Effect of TiO2 on the Crushing Strength and Smelting Mechanism of High-Chromium Vanadium-Titanium Magnetite Pellets

Abstract

The effect of TiO 2 on the crushing strength for high-Cr V-Ti magnetite pellets was studied in this paper. On one hand, the crushing strength obviously decreased with the increasing TiO 2 contents. On the other hand, the crushing strength had an obvious increase after grinding treatment for the high-Cr V-Ti magnetite and titanium concentrate. It is found that the crushing strength has great relations with the mineral phase and microstructure. The effect of TiO 2 on the smelting mechanism for high-Cr V-Ti magnetite pellets was also studied in this paper. With the increasing TiO 2 contents in the range of 2.47 to 12.14 pct, the softening start temperature and softening temperature gradually increased, and the softening zone gradually narrowed down; the melting start temperature and the dripping temperature increased, and the melting-dripping temperature zone also increased. The permeability index increased with the increasing TiO 2 contents as a whole. In the process of slag-iron's dripping and separating, it is proposed that amounts of Cr and V moving to the melted iron are obviously more than those moving to the slag, while amount of Ti moving to slag is much greater than that moving to the melted iron. It is demonstrated that Ti(C,N) generates increasingly with the increasing TiO 2 contents and accumulates as especial regular rigid granules on the surface of coke. The size of melted iron decreased with the increasing TiO 2 contents, and this is in accordance with the present investigations that the dripping difficulty increased with the increasing TiO 2 contents.

Effect of Cr₂O₃ on the Reduction and Smelting Mechanism of High-Chromium Vanadium-titanium Magnetite Pellets

“…Cheng et al 5) investigated the non-isothermal reduction kinetics and mechanism of high-chromium vanadium-titanium magnetite pellets in the lumpy zone of BF, and Liu et al 6) studied the reduction process of pellets containing high-chromium vanadium-titanium magnetite in the cohesive zone. Cheng et al 7) researched the smelting mechanism of TiO 2 effects on the crushing strength and smelting mechanism of high-chromium vanadium-titanium magnetite pellets. However, all these Cr 2 O 3 contents of experimental oxidized pellet samples in these studies were lower than 0.6 mass -%, and little attention has been devoted to study the smelting mechanism of pellet samples with relatively higher Cr 2 O 3 contents to reveal the Cr 2 O 3 effects during reduction and smelting.…”

“…In this paper, the purpose is further perfecting the high chromium vanadium-titanium smelting mechanism on the basis of having accomplished the study on the effect of TiO 2 on the smelting mechanism of high chromium vanadiumtitanium pellets, 7) and in order to accomplish this purpose, researches were carried out for the effect of Cr 2 O 3 on the reduction mechanism and on the softening-melting-dripping behavior and mechanism of high chromium vanadiumtitanium pellets under the simulated blast furnace condition with different characterized means including ICP-AES, XRF, XRD and SEM -EDS described with individual parameters in the subsequent experimental part.…”

“…For high chromium vanadium-titanium magnetite, researches have been carried out for several years, [3][4][5][6][7] but systematical researches are still scarce. The ores can been used through blast furnace process or direct reduction technology including Midrex, HYL-I, HYL-III, and Rotary hearth.…”

Effect of TiO2 on the Sintering Behavior of Chromium-Bearing Vanadium–Titanium Magnetite

“…Similar types of ores are mainly distributed in Russia, Canada, Australia and other places [3,4]. As it is known, many studies have been done for the ordinary VTM, while the studies on CVTM with complex phase compositions and different properties are scarce [5,6]. Owing to the immature production technology of CVTM in the blast furnace (BF) process, the abundant quantity of such CVTM has not been exploited and efficiently used on a large scale.…”

Influence of Coke Ratio on the Sintering Behavior of High-Chromium Vanadium-Titanium Magnetite

“…The integrated utilization of HCVTM is extremely difficult, due to the complicated mineral composition. Currently, it is mentioned that blast furnace smelting of HCVTM is the best choice in industrial production [4,5]. Our previous work was a fundamental study to optimize the composites ratio of HCVTM before feeding it into a blast furnace [6][7][8][9][10].…”