Metallurgical Research Articles

Development of Software for Hydrometallurgical Calculation of Metal Extraction

Hydrometallurgy plays a critical role in the metallurgical industry by providing an efficient method for extracting metals from ores and secondary materials using aqueous solutions. This approach is particularly advantageous for processing low-grade and complex ores, as well as secondary resources that cannot be effectively processed by traditional pyrometallurgical methods. The objective of this study is to develop specialized software to automate and optimize the calculations necessary for metal extraction in hydrometallurgical processes. The software integrates a complete computational framework for automating the various stages of the hydrometallurgical process, including ore composition initialization, total element mass calculations, and the determination of metal concentrations in both metal products (matte) and by-products (slag). The methodology involves the design and implementation of a web-based application using Django for the user interface and MySQL for robust data storage. The computational module, written in Python, automates the mathematical operations required to simulate complex chemical reactions and metal extraction processes. This module supports real-time processing and ensures accurate calculations for each stage of metal extraction, including leaching, extraction, re-extraction, sorption, and electrolysis. The software also features detailed tables and dynamic graphs that allow users to analyze the distribution of valuable metals and assess the influence of key operational parameters on extraction efficiency. The results show that the developed software successfully manages large datasets, enhances the precision of hydrometallurgical calculations, and minimizes the risk of human error. The implementation of the software leads to significant improvements in the economic efficiency of production by optimizing metal recovery rates and reducing operational costs. Additionally, it supports comprehensive process control by providing actionable insights into each stage of extraction, thus improving the quality of the final metal product. Overall, the software represents a significant technological advancement in the field, offering a scalable solution for industries aiming to streamline hydrometallurgical processes.

Distribution of Pb, Zn, Fe, As, Sn, Sb, Bi, and Ni Between Oxide Liquid and Metal in the ‘CuO0.5’-CaO-AlO1.5 System in Equilibrium with Cu Metal at 1400 °C

AbstractThe increasing complexity of ore resources and recycled materials in the feed of pyrometallurgical processes present a technical challenge to the metallurgical engineers working on maximizing the recovery of the valuable elements and minimizing the environmental impact of the processes. To address this challenge, the availability of computational tools that can predict the mass and energy balance in complex systems is required. Then, the accurate description of phase equilibria in the complex multicomponent systems describing the chemistry of the pyrometallurgical processes becomes critical for the correct implementation of the indicated tools and facing the outlined industrial challenges. In the present study, the distribution of selected elements (Pb, Zn, Fe, As, Sn, Sb, Bi, and Ni) between oxide liquid and metal in the ‘CuO0.5’–CaO–AlO1.5 system in equilibrium with Cu metal at 1400 °C (liquidus of CaAl2O4) was experimentally studied using the equilibration and quenching technique followed by the electron probe X-ray microanalysis of the resulted samples. The study covered a wide range of effective p(O2) over the system from 10−11 to 10−3.5 (corresponding to formation of immiscible CuO0.5-rich slag). To avoid loss of volatile elements (Pb, Zn, As, Sn, Sb, and Bi), a correlation between ‘CuO0.5’ in oxide liquid and p(O2) in open system was obtained first, followed by studying the volatile elements distribution in closed conditions (Al2O3 crucible sealed in SiO2 ampoule), where ‘CuO0.5’ concentration was used as a marker to evaluate the effective p(O2) over the system. The experimental results were then used for the optimization of the thermodynamic model parameters of the system as part of the integrated experimental and self-consisting thermodynamic modeling research program of phase equilibria in the Cu–Pb–Zn–Fe–Ca–Si–Al–Mg–O–S–(As, Sn, Sb, Bi, Ag, Au, Ni, Cr, Co, and Na) gas/oxide liquid/matte/speiss/metal/solids system. Graphical Abstract

Recent Advances in Metallurgical Extractive Processes

Recent Advances in Metallurgical Extractive Processes

Calculation model of enjoyment of dust particles by swirking flow in gas flowes

An analysis of the reasons for the formation of deposits in the flue ducts of aspiration systems was carried out. Problems have been noted in removing deposits with compressed air. The purpose of the work is to solve the problems of aspiration systems and reduce the formation of dust deposits in gas ducts. This is possible due to the swirling of the compressed air flow when purging the gas duct. Despite significant pressure losses when organizing flow swirl, compressed air consumption is reduced by 20–40%. A computational model of the entrainment of dust particles by a swirling flow in gas ducts is presented. To describe the physical model of the movement of a dust particle in a swirling gas flow flowing in a gas duct with a circular cross-section, polar coordinates are used. Dependencies have been deter-mined to determine the value of the average axial velocity of the swirling flow required to move a particle along the gas duct. A diagram of the coordinate axes and forces acting on the particle is presented. The forces acting on the dust particle and its connections with the inner surface of the flue are replaced by the reaction of the flue wall. By decomposing the wall reaction into tangential and normal components, differential equations were obtained that describe the motion of the particle. The dust particle is significantly influenced by the forces of resistance to flow around the gas flow Fμ, the friction force on the wall of the gas duct Ffr, the weight of the particle P, the normal reaction of the wall of the gas duct N. Analysis of the fractional composition of various dusts contained in gases aspirated from the equipment of the metallurgical industry and the production of electrode materials showed that For these dusts, the optimal flow is a weak swirl of intensity W*= 0.5–0.8. This swirling intensity can be achieved by introducing a flow of compressed air when blowing at an angle of 36–48°.

Teaching Aid Regarding the Application of Advanced Organic Petrography in Recycling End-of-Life Lithium-Ion Batteries

This teaching aid aims to illustrate a range of the most common materials in end-of-life (EoL) lithium-ion batteries (LIBs) to demonstrate the usefulness of advanced organic petrography in the characterization of EoL LIB materials and to assess the efficiency of LIB recycling processes from the pre-processing stage up to the impurities of the metallurgical processes. Additionally, it may be useful for students, petrographers, and professionals in battery development and recycling.

Phosphorus removal from steelmaking slag by selective leaching in the steel pickling waste liquor

Steelmaking slag and steel pickling waste liquor (SPWL) are two kinds of by-products in steel plants. The existence of phosphorus (P) in steelmaking slag is the main factor affecting its reuse within the steelmaking process. To remove P from steelmaking slag with a low-cost method, selective leaching was proposed by using SPWL as a leaching agent. SPWL generally contains a small amount of Fe3+ ions, and thus the effect of Fe3+ content in SPWL on the dissolution behavior (especially P element) of steelmaking slag was investigated, as well as the pH value and steelmaking slag type. The dissolution ratios of P from various slags in the SPWL containing 500 ppm Fe3+ exceeded 95 % at pH 1.5 while those of Fe, Mn, and Al were very low, exhibiting satisfied selective leaching of P. Increasing pH value and Fe3+ content (in SPWL) resulted in a decreasing P dissolution ratio while exerting an insignificant effect on the dissolution of other elements. The FeHPO4+ was predicted as the predominant species during leaching and the transformation of FeHPO4+ to FePO4 could be present. When the SPWL containing 800 ppm Fe3+ was used, FePO4 was observed in the residues after leaching at pH 2.0, resulting in a worse removal of P from slag. However, the residues including massive valuable components had an extremely low P content after leaching in the SPWL containing 500 ppm Fe3+ at pH 1.5, which can be used as a flux in the metallurgical process. To ensure a high P removal rate from steelmaking slag and to prevent FePO4 precipitation during leaching, a relatively low pH and Fe3+ content in the SPWL are necessary.

VOF-based modeling study of surface oscillation behavior and gas–liquid stirring dynamics in the bottom-blown reactors

Gas bottom-blown reactors are widely employed in the chemical, metallurgical, and biochemical industries due to their superior mixing capabilities. This study numerically investigates the gas–liquid flow hydrodynamics and bubble dynamics in a bottom-blown system with a circular boundary using the volume of fluid approach. Following the experimental validation of the mathematical model, the study evaluates the effects of gas flow rates, liquid heights, and fluid medium properties on both the dynamics of the bubble swarm and the mixing characteristics of the flow field. The results indicate that: (1) Rising bubbles disturb the fluid, generating numerous vortices that facilitate momentum transfer for effective gas stirring; (2) The height of the liquid surface oscillation during the bottom-blown process exhibits significant temporal variation, with the peak showing clear lateral swings; (3) Due to the nonlinear interactions involving bubble coalescence and breakup during their ascent, along with constructive and destructive interference between liquid surface waves, the liquid surface can exhibit violent fluctuations at certain moments; (4) Bubble size and aspect ratio significantly influence liquid surface oscillations; (5) The bubble rising path displays instability due to vortex shedding, with some vortices forming at locations where the bubble shape changes abruptly. A bubble velocity prediction equation is proposed: uc=σ5.2737Lcρc4.2737/16156μl9.5475.

Mechanistic understanding of banded microstructure and its effect on anisotropy of toughness in low carbon-low alloy steel

In this study, the relationship between the anisotropy of toughness and microstructure in low carbon low alloy steel treated by quenching and tempering (QT) heat treatment was investigated with the aid of scanning electron microscope, electron back-scattered diffraction and transmission electron microscope combined with energy disperse spectroscopy techniques. Results show that the impact toughness of the quenched steel plate along the longitudinal and transverse directions are little different. However, after tempering, the longitudinal impact toughness of QT steel plate is improved by 88%, while the transverse impact toughness is slightly decreased, leading to a significant anisotropy of toughness. Microstructural characterizations reveal that banded microstructure with coarse grain size exists along longitudinal direction (i.e., rolling direction) of steel plate, which is attributed to co-segregation of Mn and C and the resulting uneven recrystallization during hot rolling. After tempering, fine and dispersed carbides are precipitated in matrix microstructure, but high-density coarse carbides are formed within banded microstructure. It is suggested that the coarse grains and high-density coarse carbides significantly deteriorate the resistance against crack propagation along banded microstructure, leading to the anisotropy of toughness of QT steel plate. The findings of this study will aid to design metallurgical processes including chemical composition design, hot rolling, and heat treatments to eliminate the anisotropy of toughness of low alloy steels with high strength and toughness.

A IMPLANTAÇÃO DA METODOLOGIA 5S EM UMA CÉLULA DE MONTAGEM DE UMA INDÚSTRIA METALÚRGICA

The 5S methodology originates from Japan and is based on the application of five concepts: Seiri, Seiton, Seiso, Seiketsu, and Shitsuke. The 5S method focuses on organizing different sectors of a company based on organization, standardization, cleanliness, and discipline. It is a behavioral improvement program characterized by fostering teamwork, organizing the work environment, preserving employee well-being, maintaining productivity, and emphasizing cleanliness and organization. The objective of this work is to describe the implementation of the 5S methodology through the physical rearrangement in a medium-sized metallurgical industry. The research, characterized as a case study in a company in the interior of the state of São Paulo, is carry out applied and qualitative approach, presenting the implementation of a 5S improvement project through physical rearrangement. The choose of the 5S methodology is due to the fact that consolidating, enhancing, or creating an organizational routine facilitates the adoption of the studied concepts in a real case within a medium-sized industry that manufactures and sells fitness equipment. The implementation of the 5S program began with the approval of the management, achieved through awareness demonstrated by photographic evidence showing the current status of the company. This project’s implementation was necessary due to the evident problems arising from a lack of organization, cleanliness, and the conditions where the products were found in the sector. Its implementation led to a significant improvement in production processes in terms of quality, efficiency, and productivity, as well as enhancements in visual aspects and workplace conditions. It can be concluded that the 5S Program is a simple philosophy that is easy to implement, but its results entirely depend on the level of engagement of the people involved. Although challenges exist in the implementation process, particularly of a behavioral nature, technical improvements were also observed, resulting in a more positive work environment and a more efficient industrial routine. Despite still having many actions to be taken, it is considered that the 5S Program was successful in its implementation.

Heat-resistant concretes based on cement binders and waste from the metallurgical industry

The main direction of the development of heat-resistant concrete production is the use of new materials, ensuring mechanization and industrialization of construction, increasing the performance characteristics of refractory compositions, reducing material consumption, introducing waste-free technologies in the production of concrete with increased physical and mechanical characteristics under prolonged exposure to high temperatures on cement binders and waste from the metallurgical industry and reducing environmental pollution. A significant environmental impact on the environment is exerted by large-tonnage technogenic waste produced by JSC «Aluminum of Kazakhstan» – bauxite sludge obtained by processing bauxite into alumina containing 42.7% Fe2O3. The prospects of its application as a filler in heat-resistant concretes are considered, which makes it possible to increase the physico-mechanical and thermal characteristics. The composition and properties of this waste and the change in the properties of heat-resistant concrete during the introduction of filler have been studied. Reactive alumina has been studied, which is 99.9% submicron alumina with a very low content of Na2O oxide. It is shown that the properties of concrete change after the introduction of iron-containing waste in the amount of 5% and reactive alumina – 37.5% and 38.8%. Their volumetric weight, control strength, and other properties are increased. The improvement of physical, mechanical, and thermal characteristics depends on the structure and neoplasms in the obtained samples. Samples of heat-resistant concrete were analyzed using electron probe X-ray spectral qualitative and quantitative microanalysis and X-ray fluorescence spectrometry and it was shown that the iron-alumina waste contributes to the compaction of the structure due to its resistance to delamination and has increased fluidity at low humidity in the cementing mass. For further investigation of the physical-thermal characteristics, depending on the structure and neoplasms in the obtained samples, a petrographic method using a polarization microscope in transmitted and reflected light is required.

Manufacturing production as a source of growth: the case of Portugal

The aim of this paper is to test the relationship between manufacturing production and economic growth in Portugal from the 1950s to the present day, following Nicholas Kaldor’s (1908–1986) thinking, which assumes that manufacturing is the true engine of the economic activity of a country. By estimating a series of econometric models, including a Vector Autoregressive (VAR) model, it was possible to identify a positive relationship between growth and manufacturing production since the 1950s. The results also show that each increase of 1 percentage point (pp) in real growth rate of the production of basic metallurgical industries and manufacture of metallic products in a certain year t−1 for the period 1956–2019, caused an increase of 0.07 pp in the Portuguese economic growth during a following year t on average. We hope that these findings will stimulate new and interesting research regarding the important issues of manufacturing production and economic growth.

Modeling Freeze‐Lining Formation: A Case Study in the Slag Fuming Process

Slag fuming (SF) is a metallurgical process designed to recycle Zn‐containing slags derived from various industrial residues. To protect the reactor from corrosive molten slag, a deliberate as‐solidified slag layer, known as a freeze lining (FL), is formed on the reactor walls using intense water‐cooled jackets. In this article, a computational‐fluid‐dynamics‐based model capable of simulating FL formation in a SF furnace is presented. To capture the complex multiphase flow dynamics, heat transfer, and FL formation during SF, a volume‐of‐fluid model is coupled with a mixture continuum solidification model. Three phases are considered: gas, liquid bulk slag, and solid slag (FL). Moreover, two types of FL are distinguished: one that solidifies on the reactor wall in the bulk slag region and another that solidifies on the reactor wall in the freeboard region owing to slag splashing. Comparisons between calculated FL thickness and heat fluxes and corresponding industrial data demonstrate satisfactory agreement. In this outcome, the robustness of the model is underscored and confidence in its accuracy is instilled. In the simulation results, valuable insights are provided into the evolution of the fuming process, particularly regarding the slag bath temperature, slag splashing dynamics, FL formation, local heat fluxes through the reactor wall, and global net energy balance.

Prediction model of permeability index for blast furnace based on WD-NL-transformer

The permeability index is an important variable to reflect the operating state of a blast furnace quickly, intuitively and comprehensively. Given the multi-scale, nonlinear and massive characteristics of the blast furnace smelting process data, a prediction model of permeability index based on the WD-NL-transformer (wavelet de-noising-nonlinear-transformer) method was proposed. The key variables affecting permeability index were selected from multiple perspectives by Pearson correlation coefficient and copula entropy. The extreme outliers were optimised using box plots and Lagrange linear interpolation. A data set was constructed after wavelet de-noising to build the prediction model with nonlinear processing capability, time-series prediction capability, and early stopping method. The results show that the MSE of WD-NL-transformer is 0.0093, with the RMSE of 0.0086. Meanwhile, the R2 is 0.9859, and the running time is 19.59 s, which means the model has great prediction accuracy and inference speed. The proposed model could provide theoretical support for advanced control of permeability index, which is of practical significance to ensure the stability of blast furnace smelting and accelerate the metallurgical process of intelligent automation.

CO2 plasma inducing steel-slag with active sites for efficient growth of carbon nanotubes for the high-performance microwave absorption

As a solid waste generated in the metallurgical process, the highly efficient catalysis of steel-slag for carbon nanotube (CNT) growth remains a huge challenge. Herein, a CO2 plasma-inducing approach for modifying the steel-slag catalyst with rich active sites was developed for CNT growth in the chemical vapor deposition (CVD) process. Furthermore, the high-energy CO2 plasma refines the particles on the steel-slag surface, reducing the particle size on the surface of steel-slag effectively increasing the active sites of the catalyst. In addition, the thermal effect generated by the gas molecule ionization process under CO2 increases the background temperature of the steel-slag, and the interaction between the oxygen-active substances produced and the iron oxide on the surface of steel-slag undergoes an oxidation reaction upon full contact with high-energy particles, which greatly improves the catalytic efficiency of the steel-slag as a catalyst for CNT, and increases the catalytic efficiency by 50 % compared with the non-plasma modified steel-slag as a catalyst for catalyzing CNTs. In addition, catalytically grown CNTs encapsulate magnetic steel-slag catalysts to form a three-dimensional CNT network structure, with high-performance electromagnetic wave absorption. The composite absorbing material with a thickness of only 3.55 mm has a minimum absorption rate of −64.08 dB for electromagnetic waves at a frequency of 7.9 GHz. The dielectric and the magnetic loss of steel-slag lead to enhanced electromagnetic wave absorption. Therefore, this study provides an inexpensive and environmentally friendly idea for the design of high-efficiency CNT growth and solid waste catalyst modification synthesized with high-performance absorbers.

Simulation-Based Design for Recycling of Car Electronic Modules as a Function of Disassembly Strategies

Modules (or parts) of a car are a complex functional material combination used to deliver a specified task for a car. Recovering all materials, energy, etc., into high-grade materials at their end of life (EoL) is impossible. This is dictated by the second law of thermodynamics (2LT) and thence economics. Thus, recyclability cannot be conducted with simplistic mass-based approaches void of thermodynamic considerations. We apply, in this paper, a process simulation model to estimate the true recyclability of various SEAT (Volkswagen Group) car parts within the EU H2020 TREASURE project. This simulation model is developed with 190 reactors and over 310 feed components with over 1000 reaction species in the 880 streams of the flowsheet. The uniqueness of the work in this paper is to apply the full material declaration (FMD) and bill of materials (BOM) of all 310 materials in the parts as a feed to the process simulation model to show the parts’ true recyclability. We classified all parts into categories, i.e., copper-rich, steel-rich and plastic-rich, to maximally recover metals at the desired material quality, as well as energy. Recyclability is understood to create high-grade products that can be applied with the same functional quality in these parts. In addition, disassembly strategies and related possible redesign show how much recyclability can be improved. Process simulation permits the creation of alloys, phases, materials, etc., at a desired quality. The strength of the simulation permits any feed from any End-of-Life part to be analyzed, as long as the FMD and BOM are available. This is analogous to any mineral and metallurgical engineering process simulation for which the full mineralogy must be available to analyze and/or design flowsheets. This paper delivers a wealth of data for various parts as well as the ultimate recovery of materials, elements, and energy. The results show clearly that there is no one single recycling rate for elements, materials, and alloys. It is in fact a function of the complexity and material combinations within the parts. The fact that we use a thermochemical-based process simulator with full compositional detail for the considered parts means full energy balances as well as exergy dissipation can be evaluated. This means that we can also evaluate which parts, due complex mixtures of plastics, are best processed for energy recovery or are best for material and metal recovery, with thermochemistry, reactor technology and integrated flowsheets being the basis.

Mullite–Silicate Proppants Based on High-Iron Bauxite and Waste from Metallurgical Industry in Kazakhstan

Mullite–Silicate Proppants Based on High-Iron Bauxite and Waste from Metallurgical Industry in Kazakhstan

High-Temperature Creep Resistance of FeAlOY ODS Ferritic Alloy.

A significant effort in optimizing the chemical composition and powder metallurgical processing led to preparing new-generation ferritic coarse-grained ODS alloys with a high nano-oxide content. The optimization was aimed at high-temperature creep and oxidation resistance at temperatures in the range of 1100-1300 °C. An FeAlOY alloy, with the chemical composition Fe-10Al-4Cr-4Y2O3 (wt. %), seems as the most promising one. The consolidation of the alloy is preferably conducted by hot rolling in several steps, followed by static recrystallization for 1 h at 1200 °C, which provides a stable coarse-grain microstructure with homogeneous dispersion of nano-oxides. This represents the most cost-effective way of production. Another method of consolidation tested was hot rotary swaging, which also gave promising results. The compression creep testing of the alloy at 1100, 1200, and 1300 °C shows excellent creep performance, which is confirmed by the tensile creep tests at 1100 °C as well. The potential in such a temperature range is the target for possible applications of the FeAlOY for the pull rods of high-temperature testing machines, gas turbine blades, or furnace fan vanes. The key effort now focuses on expanding the production from laboratory samples to larger industrial pieces.

Modelling and experimental study on pipeline defect characterisations using a pulsed eddy current measurement

ABSTRACT Pipelines are widely used as the main transportation method in petrochemical and metallurgical industries. However, the special nature of the materials transported in pipelines means they are often subjected to high temperature, high pressure and corrosive conditions. This can lead to defects, such as thinning and cracking, resulting in pipeline failure and causing serious economic losses. Therefore, regular non-destructive testing of pipelines is particularly important. This paper uses the non-destructive testing method with pulsed eddy current technology to characterise pipeline thinning and defects. A preliminary study is conducted on the pulsed eddy current detection signal patterns for pipeline crack defects with varying orientations and quantities. A more portable pulsed eddy current detection device with an extended wall thickness detection range is developed. It can achieve measurements with a maximum thickness of 30 mm for detections of pipelines with rectangular defects and thickness-stepped reduced. The experimental results are consistent with modelling results, and the accuracy for pipelines with insulation layer is also investigated. On-site measurements using the PEC system are conducted on equipment sections with pipe thickness within 20 mm in a petrochemical plant. It is confirmed that the developed PEC inspection device can accurately characterises the thickness of pipelines with 0–50 mm cladding.

A review of in-situ high-temperature characterizations for understanding the processes in metallurgical engineering

A review of in-situ high-temperature characterizations for understanding the processes in metallurgical engineering

Oxygen Content Control in the Electroslag Remelting Process: An Incremental Learning Strategy Based on Optimized Wasserstein Generative Adversarial Network with Gradient Penalty Data Augmentation

Electroslag remelting (ESR) is essential for producing high‐end special steel, but its complex process and numerous influencing factors make quality control challenging. This study addresses oxygen content control during ESR using a big data machine learning approach. An incremental learning strategy is proposed based on an optimized Wasserstein generative adversarial network with gradient penalty (WGAN‐GP) for data enhancement, focusing on G20Cr2Ni4A bearing steel. The WGAN‐GP model enhances time‐series data and metadata, utilizing long short‐term memory networks, fully connected networks, and attention mechanisms. The effectiveness of data enhancement is verified using a deep neural network classifier and statistical methods. Data is divided into historical and data streams, with an incremental learning strategy based on histogram gradient boosting regression trees to prevent catastrophic forgetting and improve efficiency through knowledge distillation and real‐time hyperparameter adjustment. Results show that the data augmentation method significantly improves model generalization and accuracy in small sample metallurgy. The incremental learning strategy enhances prediction accuracy for oxygen content, contributing to better cleanliness quality of electroslag steel. This study offers a novel approach for addressing small sample challenges in metallurgical processes.