Effect of Titanomagnetite Ironsand Coal Composite Hot Briquette on Softening-melting Performance of Mixed Burden under Simulated Blast Furnace Conditions

Abstract

Titanomagnetite ironsand coal composite hot briquette (ICHB) was proposed as a novel type of burden to enhance the incremental and high-efficiency utilization of ironsand in blast furnace. ICHB was prepared firstly under laboratory conditions, with a compressive strength higher than 3 000 N. Then the national charging ratio of ICHB in the mixed burdens was explored to conduct softening-melting experiments with the simulated BF conditions. Finally the softening-melting-dripping mechanism of mixed burdens was discussed by thermodynamic calculations, SEM-EDS, and XRD detections in this work. It was showed that the softening-melting-dripping behavior and the permeability of mixed burdens could be improved obviously by an appropriate ICHB charging. With the increasing of ICHB charging ratio, the location of cohesive zone was shifted down gradually and its thickness was the narrowest at the ICHB charging ratio of 10%, which was beneficial to BF smelting. Meanwhile, the dripping ratio of mixed burden also achieved the maximum value of 66.71% when the ICHB charging ratio was 10%. However, the excessive ICHB charging would promote the precipitation of Ti(C,N) with a high melting point at the interface between metal and slag, which resulted in the deterioration of dripping and further worsening the gas permeability of mixed burdens. Comprehensively considering the softening-melting-dripping behavior and the permeability of mixed burden, and the precipitation of Ti(C,N), the recommended ICHB charging ratio was 10%.

Effect of Top Gas Recycling Technology on the Softening, Melting and Dropping Behavior of V–Ti Bearing Burden in COREX Process

“…6). 38,39) In stage Ⅱ of the pressure drop curve, the amount of dropping slag decreases with the increasing N 2 concentration, that is, the amount of residual slag in the crucible is increased (Fig. 4); and with the increase of temperature, the Ti(C, N) produced by the reaction of residual slag and coke increases.…”

“…4); and with the increase of temperature, the Ti(C, N) produced by the reaction of residual slag and coke increases. Eventually, they leads to the slag thickening and foaming, 38,39) resulting in a sharp rise in pressure drop curve, and the deterioration of the gas permeability of the V-Ti bearing burden (Fig. 6).…”

Comprehensive Research about Critical Interaction Region Named Cohesive Zone in Series of Dissected Blast Furnaces

“…Hence a series of studies about the behavior of burden in cohesive zone have been reporting in the past two years, such as the comparison between sinter, olivine pellet and acid pellet, [64][65][66] the high temperature interaction between different charge, 67,68) the effect of certain content (C 2 S 69) ) or certain condition (pre-reduction degree, 70) atmosphere and basicity 71) ) on the phase formation, the properties of some special feed materials like high Al 2 O 3 content feed charge, 72) high titanium sinter, 46) and titanomagnetite ironsand coal composite hot briquette. 73) The cognition process of cohesive zone is a process of mutual support and cooperation of various methods. Among them, due to the intuitiveness and authenticity of dissection investigation itself, it still occupies a significant guiding position.…”