Laboratory study of phase transitions and mechanism of reduction of FeO from high Ti-bearing blast furnace primary slag by graphite

Abstract

The reduction of FeO from iron-saturated FeO-CaO-SiO 2 -MgO-Al 2 O 3 -TiO 2 slags by graphite has been studied under static conditions between 1473 and 1623 K. The results show that the Fe/Ti mole ratio in the sample matrix decreases with increasing time and temperature. Most of the FeO was reduced within the first 10 min at 1573 K. The degree of reduction was found to increase rapidly with increasing temperature below 1573 K and was controlled not only by the effective diffusivity of CO and FeO concentration, but also the formation of iron-titanium oxide in the sample. At the same time and temperature, the degree of reduction of FeO in Ti-bearing slag was higher than that of Ti-free slag, because TiO 2 can decrease the liquidus temperature and prompt reduction of the slag.

Effect of B2O3on reduction of FeO in Ti bearing blast furnace primary slag

“…4 The reaction conditions of the experiments for all samples are given in Table 2. Each sample was placed in a graphite crucible and introduced from the bottom of the vertical tube furnace and suspended by the platinum wire.…”

“…4 The slag was pre-melted, quenched, crushed and ground. 1-3 mass-% B 2 O 3 was then added (see Table 1).…”

“…In order to improve blast furnace operations for the processing of vanadium-titanomagnetite ore, a series of studies by the authors have been carried out by adding B 2 O 3 to the iron ore. [1][2][3] In a parallel study by the authors, 4 the phase transition and mechanism of reduction of FeO from high Ti bearing blast furnace primary slag by graphite were studied in the laboratory where it was found that the degree of reduction of FeO in Ti bearing slag was controlled not only by the effective diffusivity of CO and FeO concentration, but also the formation of iron-titanium oxide in the sample. However, the influence of B 2 O 3 on reduction of FeO from iron saturated FeO-CaO-SiO 2 -MgO-Al 2 O 3 -TiO 2 slags was still unclear.…”

Effect of Erosion Behavior of FeO-CaO-SiO2-MgO-Al2O3 Blast Furnace Primary Slag on Al2O3 Substrate

“…Compared with the final slag, the slag system formed in the lower part of the BF, which is composed of primary slag and bosh slag, has distinct characteristics and different slag behavior [5][6][7][8][9], which has not been fully elucidated to date. In the BF process, it is generally believed that the BF primary slag has more research significance than the final slag [10].…”

Ti3O5 and Al2TiO5 Crystals Flotation Characteristics from Ti-bearing Blast Furnace Slag: A Density Functional Theory and Experimental Study

“…In our previous research [9][10][11][12][13][14][15][16], Ti-bearing ore sintering and Ti-bearing slag characteristics were studied systematically. B 2 O 3 was chosen as the modifier for obtaining the Ti-rich phases, and the results showed that the rise of the (Mg + Al)/(Ca + Si) ratio and B 2 O 3 in slag were beneficial to form [TiO 6 ] 8− octahedral units and thus beneficial to the precipitation of anosovite from the TBBF slag [14,15].…”