Hydrogen-based direct reduction of industrial iron ore pellets
The change in pellet size during the reduction was negligible, except at elevated temperatures due to crack formation. ... Effect of Amount of Carbon on the Reduction Efficiency of Iron Ore-Coal Composite Pellets in Multi-layer Bed Rotary Hearth Furnace (RHF) ... Mathematical model of direct reduction shaft furnace and its …
اقرأ أكثر
Reduced Carbon Consumption and CO2 Emission at the Blast Furnace …
Lowering the carbon consumption and fossil CO2 emissions is a priority in blast furnace (BF) ironmaking. Renewable biomass is one option that can play an important role in future low-carbon ironmaking particularly in the countries rich in biomass resources. In this study, full-scale trials to investigate the impact of briquettes containing torrefied …
اقرأ أكثر
Sticking Behavior of Pellets During Direct Reduction
A series of reduction experiments of iron ore pellets with hydrogen, carbon monoxide and their mixture were carried out in a laboratory scale shaft furnace. The sticking behavior accompanying ...
اقرأ أكثر
Reduction process and zinc removal from composite briquettes
In this study, composite briquettes were prepared using gravity dust and converter sludge as the main materials; these briquettes were subsequently reduced in a tube furnace at 1000–1300°C for 5–30 min under a nitrogen atmosphere. The effects of reaction temperature, reaction time, and carbon content on the metallization and …
اقرأ أكثر
Comparative Study on the Kinetics of the Isothermal …
The basket was kept inside the shaft furnace at given temperatures of 900, 1000, 1100 and 1200 C for desired times of 15, 30, 45, 60, and 90 min. The mass changes ... The phase compositions of the composite pellets after the reduction were analyzed by X-ray diffraction (XRD) (D/max 2500 PC, Rigaku, Tokyo, Japan) using Cu K
اقرأ أكثر
A Review on the Modeling of Gaseous Reduction of Iron Oxide Pellets
The breakthrough route involving a reduction shaft furnace operated with pure hydrogen gas (here called H 2 -SF) and the electric arc furnace is widely accepted as one of the ... Modelling the reduction of an iron ore-coal composite pellet with conduction and convection in an axisymmetric temperature field. Jingyu Shi E. Donskoi D. McElwain …
اقرأ أكثر
Iron ore pellet disintegration mechanism in simulated shaft …
The disintegration behavior and mechanism of iron ore pellet in simulated shaft furnace conditions were investigated in details. Effects of temperature, reducing gas and gangue compositions were emphatically discussed. It was found that pellet …
اقرأ أكثر
Mathematical Model of the Shaft Furnace for Reduction of Iron-Ore Pellet
Synopsis: A mathematical model of the shaft furnace is developed for gaseous reduction of iron-ore pellet. In the model, the reduction of iron-oxide is defined as the multi-stage successive reaction and the reduction rate equations are derived from the multi-interface core model in a single pellet. This model is applied to the simulation for the changes of …
اقرأ أكثر
Smelting Reduction: Most Efficient Technologies for Greenhouse
The shaft furnace is a modified MIDREX DRI countercurrent reactor without a cooling zone in which lump ore or/and pellets are reduced to approximately 85% metallization. The hot DRI at a temperature of approximately 800 °C is discharged from the shaft furnace by means of horizontal screw conveyors to the charging pipes of the …
اقرأ أكثر
Detailed Modeling of the Direct Reduction of Iron Ore in a Shaft Furnace
This paper addresses the modeling of the iron ore direct reduction process, a process likely to reduce CO 2 emissions from the steel industry. The shaft furnace is divided into three sections (reduction, transition, and cooling), and the model is two-dimensional (cylindrical geometry for the upper sections and conical geometry for the …
اقرأ أكثر
Smelting Reduction Ironmaking | SpringerLink
The upper prereduction shaft furnace, similar to the Midrex shaft furnace, uses the top-loaded lump ore (natural lump, pellet, and sinter) to complete the …
اقرأ أكثر
On the reduction behavior, structural and mechanical features of …
Effect of residual volatile matter on reduction of iron oxide in semi-charcoal composite pellets. ISIJ Int. (2010) J.P ... followed by carbonization in a shaft furnace [20–25]. ... The interaction mechanism is indicated that the gasification of ICHB and the reduction of pellet are mutually promoted through increasing the reducing potential in ...
اقرأ أكثر
Direct reduction of iron ore pellets by H2 and CO: In-situ
The pellets were reduced in hydrogen atmosphere in a laboratory shaft furnace in the temperature ranges of 600–1200 °C at the pressures of 1 and 5 bar. The pellets' reduction behaviour was analysed in terms of time to reduction, rate of reduction and kinetics constant.
اقرأ أكثر
Adapting to Raw Materials Challenges: Part 1
A reduction in metallization increases the required energy to melt the material. DRI or HBI with very low metallization may result in significant iron loss to the slag in the EAF. General pellet chemistry – The type and percentages of chemical elements will determine the tendency of pellets to stick and form clusters in the shaft furnace ...
اقرأ أكثر
Reducing gas composition optimization for COREX® pre-reduction shaft
In present research, the reduction behaviours of iron oxides inside the COREX pre-reduction shaft furnace with the reducing gas of CO-H 2 mixture were simulated. The reducing gas temperature ranges investigated in this model are from 1123K to 1273K, and at each temperature level, the mole fraction of H 2 increases from 0 to …
اقرأ أكثر
A review of ironmaking by direct reduction processes: Quality
2. Overview of DR processes. Direct reduction processes reduce iron ore (in the form of lumps, pellets or fines) to the solid state using a reducing. gas to produce Direct Reduced Iron (also known ...
اقرأ أكثر
A Process For Reduction Of Composite Agglomerates Of High …
Midrex Shaft Furnace : The Midrex™ direct reduction process is based upon a low pressure, moving bed shaft furnace where the reducing gas moves counter- current to the lump iron oxide ore or iron oxide pellet solids in the bed. The reducing gas (from 10.20% CO and 80-90% H2) is produced form natural gas
اقرأ أكثر
Detailed Modeling of the Direct Reduction of Iron Ore in a Shaft …
In a DR shaft furnace, a charge of pelletized or lump iron ore is loaded into the top of the furnace and is allowed to descend, by gravity, through a reducing gas. …
اقرأ أكثر
Influence of Parameters on the Pre-Reduction Process of …
VTM carbon composite pellets were prepared with a certain amount of VTM concentrates, coals, and molasses in a disc ... Yang, S.D.; Zhou, Q.; Zhang, L.H. Basic characteristics of the shaft furnace of COREX (R) smelting reduction process based on iron oxides reduction simulation. ISIJ Int. 2010, 50, 1032–1039. [Google Scholar] ...
اقرأ أكثر
Study on sticking mechanism of pellets under low H2/CO conditions
The sticking behavior of pellets with high-grade and low gangue composition in the gas-based reduction shaft furnace was studied by means of SEM, EDS and reduction kinetics at different temperature and different H 2 /CO in low H 2 /CO conditions. The following conclusions were drawn: (1) The SI of the pellets increased with the …
اقرأ أكثر
Alternative emerging ironmaking technologies for energy
A number of processes are already under development that use composite pellets of ore or waste oxides and a carbonaceous material, such as coal or coke, which are reduced in the solid state using a rotary hearth or similar type of furnace. ... MIDREX Technologies, Inc. Direct reduction–shaft furnace and rotary hearth furnace (RHF); …
اقرأ أكثر
Sticking behaviour and mechanism of iron ore pellets in …
The reduction temperature is 800–850°C in the COREX-3000 shaft furnace of Baosteel. Higher temperature than this will cause sticking. To study the behaviour of pellets, the exper-imental ...
اقرأ أكثر
Mathematical simulation of direct reduction process in zinc-bearing pellets
A one-dimensional unsteady mathematical model was established to describe direct reduction in a composite pellet made of metallurgical dust. The model considered heat transfer, mass transfer, and chemical reactions including iron oxide reductions, zinc oxide reduction and carbon gasification, and it was numerically solved …
اقرأ أكثر
Direct reduction swelling behavior of pellets in hydrogen-based …
Direct reduction swelling behavior of pellets in hydrogen-based shaft furnaces under typical atmospheres Published: 22 August 2022 Volume 29, pages …
اقرأ أكثر
Reducing gas composition optimization for COREX® …
When the reducing gas temperature is below 1173K, pure CO is the optimal reducing gas composition, while as the reducing gas …
اقرأ أكثر
Minerals | Free Full-Text | New Trends in the Application of
The iron and steel industry is still dependent on fossil coking coal. About 70% of the total steel production relies directly on fossil coal and coke inputs. Therefore, steel production contributes by ~7% of the global CO2 emission. The reduction of CO2 emission has been given highest priority by the iron- and steel-making sector due to the …
اقرأ أكثر
(PDF) Computational Analysis of The Performance of Shaft Furnaces …
The energy profile, productivity, and carbon emission of the traditional shaft furnace were compared with the simulated results after partial replacement of the burden with self-reducing pellets ...
اقرأ أكثر
Kinetics of iron ore pellets reduced by H
The pellets were reduced in hydrogen atmosphere in a laboratory shaft furnace in the temperature ranges of 600–1200 °C at the pressures of 1 and 5 bar. The pellets' reduction behaviour was analysed in terms of time to reduction, rate of reduction and kinetics constant.
اقرأ أكثر
Reducing gas composition optimization for COREX® …
A two-dimensional mathematical model is developed to describe iron oxides reduction in the shaft furnace of COREX® smelting reduction process. ... of iron ore-carbon composite pellets by CO or …
اقرأ أكثر
Effects of Temperature and Atmosphere on Pellets Reduction …
DOI: 10.1016/S1006-706X(12)60144-7 Corpus ID: 136862607; Effects of Temperature and Atmosphere on Pellets Reduction Swelling Index @article{Wang2012EffectsOT, title={Effects of Temperature and Atmosphere on Pellets Reduction Swelling Index}, author={Zhaodong Wang and Mansheng Chu and Zhenggen Liu and Zhuang-yin Chen …
اقرأ أكثر