scholarly journals Effect of basicity on the reduction swelling properties of iron ore briquettes

2021 ◽  
Vol 40 (1) ◽  
pp. 193-203
Author(s):  
Guo-Cheng Zhang ◽  
Guo-Ping Luo ◽  
Peng-Fei Jia ◽  
Yi-Ci Wang ◽  
Yi-Fan Chai
Keyword(s):  
Solid Solution ◽  
Iron Ore ◽  
Slag Phase ◽  
Reduction Process ◽  
Sem Analysis ◽  
Swelling Properties ◽  
Iron Concentrate ◽  
Iron Whiskers ◽  
Reduction Swelling ◽  
Bayan Obo

Abstract The influence mechanism of basicity on the reduction swelling index (RSI) of iron ore briquettes was investigated using the SEM analysis and Factsage 7.3 thermodynamic calculations based on the addition of pure CaO to Bayan Obo iron concentrate. The results revealed that the solid solution of Ca2+ in the FeO lattice increased with the basicity of the briquettes, whereas the diffusion channels of Fe2+ ions increased during the reduction process from FeO to Fe and resulted in the formation of a great number of slender and anisotropic iron whiskers, which consequently increased the RSI. Furthermore, the melting point of the slag phase decreased as the CaO content increased; this reduced its ability to resist the reduction swelling of iron oxides. When the basicity was increased from 0.3 to 0.8, the RSI reached a maximum of 69.85%. However, due to the saturated solid solution of Ca2+ in FeO lattice, as the basicity further increased from 0.8 to 1.2, excess CaO melting into the slag phase promoted the precipitation of spinel minerals with high melting points and difficult reduction properties. Thus, the diffusion of Fe2+ and the growth of the iron whiskers were hindered, and the RSI was reduced.

Mechanism on reduction swelling of pellets prepared from Bayan Obo iron ore concentrate

2021 ◽  
pp. 1-11
Author(s):  
Yingjie Fan ◽  
Yunhao Zhang ◽  
Zhichao Li ◽  
Yifan Chai ◽  
Yici Wang ◽  
...  
Keyword(s):  
Iron Ore ◽  
Reduction Swelling ◽  
Bayan Obo ◽  
Iron Ore Concentrate

Fundamental Study on Application of Gas-Based Shaft Furnace Direct Reduction Process to High Efficiency and Clean Utilization of Paigeite

2011 ◽  
Vol 233-235 ◽  
pp. 753-758
Author(s):  
Zhao Cai Wang ◽  
Man Sheng Chu ◽  
Zhuang Nian Li ◽  
Jue Tang ◽  
Qing Jie Zhao ◽  
...  
Keyword(s):  
Electric Furnace ◽  
Shaft Furnace ◽  
Direct Reduction ◽  
Reduction Process ◽  
Technical Problems ◽  
Direct Reduction Process ◽  
Comprehensive Utilization ◽  
Iron Concentrate ◽  
New Process ◽  
Reduction Swelling

The paigeite resources are abundant in China, but most of them are difficult to be utilized efficiently because of the current technical problems on industrial practice. It is necessary to perfected and innovated for comprehensive utilization of paigeite. The new process of gas-based shaft furnace direct reduction-electric furnace smelting separation provides a new way to efficient and clean comprehensive utilization of paigeite resources. In this paper, the pellets are prepared from boron-bearing iron concentrate. The mechanisms of roasting, the rules of reduction, and the properties of reduction swelling are also investigated. And then the pellets after reduction are smelted and separated in electric furnace to study the properties of products and analyze the feasibility and superiority of new technique. The results showed that boron-bearing iron concentrate is a kind of good raw material for pelletizing process. The properties of boron-bearing pellets after roasting for 20 min at 1200°C could meet to the requirements of gas-based shaft furnace direct reduction process, which exhibited fast reaction rate, good reduction swelling properties and high compressive strength both before and after reduction. With the new process, the efficient separation of boron and iron can be realized. The high boron grade and high activity of boron-rich slag obtained from new process can be used directly in boric acid manufacture. The new process shows excellent tech-economy feasibility to achieve efficiency and clean comprehensive utilization of paigeite resources.

scholarly journals Effect of K and Na on reduction swelling performance of oxidized roasted briquettes

2021 ◽  
Vol 40 (1) ◽  
pp. 241-252
Author(s):  
Wei Song ◽  
Guo-Ping Luo ◽  
Chen-Chen Sun ◽  
Jing Zhang ◽  
Jian-Guo Zhu
Keyword(s):  
Alkali Metal ◽  
Potassium Oxide ◽  
Oriented Growth ◽  
Iron Concentrate ◽  
The Third ◽  
Influencing Mechanism ◽  
Composition And Structure ◽  
Third Stage ◽  
Iron Whiskers ◽  
Reduction Swelling

Abstract The presence of potassium oxide (K2O) and sodium oxide (Na2O) causes high reduction swelling of pellets of Bayan Obo iron concentrate during reduction and thus affects the permeability of blast gases during blast furnace operations. The influencing mechanism of K2O and Na2O on the swelling behavior of reduction reactions (1) Fe2O3 → Fe3O4, (2) Fe3O4 → Fe x O, and (3) Fe x O → Fe was researched by adding (K2O + Na2O) to Australian fine ore briquettes. The mineral composition and structure of the briquettes, as well as the reduction swelling after the three reactions coupled with the morphology and lattice parameters of the reduced products, were studied. From the results, the swelling index with 0.6% (K2O + Na2O) added was 8.52%, 7.91%, and 33.81%, respectively, and without were 12.36%, 3.27%, and 12.61%, respectively, for the three reactions. The swelling index of the first reaction (Fe2O3 → Fe3O4) is reduced because alkali metal suppresses crystal cracking. The swelling mainly occurs at the third stage (Fe x O → Fe), because K2O and Na2O enhance the oriented growth of iron whiskers, as well as make them smaller. Crystal transformation does not occur at the second stage (Fe3O4 → Fe x O) and the reduction swelling is small, but the swelling index of the briquettes with added with K2O and Na2O increases (7.91% compared to 3.27%). The main reason is that the alkali metal reduces the melting point of the slag phase and promotes the cascade crystallization of FeO. Therefore, the abnormal swelling of briquettes caused by K and Na is mainly caused by the growth of iron whiskers at the third stage.

Reduction process of rare earth Bayan Obo complex iron ore by carbon monoxide at 1073–1273 K

2016 ◽  
Vol 44 (6) ◽  
pp. 430-436 ◽  
Author(s):  
X. F. She ◽  
Y. X. Zhao ◽  
F. Feng ◽  
J. S. Wang
Keyword(s):  
Carbon Monoxide ◽  
Rare Earth ◽  
Iron Ore ◽  
Reduction Process ◽  
Bayan Obo

Construction of Ore Slurry Pipeline of Bayan Obo

2011 ◽  
Vol 339 ◽  
pp. 234-242
Author(s):  
Jun Qing Tan
Keyword(s):  
Iron Ore ◽  
Freezing Temperature ◽  
Pipeline System ◽  
Technical Problems ◽  
Iron Concentrate ◽  
Rugged Terrain ◽  
Pump Station ◽  
Bayan Obo ◽  
Water Pipeline ◽  
Iron Ore Concentrate

As the largest ore slurry pipeline system,and the third iron concentrate slurry pipeline interiorly, include the longest water pipeline with only one pump station in China, Bayan Obo slurry pipeline engineering of Baotou has been operated. It can transports 5.5 million tonnes of iron ore concentrate and 2000 million m3/h of water per year. In order to overcome freezing temperature and rugged terrain,many technical problems has been resolved in the period of construction.

Carbon Doped Iron Ore Using Palm Kernel Shell

2013 ◽  
Vol 701 ◽  
pp. 28-31 ◽  
Author(s):  
Rusila Zamani Abd Rashid ◽  
Hadi Purwanto ◽  
Hamzah Mohd Salleh ◽  
Mohd Hanafi Ani ◽  
Nurul Azhani Yunus ◽  
...  
Keyword(s):  
Iron Ore ◽  
Palm Kernel ◽  
Reduction Process ◽  
Attractive Alternative ◽  
Low Grade ◽  
Iron Ores ◽  
Solid Carbon ◽  
Green Composite ◽  
Biomass Waste ◽  
Palm Kernel Shell

This paper pertains to the reduction process of local low grade iron ore using palm kernel shell (PKS). It is well known that low grade iron ores contain high amount of gangue minerals and combined water. Biomass waste (aka agro-residues) from the palm oil industry is an attractive alternative fuel to replace coal as the source of energy in mineral processing, including for the treatment and processing of low grade iron ores. Both iron ore and PKS were mixed with minute addition of distilled water and then fabricated with average spherical diameter of 10-12mm. The green composite pellets were subjected to reduction test using an electric tube furnace. The rate of reduction increased as temperature increases up to 900 °C. The Fe content in the original ore increased almost 12% when 40 mass% of PKS was used. The reduction of 60:40 mass ratios of iron ore to PKS composite pellet produced almost 11.97 mass% of solid carbon which was dispersed uniformly on the surface of iron oxide. The aim of this work is to study carbon deposition of PKS in iron ore through reduction process. Utilization of carbon deposited in low grade iron ore is an interesting method for iron making process as this solid carbon can act as energy source in the reduction process.

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

Enhancing adsorptive removal of sulfate by metal layered double hydroxide functionalized Quartz-Albitophire iron ore waste: preparation, characterization and properties

RSC Advances ◽  
2016 ◽  
Vol 6 (72) ◽  
pp. 67630-67642 ◽  
Author(s):  
B. Sadeghalvad ◽  
A. Azadmehr ◽  
A. Hezarkhani
Keyword(s):  
Layered Double Hydroxide ◽  
Iron Ore ◽  
Sem Analysis ◽  
Adsorptive Removal ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Mineral Waste

In this study, the seemingly worthless Quartz-Albitophire iron ore mineral waste has been modified with metal double hydroxides (Mg–Al, Ni–Fe, Ni–Al and Mg–Fe) and utilized as a sulfate adsorbent which is characterized by XRD, XRF, FTIR and SEM analysis.

scholarly journals Effect of Different Additives on Reaction Characteristics of Fluorapatite During Coal-Based Reduction of Iron Ore

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 923 ◽  
Author(s):  
Yongsheng Sun ◽  
Wentao Zhou ◽  
Yuexin Han ◽  
Yanjun Li
Keyword(s):  
Iron Ore ◽  
Contact Point ◽  
Energy Dispersive Spectrometer ◽  
Structural Evolution ◽  
Reduction Process ◽  
Reduction Degree ◽  
Reduction Temperature ◽  
Exponential Factor ◽  
Reduction Time ◽  
Effect Mechanism

In the coal-based reduction of high phosphorus oolitic hematite, it is particularly important to study the mechanism of phosphorus regulation during the formation of iron metals for the efficient development and utilization of iron ore. In this study, the thermodynamics of the coal-based reduction process of fluorapatite in different mineral systems, effect mechanism of the reduction degree, kinetics, mineral composition, and morphology of structural evolution samples were systematically investigated using FactSage software, single factor analysis, the isothermal method, X-ray diffraction (XRD), scanning electron microscope (SEM), and an energy dispersive spectrometer (EDS). Thermodynamic analysis indicates that the effect of the SiO2–Fe2O3–C system on reducing the initial reduction temperature of fluorapatite was stronger than that of the Al2O3–Fe2O3–C system. The effect mechanism of the reduction degree demonstrates that increasing the dosage of silica, iron oxide, carbon, reduction time, and reduction temperature could promote the reduction reaction of fluorapatite under certain conditions. Dynamics analysis shows that the best kinetic mechanism functions of the SiO2–Fe2O3–C system and the Al2O3–Fe2O3–C system were A1/3 = 1/3(1 − α)[−ln(1 − α)]−2 and A1/2 = 1/2(1 − α)[−ln(1 − α)]−1, respectively. The activation energy and pre-exponential factor of the reduction kinetics equation in the system containing silica were significantly lower than that in the system containing alumina, which explained that the catalytic effect of silica on the reduction of calcium fluorophosphate was far greater than that of alumina. XRD and SEM/EDS analysis indicate that the solid–solid reaction of alumina, silica, iron, and fluorapatite occurred during the reduction process, while calcium aluminate, calcium silicate, and calcium oxide were formed at the contact point. Among them, iron could absorb P2 gas so that it played a greater role in promoting the reduction of fluorapatite. Increasing the reduction temperature and prolonging the reduction time were beneficial to the reduction of fluorapatite.

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