Coal-Based Reduction on Flotation Middling from Iron Ore Containing Carbonate at Donganshan

2013 ◽  
Vol 826 ◽  
pp. 20-24
Author(s):  
Duo Zhen Ren ◽  
Hui Wen Zhou ◽  
Peng Gao ◽  
Yue Xin Han

In this paper, coal-based reduction on flotation middling from iron ore containing carbonate at donganshan was studied, during which the effect of reduction temperature, reduction time, C/O mole ratio and feed layer thickness on reduction process were carried out. The results showed that the optimal reduction conditions required a temperature of 1250°C,a duration of 70min, a C/O mole ratio of 2.0 and a feed layer thickness of 25mm, and the iron powder containing 90.27% Fe with iron recovery of 93.36% was obtained after three stages low intensity magnetic separation, which could be used to make steel. According to the chemical analysis, most of the iron minerals were reduced to metallic iron. Coal-based reduction proved to be an alternative and promising process to conduct the fine particles and powders.

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 923 ◽  
Author(s):  
Yongsheng Sun ◽  
Wentao Zhou ◽  
Yuexin Han ◽  
Yanjun Li

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.


2012 ◽  
Vol 482-484 ◽  
pp. 1354-1357
Author(s):  
Xing Juan Wang ◽  
Ran Liu ◽  
Jue Fang

It is a good way that the fluidized bed is used as a substitute for reduction shaft in Corex process. Which can reduce energy consumption, environmental pollution and construction costs further, and also improve the competitiveness of Corex and blast furnace. At present, the sticking problem is present in iron ore reduction process and interrupts the reduction process, it has become a major obstacle on the development of fluidized bed. In this paper, a visualization hot model of fluidized bed is introduced. The influence factors on sticking behavior were analyzed from reduction temperature, gas velocity, atmosphere, degree of metallization or reduction and property of iron ore, the research provided a strong theoretical basis for controlling the sticking.


2014 ◽  
Vol 941-944 ◽  
pp. 2574-2577
Author(s):  
Zhi Hong Ma ◽  
Jin Zhu Zhang ◽  
Wei Li ◽  
Jing Chen

The oolitic hematite will be a potential source of raw iron ore for the Chinese iron and steel industry. Up to now, the oolitic hematite have hardly been utilized effectively by any single traditional technology. The deep reduction assisted with microwave radiation may be a practical technology for the exploitation of oolitic hematite. The results show that the metallization rate can be obtained to 88.91%, and the iron recovery up to 90.70% for the oolitic hematite with an iron content 51.19%, when the deep reduction parameters are as follows, the reduction temperature is 1050°C, the residence time is 45min, and the ratio of reducing agent is 24%.


Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1057
Author(s):  
Carolina R. Simões ◽  
Ronald R. Hacha ◽  
Antonio G. Merma ◽  
Maurício L. Torem

Electroflotation is a clean technique potentially able to recover fine particles from mineral suspensions. The aim of the present work was to evaluate the electroflotation of fines and ultrafine particles of an itabiritic iron ore using a biosurfactant extracted from Rhodococcus opacus bacteria. Infrared spectroscopy and zeta potential measurements confirmed the interaction between the biosurfactant and the mineral surface. The isoelectric point of hematite presented a value of about pH 5.3; after interacting with the biosurfactant, a charge reversal point of pH 3.5 was observed. The biosurfactant reduced the air/water surface tension from 71 to 40 mN/m, using 25 mg/L concentration. The electroflotation process of fine and ultrafine particles was evaluated as a function of pH, biosurfactant concentration, stirring of the aqueous suspension and current density. It was observed that the iron recovery (%) and iron grade (%) were negatively affected by increasing pH value. Therefore, best results were achieved at pH 3. Biosurfactant concentration and current density positively affected both response variables. An iron recovery value of about 83% and an iron grade of about 59% were achieved for the −38 + 20 µm size fraction; whereas, higher values were attained (98% and 64%, respectively) for the finer size fraction −20 µm.


2012 ◽  
Vol 535-537 ◽  
pp. 746-749
Author(s):  
Wei Zhi Wang ◽  
Li Ping Chen ◽  
Chun Guang Yang

Test was made on separating iron from a ultra-low-grade vanadium titanium magnetite ore by a process of tailing discarding at a coarser size,staged grinding and staged low intensity magnetic separation. The results show that when the raw ore is treated by permanent dry magnetic separator with low intensity magnetic separation at 12~0 mm size,qualified tailings of about 20% yield can be discarded.The coarse concentrate is grounded in two stages. With the first stage grinding size being 45% -200 mesh and the second stage,75% -200 mesh,and then treated by two stage low intensity magnetic separation.As a result,an iron concentrate with a TFe grade of 65.80%and an iron recovery of 47.74%can be achieved.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 341
Author(s):  
Tien Hiep Nguyen ◽  
Gopalu Karunakaran ◽  
Yu.V. Konyukhov ◽  
Nguyen Van Minh ◽  
D.Yu. Karpenkov ◽  
...  

This paper presents the synthesis of Fe–Co–Ni nanocomposites by chemical precipitation, followed by a reduction process. It was found that the influence of the chemical composition and reduction temperature greatly alters the phase formation, its structures, particle size distribution, and magnetic properties of Fe–Co–Ni nanocomposites. The initial hydroxides of Fe–Co–Ni combinations were prepared by the co-precipitation method from nitrate precursors and precipitated using alkali. The reduction process was carried out by hydrogen in the temperature range of 300–500 °C under isothermal conditions. The nanocomposites had metallic and intermetallic phases with different lattice parameter values due to the increase in Fe content. In this paper, we showed that the values of the magnetic parameters of nanocomposites can be controlled in the ranges of MS = 7.6–192.5 Am2/kg, Mr = 0.4–39.7 Am2/kg, Mr/Ms = 0.02–0.32, and HcM = 4.72–60.68 kA/m by regulating the composition and reduction temperature of the Fe–Co–Ni composites. Due to the reduction process, drastic variations in the magnetic features result from the intermetallic and metallic face formation. The variation in magnetic characteristics is guided by the reduction degree, particle size growth, and crystallinity enhancement. Moreover, the reduction of the surface spins fraction of the nanocomposites under their growth induced an increase in the saturation magnetization. This is the first report where the influence of Fe content on the Fe–Co–Ni ternary system phase content and magnetic properties was evaluated. The Fe–Co–Ni ternary nanocomposites obtained by co-precipitation, followed by the hydrogen reduction led to the formation of better magnetic materials for various magnetically coupled device applications.


Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1175
Author(s):  
Qiyan Xu ◽  
Zhanghan Gu ◽  
Ziwei Wan ◽  
Mingzhu Huangfu ◽  
Qingmin Meng ◽  
...  

The effects of reduction temperature, gas linear velocity, reduction pressure, reduction time, and reducing gas on the fluidized ironmaking process were studied for the fine iron Newman ore particles (0.154–0.178 mm) and the optimal experimental operating conditions were obtained. Under the optimal conditions, the effects of the coated cow dung on the reduction of fine iron ore particles were studied, and the inhibition mechanism of cow dung on particle adhesion in the fluidized ironmaking process was elucidated. The experimental results show that the optimal operating parameters are linear velocity of 0.6 m/s, reduction pressure of 0.2 MPa, reduction temperature of 1023 K, H2 as the reducing gas, and reduction time of 60 min. Cow dung can react with oxide in the ore powder to form a high melting point substance that can form a certain isolation layer, inhibit the growth of iron whiskers, and improve the fluidization.


2013 ◽  
Vol 701 ◽  
pp. 28-31 ◽  
Author(s):  
Rusila Zamani Abd Rashid ◽  
Hadi Purwanto ◽  
Hamzah Mohd Salleh ◽  
Mohd Hanafi Ani ◽  
Nurul Azhani Yunus ◽  
...  

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.


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

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1050 ◽  
Author(s):  
Guang Wang ◽  
Jingsong Wang ◽  
Qingguo Xue

The volume shrinkage evolution of a magnetite iron ore/carbon composite pellet during solid-state isothermal reduction was investigated. For the shrinkage, the apparent activation energy and mechanism were obtained based on the experimental results. It was found that the volume shrinkage highly depended on the reduction temperature and on dwell time. The volume shrinkage of the pellet increased with the increasing reduction temperature, and the rate of increment was fast during the first 20 min of reduction. The shrinkage of the composite pellet was mainly due to the weight loss of carbon and oxygen, the sintering growth of gangue oxides and metallic iron particles, and the partial melting of the gangue phase at high temperature. The shrinkage apparent activation energy was different depending on the time range. During the first 20 min, the shrinkage apparent activation energy was 51,313 J/mol. After the first 20 min, the apparent activation energy for the volume shrinkage was only 19,697 J/mol. The change of the reduction rate-controlling step and the automatic sintering and reconstruction of the metallic iron particles and gangue oxides in the later reduction stage were the main reasons for the aforementioned time-dependent phenomena. The present work could provide a unique scientific index for the illustration of iron ore/carbon composite pellet behavior during solid-state carbothermic reduction.


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