Model Predictions of Important Bed and Gas Properties during Iron Ore Sintering

Abstract

A new numerical iron ore sintering model was developed recently. It takes into account most of the significant physico-chemical processes in sintering. In this study results from the model are compared with experimental results from twenty five sinter pot tests. Results indicate that the model can simulate the iron ore sintering process, as reasonable correlations between predicted and measured results were obtained in many areas. The good comparisons also indicate that the key sub-models, which have significant effects on results, viz., coke combustion, fluxes calcination, drying and condensation as well as heat and mass transfer, describe the sub-processes well. The phenomena of steady-state waste gas composition (SSWGC) and steady-state waste gas temperature (SSWGT) were simulated and analyzed by the model. A total of nine important input variables were identified and their influence on sintering time and three critical parameters which determine heat transfer during sintering were considered in the sensitivity studies. Results showed that bed bulk density, solid and gas thermal capacities, coke level and diameter and post-ignition airflow rate have the greatest influences on sintering time and the temperature profile parameters. This paper also gives suggestions on how the model can be improved.

Improving Energy Efficiency in Iron Ore Sintering through Segregation: a Theoretical Investigation

“…Jiapei ZHAO, 1) * Chin Eng LOO 1) and Benjamin George ELLIS (Received on December 1, 2015; accepted on March 17, 2016) In iron ore sintering, effective segregation of the particulate bed on the strand can result in productivity increases and decreased fuel rate. To find the optimum level of segregation for a given blend, intensive experimental work will be necessary to assess the impact of different segregation levels.…”

“…A well-validated hot model 1,5,7) has been formulated to describe heat transfer from the flame front to the bed and is used in this study. Data on segregated beds from the literature is used in the simulations.…”

“…The developed mathematical model of the iron ore sintering process 1,5,20) was used to quantify the effect of segregation on heat transfer and flame front properties. Modifications were added to take into account the variations in the segregation parameters down a bed and also variations in sintering airflow rate.…”

“…Sinter accounts for around 70 wt.% of the ferrous feed to blast furnaces in the Asia-Pacific region. 1) Sinter making is a complex process and can be viewed as comprising bed preparation under ambient conditions (or cold processing) and subjecting the bed to high temperatures by generating a narrow, moving flame front (or hot processing). The cold processing includes the blending of iron ore fines, fluxes, fuel and cold return fines, followed by the granulation process and charging of the formed granules onto the sinter strand.…”

Variation of the redox conditions and the resultant phase assemblages during iron ore sintering

“…Establishing the redox conditions during sintering was indirectly monitored by determining the CO and CO 2 contents in the off-gas (steady state waste gas composition, SSWGC) during sintering 2,3 . This is an average of all reactions taking place during sintering, reflecting both combustion and cooling conditions.…”