Thermodynamic evaluation for reduction of iron oxide ore particles in a high temperature drop tube furnace

Melting and reduction of fine iron ore particles in the gas environment of a HIsarna smelting cyclone is a critically important topic, but very limited information is currently available except for some experimental data from high temperature drop tube furnace (HTDF). This work discusses the equilibrium state of reacting iron ore in the HTDF...

Characterization of the burden behaviour of iron ore pellets mixed with nut coke under simulated blast furnace conditions

In the blast furnace, nut coke is utilized in a mixture with the ferrous burden to improve the gas permeability. Although applied in a broad range (10–40 mm, 2–23 wt-%), limited information is available on changed burden behaviour in its presence. In the present study, the detailed characterization was performed on the iron ore pellets quenched...

Reduction Kinetics of Fine Hematite Ore Particles in Suspension

Suspension reduction kinetics of hematite ore particles at 1710 K to 1785 K was described by the Johnson-Mehl-Avrami-Kolmogorov model with Avrami exponent of 1.405. The apparent activation energy is 105.5 kJ mol⁻¹ with the rate determining step of nucleation and growth. The reduction degree of the hematite at the endpoint is a...

Reduction Mechanism of Fine Hematite Ore Particles in Suspension

In order to understand the pre-reduction behaviour of fine hematite particles in the HIsarna process, change of morphology, phase and crystallography during the reduction were investigated in the high temperature drop tube furnace. Polycrystalline magnetite shell formed within 200 ms during the reduction. The grain size of the magnetite is in...

Melting behaviour of iron ore pellet bed under nut coke mixed charge conditions

The melting and dripping behaviour of an iron ore pellet bed mixed with nut coke are investigated through a series of quenching, melting and dripping experiments. In the melting bed of iron ore pellets, nut coke acts as a frame to maintain the passage for the gas flow. The iron carburisation level of the pellet shell is found to control the...

Ferrous burden behaviour under nut coke mixed charge conditions

Effect of nut coke addition with ferrous burden (pellet and sinter mixture) is experimentally investigated under simulated blast furnace conditions. Nut coke mixing degree was varied (0, 20 and 40 wt-%) as a replacement of the regular coke. During smelting, the ferrous bed evolves through three distinct stages of shrinkage due to indirect...

A comparative study of pellets, sinter and mixed ferrous burden behaviour under simulated blast furnace conditions

Physicochemical behaviour of the pellets, sinters and its mixture (60% pellets: 40% sinter) is investigated by a series of smelting and quenching experiments. For all ferrous raw-material beds, three distinct stages of bed shrinkage occur due to indirect reduction, softening and melting. However, the characteristic nature (displacement,...

Thermal decomposition reaction kinetics of hematite ore

In order to understand the thermal decomposition kinetics of hematite particles in inert atmosphere, thermogravimetriy was employed for isoconversional analysis. The kinetic triplet was estimated from the experimental data and the isothermal reaction kinetics was predicted. The results indicated that the thermal decomposition could be divided...

Review and data evaluation for high-temperature reduction of iron oxide particles in suspension

High-temperature reduction processes of iron oxide particles suspension are promising in carbon emission abatement. Recently, researchers have contributed abundant knowledge of the reaction mechanism and kinetics of iron oxide particles above 1473 K, while there was very limited information 10 years ago. Although the understanding of the high...