Properties Of Iron Ore Research Articles

Iron ore grade's impact on uniaxial compression behavior and acoustic emission characteristics

The mechanical properties of iron ore are influenced by various factors, including its grade, which consequently impacts stope stability and equipment efficiency in the mining process. In order to explore the influence and mechanism of grade on these properties, handheld XRF testing was conducted to determine the grade of iron ore samples ranging from 28% to 40%. Subsequently, the acoustic emission method was employed to acquire signals during the uniaxial compression tests. Additionally, scanning electron microscopy was utilized to examine the fracture surface, for performing a microscopic analysis of the influence mechanism of grade on the mechanical properties of iron ore. The results revealed that lower-grade iron ore exhibited larger transverse deformation, with a corresponding dominance of tensile failure. This observation aligned with the AF-RA value (Parameters of reaction crack type), which depicted a shift in the types of microcracks generated during the compression process from tensile cracks to shear cracks with the increasing grade. The content of gangue minerals diminishing as the grade increased. Consequently, the location of the cracks transitioned from the primary failure Through the gangue minerals to the primary microcracks in metallic minerals, resulting in a higher occurrence of acoustic emission events during the early loading stage and the development speed of microcracks accelerates during the loading process. The dominant frequency (Parameters of reaction crack size) of the acoustic emission signal increased from 150 kHz at a grade of 28% to 264 kHz at a grade of 40%, accompanied by a linear decrease in the proportion of low-frequency signals. The b value (indicator for quantifying the degree of damage) demonstrates a decrease with increasing grade. Overall, the content of metal minerals in the iron ore increased with the grade, resulting in polymerization. However, the influence of crack propagation on the overall strength of iron ore remained relatively minor. Macroscopically, the uniaxial compressive strength increased almost linearly with the iron ore grade.

Mineral Liberation Properties of Iron Ores with Different Grain Sizes by Particle-Bed Breakage and Traditional Grinding

ABSTRACT More efficient liberation of valuable minerals from gangue would bring enormous benefits to the comminution process and the downstream beneficiation processes. However, whether particle-bed breakage can improve liberation compared with traditional grinding has been controversial. In this study, three types of iron ores with 3–0.425 mm were comminuted to −0.425 mm via the piston-die compression unit or the dry ball mill at essentially the same grinding degrees. Liberation analysis was performed using Mineral Liberation Analyzer (MLA) for each breakage method and the size fraction product. Statistical methods based on bootstrap resampling and standardized mean differences (SMD) were used to quantitatively analyze the significance of differences in the liberation distribution of iron oxide minerals with different breakage methods. MLA tests showed that the particle-bed breakage did not significantly improve the liberation degree compared to the ball mill grinding; the maximum difference of the proportion of 80–100% liberated iron oxide mineral in a certain size fraction with the two breakage methods was only 5%. The SMD was less than 1.2 in most size/composition classes, which indicated that the difference in the liberation distribution of iron oxide minerals between the two breakage methods was not statistically significant in most size/composition classes. The particle-bed breakage slightly improved the liberation of iron oxide minerals compared to ball mill grinding at the particle size of the products close to the grain size of the iron oxide minerals in the feeds.

Information-modeling system for prediction of the composition and properties of final slag in a blast furnace in real time

The article considers general characteristics of the algorithm for prediction of the composition of the final slag in a blast furnace in real time. This algorithm is based on fundamental knowledge on the processes occurring in the furnace and general laws of transient processes. It allows predicting at the current moment of time and for every hour ten hours ahead. A linearized model of the blast furnace process and a natural-mathematical approach are used. The model takes into account the dynamic characteristics of blast furnaces in various impact channels, which change and depend on the type of impact, operating parameters of the furnaces and properties of the melted raw material. This makes it possible to adjust the model to operating conditions of the object, to take into account changes in the composition and properties of iron ore and coke, blast and regime parameters of blast furnace smelting when modeling. The software of the information-modeling system for prediction of the composition and properties of the final slag in a blast furnace in real time was developed in the C# programming language based on the ASP.NET MVC framework using the .NET 5 cross-platform. The web application includes the following main functions: visualization of change APCS parameters and design parameters over time; slag mode diagnostics; modeling of transient processes of composition and properties of slag; prediction of slag composition and properties in real time and prediction history. The software architecture is described and its operation is illustrated. An assessment of the accuracy and reliability of the simulation results based on statistical indicators was carried out. The root-mean-square deviation of the predicted basicity of the CaO/SiO2 slag from that measured at taps is 0.023, the prediction reliability is 92 %, which indicates a satisfactory agreement between the predicted and actual values of the content of individual components in the slag. The information modeling system developed on the basis of the presented algorithm is integrated into the information system of the blast furnace shop of PJSC Magnitogorsk Iron and Steel Works.

Studying the mechanical properties of iron ore concentrate briquettes

This paper studies the properties of metallurgical briquettes of iron ore concentrate with coke screenings and liquid glass as a binder. The briquettes are produced by one-sided pressing in a closed die mounted on the plates of a vertical press with a force of 100 kN. The studies were carried out in the laboratory of Spidermash LLC. The following properties of briquettes were determined: density, impact strength and compressive strength (for green and dry briquettes). The functional dependences of the mechanical properties on 4 parameters are plotted, namely on charge mixture composition (the content of iron ore concentrate and coke), binder (liquid glass) percentage in the mixture, moisture content in the mixture, and charge mixture compacting pressure. The obtained experimental data are approximated with the use of a multiplicative model, with the application of the least squares method. Various analytical models for describing the behavior of the material to be briquetted are studied. It is concluded that the multiplicative model provides a more adequate description of the mechanical properties. The quality of the multiple regression model is assessed by the adjusted coefficient of determination. The significance of the regression equation is evaluated by the Fisher criterion, and the significance of the regression coefficients is evaluated according to Student. The mechanical properties of briquettes from iron ore concentrate with coke screenings, presented in the form of analytical dependencies, are necessary to assess the strength of the briquettes when designing the briquetting process. For example, it is necessary to take into account the change in yield during briquette transportation after briquetting. These dependences are also necessary for formulating and solving problems of pressing/briquetting of finely dispersed materials, including iron ore concentrate with coke screenings.

Cracking and Microstructure Transition of Iron Ore Containing Goethite in Fe-C Melt Based on the HIsmelt Process

The phenomenon of cracking and deterioration of iron ore particles is a widespread scientific problem in the field of mineral processing and metallurgy. In this paper, the thermal decomposition properties of iron ore were investigated by a non-isothermal method using thermogravimetric equipment, and the crack evolution behavior of iron ore within Fe-C melt was investigated experimentally, by scanning electron microscopy and Micro-CT. The results show that the start decomposition temperature of #2 iron ore is 292.7 °C, which is 37.3 °C higher compared to that of #1 iron ore, because of its smaller pores and the difficulty of water vapor diffusion. The initial decomposition of iron ore is the decomposition goethite to form water vapor, and as heat transfer continues, hematite particles break into smaller particles and decompose to form Fe3O4. During the smelting reduction process, the Crack index (CI) of #1 iron ore was 5.50% at 4 s, and the CI index increased to 23.54% when time was extended to 16 s, and the internal evolved from locally interconnected holes to cracked structure. The iron ore maintains a relatively intact form during reduction within the Fe-C melt, and interfacial reduction reaction is dominant in the later stage.

Influence of iron ore properties on dioxin emissions during iron ore sintering

Iron ores are principal input materials for iron and steel-making industries. Quality of iron ores is one of the critical parameters for formation of environmental pollutants related to the steel-making process. Dioxins are identified as one of the most toxic pollutants emitted during ironmaking, specifically during the sintering process. This study applied four types of iron ores and analyzed their moisture, density, particle size distribution and element concentrations to investigate their effect on the dioxin formation during sintering. Each type of iron ore was processed in a sinter pot grate. During each processing route, exhausted dust and generated sinter products were collected and subjected to PCDD/F and PCB analysis. Statistical analysis was applied to assess correlations between properties of iron ores and exhausted dioxin emissions, identifying key contributors to dioxin formation during sintering process. Results showed that Fe in iron ores was positively and significantly related to PCB 114 formation in dust and confirmed its co-catalytic effect on dioxin formation. Concentrations of Al, Ti and Cl in iron ores greatly increased PCDD/F and PCB emissions in the sintered products compared to dioxins in dust samples. The S levels and density of iron ores were highly related to the increasing PCDD/F and PCB emissions in both sinter and dust samples. By contrast, concentrations of Si in iron ores played a significant role in decreasing PCDD/F and PCB emissions in both sinter and dust samples. This study also confirmed the optimum size (< 1 mm–2.59 mm) for iron ores, which helps reduce dioxin emissions without affecting the quality of iron and steel-making products.

Synergetic conversion laws of biomass and iron ore for syngas and direct reduced iron co-production

This work describes a system for the co-production of syngas and direct reduced iron (DRI) though the synergetic conversion of biomass and iron ore. Iron ore served as the oxygen carrier and catalyst for biomass gasification, while pine sawdust (biomass) served as the reducing agent for iron ore metallization during this reciprocal conversion process. The effects of conversion temperature, biomass to iron ore ratio and calcination time were investigated. A maximum syngas yield of 72.6% (valid gasification ratio for H and C were 68.8% and 72.7%, respectively) was obtained when biomass was gasified with iron ore (mol ratio C/Fe = 0.8) at 1000 °C for 30 min. DRI with a metallization ratio (MR) of 93.8% was produced concomitantly. The lattice oxygen and catalytic properties of iron ore promoted (i) the conversion of tar and char components into syngas and (ii) the cracking of hydrocarbons into CO and H2. Volatiles derived from biomass enhanced iron ore metallization by accelerating the reduction rate, and bio-char ensured a high MR of the final DRI. The conversion pathway for this was also elucidated. Volatiles and ∼35% of the char reacted with iron ore in the first 10 min to produce all of the H2 in the final syngas and some of the CO. The remaining 65% of the char was gasified in the next 20 min to generate the rest of the CO. The lattice oxygen of iron ore played the key role in early gasification, and the fresh metallic iron played a key role in the subsequent catalysis. This co-conversion approach described herein has potential applications in green fuel gasification or DRI processes.

A Short Review of the Effect of Iron Ore Selection on Mineral Phases of Iron Ore Sinter

The sintering process is a thermal agglomeration process, and it is accompanied by chemical reactions. In this process, a mixture of iron ore fines, flux, and coal particles is heated to about 1300 °C–1480 °C in a sinter bed. The strength and reducibility properties of iron ore sinter are obtained by liquid phase sintering. The silico-ferrite of calcium and aluminum (SFCA) is the main bonding phase found in modern iron ore sinters. Since the physicochemical and crystallographic properties of the SFCA are affected by the chemical composition and mineral phases of iron ores, a crystallographic understanding of iron ores and sintered ore is important to enhance the quality of iron ore sinter. Scrap and by-products from steel mills are expected to be used in the iron ore sintering process as recyclable resources, and in such a case, the crystallographic properties of iron ore sinter will be affected using these materials. The objective of this paper is to present a short review on research related to mineral phases and structural properties of iron ore and sintered ore.

Natural hematite properties of Lampakuk, Aceh Besar iron ore extracted by precipitation method

In this paper, the mineral content and its magnetic properties of iron ore from Lampakuk iron ore area, Aceh province were studied. The iron ore was prepared by co-precipitation method. As the results, the main mineral and chemical compositions of samples which were investigated by XRD and XRF analysis tests, showed that the Lampakuk iron ore contain Fe2O3 (86.8188%) and some minor impurities, such as SiO2, MnO, and Al2O3 in varying proportions. Compare to XRD results, it was consistent with XRF, the phase compositions of iron ore are mainly hematite (Fe2O3). The XRD revealed that hematite is the major mineral components in the Lampakuk iron ores. The magnetic properties of the samples after milling showed there has been increased in the remanent (Br) and coercivity (Hc), while the magnetic saturation (Ms) was decreased. The electron microscope identification inform that the particle were agglomerated.

An assessment of Blaine’s air permeability method to predict the filtration properties of iron ore concentrates

The design of new filtration equipment and its further insertion into full-scale industrial use requires to perform a filtration-testing project. Usually, a complete, standard project depends on the transportation of a significant amount of test materials to a remote laboratory or moving and adjusting a pilot-scale filter directly in the plant area. These transportation expenses can affect the cost of the entire testing project dramatically. Additionally, maturing mining technology and the gradual depletion of mineral deposits have led to the continually growing costs of available sample materials. Suppliers of filtration equipment are actively searching for new testing methodologies to be able to design full-scale equipment with a minimum testing time, cost, and sample size. This paper investigates the applicability of simple particle size testing equipment – a Blaine’s air permeability apparatus – for the estimation of the filtration behavior of iron ore concentrates from samples as small as just a few grams. The results of experiments performed with mixtures of iron concentrates showed that the testing equipment, along with proposed methodologies with regression equations and empirically determined parameters, could be applicable for rough and express estimation of average specific cake resistance.

A STUDY ON THE EXAMINATION OF THE SINTER METALOGRAPHIC STRUCTURE

Sintering process is carried out domestic and imported iron ore powders, fluxes (limestone, dolomite etc.), coke dust, metallurgical recycling powders and slag forming agents. The purpose of the sintering process is to produce a charging material with suitable thermal, mechanical, physical and chemical properties that can be fed into the blast furnace. Nowadays, in order to obtain process and operating parameters that will work with the best sinter quality, extensive researches have been made by iron and steel industry. The sinter quality parameters followed by the sinter blend loaded on the sinter strand and then granulated were examined. In the sintering process, the temperature rises to 1450 oC, partially melting between the sinter grains and a series of reactions take place in the sinter matrix to be charged into the blast furnace to produce liquid crude iron. Many different approaches have been used to estimate sinter quality, to explain the effects of iron ore properties and process variables on sintering mechanisms, and to characterize sinter mineralogy of iron ore. We can obtain chemical analysis of the phases by scanning electron microscopy (SEM) technique, but full consistency with images is not always possible and especially SFCA (silico-ferrite of calcium and aluminium) and SFCA-I phases are difficult to distinguish from each other and future studies are required in this field. The mineralogy and microstructure of the sinter plays an important role in determining the physical and metallurgical properties of the iron ore sinter. Mineralogical characterization of sinter phases; it is a complementary tool to conventional physical and metallurgical tests applied to iron ore sinter to evaluate and estimate sinter quality. Measurement techniques used in this study; optical image analysis and X-ray diffraction (XRD), scanning electron microscopy (SEM), energy distribution spectroscopy (EDS), the results from raw data converted to autoquan format will be explained on the new studies on the interpretation of the Rietveld system. Depending on the measurement objectives of each technique, the quantification of the crystal phases, the relationship between the measurement results, the chemical composition of the phases and the relations between the minerals, as well as their advantages and disadvantages will be explained.

Study of hematite mineral (Fe2O3) extracted from natural iron ore prepared by co-precipitation method

The minerals content and its magnetic properties of iron ore from Lhoong mining area, Aceh province were studied. The iron ore was prepared by co-precipitation method. As the results, the main mineral and chemical compositions of samples which were investigated by XRD and XRF analysis tests, showed that the Lhoong iron ore contain Fe2O3 (93.88%) and some minor impurities, such as SiO2, MnO, and Al2O3 in varying proportions. Compare to XRD results, it was consistent with XRF, the phase compositions of iron ore are mainly hematite (Fe2O3). The XRD revealed that hematite is the major mineral components in the Lhoong iron ores. The magnetic properties of the samples after milling showed there has been increased in the remanent (Br) and coercivity (Hc). The electron microscope identification inform that the particle were agglomerated.

Effect of molasses binder on the physical and mechanical properties of iron ore pellets

Molasses was used as an alternative binder to the bentonite binder. The change in moisture absorption by pellets prepared with different iron ores and different molasses contents were investigated. Iron ore properties exerted the major effect on pellet behavior and final pellet quality. The absorbed moisture content of pellets prepared without binder, bentonite-added pellets, and molasses-added pellets were in the range of 7.72%–9.95%, 9.62%–10.84%, and 6.14%−6.69%, respectively. The wet pellet compressive strength of molasses-added pellets (43–230 N/pellet) was superior to that of bentonite-added pellets (9.47–11.92 N/pellet). The compressive strength of dried molasses-modified pellets increased to 222–394 N/pellet, which is currently the highest value achieved for dried pellets.

Chemical, physical, thermal, textural and mineralogical studies of natural iron ores from Odisha and Chhattisgarh regions, India

The chemical, physical, thermal and texture properties of iron ores from different regions of Odisha and Chhattisgarh regions, India, have been investigated to understand the compositional variations of Fe, Al2O3, SiO2, S and P. They were analyzed for its susceptibility to meet the industrial requirements, for various iron manufacture techniques. Chemical analysis indicated that the majority of the iron ores is rich in hematite (> 90 wt%), poor in gangue (<4.09 wt% SiO2 and <3.8 wt% Al2O3) and deleterious elements (P<0.065 wt% and S<0.016 wt%) in all these iron ores found to be low. XRD peaks reviled that the gangue is in the form of kaolinite and quartz, and same was observed in Fourier transform infrared (FTIR) spectroscopy in the range of 914 to 1034 cm–1. The iron ores were found to have excellent physical properties exemplify with tumbler index (82 wt%–91 wt%), abrasion index (1.27wt%–4.87 wt%) and shatter index (0.87wt%–1.64 wt%). FTIR and thermal analysis were performed to assimilate the analysis interpolations. It was found that these iron ores exhibit three endothermic reactions, which are dehydration below 447 K with mass loss of 0.13 wt% to 1.7 wt%, dehydroxylation at 525–609 K with mass loss of 1.09 wt%–4.49 wt% and decomposition of aluminosilicates at 597–850 K with mass loss of 0.13 wt%–1.15 wt%. From this study, we can conclude that due to its excellent physico-chemical characteristics, these iron ores are suitable for BF and DRI operations.

Study of the Magnetic Properties of Haematite Based on Spectroscopy and the IPSO-ELM Neural Network

The detection of the magnetic properties of haematite plays an important role in the adjustment of the beneficiation process of haematite and the improvement of metal recovery. The existing methods for measuring the magnetic properties of iron ore either have large errors or take a long time. Therefore, it is very necessary to find a method that can quickly and accurately detect the magnetic properties of haematite. This paper presents a method to detect the magnetic properties of haematite based on the extreme learning machine based on the improved particle swarm optimization (IPSO-ELM) algorithm and spectroscopy. The improved particle swarm optimization algorithm is used to optimize the input weights, hidden layer deviations, and hidden layer nodes of the ELM network. Introducing the linear decreasing inertia weight for the particle swarm algorithm, taking into account the norm of the output weight in the particle update process and using the variation idea to change the length of the particle give the IPSO-ELM better stability and generalization ability. The experimental results show that the IPSO-ELM prediction model has a good prediction performance and has better generalization ability than that of the ELM and PSO-ELM prediction models. Compared with traditional chemical analysis methods and manual methods, this method has great advantages in terms of economy, speed, and accuracy.

Prediction of rotary drilling penetration rate in iron ore oxides using rock engineering system

Prediction of the drilling penetration rate is one of the important parameters in mining operations. This parameter has a direct impact on the mine planning and cost of mining operations. Generally, effective parameters on the penetration rate is divided into two classes: rock mass properties and specifications of the machine. The chemical components of intact rock have a direct effect in determining rock mechanical properties. Theses parameters usually have not been investigated in any research on the rock drillability. In this study, physical and mechanical properties of iron ore were studied based on the amount of magnetite percent. According to the results of the tests, the effective parameters on the penetration rate of the rotary drilling machines were divided into three classes: specifications of the machines, rock mass properties and chemical component of intact rock. Then, the rock drillability was studied using rock engineering systems. The results showed that feed, rotation, rock mass index and iron oxide percent have important effect on penetration rate. Then a quadratic equation with 0.896 determination coefficient has been obtained. Also, the results showed that chemical components can be described as new parameters in rotary drill penetration rate.

МЕТОДЫ ВЫБОРА РАЦИОНАЛЬНОГО СОСТАВА ДОМЕННОЙ ШИХТЫ

The aim of the work is to solve the problem of choosing the optimal composition of iron ore materials for blast furnace loading. An analytical review of the existing approaches to assessing the quality and methods for selecting a rational composition of iron ore materials implemented as part of the control system of domestic and foreign blast furnaces in modern conditions has been carried out. A method of modeling the processes of directional formation of melts, developed at the Iron and Steel Institute, is proposed. The description of the processes of transformation of iron ore materials in a blast furnace and the properties of liquid smelting products was carried out using the parameters of interatomic interaction in melts. The technique uses a set of integral criteria and physicochemical models that allow estimating charge, gas-dynamic and temperature melting conditions. The influence of the quality of iron ore on the properties of primary melts and final products of blast-smelting is analyzed. An integral indicator of the quality of the charge and an integral indicator of the temperature blast mode have been developed. The main difference of the proposed approach to the selection of the composition of the charge from similar developments focused on the traditional criterion «basicity of the final slag» is the use of a set of physico-chemical criteria that characterize the quality and properties of iron ore, primary and final blast furnace slag. The use of the developed prognostic models and criteria as part of automated blast furnace control systems allows us to predict the chemical composition of iron and slag. Stabilization of slag properties within the specified limits ensures the smelting of cast iron of the required composition and a reduction in coke consumption in the current unstable conditions of smelting iron.

Recovery and separation of iron from iron ore using innovative fluidized magnetization roasting and magnetic separation

In this investigation, a pilot-scale fluidized magnetization roasting reactor was introduced and used to enhance magnetic properties of iron ore. Consequently, the effects of roasting temperature, reducing gas CO flow rate, and fluidizing gas N2 flow rate on the magnetization roasting performance were studied. The results indicated that the hematite was almost completely converted into magnetite by a gas mixture of 4 Nm3/h CO and 1 Nm3/h N2 at roasting temperature of 540?C for about 30 s. Under optimized conditions, a high grade concentrate containing 66.84% iron with iron recovery of 91.16% was achieved. The XRD, VSM, and optical microscopy (OM) analyses revealed that most of the hematite, except some coarse grains, was selectively converted to magnetite, and that the magnetic properties were greatly enhanced. Thus, their separation from non-magnetic gangue minerals was facilitated.

Prediction of Iron Ore Sinter Properties Using Statistical Technique

Due to the drastic change in iron ore qualities, maintaining consistency in sinter property has become a challenge for steel manufacturing industries, resulting the irregularities and disturbances in the blast furnace iron making. The present work aimed to develop a prediction model for physical, mechanical and high temperature properties of iron ore sinter well in advance from the plant process parameters to support smooth functioning of the furnace. Correlation matrix, multiple linear regression and artificial neural network (ANN) analysis were performed for the development of the model. This predictive system for three important sinter properties [Mean particle size (MPS), tumbler index (TI) and reduction degradation index (RDI)] was established based on back propagation (BP) neural network, which was trained and tested by actual plant data. The prediction accuracy of MPS, TI and RDI using that ANN model is 79, 91 and 76 %, respectively. A user-friendly graphical user interface has been developed using C language based on the model. The application results showed that the prediction system had high accuracy rate, stability and reliability.

Correlating mechanical properties of sinter phases with their chemistry and its effect on sinter quality

In this study, pot sinter tests were carried out to study the sintering properties of iron ores of different alumina (2–4–6%) level. It was observed that the 6% alumina level ores have a higher RDI values and decreased tumbler index (TI) compared to its other two counterparts. It was observed that an increase in composite fracture toughness (CFT) of sinter improves the Tumbler as well as RDI of the sinter. Beyond 4 CFT there is remarkable improvement in TI, RDI and RI values. The mechanical strength parameters of sinter phases were further correlated and analysed with respect to the chemistry of sinter and mineralogy of sinter phases. There is strong evidence which suggests that the Al2O3 deteriorates the strength of the phases by making them hard and thus generating cracks in them. Unlike alumina, CaO and SiO2 tend to stabilise and improve the strength of the phase.