Processes

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6 pages, 223 KiB

Open AccessEditorial

Special Issue on “Process Modeling in Pyrometallurgical Engineering”

by Henrik Saxén, Marco A. Ramírez-Argáez, Alberto N. Conejo and Abhishek Dutta

Processes 2021, 9(2), 252; https://doi.org/10.3390/pr9020252 - 29 Jan 2021

Cited by 1 | Viewed by 1406

Abstract

This Special Issue on “Process Modeling in Pyrometallurgical Engineering” consists of 39 articles, including two review papers, and covers a wide range of topics related to process development and analysis based on modeling in ironmaking, steelmaking, flash smelting, casting, rolling operations, etc [...] [...] Read more.

This Special Issue on “Process Modeling in Pyrometallurgical Engineering” consists of 39 articles, including two review papers, and covers a wide range of topics related to process development and analysis based on modeling in ironmaking, steelmaking, flash smelting, casting, rolling operations, etc [...] Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

Research

Jump to: Editorial, Review

22 pages, 2992 KiB

Open AccessArticle

Quantitative Methods to Support Data Acquisition Modernization within Copper Smelters

by Alessandro Navarra, Ryan Wilson, Roberto Parra, Norman Toro, Andrés Ross, Jean-Christophe Nave and Phillip J. Mackey

Processes 2020, 8(11), 1478; https://doi.org/10.3390/pr8111478 - 17 Nov 2020

Cited by 13 | Viewed by 3242

Abstract

Sensors and process control systems are essential for process automation and optimization. Many sectors have adapted to the Industry 4.0 paradigm, but copper smelters remain hesitant to implement these technologies without appropriate justification, as many critical functions remain subject to ground operator experience. [...] Read more.

Sensors and process control systems are essential for process automation and optimization. Many sectors have adapted to the Industry 4.0 paradigm, but copper smelters remain hesitant to implement these technologies without appropriate justification, as many critical functions remain subject to ground operator experience. Recent experiments and industrial trials using radiometric optoelectronic data acquisition, coupled with advanced quantitative methods and expert systems, have successfully distinguished between mineral species in reactive vessels with high classification rates. These experiments demonstrate the increasing potential for the online monitoring of the state of a charge in pyrometallurgical furnaces, allowing data-driven adjustments to critical operational parameters. However, the justification to implement an innovative control system requires a quantitative framework that is conducive to multiphase engineering projects. This paper presents a unified quantitative framework for copper and nickel-copper smelters, which integrates thermochemical modeling into discrete event simulation and is, indeed, able to simulate smelters, with and without a proposed set of sensors, thus quantifying the benefit of these sensors. Sample computations are presented, which are based on the authors’ experiences in smelter reengineering projects. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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12 pages, 4855 KiB

Open AccessArticle

Evolution and Physical Characteristics of a Raceway Based on a Transient Eulerian Multiphase Flow Model

by Xing Peng, Jingsong Wang, Haibin Zuo and Qingguo Xue

Processes 2020, 8(10), 1315; https://doi.org/10.3390/pr8101315 - 20 Oct 2020

Cited by 5 | Viewed by 2119

Abstract

In industrial processes, a semi-cavity area formed by airflow wherein the particles circulate is called a “raceway”. In a blast furnace, the role of the raceway is particularly important. To understand and predict the evolution and physical characteristics of the raceway, a three-dimensional [...] Read more.

In industrial processes, a semi-cavity area formed by airflow wherein the particles circulate is called a “raceway”. In a blast furnace, the role of the raceway is particularly important. To understand and predict the evolution and physical characteristics of the raceway, a three-dimensional transient Eulerian multiphase flow model in a packed particle bed was developed. In the model, it was assumed that the gas and solid (particle) phases constitute an interpenetrating continuum. The gas-phase turbulence was described as a k–ε dispersed model. The gas-phase stress was considered in terms of the effective viscosity of the gas. The solid-phase constitutive relationship was expressed in terms of solid stress. It was found that the evolution process of the raceway can be divided into three stages: (1) rapid expansion, (2) slow contraction, and (3) gradual stabilization. When the blast velocity was increased from 150 m/s to 300 m/s, the surface area of the raceway increased from 0.194 m² to 1.644 m². The depth and height of the raceway increased considerably with velocity, while the width slightly increased. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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34 pages, 23280 KiB

Open AccessFeature PaperArticle

Modeling the Effect of Scrap on the Electrical Energy Consumption of an Electric Arc Furnace

by Leo S. Carlsson, Peter B. Samuelsson and Pär G. Jönsson

Processes 2020, 8(9), 1044; https://doi.org/10.3390/pr8091044 - 26 Aug 2020

Cited by 8 | Viewed by 4592

Abstract

The melting time of scrap is a factor that affects the Electrical Energy (EE) consumption of the Electric Arc Furnace (EAF) process. The EE consumption itself stands for most of the total energy consumption during the process. Three distinct representations of scrap, based [...] Read more.

The melting time of scrap is a factor that affects the Electrical Energy (EE) consumption of the Electric Arc Furnace (EAF) process. The EE consumption itself stands for most of the total energy consumption during the process. Three distinct representations of scrap, based partly on the apparent density and shape of scrap, were created to investigate the effect of scrap on the accuracy of a statistical model predicting the EE consumption of an EAF. Shapley Additive Explanations (SHAP) was used as a tool to investigate the effects by each scrap category on each prediction of a selected model. The scrap representation based on the shape of scrap consistently resulted in the best performing models while all models using any of the scrap representations performed better than the ones without any scrap representation. These results were consistent for all four distinct and separately used cleaning strategies on the data set governing the models. In addition, some of the main scrap categories contributed to the model prediction of EE in accordance with the expectations and experience of the plant engineers. The results provide significant evidence that a well-chosen scrap categorization is important to improve a statistical model predicting the EE and that experience on the specific EAF under study is essential to evaluate the practical usefulness of the model. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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17 pages, 4727 KiB

Open AccessFeature PaperArticle

Numerical Modeling of Equal and Differentiated Gas Injection in Ladles: Effect on Mixing Time and Slag Eye

by Luis E. Jardón-Pérez, Carlos González-Rivera, Marco A. Ramirez-Argaez and Abhishek Dutta

Processes 2020, 8(8), 917; https://doi.org/10.3390/pr8080917 - 02 Aug 2020

Cited by 11 | Viewed by 2346

Abstract

Ladle refining plays a crucial role in the steelmaking process, in which a gas stream is bubbled through molten steel to improve the rate of removal of impurities and enhance the transport phenomena that occur in a metallurgical reactor. In this study, the [...] Read more.

Ladle refining plays a crucial role in the steelmaking process, in which a gas stream is bubbled through molten steel to improve the rate of removal of impurities and enhance the transport phenomena that occur in a metallurgical reactor. In this study, the effect of dual gas injection using equal (50%:50%) and differentiated (75%:25%) flows was studied through numerical modeling, using computational fluid dynamics (CFD). The effect of gas flow rate and slag thickness on mixing time and slag eye area were studied numerically and compared with the physical model. The numerical model agrees with the physical model, showing that for optimal performance the ladle must be operated using differentiated flows. Although the numerical model can predict well the hydrodynamic behavior (velocity and turbulent kinetic energy) of the ladle, there is a deviation from the experimental mixing time when using both equal and differentiated gas injection at a high gas flow rate and a high slag thickness. This is probably due to the insufficient capture of the velocity field near the water–oil (steel–slag) interface and slag emulsification by the numerical model, as well as the complicated nature of correctly simulating the interaction between both gas plumes. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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10 pages, 4539 KiB

Open AccessArticle

Effect of Cambered and Oval-Grooved Roll on the Strain Distribution During the Flat Rolling Process of a Wire

by Joong-Ki Hwang

Processes 2020, 8(7), 876; https://doi.org/10.3390/pr8070876 - 20 Jul 2020

Cited by 5 | Viewed by 3118

Abstract

The effect of the roll design on the strain distribution of the flat surface, lateral spreading, and the strain inhomogeneity of a flat-rolled wire were investigated during the flat rolling process. Oval-grooved and cambered rolls with various radii were applied to the flat [...] Read more.

The effect of the roll design on the strain distribution of the flat surface, lateral spreading, and the strain inhomogeneity of a flat-rolled wire were investigated during the flat rolling process. Oval-grooved and cambered rolls with various radii were applied to the flat rolling process based on a numerical simulation. The effective strain on the flat surface of the wire increased when using a cambered roll due to the highly intensified contact pressure on the flat surface, while the effective strain on the flat surface of the wire decreased when using an oval-grooved roll. Lateral spreading decreased when using an oval-grooved roll because the spread in the free surface area of the wire was highly restricted by the oval-grooved roll shape. In contrast, the spread in the surface area increased when using a cambered roll due to the less-restricted metal flow at the free surface. Accordingly, a cambered roll with a small radius is highly recommended in order to improve the surface quality of flat-rolled wires. This is beneficial for industrial plants because the cambered roll can be easily applied in flat rolling plants. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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20 pages, 4811 KiB

Open AccessFeature PaperArticle

On the Impacts of Pre-Heated Natural Gas Injection in Blast Furnaces

by Tyamo Okosun, Samuel Nielson, John D’Alessio, Shamik Ray, Stuart Street and Chenn Zhou

Processes 2020, 8(7), 771; https://doi.org/10.3390/pr8070771 - 01 Jul 2020

Cited by 19 | Viewed by 4727

Abstract

During recent years, there has been great interest in exploring the potential for high-rate natural gas (NG) injection in North American blast furnaces (BFs) due to the fuel’s relatively low cost, operational advantages, and reduced carbon footprint. However, it is well documented that [...] Read more.

During recent years, there has been great interest in exploring the potential for high-rate natural gas (NG) injection in North American blast furnaces (BFs) due to the fuel’s relatively low cost, operational advantages, and reduced carbon footprint. However, it is well documented that increasing NG injection rates results in declining raceway flame temperatures (a quenching effect on the furnace, so to speak), with the end result of a functional limit on the maximum injection rate that can be used while maintaining stable operation. Computational fluid dynamics (CFD) models of the BF raceway and shaft regions developed by Purdue University Northwest’s (PNW) Center for Innovation through Visualization and Simulation (CIVS) have been applied to simulate multi-phase reacting flow in industry blast furnaces with the aim of exploring the use of pre-heated NG as a method of widening the BF operating window. Simulations predicted that pre-heated NG injection could increase the flow of sensible heat into the BF and promote complete gas combustion through increased injection velocity and improved turbulent mixing. Modeling also indicated that the quenching effects of a 15% increase in NG injection rate could be countered by a 300K NG pre-heat. This scenario maintained furnace raceway flame temperatures and top gas temperatures at levels similar to those observed in baseline (stable) operation, while reducing coke rate by 6.3%. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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18 pages, 4878 KiB

Open AccessFeature PaperArticle

3D Integrated Modeling of Supersonic Coherent Jet Penetration and Decarburization in EAF Refining Process

by Yuchao Chen, Armin K. Silaen and Chenn Q. Zhou

Processes 2020, 8(6), 700; https://doi.org/10.3390/pr8060700 - 17 Jun 2020

Cited by 13 | Viewed by 3980

Abstract

The present study proposes a complete 3D integrated model to simulate the top-blown supersonic coherent jet decarburization in the electric arc furnace (EAF) refining process. The 3D integrated model avoids the direct simulation of the supersonic coherent jet interacting with the liquid steel [...] Read more.

The present study proposes a complete 3D integrated model to simulate the top-blown supersonic coherent jet decarburization in the electric arc furnace (EAF) refining process. The 3D integrated model avoids the direct simulation of the supersonic coherent jet interacting with the liquid steel bath and provides a feasible way to simulate the decarburization in the liquid steel-oxygen two-phase reacting flow system with acceptable computational time. The model can be used to dynamically predict the details of the molten bath, including 3D distribution of in-bath substances, flow characteristics and bath temperature and provide a basis for optimizing the decarburization rate or other required parameters during the refining process. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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19 pages, 12770 KiB

Open AccessArticle

Numerical Modeling of Transport Phenomena in the Horizontal Single Belt Casting (HSBC) Process for the Production of AA6111 Aluminum Alloy Strip

by Usman Niaz, Mihaiela Minea Isac and Roderick I. L. Guthrie

Processes 2020, 8(5), 529; https://doi.org/10.3390/pr8050529 - 30 Apr 2020

Cited by 6 | Viewed by 3477

Abstract

In this research study, numerical modelling and experimental casting of AA6111 strips, 250 mm wide, 6 mm thick, was conducted. The velocity of the molten AA6111 alloy at the nozzle slot outlet was raised to 2 m/s, whilst the belt speed was kept [...] Read more.

In this research study, numerical modelling and experimental casting of AA6111 strips, 250 mm wide, 6 mm thick, was conducted. The velocity of the molten AA6111 alloy at the nozzle slot outlet was raised to 2 m/s, whilst the belt speed was kept at 0.3 m/s. The numerical model demonstrates considerable turbulence/fluctuations in the flow of the molten AA6111 alloy in the HSBC process, rendering its free surface highly non-uniform and uneven. These discontinuites in the flow resulted from the sudden impact of molten metal onto the inclined refractory plane, and then onto the slowly moving belt. However, it has been determined that these surface variations are rapidly damped, and as such are not detrimental to final strip surface quality. Any surface perturbations remaining can be eliminated via hot plastic deformation. The experimental findings are in accordance with the model predictions. Furthermore, at high metal heads inside the delivery launder, the molten metal was observed to be flowing inwards towards the center of the strip, thereby filling the centre depression region, formed otherwise. The model predictions were validated against experimental findings. A surface roughness and microstructural analysis was also conducted to determine the surface and bulk quality of the as-cast strip. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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17 pages, 5505 KiB

Open AccessFeature PaperArticle

Computational Approaches for Studying Slag–Matte Interactions in the Flash Smelting Furnace (FSF) Settler

by Jani-Petteri Jylhä, Nadir Ali Khan and Ari Jokilaakso

Processes 2020, 8(4), 485; https://doi.org/10.3390/pr8040485 - 22 Apr 2020

Cited by 10 | Viewed by 6661

Abstract

Computational methods have become reliable tools in many disciplines for research and industrial design. There are, however, an ever-increasing number of details waiting to be included in the models and software, including, e.g., chemical reactions and many physical phenomena, such as particle and [...] Read more.

Computational methods have become reliable tools in many disciplines for research and industrial design. There are, however, an ever-increasing number of details waiting to be included in the models and software, including, e.g., chemical reactions and many physical phenomena, such as particle and droplet behavior and their interactions. The dominant method for copper production, flash smelting, has been extensively investigated, but the settler part of the furnace containing molten high temperature melts termed slag and matte, still lacks a computational modeling tool. In this paper, two commercial modeling software programs have been used for simulating slag–matte interactions in the settler, the target being first to develop a robust computational fluid dynamics (CFD) model and, second, to apply a new approach for molten droplet behavior in a continuum. The latter is based on CFD coupled with the discrete element method (DEM), which was originally developed for modeling solid particle–particle interactions and movement, and is applied here for individual droplets for the first time. The results suggest distinct settling flow phenomena and the significance of droplet coalescence for settling velocity and efficiency. The computing capacity requirement for both approaches is the main limiting factor preventing full-scale geometry modeling with detailed droplet interactions. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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23 pages, 2894 KiB

Open AccessArticle

Dynamic Modeling and Simulation of Basic Oxygen Furnace (BOF) Operation

by Daniela Dering, Christopher Swartz and Neslihan Dogan

Processes 2020, 8(4), 483; https://doi.org/10.3390/pr8040483 - 21 Apr 2020

Cited by 21 | Viewed by 10046

Abstract

Basic oxygen furnaces (BOFs) are widely used to produce steel from hot metal. The process typically has limited automation which leads to sub-optimal operation. Economically optimal operation can be potentially achieved by using a dynamic optimization framework to provide operators the best combination [...] Read more.

Basic oxygen furnaces (BOFs) are widely used to produce steel from hot metal. The process typically has limited automation which leads to sub-optimal operation. Economically optimal operation can be potentially achieved by using a dynamic optimization framework to provide operators the best combination of input trajectories. In this paper, a first-principles based dynamic model for the BOF that can be used within the dynamic optimization routine is described. The model extends a previous work by incorporating a model for slag formation and energy balances. In this new version of the mathematical model, the submodel for the decarburization in the emulsion zone is also modified to account for recent findings, and an algebraic equation for the calculation of the calcium oxide saturation in slag is developed. The dynamic model is then used to simulate the operation of two distinct furnaces. It was found that the prediction accuracy of the developed model is significantly superior to its predecessor and the number of process variables that it is able to predict is also higher. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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16 pages, 3670 KiB

Open AccessArticle

Combustion Kinetics Characteristics of Solid Fuel in the Sintering Process

by Jihui Liu, Yaqiang Yuan, Junhong Zhang, Zhijun He and Yaowei Yu

Processes 2020, 8(4), 475; https://doi.org/10.3390/pr8040475 - 17 Apr 2020

Cited by 5 | Viewed by 2839

Abstract

In order to systematically elucidate the combustion performance of fuel during sintering, this paper explores the influence of three factors, namely coal substitution for coke, quasi-particle structure and the coupling effect with reduction and oxidation of iron oxide, on fuel combustion characteristics, and [...] Read more.

In order to systematically elucidate the combustion performance of fuel during sintering, this paper explores the influence of three factors, namely coal substitution for coke, quasi-particle structure and the coupling effect with reduction and oxidation of iron oxide, on fuel combustion characteristics, and carries out the kinetic calculation of monomer blended fuel (MBF) and quasi-granular fuel (QPF). The results show that replacing coke powder with anthracite can accelerate the whole combustion process. MBF and QPF are more consistent with the combustion law of the double-parallel random pore model. Although the quasi-particle structure increases the apparent activation energy of fuel combustion, it can also produce a heat storage effect on fuel particles, improve their combustion performance, and reduce the adverse effect of diffusion on the reaction process. In the early stage of reaction, the coupling between combustion of volatiles and reduction of iron oxide is obvious. The oxidation of iron oxide will occur again when the combustion reaction of fuel is weakened. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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15 pages, 7114 KiB

Open AccessArticle

Temperature Distribution Estimation in a Dwight–Lloyd Sinter Machine Based on the Combustion Rate of Charcoal Quasi-Particles

by Ziming Wang, Ko-ichiro Ohno, Shunsuke Nonaka, Takayuki Maeda and Kazuya Kunitomo

Processes 2020, 8(4), 406; https://doi.org/10.3390/pr8040406 - 31 Mar 2020

Cited by 2 | Viewed by 2669

Abstract

The coke combustion rate in an iron ore sintering process is one of the most important determining factors of quality and productivity. Biomass carbon material is considered to be a coke substitute with a lower CO₂ emission in the sintering process. The [...] Read more.

The coke combustion rate in an iron ore sintering process is one of the most important determining factors of quality and productivity. Biomass carbon material is considered to be a coke substitute with a lower CO₂ emission in the sintering process. The purpose of this study was to investigate the combustion rate of a biomass carbon material and to use a sintering simulation model to calculate its temperature profile. The samples were prepared using alumina powder and woody biomass powder. To simplify the experimental conditions, alumina powder, which cannot be reduced, was prepared as a substitute of iron ore. Combustion experiments were carried out in the open at 1073 K~1523 K. The results show that the combustion rates of the biomass carbon material were higher than that of coke. The results were analyzed using an unreacted core model with one reaction interface. The kinetic analysis found that the k_c of charcoal was higher than that of coke. It is believed that the larger surface area of charcoal may affect its combustion rate. The analysis of the sintering simulation results shows that the high temperature range of charcoal was smaller than that of coke because of charcoal’s low fixed carbon content and density. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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17 pages, 3358 KiB

Open AccessArticle

Experiments and 3D Molecular Model Construction of Lignite under Different Modification Treatment

by Jihui Liu, Shuang Qiu, Zhijun He and Yaowei Yu

Processes 2020, 8(4), 399; https://doi.org/10.3390/pr8040399 - 29 Mar 2020

Cited by 5 | Viewed by 2502

Abstract

In this paper, Huolinhe lignite was selected as the lignite experimental sample, using microwave modification and ultrasonic modification separately as improvement methods. The three-dimensional molecular models of HLH before and after modification were established base on the parameters obtained by ¹³C NMR, [...] Read more.

In this paper, Huolinhe lignite was selected as the lignite experimental sample, using microwave modification and ultrasonic modification separately as improvement methods. The three-dimensional molecular models of HLH before and after modification were established base on the parameters obtained by ¹³C NMR, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (Raman), and Fourier transform infrared (FTIR). After the microwave treatment, the methylene carbon in the HLH coal sample structure mostly exists in the form of long straight chains, and after microwave and ultrasonic treatment, the -OH content of oxygen atoms in the coal sample increases, and form the CO- and the COO-. The proportion is decreasing. The models were adjusted and tested by the covalent bond concentration method and carbon chemical shift spectra calculation using Chemdraw software. A new method is proposed to study the structure and physicochemical properties of lignite modification from the molecular point of view through this study. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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15 pages, 2700 KiB

Open AccessArticle

Fault Detection and Identification of Blast Furnace Ironmaking Process Using the Gated Recurrent Unit Network

by Hang Ouyang, Jiusun Zeng, Yifan Li and Shihua Luo

Processes 2020, 8(4), 391; https://doi.org/10.3390/pr8040391 - 27 Mar 2020

Cited by 20 | Viewed by 3137

Abstract

It is of critical importance to keep a steady operation in the blast furnace to facilitate the production of high quality hot metal. In order to monitor the state of blast furnace, this article proposes a fault detection and identification method based on [...] Read more.

It is of critical importance to keep a steady operation in the blast furnace to facilitate the production of high quality hot metal. In order to monitor the state of blast furnace, this article proposes a fault detection and identification method based on the multidimensional Gated Recurrent Unit (GRU) network, which is a kind of recurrent neural network and is highly effective in handling process dynamics. Comparing to conventional recurrent neural networks, GRU has a simpler structure and involves fewer parameters. In fault detection, a moving window approach is applied and a GRU model is constructed for each process variable to generate a series of residuals, which is further monitored using the support vector data description (SVDD) method. Once a fault is detected, fault identification is performed using the contribution analysis. Application to a real blast furnace fault shows that the proposed method is effective. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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11 pages, 2852 KiB

Open AccessArticle

Simulation Study and Industrial Application of Enhanced Arsenic Removal by Regulating the Proportion of Concentrates in the SKS Copper Smelting Process

by Qinmeng Wang, Qiongqiong Wang, Qinghua Tian and Xueyi Guo

Processes 2020, 8(4), 385; https://doi.org/10.3390/pr8040385 - 26 Mar 2020

Cited by 8 | Viewed by 2843

Abstract

Arsenic removal is a crucial issue in all copper smelters. Based on the Fangyuan 1^# smelter, the effects of major elements (Cu, Fe and S) in sulfide concentrates on arsenic removal in the SKS copper smelting process were studied in this paper. [...] Read more.

Arsenic removal is a crucial issue in all copper smelters. Based on the Fangyuan 1^# smelter, the effects of major elements (Cu, Fe and S) in sulfide concentrates on arsenic removal in the SKS copper smelting process were studied in this paper. The results show that Cu, Fe and S in concentrates have a significant influence on the oxygen/sulfur potential of smelting systems, and also affect the efficiency of arsenic removal. By regulating the proportion of the major elements in sulfide concentrates, the concentrate composition was changed from its original proportions (Cu 24.4%, Fe 26.8%, S 28.7%, and other 20%) to optimized proportions (Cu 19%, Fe 32%, S 29%, and other 20%). The distribution of arsenic among three phases in the original production process (gas 82.01%, slag 12.08%, matte 5.91%) was improved to obtain an optimal result (gas 94.37%, slag 3.45%, matte 2.18%). More arsenic was removed into the gas phase, and the mass fraction of arsenic in matte was reduced from 0.07% to 0.02%. The findings were applied to actual production processes in several other copper smelters, such as the Hengbang copper smelter, Yuguang smelter and Fangyuan 2^# smelter. Therefore, the optimized result obtained in this work could provide direct guidance for actual production. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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15 pages, 3012 KiB

Open AccessArticle

Machine Learning-Based Prediction of a BOS Reactor Performance from Operating Parameters

by Alireza Rahnama, Zushu Li and Seetharaman Sridhar

Processes 2020, 8(3), 371; https://doi.org/10.3390/pr8030371 - 23 Mar 2020

Cited by 12 | Viewed by 3422

Abstract

A machine learning-based analysis was applied to process data obtained from a Basic Oxygen Steelmaking (BOS) pilot plant. The first purpose was to identify correlations between operating parameters and reactor performance, defined as rate of decarburization (dc/dt). Correlation analysis showed, as expected a [...] Read more.

A machine learning-based analysis was applied to process data obtained from a Basic Oxygen Steelmaking (BOS) pilot plant. The first purpose was to identify correlations between operating parameters and reactor performance, defined as rate of decarburization (dc/dt). Correlation analysis showed, as expected a strong positive correlation between the rate of decarburization (dc/dt) and total oxygen flow. On the other hand, the decarburization rate exhibited a negative correlation with lance height. Less obviously, the decarburization rate, also showed a positive correlation with temperature of the waste gas and CO₂ content in the waste gas. The second purpose was to train the pilot-plant dataset and develop a neural network based regression to predict the decarburization rate. This was used to predict the decarburization rate in a BOS furnace in an actual manufacturing plant based on lance height and total oxygen flow. The performance was satisfactory with a coefficient of determination of 0.98, confirming that the trained model can adequately predict the variation in the decarburization rate (dc/dt) within BOS reactors. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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14 pages, 3953 KiB

Open AccessArticle

Thermal Behavior of a Rod during Hot Shape Rolling and Its Comparison with a Plate during Flat Rolling

by Joong-Ki Hwang

Processes 2020, 8(3), 327; https://doi.org/10.3390/pr8030327 - 10 Mar 2020

Cited by 10 | Viewed by 6107

Abstract

The thermal behavior of a rod during the hot shape rolling process was investigated using the off-line hot rolling simulator and numerical simulation. Additionally, it was compared with a plate during the flat rolling process to understand the thermal behavior of the rod [...] Read more.

The thermal behavior of a rod during the hot shape rolling process was investigated using the off-line hot rolling simulator and numerical simulation. Additionally, it was compared with a plate during the flat rolling process to understand the thermal behavior of the rod during the hot rolling process in more detail. The temperature of the rod and plate during the hot rolling process was measured at several points with thermocouples using the rolling simulator, and then the measured temperature of each region of a workpiece was analyzed with numerical simulation. During hot rolling process, the temperature distribution of the rod was very different from the plate. The temperature deviation of the rod with area was much higher than that of the plate. The variation in effective stress of the rod along the circumferential direction can induce the temperature difference with area of the rod, whereas the plate had a relatively lower temperature deviation with area due to the uniform effective stress on the surface area. The heat generation by plastic deformation during the forming process also increased the temperature deviation of the rod with area, whereas strain distribution of the plate during flat rolling contributed to the uniformity of temperature of the plate with area. The higher temperature deviation of the rod along the circumferential and radial directions during the shape rolling process can increase the possibility of occurrence in surface defects compared to the plate during flat rolling. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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14 pages, 11263 KiB

Open AccessArticle

Numerical Analysis on Velocity and Temperature of the Fluid in a Blast Furnace Main Trough

by Yao Ge, Meng Li, Han Wei, Dong Liang, Xuebin Wang and Yaowei Yu

Processes 2020, 8(2), 249; https://doi.org/10.3390/pr8020249 - 22 Feb 2020

Cited by 7 | Viewed by 3222

Abstract

The main trough is a part of the blast furnace process for hot metal and molten slag transportation from the tap hole to the torpedo, and mechanical erosion of the trough is an important reason for a short life of a campaign. This [...] Read more.

The main trough is a part of the blast furnace process for hot metal and molten slag transportation from the tap hole to the torpedo, and mechanical erosion of the trough is an important reason for a short life of a campaign. This article employed OpenFoam code to numerically study and analyze velocity, temperature and wall shear stress of the fluids in the main trough during a full tapping process. In the code, a three-dimensional transient mass, momentum and energy conservation equations, including the standard k-ε turbulence model, were developed for the fluid in the trough. Temperature distribution in refractory is solved by the Fourier equation through conjugate heat transfer with the fluid in the trough. Change velocities of the fluid during the full tapping process are exactly described by a parabolic equation. The investigation results show that there are strong turbulences at the area of hot metal’s falling position and the turbulences have influence on velocity, temperature and wall shear stress of the fluid. With the increase of the angle of the tap hole, the wall shear stress increases. Mechanical erosion of the trough has the smallest value and the campaign of the main trough is estimated to expand over 5 days at the tap hole angle of 7°. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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18 pages, 7279 KiB

Open AccessArticle

A Mathematical Model Combined with Radar Data for Bell-Less Charging of a Blast Furnace

by Meng Li, Han Wei, Yao Ge, Guocai Xiao and Yaowei Yu

Processes 2020, 8(2), 239; https://doi.org/10.3390/pr8020239 - 20 Feb 2020

Cited by 11 | Viewed by 3934

Abstract

Charging directly affects the burden distribution of a blast furnace, which determines the gas distribution in the shaft of the furnace. Adjusting the charging can improve the distribution of the gas flow, increase the gas utilization efficiency of the furnace, reduce energy consumption, [...] Read more.

Charging directly affects the burden distribution of a blast furnace, which determines the gas distribution in the shaft of the furnace. Adjusting the charging can improve the distribution of the gas flow, increase the gas utilization efficiency of the furnace, reduce energy consumption, and prolong the life of the blast furnace. In this paper, a mathematical model of blast furnace charging was developed and applied on a steel plant in China, which includes the display of the burden profile, burden layers, descent speed of the layers, and ore/coke ratio. Furthermore, the mathematical model is developed to combine the radar data of the burden profile. The above model is currently used in Nanjing Steel as a reference for operators to adjust the charging. The model is being tested with a radar system on the blast furnace. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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14 pages, 4522 KiB

Open AccessArticle

Numerical Study of Binary Trickle Flow of Liquid Iron and Molten Slag in Coke Bed by Smoothed Particle Hydrodynamics

by Shungo Natsui, Kazui Tonya, Hiroshi Nogami, Tatsuya Kikuchi, Ryosuke O. Suzuki, Ko-ichiro Ohno, Sohei Sukenaga, Tatsuya Kon, Shingo Ishihara and Shigeru Ueda

Processes 2020, 8(2), 221; https://doi.org/10.3390/pr8020221 - 14 Feb 2020

Cited by 8 | Viewed by 3266

Abstract

In the bottom region of blast furnaces during the ironmaking process, the liquid iron and molten slag drip into the coke bed by the action of gravity. In this study, a practical multi-interfacial smoothed particle hydrodynamics (SPH) simulation is carried out to track [...] Read more.

In the bottom region of blast furnaces during the ironmaking process, the liquid iron and molten slag drip into the coke bed by the action of gravity. In this study, a practical multi-interfacial smoothed particle hydrodynamics (SPH) simulation is carried out to track the complex liquid transient dripping behavior involving two immiscible phases in the coke bed. Numerical simulations were performed for different conditions corresponding to different values of wettability force between molten slag and cokes. The predicted dripping velocity changes and interfacial shape were investigated. The relaxation of the surface force of liquid iron plays a significant role in the dripping rate; i.e., the molten slag on the cokes acts as a lubricant against liquid iron flow. If the attractive force between the coke and slag is smaller than the gravitational force, the slag then drops together with the liquid iron. When the attractive force between the coke and slag becomes dominant, the iron-slag interface will be preferentially detached. These results indicate that transient interface morphology is formed by the balance between the momentum of the melt and the force acting on each interface. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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18 pages, 3596 KiB

Open AccessArticle

Parametric Dimensional Analysis on a C-H₂ Smelting Reduction Furnace with Double-Row Side Nozzles

by Jinyin Xie, Bo Wang and Jieyu Zhang

Processes 2020, 8(2), 129; https://doi.org/10.3390/pr8020129 - 21 Jan 2020

Cited by 6 | Viewed by 2772

Abstract

Higher requirements for steel smelting technology have been put forward based on the increasing awareness of energy conservation and environmental protection. In the field of iron making, carbon reduction processes are often used. In this study, molten iron was smelted by designing a [...] Read more.

Higher requirements for steel smelting technology have been put forward based on the increasing awareness of energy conservation and environmental protection. In the field of iron making, carbon reduction processes are often used. In this study, molten iron was smelted by designing a C-H₂ smelting reduction method. Although previous researchers have studied this through a large number of physical and numerical simulations, they have not yet refined general laws from the perspective of dimensional analysis. In this paper, a double-row side blow hydraulics simulation was carried out in the C-H₂ smelting reduction furnace, and an entire list of dimensionless groups of input and output parameters was proposed based on its hydraulics simulation data. The expressions between the dimensionless group of mixing time and dimensionless groups such as Capillary number (Ca) and Lagrange group (La₁) were obtained by multiple linear regression based on the experimental research results and data analysis. By verifying the calculated and experimental values of the dimensionless group of mixing time, it can be seen that both have a good positive correlation. This study provides a better methodology for controlling key parameters and lays the foundation for the optimal design of the process parameters for the C-H₂ smelting reduction furnace. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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14 pages, 3132 KiB

Open AccessArticle

Model and Algorithm for Planning Hot-Rolled Batch Processing under Time-of-Use Electricity Pricing

by Zhengbiao Hu, Dongfeng He, Wei Song and Kai Feng

Processes 2020, 8(1), 42; https://doi.org/10.3390/pr8010042 - 01 Jan 2020

Cited by 12 | Viewed by 3264

Abstract

Batch-type hot rolling planning highly affects electricity costs in a steel plant, but previous research models seldom considered time-of-use (TOU) electricity pricing. Based on an analysis of the hot-rolling process and TOU electricity pricing, a batch-processing plan optimization model for hot rolling was [...] Read more.

Batch-type hot rolling planning highly affects electricity costs in a steel plant, but previous research models seldom considered time-of-use (TOU) electricity pricing. Based on an analysis of the hot-rolling process and TOU electricity pricing, a batch-processing plan optimization model for hot rolling was established, using an objective function with the goal of minimizing the total penalty incurred by the differences in width, thickness, and hardness among adjacent slabs, as well as the electricity cost of the rolling process. A method was provided to solve the model through improved genetic algorithm. An analysis of the batch processing of the hot rolling of 240 slabs of different sizes at a steel plant proved the effectiveness of the proposed model. Compared to the man–machine interaction model and the model in which TOU electricity pricing was not considered, the batch-processing model that included TOU electricity pricing produced significantly better results with respect to both product quality and power consumption. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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13 pages, 2776 KiB

Open AccessArticle

Understanding TiN Precipitation Behavior during Solidification of SWRH 92A Tire Cord Steel by Selected Thermodynamic Models

by Lu Wang, Zheng-Liang Xue, Yi-Liang Chen and Xue-Gong Bi

Processes 2020, 8(1), 10; https://doi.org/10.3390/pr8010010 - 19 Dec 2019

Cited by 15 | Viewed by 2297

Abstract

Tire cord steel is widely used in the tire production process of the vehicle manufacturing industry due to its excellent strength and toughness. Titanium nitride (TiN) inclusion, existing in tire rod, has a seriously detrimental effect on the fatigue and drawing performances of [...] Read more.

Tire cord steel is widely used in the tire production process of the vehicle manufacturing industry due to its excellent strength and toughness. Titanium nitride (TiN) inclusion, existing in tire rod, has a seriously detrimental effect on the fatigue and drawing performances of the tire steel. In order to control its amount and morphology, the precipitation behavior of TiN during solidification in SWRH 92A tire cord steel was analyzed by selected thermodynamic models. The calculated results showed that TiN cannot precipitate in the liquid phase region regardless of the selected models. However, the precipitation of TiN in the mushy zone would occur at the final stage during the solidification process (at solid fractions greater than 0.98) if the LRSM (Lever-rule model was applied for the N and Scheil model for Ti) or Ohnaka models (without considering the effect of carbon on secondary dendrite arm spacing (SDAS)) were adopted. For the Ohnaka model, in the case when the effect of carbon on SDAS was considered, TiN would probably precipitate in the solid phase zone rather than precipitate in the liquid phase region or mushy zone. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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12 pages, 5629 KiB

Open AccessArticle

Validation of the Burden Distribution of the 1/3-Scale of a Blast Furnace Simulated by the Discrete Element Method

by Hiroshi Mio, Yoichi Narita, Kaoru Nakano and Seiji Nomura

Processes 2020, 8(1), 6; https://doi.org/10.3390/pr8010006 - 18 Dec 2019

Cited by 15 | Viewed by 2935

Abstract

The objective of this paper was to develop a prediction tool for the burden distribution in a charging process of a bell-less-type blast furnace using the discrete element method (DEM). The particle behavior on the rotating chute and on the burden surface was [...] Read more.

The objective of this paper was to develop a prediction tool for the burden distribution in a charging process of a bell-less-type blast furnace using the discrete element method (DEM). The particle behavior on the rotating chute and on the burden surface was modeled, and the burden distribution was analyzed. Furthermore, the measurements of the burden distribution in a 1/3-scale experimental blast furnace were performed to validate the simulated results. Particle size segregation occurred during conveying to the experimental blast furnace. The smaller particles were initially discharged followed by the larger ones later. This result was used as an input in the simulation. The burden profile simulated using DEM was similar to the experimental one. The terrace was found at the burden surface subsequent to ore-charging, and its simulated position simulated agreed with that of the experimental result. The surface angle of the ore layer was mostly similar. The simulated ore to coke mass ratio (O/C) distribution in the radial direction and the mean particle diameter distribution correlated with the experimental results very well. It can be concluded that this method of particle simulation of the bell-less charging process is highly reliable in the prediction of the burden distribution in a blast furnace. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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15 pages, 5190 KiB

Open AccessFeature PaperArticle

Model Study on Burden Distribution in COREX Melter Gasifier

by Haifeng Li, Zongshu Zou, Zhiguo Luo, Lei Shao and Wenhui Liu

Processes 2019, 7(12), 892; https://doi.org/10.3390/pr7120892 - 01 Dec 2019

Cited by 5 | Viewed by 3172

Abstract

COREX is one of the commercialized smelting reduction ironmaking processes. It mainly includes two reactors, i.e., a (reduction) shaft furnace (SF) and a melter gasifier (MG). In comparison with the conventional blast furnace (BF), the COREX MG is not only equipped with a [...] Read more.

COREX is one of the commercialized smelting reduction ironmaking processes. It mainly includes two reactors, i.e., a (reduction) shaft furnace (SF) and a melter gasifier (MG). In comparison with the conventional blast furnace (BF), the COREX MG is not only equipped with a more complicated top charging system consisting of one gimbal distributor for coal and eight flap distributors for direct reduction iron (DRI), but also the growth mechanism of its burden pile is in a developing phase, rather than that in a fully-developed phase in a BF. Since the distribution of charged burden plays a crucial role in determining the gas flow and thus in achieving a stable operation, it is of considerable importance to investigate the burden distribution influenced by the charging system of COREX MG. In the present work, a mathematical model is developed for predicting the burden distribution in terms of burden layer structure and radial ore/coal ratio within the COREX MG. Based on the burden pile width measured in the previous physical experiments at different ring radii on a horizontal flat surface, a new growth mechanism of burden pile is proposed. The validity of the model is demonstrated by comparing the simulated burden layer structure with the corresponding results obtained by physical experiments. Furthermore, the usefulness of the mathematical model is illustrated by performing a set of simulation cases under various charging matrixes. It is hoped that the model can be used as a what-if tool in practice for the COREX operator to gain a better understanding of burden distribution in the COREX MG. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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9 pages, 2777 KiB

Open AccessArticle

Numerical Simulation of the Raceway Zone in Melter Gasifier of COREX Process

by Ye Sun, Ren Chen, Zuoliang Zhang, Guoxi Wu, Huishu Zhang, Lingling Li, Yan Liu, Xiaoliang Li and Yan Huang

Processes 2019, 7(12), 867; https://doi.org/10.3390/pr7120867 - 20 Nov 2019

Cited by 5 | Viewed by 2230

Abstract

The physical and chemical processes in the raceway zone of the COREX melter–gasifier express are similar to those inside the blast furnace. Based on the research achievements on blast furnaces, the unsteady numerical simulation of a gas-solid two-phase in the raceway was carried [...] Read more.

The physical and chemical processes in the raceway zone of the COREX melter–gasifier express are similar to those inside the blast furnace. Based on the research achievements on blast furnaces, the unsteady numerical simulation of a gas-solid two-phase in the raceway was carried out by using computational fluid software. The formation process of the raceway in the COREX melter–gasifier was simulated. The shape and size of the raceway were obtained. Then, the effect of gas flow on the depth and height of the raceway was analyzed in this paper. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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17 pages, 3768 KiB

Open AccessFeature PaperArticle

Development of an Electric Arc Furnace Simulator Based on a Comprehensive Dynamic Process Model

by Thomas Hay, Thomas Echterhof and Ville-Valtteri Visuri

Processes 2019, 7(11), 852; https://doi.org/10.3390/pr7110852 - 14 Nov 2019

Cited by 13 | Viewed by 4924

Abstract

A simulator and an algorithm for the automatic creation of operation charts based on process conditions were developed on the basis of an existing comprehensive electric arc furnace process model. The simulator allows direct user input and real-time display of results during the [...] Read more.

A simulator and an algorithm for the automatic creation of operation charts based on process conditions were developed on the basis of an existing comprehensive electric arc furnace process model. The simulator allows direct user input and real-time display of results during the simulation, making it usable for training and teaching of electric arc furnace operators. The automatic control feature offers a quick and automated evaluation of a large number of scenarios or changes in process conditions, raw materials, or equipment used. The operation chart is adjusted automatically to give comparable conditions at tapping and allows the assessment of the necessary changes in the operating strategy as well as their effect on productivity, energy, and resource consumption, along with process emissions. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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12 pages, 2523 KiB

Open AccessArticle

Titanium Distribution Ratio Model of Ladle Furnace Slags for Tire Cord Steel Production Based on the Ion–Molecule Coexistence Theory at 1853 K

by Jialiu Lei, Dongnan Zhao, Wei Feng and Zhengliang Xue

Processes 2019, 7(11), 788; https://doi.org/10.3390/pr7110788 - 01 Nov 2019

Cited by 4 | Viewed by 2388

Abstract

High-strength tire cord steel is mainly used in radial ply tires, but the presence of brittle Ti inclusions can cause failure of the wires and jeopardize their performance in production. In order to control the titanium content during steel production, a thermodynamic model [...] Read more.

High-strength tire cord steel is mainly used in radial ply tires, but the presence of brittle Ti inclusions can cause failure of the wires and jeopardize their performance in production. In order to control the titanium content during steel production, a thermodynamic model for predicting the titanium distribution ratio between CaO–SiO₂–Al₂O₃–MgO–FeO–MnO–TiO₂ slags during the ladle furnace (LF) refining process at 1853 K has been established based on the ion–molecule coexistence theory (IMCT), combined with industrial measurements, and the effect of basicity on the titanium distribution ratio was discussed. The results showed that the titanium distribution ratio predicted by the developed IMCT exhibited a dependable agreement with the measurements, and the optical basicity is suggested to reflect the correlation between basicity and the titanium distribution ratio. Furthermore, quantitative titanium distribution ratios of TiO₂, CaO·TiO₂, MgO·TiO₂, FeO·TiO₂, and MnO·TiO₂ were acquired by the IMCT model, respectively. Calculation results revealed that the structural unit CaO plays a pivotal role in the slags in the de-titanium process. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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12 pages, 3629 KiB

Open AccessArticle

Arsenic Removal from Arsenopyrite-Bearing Iron Ore and Arsenic Recovery from Dust Ash by Roasting Method

by Rijin Cheng, Hua Zhang and Hongwei Ni

Processes 2019, 7(10), 754; https://doi.org/10.3390/pr7100754 - 16 Oct 2019

Cited by 17 | Viewed by 4502

Abstract

In most cases, arsenic is an unfavorable element in metallurgical processes. The mechanism of arsenic removal was investigated through roasting experiments performed on arsenopyrite-bearing iron ore. Thermodynamic calculation of arsenic recovery was carried out by FactSage 7.0 software (Thermfact/CRCT, Montreal, Canada; GTT-Technologies, Ahern, [...] Read more.

In most cases, arsenic is an unfavorable element in metallurgical processes. The mechanism of arsenic removal was investigated through roasting experiments performed on arsenopyrite-bearing iron ore. Thermodynamic calculation of arsenic recovery was carried out by FactSage 7.0 software (Thermfact/CRCT, Montreal, Canada; GTT-Technologies, Ahern, Germany). Moreover, the arsenic residues in dust ash were recovered by roasting dust ash in a reducing atmosphere. Furthermore, the corresponding chemical properties of the roasted ore and dust ash were determined by X-ray diffraction, inductively coupled plasma atomic emission spectrometry, and scanning electron microscopy, coupled with energy-dispersive X-ray spectroscopy. The experimental results revealed that the arsenic in arsenopyrite-bearing iron ore can be removed in the form of As₂O₃(g) in an air or nitrogen atmosphere by a roasting method. The efficiency of arsenic removal through roasting in air was found to be less than that in nitrogen atmosphere. The method of roasting in a reducing atmosphere is feasible for arsenic recovery from dust ash. When the carbon mass ratio in dust ash is 1.83%, the arsenic removal products is almost volatilized and recovered in the form of As₂O₃(g). Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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10 pages, 3421 KiB

Open AccessArticle

Bubble Motion and Interfacial Phenomena during Bubbles Crossing Liquid–Liquid Interfaces

by Hongliang Zhao, Jingqi Wang, Wanlong Zhang, Mingzhuang Xie, Fengqin Liu and Xiaochang Cao

Processes 2019, 7(10), 719; https://doi.org/10.3390/pr7100719 - 10 Oct 2019

Cited by 9 | Viewed by 3471

Abstract

In metallurgical and chemical engineering processes, the gas–liquid–liquid multiphase flow phenomenon is often encountered. The movement of bubbles in the liquid, and the influence of bubbles on the liquid–liquid interface, have been the focus of extensive research. In the present work, an air–water–oil [...] Read more.

In metallurgical and chemical engineering processes, the gas–liquid–liquid multiphase flow phenomenon is often encountered. The movement of bubbles in the liquid, and the influence of bubbles on the liquid–liquid interface, have been the focus of extensive research. In the present work, an air–water–oil system was used to explore the movement of bubbles and the phenomenon that occurs when bubbles pass through an interface with various oil viscosities at various gas flow rates. The results show that bubble movement is greatly influenced by the viscosity of the oil at low gas flow rates. The type of phase entrainment and the jet height was changed when increasing the gas flow rate. The stability of the water–oil interface was enhanced with increasing viscosity of the oil phase. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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12 pages, 7512 KiB

Open AccessFeature PaperArticle

Discrete Element Method (DEM) and Experimental Studies of the Angle of Repose and Porosity Distribution of Pellet Pile

by Han Wei, Meng Li, Ying Li, Yao Ge, Henrik Saxén and Yaowei Yu

Processes 2019, 7(9), 561; https://doi.org/10.3390/pr7090561 - 23 Aug 2019

Cited by 9 | Viewed by 4289

Abstract

The lumpy zone in a blast furnace is composed of piles formed naturally during burden charging. The properties of this zone have significant effects on the blast furnace operation, including heat and mass transfer, chemical reactions and gas flow. The properties of the [...] Read more.

The lumpy zone in a blast furnace is composed of piles formed naturally during burden charging. The properties of this zone have significant effects on the blast furnace operation, including heat and mass transfer, chemical reactions and gas flow. The properties of the layers mainly include the angle of repose and porosity distribution. This paper introduces two methods, the Discharging Method and the Lifting Method, to study the influence of the packing method on the angle of repose of the pile. The relationships of the angle of repose and porosity with physical parameters are also investigated. The porosity distribution in the bottom of a pile shows a decreasing trend from the region below the apex to the center. The coordination number of the particles is employed to explain this change. The maximum of the frequency distribution of it was found to show a negative correlation to the static friction coefficient, but becomes insensitive to the parameter as the static friction coefficient increases above 0.6. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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14 pages, 3525 KiB

Open AccessArticle

Numerical Simulation of Effects of Different Operational Parameters on the Carbon Solution Loss Ratio of Coke inside Blast Furnace

by Mingyin Kou, Heng Zhou, Li Pang Wang, Zhibin Hong, Shun Yao, Haifa Xu and Shengli Wu

Processes 2019, 7(8), 528; https://doi.org/10.3390/pr7080528 - 09 Aug 2019

Cited by 4 | Viewed by 3892

Abstract

Carbon solution loss reaction of coke gasification is one of the most important reasons for coke deterioration and degradation in a blast furnace. It also affects the permeability of gas and fluids, as well as stable working conditions. In this paper, a three [...] Read more.

Carbon solution loss reaction of coke gasification is one of the most important reasons for coke deterioration and degradation in a blast furnace. It also affects the permeability of gas and fluids, as well as stable working conditions. In this paper, a three dimensional model is established based on the operational parameters of blast furnace B in Bayi Steel. The model is then used to calculate the effects of oxygen enrichment, coke oven gas injection, and steel scrap charging on the carbon solution loss ratio of coke in the blast furnace. Results show that the carbon solution loss ratio of coke gasification for blast furnace B is almost 20% since the results of a model are probably only indicative. The oxygen enrichment and the addition of steel scrap can reduce the carbon solution loss ratio with little effect on the working condition. However, coke oven gas injection increases the carbon solution loss ratio. Therefore, coke oven gas should not be injected into the blast furnace unless the quality of the coke is improved. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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18 pages, 4479 KiB

Open AccessFeature PaperArticle

Principal Component Analysis of Blast Furnace Drainage Patterns

by Mauricio Roche, Mikko Helle and Henrik Saxén

Processes 2019, 7(8), 519; https://doi.org/10.3390/pr7080519 - 07 Aug 2019

Cited by 7 | Viewed by 3520

Abstract

Monitoring and control of the blast furnace hearth is critical to achieve the required production levels and adequate process operation, as well as to extend the campaign length. Because of the complexity of the draining, the outflows of iron and slag may progress [...] Read more.

Monitoring and control of the blast furnace hearth is critical to achieve the required production levels and adequate process operation, as well as to extend the campaign length. Because of the complexity of the draining, the outflows of iron and slag may progress in different ways during tapping in large blast furnaces. To categorize the hearth draining behavior, principal component analysis (PCA) was applied to two extensive sets of process data from an operating blast furnace with three tapholes in order to develop an interpretation of the outflow patterns. Representing the complex outflow patterns in low dimensions made it possible to study and illustrate the time evolution of the drainage, as well as to detect similarities and differences in the performance of the tapholes. The model was used to explain the observations of other variables and factors that are known to be affected by, or affect, the state of the hearth, such as stoppages, liquid levels, and tap duration. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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12 pages, 4862 KiB

Open AccessArticle

Flow Behavior and Hot Processing Map of GH4698 for Isothermal Compression Process

by Rongchuang Chen, Haifeng Xiao, Min Wang and Jianjun Li

Processes 2019, 7(8), 491; https://doi.org/10.3390/pr7080491 - 01 Aug 2019

Cited by 6 | Viewed by 2779

Abstract

An in-depth understanding of the flow behaviors of materials deformed at high temperatures is of paramount significance. However, insufficient research on the nickel-based GH4698 alloy has resulted in inaccurate material flow prediction or even cracking in the practical billet opening of GH4698 large [...] Read more.

An in-depth understanding of the flow behaviors of materials deformed at high temperatures is of paramount significance. However, insufficient research on the nickel-based GH4698 alloy has resulted in inaccurate material flow prediction or even cracking in the practical billet opening of GH4698 large forgings. In this study, hot compressions were performed at 950–1150 °C and 0.001–3 s⁻¹. Single-peaked strain-stress curves were obtained under various conditions, owing to dislocation motions in dynamic recrystallizations. The Arrhenius model was formulated to accurately describe the flow stress evolutions and the mean prediction error of the flow stress was 5.90%. Processing maps were constructed at various hot working conditions. It was found that the hot working ability of GH4698 markedly decreased under lower temperatures (950–1080 °C) and higher strain rates (0.1–3 s⁻¹). Optimal thermal processing parameters were suggested. In sum, this study systematically investigated the flow behaviors and hot working ability of GH4698 in isothermal compressions. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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9 pages, 3176 KiB

Open AccessArticle

Experimental Study on Precipitation Behavior of Spinels in Stainless Steel-Making Slag under Heating Treatment

by Jianli Li, Qiqiang Mou, Qiang Zeng and Yue Yu

Processes 2019, 7(8), 487; https://doi.org/10.3390/pr7080487 - 01 Aug 2019

Cited by 12 | Viewed by 3236

Abstract

The stability of chromium in stainless steel slag has a positive correlation with spinel particle size and a negative correlation with the calcium content of the spinel. The effect of heating time on the precipitation of spinel crystals in the CaO-SiO₂-MgO-Al [...] Read more.

The stability of chromium in stainless steel slag has a positive correlation with spinel particle size and a negative correlation with the calcium content of the spinel. The effect of heating time on the precipitation of spinel crystals in the CaO-SiO₂-MgO-Al₂O₃-Cr₂O₃-FeO system was investigated in the laboratory. Scanning electron microscopy with energy-dispersive and X-ray diffraction were adopted to observe the microstructure, test the chemical composition, and determine the mineral phases of synthetic slags, and FactSage7.1 was applied to calculate the crystallization process of the molten slag. The results showed that the particle size of the spinel crystals increased from 9.42 to 10.73 μm, the calcium content in the spinel crystals decreased from 1.38 at% to 0.78 at%, and the content of chromium in the spinel crystal increased from 16.55 at% to 22.78 at% with an increase in the heating time from 0 min to 120 min at 1450 °C. Furthermore, the species of spinel minerals remained constant. Therefore, an extension in the heating time is beneficial for improving the stability of chromium in stainless steel slag. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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15 pages, 3789 KiB

Open AccessArticle

Physical Simulation of Molten Steel Homogenization and Slag Entrapment in Argon Blown Ladle

by Fu Yang, Yan Jin, Chengyi Zhu, Xiaosen Dong, Peng Lin, Changgui Cheng, Yang Li, Lin Sun, Jianhui Pan and Qiang Cai

Processes 2019, 7(8), 479; https://doi.org/10.3390/pr7080479 - 24 Jul 2019

Cited by 8 | Viewed by 3816

Abstract

Argon stirring is one of the most widely used metallurgical methods in the secondary refining process as it is economical and easy, and also an important refining method in clean steel production. Aiming at the issue of poor homogeneity of composition and temperature [...] Read more.

Argon stirring is one of the most widely used metallurgical methods in the secondary refining process as it is economical and easy, and also an important refining method in clean steel production. Aiming at the issue of poor homogeneity of composition and temperature of a bottom argon blowing ladle molten steel in a Chinese steel mill, a 1:5 water model for 110 t ladle was established, and the mixing time and interface slag entrainment under the different conditions of injection modes, flow rates and top slag thicknesses were investigated. The flow dynamics of argon plume in steel ladle was also discussed. The results show that, as the bottom blowing argon flow rate increases, the mixing time of ladle decreases; the depth of slag entrapment increases with the argon flow rate and slag thickness; the area of slag eyes decreases with the decrease of the argon flow rate and increase of slag thickness. The optimum argon flow rate is between 36–42 m³/h, and the double porous plugs injection mode should be adopted at this time. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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13 pages, 1985 KiB

Open AccessArticle

Gaussian Process-Based Hybrid Model for Predicting Oxygen Consumption in the Converter Steelmaking Process

by Sheng-Long Jiang, Xinyue Shen and Zhong Zheng

Processes 2019, 7(6), 352; https://doi.org/10.3390/pr7060352 - 08 Jun 2019

Cited by 22 | Viewed by 3694

Abstract

Oxygen is one of the most important energies used in converter steelmaking processes of integrated iron and steel works. Precisely forecasting oxygen consumption before processing can benefit process control and energy optimization. This paper assumes there is a linear relationship between the oxygen [...] Read more.

Oxygen is one of the most important energies used in converter steelmaking processes of integrated iron and steel works. Precisely forecasting oxygen consumption before processing can benefit process control and energy optimization. This paper assumes there is a linear relationship between the oxygen consumption and input materials, and random noises are caused by other unmeasurable materials and unobserved reactions. Then, a novel hybrid prediction model integrating multiple linear regression (MLR) and Gaussian process regression (GPR) is introduced. In the hybrid model, the MLR method is developed to figure the global trend of the oxygen consumption, and the GPR method is applied to explore the local fluctuation caused by noise. Additionally, to accelerate the computational speed on the practical data set, a K-means clustering method is devised to respectively train a number of GPR models. The proposed hybrid model is validated with the actual data collected from an integrated iron and steel work in China, and compared with benchmark prediction models including MLR, artificial neural network, support vector machine and standard GPR. The forecasting results indicate that the suggested model is able to not only produce satisfactory point forecasts, but also estimate accurate probabilistic intervals. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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Review

Jump to: Editorial, Research

16 pages, 3555 KiB

Open AccessReview

Dead-Man Behavior in the Blast Furnace Hearth—A Brief Review

by Lei Shao, Qilin Xiao, Chengbo Zhang, Zongshu Zou and Henrik Saxén

Processes 2020, 8(11), 1335; https://doi.org/10.3390/pr8111335 - 22 Oct 2020

Cited by 11 | Viewed by 10873

Abstract

The blast furnace campaign length is today usually restricted by the hearth life, which is strongly related to the drainage and behavior of the coke bed in the hearth, usually referred to as the dead man. Because the hearth is inaccessible and the [...] Read more.

The blast furnace campaign length is today usually restricted by the hearth life, which is strongly related to the drainage and behavior of the coke bed in the hearth, usually referred to as the dead man. Because the hearth is inaccessible and the conditions are complex, knowledge and understanding of the state of the dead man are still limited compared to other parts of the blast furnace process. Since a number of publications have studied different aspects of the dead man in the literature, the purpose of the current review is to compile the findings and knowledge in a comprehensive document. We mainly focus on contributions with respect to the dead man state, and those assessing its influence on the hearth performance in terms of liquid flow patterns, lining wear and drainage behavior. A set of common modeling approaches in this specific furnace area is also briefly presented. The aim of the review is also to deepen the understanding and stimulate further research on open questions related to the dead man in the blast furnace hearth. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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22 pages, 651 KiB

Open AccessReview

Physical and Mathematical Modelling of Mass Transfer in Ladles due to Bottom Gas Stirring: A Review

by Alberto N. Conejo

Processes 2020, 8(7), 750; https://doi.org/10.3390/pr8070750 - 27 Jun 2020

Cited by 17 | Viewed by 3441

Abstract

Steelmaking involves high-temperature processing. At high temperatures mass transport is usually the rate limiting step. In steelmaking there are several mass transport phenomena occurring simultaneously such as melting and dissolution of additions, decarburization, refining (De-P and De-S), etc. In ladle metallurgy, refining is [...] Read more.

Steelmaking involves high-temperature processing. At high temperatures mass transport is usually the rate limiting step. In steelmaking there are several mass transport phenomena occurring simultaneously such as melting and dissolution of additions, decarburization, refining (De-P and De-S), etc. In ladle metallurgy, refining is one of the most important operations. To improve the rate of mass transfer bottom gas injection is applied. In the past, most relationships between the mass transfer coefficient (mtc) and gas injection have been associated with stirring energy as the dominant variable. The current review analyzes a broad range of physical and mathematical modeling investigations to expose that a large number of variables contribute to define the final value of the mtc. Since bottom gas injection attempts to improve mixing phenomena in the whole slag/steel system, our current knowledge shows limitations to improve mixing conditions in both phases simultaneously. Nevertheless, some variables can be optimized to reach a better performance in metallurgical ladles. In addition to this, the review also provides a state of the art on liquid–liquid mass transfer and suggests the current challenges in this field. Full article

(This article belongs to the Special Issue Process Modeling in Pyrometallurgical Engineering)

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