Iron Ore Particles Research Articles

Behavior and Kinetic Mechanism Analysis of Dissolution of Iron Ore Particles in HIsmelt Process Based on High-temperature Confocal Microscopy

In this study, high-temperature confocal microscopy (HTCM) was used to perform in situ observations of the dissolution of iron ore particles in slag at different temperatures. Moreover, the shrinking core model (SCM) is used to explain the kinetic mechanism of the dissolution of iron ore particles. The area of the undissolved fraction of iron ore particles was used to analyze the dissolution rate of iron ore particles. The results show that the kinetic mechanism of dissolution of iron ore particles can be well explained by the SCM. The dissolution of iron ore particles is controlled by the diffusion of iron ore fractions in the boundary layer. The dissolution temperature, the concentration difference of iron ore fraction at the two ends of the boundary layer, and the initial particle size of iron ore particles affect the dissolution rate of iron ore particles. The dissolution rate constant was fitted by introducing a dissolution mechanism. The activation energy of iron ore dissolved in the CaO–SiO2–MgO–Al2O3–FeO slag system is 679.13 kJ/mol. The equation for the dissolution rate constant of iron ore in HIsmelt slag is summarized.

Experimental investigation of the impact breakage characteristics between grinding media and iron ore particle in ball mills

The particle breakage of the ball mill is an extremely complicated breakage process. It is difficult to quantify and describe the particle breakage behavior. In this study, a drop-ball experimental setup was developed to demonstrate the impact process of grinding media on ore particles. The quantitative analysis of the effects of particle size, impact energy, and the number of impacts on particle breakage behavior was performed separately. The results show that the breakage probability model and product size distribution model used can be excellent to predict the particle breakage behavior for the single-particle impact experiments. The breakage probability of particles is highly sensitive to impact energy and particle size, exponentially increasing with the increase of impact energy. In addition, the application of the tn-t10 relationship provides a convenient means to characterize and predict the particle size distribution. In multi-layer particle impact experiments, the captured thickness of ore particles is approximately 2 layers during the crushing process. The broken mass of iron ore particles is proportional to the number of concessive impacts at different impact energies. This paper provides theoretical and methodological support for the evaluation and optimization of particle breakage in ball mills.

Novel 3D analysis of reduction behavior of single iron-oxide particle in CO-CO2 gas atmosphere

The production of steel, which is achieved by the reduction of iron ores mainly through indirect reduction reactions in a blast furnace, is gradually increasing worldwide. Because the reducing gas diffuses three-dimensionally, irregular particle shapes influence the reduction through differences in the diffusion length. The analysis of actual irregularly shaped iron-ore particles using existing models is difficult because they are primarily effective for 1D systems. Therefore, a novel reduction model based on the 3D diffusion equation that accommodates irregular particle shapes and 3D systems was developed in this study. The established model was validated by reproducing experimental conditions and comparing the quantified effective diffusivity and chemical reaction rate constant using the shrinking core model. In addition, the model was used to investigate the reducing behavior of an actual sintered-ore particle and the effects of particle sphericity and macro pore content. The sintered-ore particle had a higher reduction rate than that of a spherical equivalent with the same volume because sections of the surface with shorter diffusion lengths facilitated the gas diffusion. Additionally, the particle sphericity was determined to be inversely proportional to the reduction rate because the rate of gas diffusion into the particle depended on the diffusion length. With respect to porous particles, the gas was found to readily diffuse into the particles through pores, leading to a higher reduction rate for higher pore numbers. Overall, the gas diffusion was confirmed to drive the reduction reaction.

EXPLORING THE ROLE OF A BIO-SURFACTANT IN THE STABILIZATION OF HIGHLY CONCENTRATED IRON ORE SLURRY

The formulation and stabilization of highly concentrated solid-water slurry for transportation are gaining high interest. The influence of saponin extracted from A. auriculiformis on the stabilization of a high-grade iron ore sample in the slurry was studied. The collected iron ore powder and dried iron ore slurry samples were compared with the help of UV-vis, XRF, XRD, SEM, and EDS analysis. Moreover, the DSC spectral graph for both heat flow and mass loss with respect to time is plotted. The results confirmed that the surfactant molecules (aqueous A. auriculiformis) coated well on the iron surface which form an effective barrier between the iron ore particles. Further, the solubility of iron ore powder increased after adding an aqueous extract of Acacia auriculiformis as evident from the UV-vis spectral study.

Influence of Surfactant for Stabilization and Pipeline Transportation of Iron Ore Water Slurry: A Review.

Iron ore is generally transported using a traditional method that releases significant amounts of dust into the environment. In contrast, the pipeline transportation of slurry is noticeably a sustainable approach for efficiently transporting iron ore by reducing the environmental pollution. The interparticle interaction of the iron ore particles should be mutually repulsive for steady dispersion. Surfactants and polymers adsorb efficiently at the solid/liquid interface due to their amphiphilic character, rendering the surface hydrophilic or hydrophobic to create a stable dispersion. The present review discusses the interaction of surfactants on the stabilization of solid particles for the ease of pipeline transportation using various types of stabilization mechanisms. In addition to the effect of surfactant alone, its combination with some other parameters such as particle size distribution, temperature, solid concentration, etc. has been discussed. The review also describes the detailed classification of iron ore, surfactant, and characteristic properties of surfactants.

Evolution of Nusselt Correlation for Recovery of Waste Heat from Industry Flue Gases using Quarry Dust and Iron Ore Particles

Evolution of Nusselt Correlation for Recovery of Waste Heat from Industry Flue Gases using Quarry Dust and Iron Ore Particles

Effects of operation parameters on particle mixing performance in a horizontal high shear mixer

Abstract Particle mixing is an important unit operation in many industry processes. This work employed the discrete element method (DEM) to characterize the mixing performance of iron ore particles in a horizontal high shear mixer. The simulation results were first compared with the positron emission particle tracking (PEPT) data reported by Forrest et al. to validate the DEM model. Then the effects of key operation factors such as impeller rotation speed, number of impellers and filling ratio on the mixing efficiency were discussed. The Lacey mixing index was employed to evaluate the mixing performance. The results show that the mixing efficiency of particles increased with increasing the number of impellers and their rotation speeds. On the other hand, the filling ratio was negatively related to the particles velocity and the mixing efficiency. This was because the effective space left for free movement of particles decreased as the filling ratio increased, and the mixing of particles was therefore restricted. In addition, the mixing rate of particles in the axial direction of the high shear mixer was much slower than that in the radial direction.

Influence of a plant-based surfactant on improving the stability of iron ore particles for dispersion and pipeline transportation

This investigation addresses the study of the effects of the saponin isolated from the fruits of Sapindus laurifolia (S. laurifolia) as a dispersing and stabilizing agent in the pipeline transportation of iron ore (IO) particles. Two types of IO samples named S1 and S2, which are primarily constituted of hematite (Fe2O3) are taken for the study. The rheological behavior of iron ore water slurry (IOWS) has been studied as a function of saponin dosages, IO concentration, pH, temperature, and the shear rate-shear stress relationship. The isoelectric point of IOWS is calculated by the variation of zeta potential with pH. A suitable mechanism model is given to describe the interaction between S. laurifolia and IO particles. The economic effect of the dispersant has been examined based on slurry head loss, solids conveying rate, hydraulic power need, and specific power consumption (SPC) for the proposed IOWS pipeline to be introduced into commercial operation.

Research Regarding Iron Sludge Recovery Technology

Abstract One of the most important wastes in iron metallurgy is the blast furnace sludge. This sludge consists of fine particles of iron ore, coke and fine particles of flux. The furnace sludge is characterized by the chemical composition similar to that of the furnace load, the major difference being the concentration of zinc and lead. Due to the similarity with the blast furnace load, this material, after pelletization, can be recycled in the technological process. However, this recirculation is limited by the zinc content, which significantly disrupts the operation of the furnace. This paper presents tests to reduce the zinc content of the furnace sludge by hydrometallurgical and pyrometalurgical processes.

Numerical Simulation of Flash Reduction of Iron Ore Particles with Biomass Syngas

Numerical Simulation of Flash Reduction of Iron Ore Particles with Biomass Syngas

Direct reduction of fluxed iron ore pellets made from coarse iron ore particles

ABSTRACT The preparation of finer iron ore particles which can be used suitably in pelletization, decreases the binder requirement in the process, but increases the energy consumption during crushing and ball milling. Therefore, using relatively coarser iron ore particles with a suitable binder may help decrease energy input and slag volume. The present study was undertaken for the utilisation of iron ore fines in the range of −0.25 + 0.05 mm along with a suitable binder. Iron ore fines were classified into three size ranges (SR1(−0.25 + 0.1), SR2(−0.1 + 0.05) and SR3(−0.05)mm). Pellets of the above material were prepared using lime as a binder for basicity 0, 1 and 2 respectively, to observe hardening and reduction behaviour. Hardened pellets were characterised using cold crushing strength and porosity. Reduced pellets were characterised using XRD and SEM. It was observed that the cold crushing strength of hardened fluxed pellets decreased from 222 to 12 kg/pellet, and porosity increased from 30 to 43% with an increase in selected particle size. %Reduction increases from 89 to 99% with an increasing iron ore particle size. X-ray diffraction and scanning electron microscopy study confirms the increase in Fe content and iron whiskers growth in reduced pellets with increasing particle size. The optimum property was observed for the SR2 size range with the lime binder, which can produce highly reducible DRI (90–99%).

Numerical study of the dynamic behaviour of iron ore particles during wet granulation process using discrete element method

Iron ore granulation process is simulated by the discrete element method to understand the dynamic behaviour of iron ore particles. The results show that the macroscopic particle flow transits from rolling regime to cascading regime after water addition, with the angle of repose of particles increasing and the level of particle size segregation decreasing. The moisture distribution becomes more uniform through particle tumbling, which improves the granule growth. The microdynamic behaviours of the fines, intermediates and nuclei during the auto-layering process have been studied respectively. The variations in the average contact number, kinetic and rotational energy per particle with granulation time are analysed. The optimal moisture contents for Ores N, M and Y are estimated as 6.46 wt%, 9.12 wt% and 8.70 wt%, respectively. The numerical results are generally in accordance with the corresponding experimental ones, which basically validates the DEM modelling of iron ore granulation presented in this paper.

Evaluation of the Use of Organic Acids in the Reduction of Phosphorus Content in Iron Ore Particles

Evaluation of the Use of Organic Acids in the Reduction of Phosphorus Content in Iron Ore Particles

Evaluation of the Use of Organic Acids in the Reduction of Phosphorus Content in Iron Ore Particles

Evaluation of the Use of Organic Acids in the Reduction of Phosphorus Content in Iron Ore Particles

Evaluation of the Use of Burkolderia Caribensis Bacteria for the Reduction of Phosphorus Content in Iron Ore Particles

With the growing industrialization, there is a constant increase in the world demand for iron ore, thus implying an increase in the volume of mining, resulting in the extraction of ores with higher levels of silicon, phosphorus and sulfur impurities. Therefore, it is highly relevant to use beneficiation techniques that allow the use of iron ores with high levels of impurities, and it is known that a widely used alternative is to perform a pre-treatment of iron ore particles in order to reach the limit of acceptable phosphorus before application in steel production. Therefore, this study aims to evaluate the pre-treatment process of iron ore particles aiming at reducing the phosphorus content using the bacterial strain burkolderia caribensis in contaminated iron ore samples. Through the rotatable central composite design technique, it was possible to evaluate the best conditions for the use of the bacterial strain to reduce the phosphorus content in the particles. The results indicated that the developed process has relevant applicability. The results contribute to a better understanding of the use of the bacterial strain as a pretreatment process to reduce the phosphorus content of iron ore particles and also to the development of new cleaner technologies.

A Novel Model-Based Defogging Method for Particle Images With Different Fog Distributions

Defogging of particle images is a common task in machine vision-based measurement of particle size distribution (PSD) for granular materials or products. Current defogging methods are challenged by particle images captured in industrial environment, where artificial light is dominant in the imaging process and the fog is often unevenly distributed in the image due to its rapid and random movement. The recovered images may contain serious overexposures and result in failures in PSD measurement. To solve this problem, we propose a novel model-based defogging method for particle images with different fog distributions. First, a physical model is established to describe the image formation in industrial foggy environment with artificial light. Then, an adaptive method is proposed to estimate the range of the key model parameter (light intensity coefficient) and to obtain candidate defogged images. Finally, the fog-free image is generated by fusing the candidate images to reduce overexposures while retaining the image brightness. The proposed method was validated experimentally using iron ore particle images and compared with ten current defogging methods. Results demonstrate that our proposed method is adaptive to different illuminations and different fog contributions. It outperforms other defogging methods in removing unevenly distributed fog from the image and thus greatly improves the measuring accuracy of particle size. The proposed image defogging method can be integrated into machine vision systems for particle-handling processes to facilitate PSD measurement in foggy environment. The sample implementation of the proposed method is available at “ <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">https://github.com/zhoushuyi/particle-image-defog</uri> .”

A Phenomenological Model for Particle Kinetics in Drum-type Wet Low-Intensity Magnetic Separation*

Drum-type wet low-intensity magnetic separation (WLIMS) is a versatile technique widely employed in the mining industry for the treatment of iron ores. Its design and operation are rather simple and straightforward. Yet, understanding the process performance from a fundamental point of view still remains a puzzling task due to a number of complex subprocesses involved in the separation. Most of the models for drum-type WLIMS thus are based on empirical approaches. This work presents a modeling strategy that integrates ore properties and equipment characteristics to describe the behavior of iron ore particles. It relies on interpreting a laboratory-scale drum-type wet magnetic separator as a continuously stirred tank reactor. It merges the benefits of phenomenological and empirical modeling to express the particle kinetic rate constants as a function of the separation principles and ore characteristics. Results suggest that the kinetic model satisfactorily reproduces the experimental observations in terms of particle-classified magnetite recovery. The approach is promising for obtaining early information on the behavior of the particles at different stages of the iron ore beneficiation chain, especially for production planning, circuit layout and optimization.

Behavior and Kinetic Analysis of Dissolution of Iron Ore Particles in Hismelt Process Based on High-Temperature Confocal Microscopy

Behavior and Kinetic Analysis of Dissolution of Iron Ore Particles in Hismelt Process Based on High-Temperature Confocal Microscopy

Application of magnetic separation and reverse anionic flotation to concentrate fine particles of iron ore with high sulfur content

Application of magnetic separation and reverse anionic flotation to concentrate fine particles of iron ore with high sulfur content

Effect of Coated Cow Dung on Fluidization Reduction of Fine Iron Ore particles

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.