Influence of Coke Breeze Positioning on the Sintering Behavior of Pellets and Raw Material Bed with Embedded Pellets

Abstract

The influence of coke breeze positioning on the sintering behavior of pellets and raw material bed with embedded pellets was investigated. With increasing the coke breeze ratio in the green pellet made from ore and coke mixture fine of -125 μm, the tensile strength of the green and dried pellets decreased.Based on the evaluations under the green and dried pellet equations concerning particle bond, it was presumed these results were caused by the decrease in the contact points between particles due to the reduction of mixture fine's specific surface area.With increasing the coke breeze ratio in the nucleus pellet, the tensile strength of the burned pellets also decreased. From the change in the porosity up to 900°C, sintering was predominant to the tensile strength. In the temperature from 900°C to 1 200°C, the increase of strength became small by adding coke breeze in the nucleus pellet. It was presumed this result was caused by remarkable increase of void after coke combustion.In the sintering of raw material bed with embedded the coke breeze coating pellet, the surrounding temperature of pellet increased and the large void was generated below the pellet. Based on the 2-dimensional numeric evaluation, it was found the heat amounts of the pellet and gas heated by coke combustion were transported to the region under the pellet where the gas flow rate was low. It was considered this heat concentration caused the remarkable melting and large void formation.

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

“…The reduction of specific surface area could decrease the contact points among the particles, which resulted in the decrease of ICHB strength. 31) In this experiment, ironsand was pretreated by wet grinding for 1 hour to enhance the specific surface area, thereby increasing the strength of ICHB. After wet grinding, the specific surface area of ironsand increased from 523 cm 2 /g to 3 258 cm 2 /g, and its size distribution was similar to that of VTM.…”

A Novel Approach for Utilization of Ultra-Fines Iron Ore in Sintering Process

“…[4][5][6] The influence of coke breeze coated pellets on the sintering process was investigated. [7] The combustion of coke breeze is promoted by arranging the coke breeze in the coating layer of pellets and resulted in higher temperature inside and around the pellets which caused a remarkable melting and large void formation. The behaviour of coke combustion in fine layer of quasiparticle in iron ore sintering was studied.…”

“…The investigations carried out on pelletized sintering indicated the decreasing of coke consumption in the blast furnace in addition to increasing the productivity rate and smoothing operation . The influence of coke breeze coated pellets on the sintering process was investigated . The combustion of coke breeze is promoted by arranging the coke breeze in the coating layer of pellets and resulted in higher temperature inside and around the pellets which caused a remarkable melting and large void formation.…”