employed to control the reduction atmosphereand temperature, the influences of which were investigated on generation state of Ti(C,N). The results showed that: only TiC was found and produced at about1400℃underAr atmosphere; while under N2atmosphere, TiN was dominant in Ti(C, N), in whichTiN formed at some1350℃and TiC formed at some1500℃; Ti(C, N) mainly formedon the border between the slag and the graphite; the content of Ti(C, N) increased withthe increase of reduction temperature and dispersed into the slag body.