Kinds Of Iron Ores Research Articles

Direct reduction of iron-ore with hydrogen in fluidized beds: A coarse-grained CFD-DEM-IBM study

Hydrogen metallurgy technology uses hydrogen as the reducing agent instead of carbon reduction, which is one of the important ways to reduce carbon dioxide emissions and ensure the green and sustainable development of iron and steel industry. Due to the advantages of high gas-solid contact efficiency and outstanding mass and heat transfer, direct reduction of iron ore in fluidized beds has attracted much attention. Based on the three-layer unreacted shrinking core model and considering the diversity of particle structure during the reaction process, a multi-reaction path (multi-resistance network) model was established. In this study, a coarse-grained CFD-DEM-IBM solver based on hybrid CPU–GPU computing is developed to simulate the direct reduction process of two kinds of iron ore with hydrogen in fluidized beds, where the developed unreacted shrinking core model is used to model the reduction reactions, a coarse-grained model and multiple GPUs enable the significant acceleration of particle computation, and the immersed boundary method (IBM) enables the use of simple mesh even in complex geometries of reactors. The predicted results of particle reduction degree are in good agreement with the experimental values, which proves the correctness of the CFD-DEM-IBM solver. In addition, the effects of reaction kinetic parameters and operating temperature on particle reduction degree are also investigated. Present study provides a method for digital design, optimization and scale-up of ironmaking reactors.

Iron ore or manganese ore filled constructed wetlands enhanced removal performance and changed removal process of nitrogen under sulfamethoxazole and trimethoprim stress.

Iron ore and manganese ore were used as substrate of constructed wetlands (CWs) to enhance nitrogen (N) removal. However, the N purification performance in CWs filled with iron or manganese ore under antibiotics stress needs further study. In this study, three groups of CWs filled with river sand, limonite (a kind of iron ore), and manganese ore sand were constructed, which were named as C-CWs, Fe-CWs, and Mn-CWs, respectively. The effect and mechanism of the composite antibiotics sulfamethoxazole (SMX) and trimethoprim (TMP) on N removal in CWs were investigated. While the addition of SMX and TMP inhibited about 40% nitrification and promoted about 25% denitrification in all CWs, Fe-CWs and Mn-CWs always had better N removal performance than C-CWs. Changes in microbial community structure in CWs indicated that the better N removal performance in Fe-CWs and Mn-CWs was attributed to the presence of more abundant and diverse N-associated bacteria, especially Fe- and Mn-driven autotrophic denitrifying bacteria. What's more, the addition of iron ore or manganese ore contributed to the better N removal performance with highest relative abundance of N-transferring bacteria under antibiotics stress.

Comprehensive evaluation of sintering basic characteristics of iron ore based on grey relational analysis

Sintering basic characteristics of fourteen iron ores were comprehensively evaluated using micro-sinter and grey relational analysis methods. The results show that magnetite has a low assimilability, high bonding phase strength, and high crystal strength. Hematite presents a good assimilability, while limonite exhibits a strong assimilability, but the bonding phase strength and crystal strength of these two kinds of iron ores are comparatively low. Great difference in liquid flowability exists for the same kind of iron ores. When the assimilation temperature of the sinter mixture is too high, limonite can be added; when the bonding phase strength or crystal strength of the sinter mixture is too low, magnetite can be added. The liquid fluidity of the sinter mixture can be adjusted according to the ratios of corresponding iron ores. Grey relational analysis is an effective method to evaluate the comprehensive sintering characteristics of iron ores, which can provide theoretical basis for the purchasing department of the steel enterprises.

Development of heat-transfer circuits in the blast furnace

The development of heat-transfer circuits in the blast furnace as the technologies of blast-furnace smelting are improved are considered. It is shown that there are two zones of intense heat-transfer, and in modern conditions, when different kinds of iron ore are smelted, the use of combined blast with high parameters is a prerequisite for the stability of blastfurnace smelting operation and the smelting efficiency.

The control of H2S in biogas using iron ores as in situ desulfurizers during anaerobic digestion process.

In this study, five kinds of iron ores, limonite, hematite, manganese ore, magnetite and lava rock, were used as the in situ desulfurizers in the anaerobic digestion reactors to investigate their effects on controlling H2S in biogas. The results show that the addition of the five iron ores could significantly control the content of H2S in biogas, with the best performance for limonite. As limonite dosages increase (10-60g/L), the contents of H2S in biogas were evidently decreased in the digesters with different initial sulfate concentrations (0-1000mg/L). After the anaerobic digestion, the removed sulfur was mostly deposited on the surface of limonite. A possible mechanism of H2S control in biogas by limonite was proposed preliminarily, including adsorption, FeS precipitation, and Fe (III) oxidation. The results demonstrated that limonite was a promising in situ desulfurizer for controlling H2S in biogas with low cost and high efficiency.

Experimental smelting of iron ores from Elba Island (Tuscany, Italy): Results and implications for the reconstruction of ancient metallurgical processes and iron provenance

Iron deposits from Elba Island (Tuscan Archipelago) were extensively exploited since the 1st millennium BC: both raw iron ore and smelted blooms were extensively traded through the Mediterranean region. Within the frame of the multidisciplinary research Project “AITHALE” (from the Greek name for Elba Island), we have performed a series of archaeometallurgical experiments primarily to investigate the traceability of Elban iron ores during the various steps of the chaîne opératoire of bloomery iron production. Results of experiments performed both in the field (reconstruction of a bloomery furnace) and in the laboratory (smelting experiments carried out in a gas mixing furnace) are discussed in the text. Slags produced by smelting of W-Sn-rich iron (hematite) ores, like those from Elba island, show the presence of these elements in phases of their own, either relic (scheelite, ferberite, cassiterite) and/or newly formed (iron-tin alloys). Iron bloom obtained from this kind of iron ore could also bear evidence of the peculiar geochemistry of smelted ore, with tungsten preferentially associated with slag inclusions and tin eventually enriched in the metallic phase.

Effects of Iron Ores on the Pyrolysis Characteristics of a Low-Rank Bituminous Coal

This work investigates the effects of two kinds of iron ore on the pyrolysis characteristics of a low-rank bituminous coal from Hami, China. The pyrolysis and its product distribution were studied using a thermogravimetric analyzer and a fixed bed reactor. A gas chromatograph and a gas chromatograph–mass spectrometer were employed to test the properties and composition of the pyrolytic products. Results showed that the pyrolysis temperature of the raw coal ranged mainly from 350 to 650 °C. The weight-loss rate reached a maximum of 6.95%/min at 443 °C. The weight loss was 44.27% at the final pyrolysis temperature of 750 °C. The tar yield of raw coal was 9.51% in the fixed bed reactor at 600 °C. Adding iron ore, which was intended for a lower tar yield and a higher fraction of light tar (boiling point <360 °C), had a catalytic effect on the pyrolysis of raw coal. With separate addition of hematite and specularite, both having a mass of 20% of the raw coal, coal weight loss increased by 3.86% and 5.56%, resp...

水素還元によって得られた純鉄中の不純物の熱力学

Hydrogen itself is not a primary energy and needs an energy for its production, which means that CO2 will be exhausted during the production process, more or less. However, when a Green Hydrogen can be produced, it is a best way to use the hydrogen instead of carbon.In this study, two kinds of iron ore were reduced and melted both under hydrogen and carbon atmosphere. The obtained iron metal under hydrogen atmosphere was quite pure one. The impurities in the metal were chemically and thermodynamically analyzed. The characteristics and benefits of hydrogen reduction were discussed in comparison with the carbon reduction.The content of silicon in the metal under hydrogen atmosphere was one tenth to the iron obtained by carbon reduction. Manganese was about one third to one tenth against the carbon reduction. However, phosphorus in the hydrogen reduction was almost the same level to the carbon reduction. Sulfur content became half in the hydrogen reduction. Moreover, the content of hydrogen in the metal was the same level between the hydrogen reduction and the carbon reduction. It was found that the rate of hydrogen evolution from a molten metal during solidification was fast significantly. The activities of elements in the metal were calculated through the thermochemical data, and the relationships among those elements were elucidated.From the thermodynamic analysis, a high oxygen activity in the metal obtained under hydrogen atmosphere caused to a low content of impurities and high activity of oxides related.

An intelligent integrated optimization system for the proportioning of iron ore in a sintering process

The proportioning of iron ore is the first step of the sintering process. It mixes different kinds of iron ores with coke, limestone, dolomite, and returned sinter to produce a raw mix for the production of qualified sinter. The chemical components and proportions of the raw materials determine the chemical and physical characteristics of the resulting sinter, and thus the quality of the sinter and the amount of SO2 emissions. The prices of the raw materials and their proportions determine the price of the sinter. In this study, an intelligent integrated optimization system (IIOS) was developed for the proportioning step, which contains two phases: the first and second proportionings. First, the sintering process was analyzed, and the requirements of the proportioning step were specified. Next, an IIOS with two levels (intelligent integrated optimization, basic automation) was built. In the intelligent integrated optimization level, an intelligent integrated optimizer (IIO) produces an optimal dosing scheme. The IIO has three parts: a cascade integrated quality-prediction model, the optimization of the first proportioning, and the optimization of the second proportioning. Computational intelligence methods predict the quality of sinter. Then, the predicted quality indices are fed back to the optimizations of the first and second proportionings to find feasible optimal dosing schemes. The IIOS was implemented in an iron and steel plant. Actual runs show that the system reduced production costs by 43.014CNY/t and SO2 emissions by 0.001% on average.

Characterization and Concentration Studies of Jalal Abad Iron Mine / Charakterystyka I Badania Koncentracji W Kopalni Rud Żelaza Jalal Abad

Abstract Characterization and determination of liberation degree are the first stages of ore dressing. Block 4 of Jalal Abad mine, Kerman province, Iran, has three kinds of iron ores; D1, D2 and D3, with different grades. In this research, chemical analysis, mineralogy, liberation degree and magnetic enrichment studies were done by XRF, XRD, microscopic sections and Davis tube, respectively. The results indicated that D1, D2 and D3 had average iron grades of 58, 52 and 38%, respectively. The minerals of Magnetite, Hematite, Dolomite, Calcite and Quartz were distinguished. Average liberation degree was estimated about 500 μm by Microscopic studies. The results of magnetic tests showed that iron grade of D1, D2 and D3 concentrates increased to 70.46, 63.98 and 45.37%, respectively. The optimization of blending was investigated for production of accumulated concentrate with desirable iron grade (68%) using MATLAB software.

Rules of Assimilation of Single Ore and Mixed Ores

Assimilation behaviors of 7 kinds of iron ores from Australia, Brazil, India, South Africa and China were evaluated and analyzed. On the basis of that, four ore blending principles were proposed, and seven groups of iron ore powder blending schemes were designed. The ores of different types or from different places are shown apparently different in assimilation. The assimilation of hematite in Australia, Brazil and India is relatively high, but the assimilation of magnetite in South Africa and China and specularite in China is relatively low. The assimilation of the ores has negative correlation with MgO content and binary basicity, while the assimilation of the ores has positive correlation with porosity, SiO2 and Al2O3 contents, and crystal water. The iron ores with smaller crystal size and microstructure looseness have relatively higher assimilation. Assimilation of mixed ores has relationship of linear, arch and “S” types to the ratio of single iron ore powder. When the charge ratio of ore is less than 25%, it possesses additivity, providing theoretical basis for optimization of ore matching.

Separation of Weak Magnetic Iron Ore with Micro-Fine Particle

In this paper, separation of weak magnetic iron ore with micro-fine particle was summarized on the base of the reason why this kind of iron ore was so difficult to be used. The methods used now for the fine particle separation were narrated. Four aspects were proposed to utilize the resource with high efficient.

Mixed State and High Effective Utilization of Pilbara Blending Iron Ore Powder

Pilbara blending iron ore powder (PB powder) is blending ores with good and poor quality iron ores, so how to use PB power effectively is a problem. The self-characteristics of PB powder and its single-components were studied respectively, such as the macroscopic properties, microscopic properties, and high-temperature properties; the behavior and effect in the sintering were mastered. Then based on the new ore-proportioning idea of iron ores sintering characteristics complementary, the principles on the effective use of PB powder were discussed, and was further validated through the sintering pot test and industrial production. The results show that; PB powder is composed of three kinds of iron ore, and the sintering characteristics of different iron ores are obviously discrepant. With the ore-proportioning optimization based on the iron ores sintering characteristics complementary, the proportion of PB iron ore powder can be increased to more than 455%.

炭材内装塊成鉱の反応挙動に及ぼす鉄鉱石および石炭性状の影響

Four kinds of carbon composite iron ore briquette (CCB) were made by mixing two kinds of iron ores and coals that have different properties such as hematite, magnetite, fluidity and non-fluidity coal. The reaction behavior of those CCB was examined at the temperatures of 1273–1473K in N2 gas atmosphere. The effect of iron ore and coal properties on reaction behavior of CCB was investigated. In the case of CCB that mixed fluidity coal, gasification and reduction rates of the CCB were fast because the contact of iron ore and coal improved. In the case of CCB that mixed hematite ore, reduction rate of the CCB was fast because the reduction rate of hematite ore is faster than that of magnetite ore. Therefore, the reaction rate of CCB that mixed fluidity coal and hematite ore was the fastest in samples.

エチオピア西南部における伝統製鉄技術の冶金学的検証

An abandoned traditional steelmaking in Southwest Ethiopia (Dime) has been restored, and the technology and knowledge used for the operation have been metallurgically analyzed. The restoration was carried out with local blacksmiths from September to October in 2004, and the steelmaking operation including mining, construction of a furnace and charcoal production, etc was successfully performed. Produced sponge iron contains 0.31∼0.48 mass% carbon without any impurities. The yield ratio of the iron was about 40%. The collected slag contains the elements of Fe, Si, Al, K, P, Ti and Mn, which are typical components of slag. The blacksmiths used three kinds of iron ore, named “Balt”, “Bullo” and “Gachi”. The former two ores mainly consist of goethite (α-FeO(OH)) and kaolinite (Al2O3•2SiO2•2H2O). The latter includes calcium phosphate hydrate (Ca3(PO4)2•xH2O) in its white part, as well as the goethite and kaolinite. The reason why the local blacksmiths specifically selected “Gachi” as the best ore for their steelmaking was discussed from the viewpoint of slag forming ability.

鉄鉱石の造粒に及ぼす添加水分量と濡れ性の影響

As the fundamental study for determining the optimum moisture content for granulated particle, the contact angle between iron oxide and water was measured by the sessile drop method using reagent hematite samples that have different porosity and five kinds of iron ores. The granulation experiment was conducted by using five kinds of iron ores and the effects of adding moisture and wettability on the granulation property were investigated. The contact angle of reagent hematite sample and iron ore became large as the surface roughens becomes large. Therefore, the wettability between iron oxide and water greatly influenced the surface roughness of iron oxide. When iron ore with high wettability was used for nuclei particles, it can be granulated under all conditions in this study. On the other hand, when iron ore with low wettability was used for the nuclei particles, it was remained some fine iron ore particles without granulating. Therefore, when iron ore with low wettability was used for the nuclei particles, it was necessary to increase the adding moisture in order to improve the granulation property of fine particles. The fracture strength increased with decreasing the contact angle without regard to the kind of iron ore using for nuclei particles. Consequently, It was necessary to increase the adding moisture in order to improve the fracture strength.

Effect of Adding Moisture and Wettability on Granulation of Iron Ore

As the fundamental study for determining the optimum moisture content for granulated particle, the contact angle between iron oxide and water was measured by the sessile drop method using reagent hematite samples that have different porosity and five kinds of iron ores. The granulation experiment was conducted by using five kinds of iron ores and the effects of adding moisture and wettability on the granulation property were investigated. The contact angle of reagent hematite sample and iron ore became large as the surface roughens becomes large. Therefore, the wettability between iron oxide and water greatly influenced the surface roughness of iron oxide. When iron ore with high wettability was used for nuclei particles, it can be granulated under all conditions in this study. On the other hand, when iron ore with low wettability was used for the nuclei particles, it was remained some fine iron ore particles without granulating. Therefore, when iron ore with low wettability was used for the nuclei particles, it was necessary to increase the adding moisture in order to improve the granulation property of fine particles. The fracture strength increased with decreasing the contact angle without regard to the kind of iron ore using for nuclei particles. Consequently, It was necessary to increase the adding moisture in order to improve the fracture strength.

Reactivity and durability of iron oxide high temperature desulfurization sorbents

As iron oxide high-temperature desulfurization sorbents, eight kinds of iron ores and sorbents prepared from iron ore powder and blast furnace dust using binder were examined. SiO 2 , TiO 2 , and Al 2 O 3 were used as binders. The potential of these sorbents to remove H 2 S was tested before and after activation with H 2 , and also their mechanical strength (compressive strength) was measured. Reactivity of iron ore was not correlated to its compressive strength, but the compressive strength of the iron ore was roughly correlated to its bulk density. SiO 2 was useful as a binder. Na present as an impurity in SiO 2 binder induced localization of SiO 2 in the pellet at the high temperature calcination step

Grinding of mixtures of coal and iron ore in order to prepare material for coal liquefaction

Ball mill tests on the laboratory scale were carried out in order to prepare materials for coal liquefaction. The samples used were coal, iron ore and mixtures of these materials. The reason why an iron ore was selected as a component of the binary mixture is that, sometimes, some kinds of iron ore have been used as a disposable catalyst in a reaction of coal liquefaction and its mechanical properties and grindability are not similar to those of coal. In a simultaneous grinding of a mixture of these materials, iron ore had the effect of fine grinding of the coal. It was found that simultaneous grinding was a feasible method of preparation of feed material for coal liquefaction.

熱間に於ける鐵鑛石並に耐火爐材の瓦斯通氣率の變化 (其一)

An arrangement for measuring the behavior of the permeability of gas as the temperature of the specimen rises up to 800°C continuously, the specimens measured being eight iron ores and five types of refractory brick. Some of the important results are as follows:(1) The gas permeability decreases with the temperature in the logarithmic power if the expansion of the specimen increases linearly as temperature rises, this comes to the contrary to the common idea that the pores would open as the specimen expands.(2) The course of the gas permeability curve can be classified in three types from the results measured with the eight iron ores, such as limonitic, hematic, and magnetic type, which would be characterized due to the nature of original formation of the specimen, but not the kind of iron ore.(3) The limonite is generally most permeous to gas up to 800°C, hematite comes next to it, and the magnetite is most impermeous, the ratio of the permeability for the three types of iron ore being about the order of 100-10000 for the limonite, 1-10 for hematite, and 0-1 for magnetite.(4) From the measuring of the permeability with the preheated ore up to 800°C before the test, it is found that to be subjected to preheating is very effectual treatment for the iron ore, for it increases in some cases as much ten times as the original raw ore.