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Article
Publication date: 9 August 2011

Anna‐Lena Ljung, T. Staffan Lundström and Kent Tano

The purpose of this paper is to numerically model convective drying of a two‐dimensional iron ore pellet subjected to turbulent flow.

Abstract

Purpose

The purpose of this paper is to numerically model convective drying of a two‐dimensional iron ore pellet subjected to turbulent flow.

Design/methodology/approach

Simulations of the iron ore pellet drying process are carried out with commercial computational fluid dynamics software. The moisture distribution inside the pellet is calculated from a diffusion equation and drying due to evaporation at the surface is taken into account.

Findings

The results show an initial warm up phase with a succeeding constant rate drying period. Constant drying rate will only be achieved if the surface temperature is constant. The falling rate period will subsequently start at the forward stagnation point when the minimum moisture content is reached, while other parts of the surface still provide enough moisture to allow surface evaporation. The phases will thus coexist for a period of time.

Research limitations/implications

Owing to the complex physical processes involved in iron ore pellet drying, some parameters in the model are based on estimations. The effective diffusivity should, for example, in the future be investigated more thoroughly. It is also important to extend the model so that the falling rate drying period is also included. The model is at present undergoing further validation.

Practical implications

The simulations can provide detailed information on some key fluid dynamics and physical processes that an iron ore pellet undergoes during drying.

Originality/value

The simulations enhance the understanding of iron ore pellet drying and the model provides a complement to experimental investigations when optimizing the drying process.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 21 no. 6
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 23 June 2020

A. Hossein Madadi-Najafabadi and Abolfazl Masoumi

This paper aims to analyze the abrasive damage of iron ore pellets (IOP) during charge inside day-bins in iron making plants. The rock-ladder structure of day-bin is the…

Abstract

Purpose

This paper aims to analyze the abrasive damage of iron ore pellets (IOP) during charge inside day-bins in iron making plants. The rock-ladder structure of day-bin is the spotlight of this study. A numerical-analytical method is used to investigate the main geometrical features of the mentioned structure. Practical results of this study are expected to result in optimization of rock-ladder structure to reduce fine generation and lump formation during pellets downfall on the floors of rock-ladder.

Design/methodology/approach

One effective stage of pellets downfall on the floor of rock-ladder was simulated using discrete element method. A special post-process code is used to calculate parameters of pellets collisions for an analytical model which estimates fine generation during collisions. The main damaging mechanism during pellets storage inside day-bin is determined based on the comparison of the numerical-analytical results and industrial reports. Different rock-ladder designs are simulated to find optimal geometry of the rock-ladder structure.

Findings

According to the results, 85.4% of fines generation takes place during downfall of IOPs on the floors of rock ladder, and the rest of the fine debris is expected to be generated due to flow down under compressive load and vibratory discharge. The present study suggests an increase in the rock ladder floors distance from 1.63 to 2 m, but this suggestion should be confirmed by another study focusing on the breakage damage of IOPs. The idea of chamfering the floors corners not only removes lump-formation zones but also results in an approximately 5.7% reduction in the fines generation rate.

Originality/value

According to the results, introduced modification ideas for rock-ladder structure can result in lower fine generation, lower lump removal cost and lower manufacturing cost of rock-ladder structure.

Details

World Journal of Engineering, vol. 17 no. 5
Type: Research Article
ISSN: 1708-5284

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Expert briefing
Publication date: 13 May 2016

Developments in the global iron ore market

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Article
Publication date: 1 January 2010

Björn Kvarnström and Erik Vanhatalo

The purpose of the paper is to explore the application of radio frequency identification (RFID) to improve traceability in a flow of granular products and to illustrate…

Abstract

Purpose

The purpose of the paper is to explore the application of radio frequency identification (RFID) to improve traceability in a flow of granular products and to illustrate examples of special issues that need to be considered when using the RFID technique in a process industry setting.

Design/methodology/approach

The paper outlines a case study at a Swedish mining company, including experiments to test the suitability of RFID to trace iron ore pellets (a granular product) in parts of the distribution chain.

Findings

The results show that the RFID technique can be used to improve traceability in granular product flows. A number of special issues concerning the use of RFID in process industries are also highlighted, for example, the problems to control the orientation of the transponder in the read area and the risk of product contamination in the supply chain.

Research limitations/implications

Even though only a single case has been studied, the results are of a general interest for industries that have granular product flows. However, future research in other industries should be performed to validate the results.

Practical implications

The application of RFID described in this paper makes it possible to increase productivity and product quality by improving traceability in product flows where traceability normally is problematic.

Originality/value

Prior research has mainly focused on RFID applications in discontinuous processes. By contrast, this paper presents a novel application of the RFID technique in a continuous process together with specific issues connected to the use of RFID.

Details

Journal of Manufacturing Technology Management, vol. 21 no. 1
Type: Research Article
ISSN: 1741-038X

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Expert briefing
Publication date: 12 May 2017

Poor fundamentals undermine the iron ore market rally.

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Article
Publication date: 5 April 2021

Saprativ Basu, Arijit Chakrabarty, Samik Nag, Kishore Behera, Brati Bandyopadhyay, Andrew Phillip Grima and Probal Ghosh

The dryer feed chute of the pellet plant plays an important role in the pelletizing process. The chute discharges sticky and moist iron ore fines (<1 mm) to the inline…

Abstract

Purpose

The dryer feed chute of the pellet plant plays an important role in the pelletizing process. The chute discharges sticky and moist iron ore fines (<1 mm) to the inline rotary dryer for further processing. Since the inception of the installation of the dryer feed chute, the poor flowability of the feed materials has caused severe problems such as blockages and excessive wear of chute liners. This leads to high maintenance costs and reduced lifetime of the liner materials. Constant housekeeping is needed for maintaining the chute and reliable operation. The purpose of this study is to redesign the dryer feed chute to overcome the above challenges.

Design/methodology/approach

The discrete element method (DEM) has been used to model the flow of cohesive materials through the transfer chute. Physical experiments have been performed to understand the most severe flow conditions. A DEM material model is also developed for replicating the worst-case material condition. After identifying the key problem areas, concept designs were proposed and simulated to assess the design improvements to increase the reliability of chute operation.

Findings

Flow simulations correlated well with the existing flow behavior of the iron ore fines inside the chute. The location of the problematic areas has been validated with that of the previously installed chute. Subsequently, design modifications have been proposed. This includes modification of deflector plate and change in slope and cross-section of the chute. DEM simulations and analysis were conducted after incorporating these design changes. A comparison in the average velocity of particle and force on chute wall shows a significant improvement using the proposed design.

Originality/value

Method to calibrate DEM material model was found to provide accurate prediction and modeling of the flow behavior of bulk material through the real transfer chute. DEM provided greater insight into the performance of the chute especially modeling cohesive materials. DEM is a valuable design tool to assist chute designers troubleshoot and verify chute designs. DEM provides a greater ability to model and assess chute wear. This technique can help in achieving a scientific understanding of the flow properties of bulk solids through transfer chute, hence eliminate challenges, ensuring reliable, uninterrupted and profitable plant operation. This paper strongly advocates the use of calibrated DEM methodology in designing bulk material handling equipment.

Details

Engineering Computations, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0264-4401

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Case study
Publication date: 31 March 2016

Sunil Sharma, Saral Mukherjee and Parvinder Gupta

The three cases (Case A: JSW Steel's Ispat Acquisition: The Opportunity; Case B: JSW Steel's Ispat Acqusition: The Setback & Case C: JSW Steel's Ispat Acquisition: The…

Abstract

The three cases (Case A: JSW Steel's Ispat Acquisition: The Opportunity; Case B: JSW Steel's Ispat Acqusition: The Setback & Case C: JSW Steel's Ispat Acquisition: The Turnaround Strategy) describe the business situation leading to acquisition of Ispat by JSW, the acquirer company's failure to realize synergies post-acquisition, and the subsequent turnaround initiatives to salvage the situation. In 2010, JSW Steel, a 14 mtpa Indian steel company acquired Ispat Steel with annual production capacity of 3 mtpa. The acquisition was part of JSW's multipronged strategy to realize its aspiration of being a 40 mtpa firm. At the time of acquisition, Ispat had huge debts, a long pipeline of unfinished projects, high production costs and unpredictable cash flows. Its main plant, Dolvi was shutdown for 45 days. However, the plant also had numerous advantages. It was located near the seashore and was technologically very advanced. Case A describes the events leading to acquisition of Ispat by JSW. It captures the facts, opinions and inferences around the acquisition decision, which were used as inputs in the due diligence process to assess synergies between JSW and Ispat. The case describes the economic, competitive, and industry factors prevailing in 2010 when JSW was thinking of acquiring Ispat.

Details

Indian Institute of Management Ahmedabad, vol. no.
Type: Case Study
ISSN: 2633-3260
Published by: Indian Institute of Management Ahmedabad

Keywords

Content available
Article
Publication date: 19 July 2021

Himani Naesstroem, Frank Brueckner and Alexander F.H. Kaplan

This paper aims to gain an understanding of the behaviour of iron ore when melted by a laser beam in a continuous manner. This fundamental knowledge is essential to…

Abstract

Purpose

This paper aims to gain an understanding of the behaviour of iron ore when melted by a laser beam in a continuous manner. This fundamental knowledge is essential to further develop additive manufacturing routes such as production of low cost parts and in-situ reduction of the ore during processing.

Design/methodology/approach

Blown powder directed energy deposition was used as the processing method. The process was observed through high-speed imaging, and computed tomography was used to analyse the specimens.

Findings

The experimental trials give preliminary results showing potential for the processability of iron ore for additive manufacturing. A large and stable melt pool is formed in spite of the inhomogeneous material used. Single and multilayer tracks could be deposited. Although smooth and even on the surface, the single layer tracks displayed porosity. In case of multilayered tracks, delamination from the substrate material and deformation can be seen. High-speed videos of the process reveal various process phenomena such as melting of ore powder during feeding, cloud formation, melt pool size, melt flow and spatter formation.

Originality/value

Very little literature is available that studies the possible use of ore in additive manufacturing. Although the process studied here is not industrially useable as is, it is a step towards processing cheap unprocessed material with a laser beam.

Details

Rapid Prototyping Journal, vol. 27 no. 11
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 7 August 2017

Guangming Chen, Dingena L. Schott and Gabriel Lodewijks

Sliding wear is a common phenomenon in the iron ore handling industry. Large-scale handling of iron ore bulk-solids causes a high amount of volume loss from the surfaces…

Abstract

Purpose

Sliding wear is a common phenomenon in the iron ore handling industry. Large-scale handling of iron ore bulk-solids causes a high amount of volume loss from the surfaces of bulk-solids-handling equipment. Predicting the sliding wear volume from equipment surfaces is beneficial for efficient maintenance of worn equipment. Recently, the discrete element method (DEM) simulations have been utilised to predict the wear by bulk-solids. However, the sensitivity of wear prediction subjected to DEM parameters has not been systemically investigated at single particle level. To ensure the wear predictions by DEM are accurate and stable, this study aims to conduct the sensitivity analysis at the single particle level.

Design/methodology/approach

In this research, pin-on-disc wear tests are modelled to predict the sliding wear by individual iron ore particles. The Hertz–Mindlin (no slip) contact model is implemented to simulate interactions between particle (pin) and geometry (disc). To quantify the wear from geometry surface, a sliding wear equation derived from Archard’s wear model is adopted in the DEM simulations. The accuracy of the pin-on-disc wear test simulation is assessed by comparing the predicted wear volume with that of the theoretical calculation. The stability is evaluated by repetitive tests of a reference case. At the steady-state wear, the sensitivity analysis is done by predicting sliding wear volumes using the parameter values determined by iron ore-handling conditions. This research is carried out using the software EDEM® 2.7.1.

Findings

Numerical errors occur when a particle passes a joint side of geometry meshes. However, this influence is negligible compared to total wear volume of a wear revolution. A reference case study demonstrates that accurate and stable results of sliding wear volume can be achieved. For the sliding wear at steady state, increasing particle density or radius causes more wear, whereas, by contrast, particle Poisson’s ratio, particle shear modulus, geometry mesh size, rotating speed, coefficient of restitution and time step have no impact on wear volume. As expected, increasing indentation force results in a proportional increase. For maintaining wear characteristic and reducing simulation time, the geometry mesh size is recommended. To further reduce simulation time, it is inappropriate using lower particle shear modulus. However, the maximum time step can be increased to 187% TR without compromising simulation accuracy.

Research limitations/implications

The applied coefficient of sliding wear is determined based on theoretical and experimental studies of a spherical head of iron ore particle. To predict realistic volume loss in the iron ore-handling industry, this coefficient should be experimentally determined by taking into account the non-spherical shapes of iron ore particles.

Practical implications

The effects of DEM parameters on sliding wear are revealed, enabling the selections of adequate values to predict sliding wear in the iron ore-handling industry.

Originality/value

The accuracy and stability to predict sliding wear by using EDEM® 2.7.1 are verified. Besides, this research accelerates the calibration of sliding wear prediction by DEM.

Details

Engineering Computations, vol. 34 no. 6
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 2 October 2007

Aditya Parida

The purpose of this case study is to identify and develop maintenance performance indicators (MPIs) for a mineral processing plant producing high quality iron ore pellets

Abstract

Purpose

The purpose of this case study is to identify and develop maintenance performance indicators (MPIs) for a mineral processing plant producing high quality iron ore pellets, as well as studying and analyzing the short plant stops and planned maintenance stops.

Design/methodology/approach

An action research approach was adopted for this study, with interactive process of interviews. The existing MPIs are analyzed and a set of MPIs are developed to measure the performance of balling area of the pelletization plant, where the effect of shorter stops in the process have been studied, analyzed and measured, and linked to the management's objectives. The utility of the MPIs are tested and validated within the framework of a multi‐criterion and hierarchical maintenance performance measurement (MPM) framework. The plant stop data of the plant were collected and analyzed for MPIs and for maintenance decision making. Some other criteria were also considered from a holistic, integrated and balanced viewpoint in the model.

Findings

This study resulted in identifying a set of MPIs for the operational level of the pelletization plant of LKAB, after analyzing the short plant stops and planned maintenance stops data, and the stakeholders' requirements. This study has identified nine MPIs at operational level or shop floor level that describe the status of plant and at the same time facilitates linking of plant performance with corporate strategy.

Practical implications

The approach used in the paper to study, analyze and develop MPIs, can be useful for plant managers and asset owners to select and develop MPIs that can describe the health status of their plant and asset and that also can be linked to the corporate strategy. The framework used to verify the multi‐criteria hierarchical framework can also be used by similar asset managers and infrastructure owners. This study has also lifted the impact of short duration stoppages, thus highlighting the total influence in terms of reduced life length, quality and productivity. This approach can be used by plant engineers, asset managers and infrastructure owners to assess the performance of maintenance process.

Originality/value

This paper presents an approach for identifying MPIs relevant to the plant status and facilitating measuring maintenance performance at corporate level in a structured way.

Details

Journal of Quality in Maintenance Engineering, vol. 13 no. 4
Type: Research Article
ISSN: 1355-2511

Keywords

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