Thermodynamic study of reduction process of Bapy deposit iron ore concentrate by coal of Karazhyra deposit

2021 ◽  
Vol 77 (3) ◽  
pp. 262-271
Author(s):  
I. A. Rybenko ◽  
B. A. Edil’baev ◽  
O. I. Nokhrina ◽  
I. D. Rozhikhina ◽  
E. V. Protopopov ◽  
...  
Keyword(s):  
Gas Phase ◽  
Iron Ore ◽  
Iron Reduction ◽  
Direct Reduction ◽  
Reduction Process ◽  
Reducing Agent ◽  
Coal Consumption ◽  
Oxidative Potential ◽  
Reduction Of Iron ◽  
Iron Ore Concentrate

In modern ferrous metallurgy, direct reduction of iron from iron ore materials is becoming increasingly common. In order to assess the feasibility of using a particular technology, it is necessary to obtain information on the reduction processes of iron oxides. Taking into consideration that experimental research is usually expensive, a computational experiment is optimal, which allows to draw conclusions about the behavior of the studied objects on the basis of modeling high-temperature processes in complex thermodynamic systems with physicochemical transformations under equilibrium and non-equilibrium conditions. As a modeling tool, the Terra software complex created at the Moscow State Technical University named after N. E. Bauman was used. As a result of thermodynamic studies boundaries of redox processes are identified and optimal temperature and consumption of reducing agent were determined, which provide maximum degree of iron reduction. The results of simulation of iron reduction process from iron ore concentrate obtained during concentration of iron ore of Bapy deposit, by coal of Karazhyra deposit (Kazakhstan) are presented. Dependencies of composition and volume of gas phase, formed as a result of volatile coal components emission in the process of heating, degree of iron reduction at various coal consumption rates on the temperature was established. It was found that the complete reduction of iron occurs at a coal consumption of 25 kg/100 kg of concentrate and a temperature of 1013 K, and the further increase in the consumption of the reducing agent leads only to a change in the ratio of CO and SO2 in the gas phase towards a decrease in the oxidative potential and an increase in the temperature of completion of the reducing process.

scholarly journals Distribution of solid-phase reduction of iron in a layer of ilmenite concentrate

2020 ◽  
Vol 63 (2) ◽  
pp. 116-121
Author(s):  
K. I. Smirnov ◽  
P. A. Gamov ◽  
V. E. Roshchin
Keyword(s):  
Iron Reduction ◽  
Solid Phase ◽  
Point Contact ◽  
Reduction Process ◽  
Reducing Agent ◽  
Metal Phase ◽  
Contact Boundary ◽  
Silicate Phase ◽  
Ilmenite Concentrate ◽  
Reduction Of Iron

Processing of titanium-containing ores with extraction of all the major elements is an urgent task of minerals rational use. It is shown that none of the existing processing schemes allows extracting of all the major useful elements at the same time from titanium-containing iron ores, i.e. – iron, titanium and vanadium. This problem can be solved using selective extraction of these elements based on new ideas about electronic reduction mechanism. Propagation of the process of solid-phase selective reduction of iron with the powder of carbon-containing material deep into the layer of grains of ilmenite concentrate from the surface of its contact was experimentally studied. The results of determining the amount of metal phase released as it moves away from the concentrate – reducing agent contact boundary are presented. Based on the results concerning amount of precipitated metal phase, a conclusion was made about diffusion processes in a layer of concentrate grains contacting only between themselves, limiting process of iron reduction. It is shown that near the plane of contact of solid reducing agent with the layer of concentrate grains, the rate of iron reduction is higher than the rate of high iron content phase precipitation from ilmenite. In depth of ilmenite concentrate layer, process of iron reduction is preceded by formation of iron-containing silicate phase from concentrate grains, where iron is reduced earlier than in ilmenite grains. Formation of iron-containing silicate phase contributes ilmenite grains sintering. It was concluded that in the concentrate layer in contact with solid reducing agent layer in absence of contact of each ilmenite grain with solid reducing agent, the point contact of grains and presence of voids between them in the layer do not prevent propagation of reduction process in the layer of grains contacting with each other only.

scholarly journals Physics and Chemistry of Solid State Direct Reduction of Iron Ore by Hydrogen Plasma

2021 ◽  
Vol 22 (2) ◽  
pp. 292-300
Author(s):  
Kali Charan Sabat
Keyword(s):  
Solid State ◽  
Large Scale ◽  
Iron Ore ◽  
Direct Reduction ◽  
Hydrogen Plasma ◽  
Standard Free Energy ◽  
Reduction Process ◽  
Capital Investments ◽  
State Reduction ◽  
Reduction Of Iron

Presently, Iron is produced from iron ores by using carbon from coal. The production process is consisting of many stages. The involvement of multi-stages needs high capital investments, large-scale equipments, and produces large amounts of carbon dioxide (CO2) responsible for environmental pollution. There have been significant efforts to replace carbon with hydrogen (H2). Although H2 is the strongest reductant, it still also has thermodynamic and kinetic limitations. However, these thermodynamic and kinetic limitations could be removed by hydrogen plasma (HP). HP comprises rovibrationally excited molecular, atomic, and ionic states of hydrogen. All of them contribute to thermodynamic advantage by making the Gibbs standard free energy more negative, which makes the reduction of iron oxides feasible at low temperatures. Apart from the thermodynamic advantage, these excited species increase the internal energy of HP, which reduces the activation energy, thereby making the reduction easier and faster. Apart from the thermodynamic and kinetic advantage of HP, the byproduct of the reaction is environmentally benign water. This review discusses the physics and chemistry of iron ore reduction using HP, emphasizing the solid-state reduction of iron ore. HP reduction of iron ore is a high potential and attractive reduction process.

Reduction Behaviour of Iron Ores by Agricultural Waste Chars

2015 ◽  
Vol 819 ◽  
pp. 31-36 ◽  
Author(s):  
Nur Farhana Diyana Mohd Yunos ◽  
Nor Athirah Aziz ◽  
Anis Nadhirah Ismail ◽  
Muhammad Asri Idris
Keyword(s):  
Metallic Iron ◽  
Carbon Dioxide Emissions ◽  
Iron Ore ◽  
Agricultural Waste ◽  
Reduction Process ◽  
Coke Coal ◽  
Vital Role ◽  
Reducing Agent ◽  
Coal Consumption ◽  
Ore Minerals

Iron and steelmaking are two of the largest energy intensive industries with the highest growth rate in energy consumption of all energy utilisation sectors. In order to meet the growing greenhouse challenges, incorporation of renewable resources to the existing and emerging metallurgical operation are desirable. In this respect, agricultural wastes can be potentially applied as fuel for ironmaking process to stabilise the greenhouse emissions as it is renewable and CO2neutral. Thus, the present study investigates the reduction behavior of iron ore minerals and growth of metallic iron in reduction process. The process was utilized palm shells char (pyrolyzed) as reducing agent at high temperature (1000°C) with inert gas oxygen within 2 hours of reduction reactions. Reducing agent plays a vital role in the reduction process where metallic iron was produced. After the reduction for sample mass ratio of 30:70 palm char over iron ore blend. Metallic iron produced was detected by XRD pattern as well as the other oxides through SEM/EDS analysis. The result indicates that palm shells char can be used as reducing agent by producing metallic iron effectively. The beneficial effect on the environment through decrease use of coke/coal consumption and carbon dioxide emissions in steelmaking process.

The sticking problem during direct reduction of fine iron ore in the fluidized bed

10.30544/378 ◽  
2004 ◽  
Vol 10 (4) ◽  
pp. 309-328 ◽  
Author(s):  
Mirko Komatina ◽  
HEINRICH W. GUDENAU
Keyword(s):  
Fluidized Bed ◽  
Iron Ore ◽  
Review Paper ◽  
Direct Reduction ◽  
Reduction Process ◽  
Experimental Investigations ◽  
Inert Material ◽  
Reduction Of Iron ◽  
Fine Iron ◽  
Direct Reduction Of Iron

In this review paper described are possible chemical reactions and their thermodynamic analysis during direct reduction. The sticking mechanism during direct reduction in the fluidized bed was analysed, and the reasons for the sticking appearance explained. The most important parameters on the sticking were analysed. The ways for prevention and observation were considered. The plan for experimental investigations was proposed. The investigations could be performed in fluidized bed reactor. Coal will be used as inert material. Separately, the influence volatile content in the coal on the reduction process and sticking appearance, will be analysed. As results of these investigations would be some improvements of the method direct reduction of iron ore in the fluidized bed.

scholarly journals Review and Thermodynamic Calculation of Gas-based Shaft Furnace Direct Reduction Ironmaking

2020 ◽  
Vol 218 ◽  
pp. 01032
Author(s):  
Weiming Luo
Keyword(s):  
Thermodynamic Calculation ◽  
Iron Ore ◽  
Shaft Furnace ◽  
Direct Reduction ◽  
Reduction Process ◽  
Reducing Agent ◽  
Reduction Degree

Different techniques have been used to study the reduction process of iron ore. In this paper, the reduction process of iron ore by CO at 200~1200°C is calculated. The effects of reducing agent overdose, reducing temperature and VCO2/(VCO+VCO2) on reducing degree were studied. The results show that the reduction degree increases with the increase of reducing agent and slows down gradually. During the reduction process, the reduction degree decreased significantly with the increase of VCO2/(VCO+VCO2). In this temperature segment, the reduction degree has a peak.

Effects of reductant type on coal-based direct reduction of iron ore tailings

2018 ◽  
Vol 42 (3) ◽  
pp. 453-466
Author(s):  
Wei WANG ◽  
Pengfei YE ◽  
Xiaoli ZHOU ◽  
C WANG ◽  
Zekun HUO ◽  
...  
Keyword(s):  
Iron Ore ◽  
Direct Reduction ◽  
Iron Ore Tailings ◽  
Reduction Of Iron ◽  
Direct Reduction Of Iron

Separation of aluminium and preparation of powdered DRI from lateritic iron ore based on direct reduction process

2016 ◽  
Vol 55 (3) ◽  
pp. 345-355 ◽  
Author(s):  
T. Jiang ◽  
L. Yang ◽  
G. Li ◽  
J. Luo ◽  
J. Zeng ◽  
...  
Keyword(s):  
Iron Ore ◽  
Direct Reduction ◽  
Reduction Process ◽  
Direct Reduction Process

A simplified approach to the simulation of direct reduction of iron ore

2010 ◽  
Vol 107 (5) ◽  
pp. 195-204 ◽  
Author(s):  
M. Vannucci ◽  
V. Colla ◽  
G. Corbo ◽  
S. Fera
Keyword(s):  
Iron Ore ◽  
Direct Reduction ◽  
Simplified Approach ◽  
Reduction Of Iron ◽  
Direct Reduction Of Iron

scholarly journals Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 751 ◽  
Author(s):  
Zhiyuan Chen ◽  
Jie Dang ◽  
Xiaojun Hu ◽  
Hongyan Yan
Keyword(s):  
Activation Energy ◽  
Direct Reduction ◽  
Reduction Process ◽  
Kinetic Mechanism ◽  
Hydrogen Atmosphere ◽  
Morphological Transformation ◽  
Iron And Steel ◽  
Multi Stage ◽  
Reduction Of Iron ◽  
Direct Reduction Of Iron

Hydrogen has received much attention in the development of direct reduction of iron ores because hydrogen metallurgy is one of the effective methods to reduce CO2 emission in the iron and steel industry. In this study, the kinetic mechanism of reduction of hematite particles was studied in a hydrogen atmosphere. The phases and morphological transformation of hematite during the reduction were characterized using X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy. It was found that porous magnetite was formed, and the particles were degraded during the reduction. Finally, sintering of the reduced iron and wüstite retarded the reductive progress. The average activation energy was extracted to be 86.1 kJ/mol and 79.1 kJ/mol according to Flynn-Wall-Ozawa (FWO) and Starink methods, respectively. The reaction fraction dependent values of activation energy were suggested to be the result of multi-stage reactions during the reduction process. Furthermore, the variation of activation energy value was smoothed after heat treatment of hematite particles.

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