On the Importance of Model Selection for CFD Analysis of High Temperature Gas-Solid Reactive Flow; Case Study: Post Combustion Chamber of HIsarna Off-Gas System

In this paper a CFD analysis of HIsarna off-gas system for post combustion of CO-H2-carbon particle mixture is presented to evaluate the effect of different sub-models and parameters on the accuracy of predictions and simulation time. The effects of different mesh type, mesh grid size, radiation models, turbulent models, kinetic mechanism,...

Computational Fluid Dynamics Modeling of HIsarna Off-Gas System: Wall Modeling and Heat Loss Prediction

The HIsarna off-gas system wall is a cooling jacket made of cooling pipes arranged in the radial direction and in a circular pattern. Part of the off-gas system cooling pipes are isolated using a low-thermal-conductivity refractory material to protect the cooling pipe from melting and thermal stresses. During long runs and due to...

CFD modelling of the off-gas system HIsarna iron making process part 2: reflux chamber geometry modification and effects on flow behaviour

A three-dimensional computational fluid dynamics (CFD) model for the HIsarna off-gas system is set up and validated by real plant data. In the model detailed reaction mechanism and kinetic data for post-combustion of CO-H2 mixture and carbon particles are incorporated. The results are presented and discussed in another study (Part 1) by the...

Experimental and Discrete Element Method Analysis of Galvanized Steel Scrap Particles Along and After an Inclined Chute

HIsarna is a novel ironmaking process with great raw materials versatility that is attractive for various secondary resources. Among the materials that can be recycled, there is steel scrap which is fed to the furnace bath through an inclined chute. The velocity distribution of the scrap particles along the chute affects the particles’...

Off-Gas System Scale-Up of HIsarna Iron-Making Process: A CFD-Based Approach

For all industrial applications, predicting system characteristics and behavior plays a vital role before constructing costly and complex multi-physic systems. Correct and reliable predictions become even more important once the aim is to go from small- to large-scale processes to establish an industrial demonstrations. In this study, a CFD...

Thermodynamic analysis of zinc ferrite (ZnFe₂O₄) formation inside the HIsarna off-gas system

HIsarna reactor is characterized by a high raw materials versatility and is therefore attractive for processing secondary iron sources. Among the materials that can be recycled through HIsarna, zinc-bearing material has drawn a special attention. Based on the plant data, once dust-containing Zinc was injected into the main reactor, a final...

Granular Flow Modeling of Galvanized Steel Scrap Injection into the HIsarna Iron-Making Reactor

Galvanized steel scrap flow and injection into the HIsarna reactor are investigated using discrete element method (DEM). The scrap particle is fed into the reactor through an inclined chute and hits the slag surface where the zinc content is evaporated and solid particles melt. A DEM model is setup and validated using experimental data...

Zinc Vaporization and Self-reduction Behavior of Industrial Waste Residues for Recycling to the HIsarna Furnace

Within the steelmaking industry, a large amount of zinc-bearing waste is produced which cannot be effectively treated through integrated steel mills. Concurrently, zinc smelters generate waste residues containing significant amounts of iron and zinc which are stored or landfilled. The zinc concentration of iron and steelmaking residues...

CFD modelling of the off-gas system of HIsarna iron making process. Part 1: model development using detailed reaction mechanism for post-combustion of CO–H₂ mixture and carbon particles

The HIsarna process is a new and breakthrough smelting reduction process for hot metal (liquid iron) production from iron ores and coal directly fed into the reactor. The flue gas from the main reactor enters the off-gas system containing small amounts of H₂, CO and carbon particles which need to be removed before further treatment...

Recovery of rare earths from glass polishing waste for the production of aluminium-rare earth alloys

The circular economy demands waste utilization for the production of high-value products, and this requires the development of novel processing routes. In this study, rare earth (La and Ce) oxides were completely (>99%) recovered from polishing waste by a combined novel reductive acid leaching and alkali treatment process. About 70% of...

Zinc Reduction/Vaporisation Behaviour from Metallurgical Wastes

The steelmaking industry produces large quantities of zinc-bearing wastes of varying forms that cannot be treated through integrated steelmaking processes. Simultaneously, by-products of the zinc industry containing great amounts of iron and zinc are stored or landfilled. The amount of zinc in these materials is generally below that which is...

Characterization and feasibility studies on complete recovery of rare earths from glass polishing waste

One of the main applications of ceria (CeO ₂ ) is its use in glass polishing. About 16,000 tonnes of rare earth oxides, which is about 10% of total rare earth production, are used for polishing applications. The waste generated in glass polishing contains rare earths, along with other impurities. In this study, two different glass...

Recovery of cerium from glass polishing waste: A critical review

Ceria is the main component in glass polishing powders due to its special physico-chemical properties. Glass polishing powder loses its polishing ability gradually during usage due to the accumulation of other compounds on the polishing powder or due to changes in the particle size distribution. The recovery of cerium from the glass polishing...

Characterisation of glass polishing waste samples

The present work describes the characterisation of the two different polishing waste samples. The samples were analysed with laser particle size analyser, XRD, XRF, TGA, and SEM. In the sample A, a large amount of calcite (CaCO3) together with silica and aluminosilicates were observed with SEM. In the minerology, only CaCO3, CeO2 and LnO0.65F1.7...