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The paper describes cementation as a suitable method applied in the refining of EAFD leachates in order to obtain required purity of ZnO for specific industrial application. For study of cementation conditions, the leachate from alkaline leaching with (NH4)2CO3 was used. The leachates contained a high amount of zinc (8000–12,000 µg/mL) and a low content of impurities such as iron, lead, copper, chromium and manganese in the range of 1–21 µg/mL. Cementation conditions were predicted by thermodynamic study, theoretically confirming the viability of the proposed experiments at the considered pH = 8–9. Cementation experiments were carried out using powdered zinc and aluminium (5 g/L) as cementation agents in the first phase separately. To increase the cementation efficiency, their combination was used (2.5:2.5 g/L or 5:5 g/L) at temperatures of 20, 40, 60 and 80 °C for 30 min. The optimum cementation conditions were established as: Zn:Al = 5:5 g/L, 60 °C. Under the given conditions, 100% of Fe, Cu, Pb and Mn were removed from the leachate. The ZnO with the maximum purity of 96.67% was obtained by crystallization of cemented leachate at 105 °C, followed by calcination at 900 °C for 4 h. ZnO with such a purity is suitable for use in the electrical or rubber industries. [ABSTRACT FROM AUTHOR]

In this paper, the Al-K2ZrF6 reaction system was used to prepare in-situ Al3Zr/AA6082 particle-reinforced aluminum matrix composites by electromagnetic stirring melt reaction method, and the friction stir welding technology was used to weld the plate. The microstructure and mechanical properties of the welded joints were studied when the rotating speed was 14000 rpm and the welding speed was 30, 50 and 70 mm/min respectively. The results show that the weld forming quality and tensile properties of the FSW joints with welding parameters of 14000 rpm and 50 mm/min are the best, the tensile strength is 142(±0.5) MPa and the elongation is 8.2%. SEM analysis shows that the particle size of the reinforcing phase in the base metal is refined to about 5-10 µm, while that in the NZ is about 1-5 µm. The grain size in the HAZ is about 20-30 µm and in the NZ is about 5-10 µm. EBSD analysis shows that the proportion of low-angle grain boundary in the NZ is 59.7% and of recrystallized grain structure is 23.65%, while the proportion of small-angle grain boundary in the HAZ is 24.35% and of recrystallized grain structure is 37.18%. It provides theoretical and experimental basis for the forming and application of friction stir welding of the composite. [ABSTRACT FROM AUTHOR]

Potassium salt of the iridium(III) chloronitro complex fac-K3[Ir(NO2)3Cl3] is obtained in the interaction of the iridium(III) trinitrotriaqua complex with potassium chloride in an aqueous solution. The salt structure is analyzed by single crystal X-ray diffraction. Crystallographic data: a = 7.3460(3) Å, b = 12.9904(5) Å, c = 13.1841(6) Å, β = 93.924(1)°, space group P21/с, Z = 4, ρcal = 3.026 g/cm3. In the crystal structure, molecules of the [Ir(NO2)3Cl3]3– complex anion having a distorted octahedral geometry (Ir–N = 2.02-2.04 Å, Ir–Cl = 2.37-2.38 Å) are arranged in layers perpendicular to the с axis. Spectral characteristics (IR, Raman, UV-vis) of the salt are determined together with its transformations during thermolysis in the inert atmosphere. Experiments are performed on sorption of the [Ir(NO2)3Cl3]3– complex on nickel hydroxide, which model iridium loss during the precious metal refining process by the precipitation scheme. [ABSTRACT FROM AUTHOR]

The present investigation delves into the potential of vertical zone refining as an effective purification technique for achieving high-purity tin (Sn) metal. The utilization of vertical zone refining offers distinct advantages over traditional horizontal zone refining, as it allows for enhanced control over the molten zone and solid–liquid interface, ultimately leading to superior impurity separation efficiency. The present study reveals that the solute partition coefficients (k0) of various impurity elements, such as Zn, Ag, Al, Mg, Ca, Ni, In, Co, Cu, As, Pb, Fe, and Bi, during the vertical zone refining process consistently demonstrate values below one. Notably, the partition coefficient of Sb deviates slightly from the others, being greater than one but approaching one. The authors achieve exceptional levels of purity in both the bottom and middle regions of the rod by subjecting the Sn melt to nine passes of vertical zone refining at a heating temperature of 405 °C and a downward pulling rate of 10 µm/s, resulting in purities exceeding 6N4. Furthermore, by evaluating the effective partition coefficients (keff), it was determined that impurity elements, such as Cu and Bi, closely approach their equilibrium partition coefficients, reaching values of approximately 0.492 and 0.327, respectively. To further enhance the purity of Sn metal and maximize product yield, we propose the utilization of electrolytic refining and vacuum distillation, with particular emphasis on the efficient separation of five specific elements, including Cu, Fe, As, Pb, and Sb. By elucidating these findings, this study not only contributes valuable insights into the efficacy of vertical zone refining as a purification technique for high-purity tin metal, but also offers important recommendations for refining strategies and impurity element separation. [ABSTRACT FROM AUTHOR]

The amount of alloy added during the LF refining process affects the hit rate of steel composition control. Therefore, improving the accuracy of the alloy addition amount can help improve efficiency and reduce production costs. To address the existing problem of inaccurate alloy addition in the refining process, the group established an alloy addition prediction model based on an improved whale swarm optimization algorithm and stochastic configuration network (LWOA-SCN) with the historical smelting data of a steel mill. The model can effectively improve the prediction accuracy and convergence speed of the model. The research results show that the model is more advantageous in improving the hit rate of alloy addition, which provides theoretical guidance for practical production. [ABSTRACT FROM AUTHOR]

The results presented in this paper are the next planned stage of research on the process of steel refining from dispersoid non-metallic phase by means of its filtration. The acquired results of macro and microstructure anlyzes, as well as steel cleanliness before and after the filtration process, reflect the course of the research and attest that it can be an effective and cheap method of refining it from non-metallic inclusions. Presented results confirm that the slenderness of a filter has a significant impact on the effectiveness of the steel filtration process. Products of deoxidation have been identified on the filtration surface of ceramic filters. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This contribution demonstrates the benefits of a transatlantic history of early modern mining that encompasses both a cross-pollination of approaches and a critical reexamination of the field's underlying assumptions. It applies to Álvaro Alonso Barba's 1640 El arte de los metales conceptual frameworks developed by historians of early modern European mining, by scholars of labor and science in the colonial Andes, and by theorists of reader reception and scholarly practice. This analysis offers a revised understanding of Pamela Long's model of the "trading zone" as a vision of knowledge production promoted by elite Europeans and shaped by the dialogic model of knowledge production taught at European universities. Parallels between Barba and the German humanist and metallurgical author Georg Agricola (1494–1555) underscore the applicability of these findings with respect to Barba for early modern mining more generally. [ABSTRACT FROM AUTHOR]

Given the complex structure of the wire rod of the stator end winding of a large turbine generator, this paper studies the equivalent method of the wire rod. We performed a three-point bending test on the wire rod structure using finite element software to obtain the bending stiffness and deflection of the wire rod. Then, the equivalent wire rod was established by a reasonable method. Moreover, the simplified wire rod is used to build the structure of turbogenerator end winding to reduce the calculation time. A mathematical model of the vibration of the stator end winding is developed by equating it to a composite shell to reflect its vibration characteristics. These research results will assist in designing and improving generator end structures. [ABSTRACT FROM AUTHOR]

Solar cells, liquid crystal displays (LCDs) and light-emitting diodes (LEDs) have become more and more important in recent decades. Crucial components of such electronic devices include rare metals (e.g., indium and gallium), which are only available in limited quantities. In order to meet their rising demand in the coming years, recycling processes, especially those that enable selective recovery of the individual components, are steadily gaining in importance. One conceivable method is particle-loaded solvent extraction followed by mechanical processing. Therefore, we first investigated the possibility of recovering individual particle fractions from a multicomponent mixture on the basis of the surface properties. Both UV–Vis spectroscopy and small-angle X-ray scattering (WAXS) were used for evaluation. The conducted experiments showed, among other things, that the indium oxide content increased from 50% to 99% in a binary system and from 33% to 94% in a ternary compound. In addition, the purification of the separated particles was examined in detail. Using UV–Vis spectrometry, it was found that permeation washing of filter cakes is suitable for removing impurities and retrieving most of the solvent used. Based on the results of the conducted laboratory tests, we finally developed a concept for the continuous and selective recovery of rare metals. [ABSTRACT FROM AUTHOR]

Argon bottom stirring is commonly practiced in secondary steelmaking processes due to its positive effects on achieving uniform temperatures and chemical compositions throughout a steel melt. It can also be used to facilitate slag metal refining reactions. The inter-mixing phenomena associated with argon gas injection through porous plugs set in the bottom and its stirring efficiency can be summarized by evaluations of 95% mixing times. This study focuses on investigating the impact of different plug positions and ratios of argon flow rates from two plugs on mixing behavior within a 110-tonne, elliptical-shaped industrial ladle. A quasi-single-phase modeling technique was employed for this purpose. The CFD findings revealed that the optimal position of the second plug is to be placed diametrically opposite the existing one at an equal mid-radius distance (R/2). An equal distribution of argon flow rates yielded the best results in terms of refractory erosion. A comparative study was conducted between single- and dual-plug-configured ladles based on flow behavior and wall shear stresses using this method. Furthermore, a transient multiphase model was developed to examine the formation of slag open eyes (SOE) for both single- and dual-plug configurations using a volume of fluid (VOF) model. The results indicated that the dual-plug configuration outperformed the current single-plug configuration. [ABSTRACT FROM AUTHOR]

The balance between the strength and the toughness of pure tantalum (Ta) fabricated with selective laser melting (SLM) additive manufacturing is a major challenge due to the defect generation and affinity for oxygen and nitrogen. This study investigated the effects of energy density and post-vacuum annealing on the relative density and microstructure of SLMed tantalum. The influences of microstructure and impurities on strength and toughness were mainly analyzed. The results indicated that the toughness of SLMed tantalum significantly increased due to a reduction in pore defects and oxygen-nitrogen impurities, with energy density decreasing from 342 J/mm3 to 190 J/mm3. The oxygen impurities mainly stemmed from the gas inclusions of tantalum powders, while nitrogen impurities were mainly from the chemical reaction between the molten liquid tantalum and nitrogen in the atmosphere. The proportion of <110> texture decreased after vacuum-annealing at 1200 °C, while that of the <100> texture increased. Concurrently, the density of dislocations and small-angle grain boundaries significantly decreased while the resistance of the deformation dislocation slip was significantly reduced, enhancing the fractured elongation up to 28% at the expense of 14% tensile strength. [ABSTRACT FROM AUTHOR]

[Display omitted] • A one-step leaching process for spent LiCoO 2 based on the mechanochemical method. • The new application of grape skins promotes the leaching of spent LiCoO 2. • Effect of mechanical activation on the interfacial reaction of spent LiCoO 2. • The mechanism of mechanochemical leaching was analyzed by BET, PSD, XRD, and XPS. A one-step system based on mechanochemical activation and the use of grape skins (GS) was proposed to recover metals from lithium-ion batteries (LIBs) cathode waste. The effects of the ball-milling (BM) speed, BM time, and quantity of added GS on the metal leaching rate were explored. The spent lithium cobalt oxide (LCO) and its leaching residue before and after mechanochemistry were characterized by SEM, BET, PSD, XRD, FT-IR, and XPS analysis. Our study shows that mechanochemistry promotes the leaching efficiency of metals from LIBs battery cathode waste by changing the cathode material properties (that is, reducing the LCO particle size (12.126 μm ∼ 0.0928 μm), increasing the specific surface area (0.123 m2/g ∼ 15.957 m2/g), enhancing the hydrophilicity and surface free energy (57.44 mN/m2 ∼ 66.18 mN/m2), promoting the generation of mesoporous structures, refining grains, disrupting the crystal structure, and increasing the microscopic strain, while deflecting the binding energy of the metal ions). A green, efficient and environmentally friendly process for the harmless and resource-friendly treatment of spent LIBs has been developed in this study. [ABSTRACT FROM AUTHOR]

Pair distribution functions (PDFs) are a leading tool for atomic structure analysis of nanomaterials. However, the most widely used programs for refining atomic structure against PDF data are based on extended crystallographic models, which cannot be applied to discrete, whole nanoparticles. This work describes a straightforward approach to simulate and refine atomistic models of discrete clusters and nanoparticles employing widely used PDF modelling programs such as PDFgui [Farrow et al. (2007). J. Phys. Condens. Matter, 19, 335219] that utilize extended crystallographic models. In this approach, the whole particle to be modelled is contained within an expanded, and otherwise empty, unit cell that is sufficiently large to avoid correlations between atoms in neighbouring unit cells over the r range analysed. The PDF of the particle is simulated as a composite using two conventional 'phases': one that calculates the atom–atom correlations and one that approximates the local number density. This approach is first validated for large nanoparticles that are well modelled by a conventional shape factor model, and then applied to simulate the PDF of discrete particles and low‐dimensional materials (graphene and MXene) and to model the experimental PDF data for single‐layer FeS nanosheets. A comparison of this approach with the DiffPy‐CMI program [Juhás et al. (2015). Acta Cryst. A71, 562–568], which calculates the PDF of discrete species, shows that the composite modelling approach is equally or more accurate. Example input files for implementing this approach within PDFgui and TOPAS [Coelho (2018). J. Appl. Cryst.51, 210–218], and recommendations for selecting model parameters for reliable application of this refinement strategy, are provided. [ABSTRACT FROM AUTHOR]

Mixing is one of the most common processes in various branches of the chemical industry: food, construction, oil refining, pharmaceuticals, and others. Increasing the intensity of mixing can be achieved by changing the speed or direction of movement of the impeller, which is confirmed by studies of domestic and foreign authors. In this paper, a planetary drive of a stirred tank is considered, which makes it possible to implement various types of uneven movement of the impeller. The advantages of the proposed mechanism over existing analogues are compactness, reliability, and ease of setting the coefficient of uneven rotation of the agitator. On the basis of the IKA laboratory reactor, an experimental setup is constructed, with the help of which comparative tests of the heat-transfer intensity in a traditional mixing device with a constant rotational speed and using the proposed planetary mechanism are carried out. As a result of the experiment, it is found that the transmission to the impeller of uneven movement can reduce the mixing time, as well as increase the energy efficiency of the apparatus. [ABSTRACT FROM AUTHOR]

Crystalline metals generally exhibit good deformability but low strength and poor irradiation tolerance. Amorphous materials in general display poor deformability but high strength and good irradiation tolerance. Interestingly, refining characteristic size can enhance the flow strength of crystalline metals and the deformability of amorphous materials. Thus, crystalline–amorphous nanostructures can exhibit an enhanced strength and an improved plastic flow stability. In addition, high-density interfaces can trap radiation-induced defects and accommodate free volume fluctuation. In this article, we review crystalline–amorphous nanocomposites with characteristic microstructures including nanolaminates, core–shell microstructures, and crystalline/amorphous-based dual-phase nanocomposites. The focus is put on synthesis of characteristic microstructures, deformation behaviors, and multiscale materials modelling. [ABSTRACT FROM AUTHOR]

LF refining slag addition is an important factor affecting the end steel composition of the refining process. In order to better control the end steel composition and improve the production efficiency, this paper uses an improved whale optimization algorithm to optimize twin support vector machines to establish a LF refining slag addition prediction model. The LWOA-TSVR model is trained and tested by historical data, and the model has a strong generalization capability and high accuracy. Applying the model to the industrial production process, it was verified that the model has high prediction accuracy and can provide guidance for the actual refining production process of LF refining slag addition, which is important for the control of the end steel composition. [ABSTRACT FROM AUTHOR]

This paper elaborates on the modeling and control of an Unmanned Aerial Vehicle (UAV) for delivery purposes, thereby integrating computer-aided design, multibody dynamic modeling, and motion control analysis in a unified framework. The UAV system designed in this study and utilized for item delivery has a quadcopter structure composed of four arms connected to a central trunk. In this investigation, the proposed design of the delivery drone is systematically modeled employing the multibody approach, while SIMSCAPE MULTIBODY is the software used for performing the dynamic analysis and for devising the final design of the control system. To this end, starting from the CAD model designed using SOLIDWORKS, the control system of the quadcopter is developed by performing dynamic simulations in the MATLAB/SIMULINK environment. Additionally, another fundamental contribution of this paper is the analytical derivation of the nonlinear set of algebraic constraint equations peculiar to the present multibody system, which characterizes the kinematics of the delivery drone and describes the relative angular velocity imposed between two rigid bodies as nonholonomic constraints. Furthermore, as discussed in detail in this paper, the choice of the propulsion system and the design of the individual components heavily depends on the structural and functional needs of the UAV under study. On the other hand, the control system devised in this work is based on cascaded Proportional-Integral-Derivative (PID) controllers, which are suitable for achieving different maneuvers that are fundamental for the motion control of the delivery drone. Therefore, the final performance of the UAV system is a consequence of the regulation of the feedback parameters that characterize the PID controllers. In this respect, the paper presents the refining of the parameters characterizing the PID controllers by using both an internal MATLAB tool, which automatically tunes the controller gains of single-input single-output systems, and by observing the resulting transient behavior of the UAV system, which is obtained through extensive dynamical simulations. The set of numerical results found in this investigation demonstrates the high performance of the dynamical behavior of the UAV system designed in this work. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The corrosion resistance of 316 stainless steel (316SS) in molten KCl-MgCl2 salts was studied through static immersion corrosion at high temperatures. Below 600 °C, the corrosion rate of 316SS increased slowly with increasing temperature. When the salt temperature rises to 700 °C, the corrosion rate of 316SS increases dramatically. The corrosion of 316SS is mainly due to the selective dissolution of Cr and Fe at high temperatures. The impurities in molten KCl-MgCl2 salts could accelerate the dissolution of Cr and Fe atoms in the grain boundary of 316SS, and purification treatment can reduce the corrosivity of KCl-MgCl2 salts. Under the experimental conditions, the diffusion rate of Cr/Fe in 316SS changed more with temperature than the reaction rate of salt impurities with Cr/Fe. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrorefining and electrodeposition treat polymetallic concentrates from WPCBs. • Electrorefining shows well-adapted metal leaching and Cu upgrading functionalities. • Cu2+, Ni2+, Fe2+, and Zn2+ sequential electrodeposition was evaluated. • Complex electrochemical response mechanism of Ni2+ to solution environment. Multi metal recycling from waste printed circuit boards (WPCBs) is attractive for resource conservation and sustainability. While smelting is commonly adopted to produce polymetallic concentrates from WPCBs, current processes cost oxidation smelting and fire refining followed by electrorefining to deport co-existing base metals and recover copper, which can cause substantial metal losses, long steps, and lack of effective methods for subsequent base metal recycling. Here, direct electrorefining of polymetallic concentrates (Cu-Ni-Fe-Pb-sn-Au-Ag) combined with electrodeposition was investigated to realize multi metal separation and purification. It was found that direct electrorefining of concentrates in H 2 SO 4 /CuSO 4 electrolyte at 0.4 V realized >98% base metal dissolution and copper production (∼99% purity), serving as a combined metal leaching and copper electrowinning procedure. PbSO 4 -SnO 2 -Cu 5 FeS 4 precipitate was formed in anode slime, with Ag-Au enriched by 8.5–61 times. Analysis on subsequent selective metal electrodeposition revealed the blocking effect of Zn2+ and overlapped potential region of Fe2+-Ni2+, emphasizing the importance of Zn and Fe pre-separation during smelting and chemical precipitation. Electrodeposition experiments demonstrated high selectivity for Cu and Ni at 0.05 and −0.7 V, where Ni2+ shows complex electroreduction behaviors. The proposed process can serve as an alternative feasible route for multi metal recycling from WPCBs. [ABSTRACT FROM AUTHOR]

Magnesium and magnesium in-situ composites have significant potential in the application of design and manufacturing for automotive and aerospace industries because of their high specific strength and reduced fuel consumption. But there are many challenges for machining of Mg based alloys and composites because of the high tendency of fire and oxidation. These challenges can be minimized through microstructural engineering. In this present study, the machining performances of AZ91 Mg alloy and in-situ hybrid TiC+TiB 2 reinforced AZ91 metal matrix composite was investigated. The effect β-Mg 17 Al 12 phases and grain refinement with and without in-situ particles on machinability were studied through microstructural engineering via aging and friction stir processing. The end milling operation was carried out at different cutting speeds ranging from 25 mm/min to 90 mm/min under dry environment by using an AlTiN-coated tungsten carbide tool. The optimum cutting speed for machining was found to be 75 mm/min based on the surface roughness values of all conditioned materials. The base material with dendritic microstructure was found to have poor machinability in terms of inadequate surface finish and edge-burrs formation. The combined effect of in-situ TiC+TiB 2 particles addition and grain refinement enhanced the machining performance of the material with superior surface finish, negligible edge-burr formation and better tool wear resistance. The influence of in-situ TiC+TiB 2 particles, β-Mg 17 Al 12 phases and grain refinement on machining characteristics are explained based on the tool wear mechanisms, chip behavior and machining induced affected zone. [ABSTRACT FROM AUTHOR]

Urban agriculture is emerging as a method to improve food security and public health in cities across the United States. However, an increased risk of exposure to heavy metals and metalloids (HMM) exists through interaction with contaminated soil. Community‐engaged research (CEnR) is one method that can promote the inclusion of all partners when studying exposures such as HMM in soil. Researchers and community gardeners co‐designed this study to measure the concentrations of lead (Pb), using X‐Ray Fluorescence (XRF) verified with Inductively Coupled Plasma‐Mass Spectrometry (ICP‐MS) in soils from 19 urban agricultural and residential sites in the Westside of Atlanta and three rural sites in Georgia. Seventeen other HMM were measured but not included in this study, because they did not pose risks to the community comparable to elevated Pb levels. Pb concentrations were compared to the Environmental Protection Agency (EPA)'s regional screening levels (RSLs) for residential soil and the University of Georgia (UGA) extension service's low‐risk levels (LRLs) for agriculture. Soils from the majority of sites had levels below EPA RSLs for Pb, yet above the UGA LRL. However, soil Pb concentrations were three times higher than the EPA RSL on some sites that contained metal refining waste or slag. Our findings led to direct action by local and federal government agencies to initiate the cleanup of slag residue. Studies involving exposures to communities should engage those affected throughout the process for maximum impact. Plain Language Summary: This study used community‐engaged participatory research to explore lead contamination in Atlanta urban growing spaces under two different sets of screening levels, which had not previously been compared in agricultural settings. While most growing sites were below the EPA regional soil screening levels, many were above the University of Georgia extension's agriculture‐specific recommendations levels. Strong relationships and communication between researchers, community gardeners, and regulatory organizations led to the discovery of contamination from metal refining waste and a subsequent Federal remediation effort. This study demonstrates the importance, impact, and need to work with community members on issues involving environmental pollution and justice. Key Points: We used community‐engaged research to measure lead in urban agriculture spacesCommunity members were involved in the entire process from sampling to resultsCommunity‐engaged science built trust and led to the designation of the site as Superfund and later to a National Priorities List [ABSTRACT FROM AUTHOR]

The fatigue life of bearing steel is closely related to the total oxygen content (T(O)) of the liquid steel. In order to stably and effectively control the T(O) during the ladle furnace (LF) refining process, we established a calculation model of optimal alkalinity for the refining slag CaO–SiO2–Al2O3–MgO–FeO–CaF2 at 1853 K based on ion–molecule coexistence theory (IMCT). Here, the influencing factors are discussed. The results show that the maximum value of N FeO occurred when the optimal alkalinity was around five at varied FeO contents, and that the optimal alkalinity basically remained the same with changes in FeO content. With the increase of MgO content, the optimal alkalinity decreased. However, the change in the value of N FeO against the higher alkalinity was not obvious at a given MgO content. The effect of Al2O3 content on the optimal alkalinity was opposite to that of MgO. With the increasing Al2O3 content, the optimal alkalinity obviously increased, while the maximum value of N FeO occurred when the Al2O3 content varied from 35 wt% to 45 wt% at higher alkalinity. The higher w(CaO)/w(Al2O3) mass ratio had a distinct effect on the value of N FeO against alkalinity, while the effect of alkalinity on the value of N FeO was not obvious at a fixed CaF2 level. This optimal alkalinity model based on IMCT can provide a certain guiding role in the process of refining slag composition optimization and is conducive to effectively controlling total oxygen content in the refining process. [ABSTRACT FROM AUTHOR]

• A novel directional salt crystallization system is designed for desalination and wastewater treatment. • The system exhibits a high evaporation rate of 2.20 kg m−2 h−1 in desalinating 15 wt% brine. • Salt crystals can be collected efficiently through continuous evaporation. Solar-driven interfacial evaporation is an efficient technology for water treatment, enabling the production of freshwater and the removal of impurities. However, achieving a high evaporation rate and a long-term stable operation is challenging due to the salt accumulation on the evaporation surface. In this study, a novel three-dimensional directional salt crystallization system is proposed. The melamine sponge modified with polydopamine and carbon black was used to transport brine, absorb sunlight, and generate steam. The non-photothermal evaporation regions were innovatively constructed by placing a thermally conductive aluminum structure with the deflector paper around the sponge, which increased the effective evaporation area of the system to accelerate the evaporation of brines from the overall system, resulting in an evaporation rate of 2.20 kg m−2 h−1 under one sun irradiation in a 15 wt% NaCl solution. Moreover, the non-photothermal evaporation regions were isolated from the evaporation interface as a salt crystallization region, which completely avoided salt accumulation at the evaporation interface and ensured the long-term stable operation of the system. Salt crystals can be easily collected by replacing the deflector paper regularly, and the salt collection efficiency is over 95 % to achieve zero-liquid discharge (ZLD) treatment. More importantly, the directional salt crystallization system achieves efficient purification of heavy metal ion wastewater and dye wastewater. Consequently, the system presents a highly efficient method for ZLD seawater treatment and wastewater purification. [ABSTRACT FROM AUTHOR]

[Display omitted] • A systematic description on oily-bubbles was provided in this review. • Their generating principle, fabricating methods were comprehensively summarized. • Typical applications of oily-bubbles were thoroughly discussed. • Challenges, limitations, and the future directions of oily-bubbles were prospected. Oily-bubbles have significant advantages including a greater contact area, stronger selectivity and higher mass transfer rate compared to bubbles, which exhibit excellent industrial prospects in mineral processing, extraction metallurgy, wastewater treatment and other fields. In recent decades, extensive research has been conducted on the enhancement of separation and mass transfer processes by oily-bubbles. Although considerable excellent results and findings have been reported, a remarkable lag is still recorded concerning the detailed explanation of their formation principle, fabrication methods and typical applications. Hence, the overarching aim of this study is to conduct a comprehensive review and provide a perspective on oily-bubbles. The generation principle and fabrication methods of oily-bubbles were comprehensively summarized based on up-to-date research progress. Subsequently, the significant role of oily-bubbles in enhancing separation and mass transfer processes, with a special emphasis on mineral and secondary resource processing, as well as in the separation and purification of metals, was thoroughly evaluated. Most importantly, the technical challenges, existing problems, and future directions of research on oily-bubbles are highlighted. In summary, this review may be helpful for improving the overall understanding of oily-bubbles and their typical applications in enhancing separation and mass transfer processes. [ABSTRACT FROM AUTHOR]

• A continuous multicolumn ion exchange process in LIB recycling is demonstrated. • 100 % purity Li + Co + Ni solution with high recovery yields was produced continuously. • Recovery rates were up to 100 %, 99.15 % and 96.97 % for Li, Ni and Co. • Effect of fresh feed and eluent flowrate on the SMB performance is demonstrated. • Axial profiles show no accumulation of sorbed metals due to effective desorption. A continuously operated ion exchange process scheme for the recovery and purification of valuable metals from acid leachates of spent Lithium-ion battery cathodes was developed. The aim is to provide a versatile and industrially feasible alternative for liquid–liquid extraction and precipitation for recycling of spent Li-ion batteries. A chelating resin with aminomethylphosphonic acid functional group (Lewatit® MDS TP 260) was used in a laboratory-scale multicolumn configuration that combined counter-current and cross-current operations. The process was operated at 60 °C with a synthetic leachate with pH 1.8 as the feed. A two-step desorption procedure (1.0 M sulfuric acid (H 2 SO 4) followed by 0.4 M potassium oxalate (K 2 C 2 O 4)) was found to prevent accumulation of strongly bound metals in the resin. 1 M H 2 SO 4 was found sufficient for regeneration. Pure raffinate containing Li, Ni, and Co was successfully separated from impurity metals (Mn, Cu, Al, and Fe). In steady state operation, no loss of ion exchange capacity was observed. The process was optimized experimentally with focus on the effect of fresh feed and eluent flow rates to increase the productivity and improve the recovery rates of the target metals while maintaining a raffinate purity of 100 %. Increasing the amount of leachate processed per switch was found to enhance the recovery of Co, Li and Ni due to the displacement effect. Very high recovery yields (96.97 % for Co, 99.15 % for Ni, and 100 % for Li) were achieved. The laboratory scale unit could process 1.64 L (L·h)−1 of leachate to yield 34.04 g (L·h)−1 of Li+Ni+Co mixture in the raffinate. Moreover, Cu+Mn and Al+Fe rich extract streams with 84.74 % and 97.46 % purities were obtained as by-products. With respect to the recovery rates, the continuous ion exchange process is superior to batchwise operation of ion exchange columns, conventional solvent extraction and not to mention precipitation processes making it a viable alternative in hydrometallurgical LIB recycling. [ABSTRACT FROM AUTHOR]

Heavy metal contamination in soil has been a global environmental concern. Taking advantage of the widely available natural condition, freezing can purge and isolate the toxic heavy metal contaminants in the soil. This study utilizes in-situ X-ray computed tomography (CT) to visualize pore-scale unidirectional freeze-driven purification processes in lead ions contaminated sand. The micron resolution observations of pore unfrozen water with various cooling rates and different freezing directions are presented. 3D CT images demonstrate the morphologies of unfrozen water trapped within the frozen zone include "saline columns" (top-down freezing) and dispersed unfrozen saline. Interestingly, a relatively pure ice layer with very low saline content emerges and thickens in frozen zones as the cooling pause duration increases. Further quantitative analyses show reducing the cooling rate can effectively increase purification fraction, reaching 52.24 % with a cooling rate of 0.125 °C/h, and enhance the saline enrichment towards the warm ends. A diagram is provided to demonstrate governing physical processes and their characteristics in four sections categorized according to the local temperature and phase diagram. These results can guide potential practices such as heavy-metal contamination remediation towards a high purification fraction. [Display omitted] • Unidirectional freezing can purge heavy metal ions in contaminated soil. • Concentrated "saline column" form in top-down freezing. • Slow diffusion of ions leads to the formation of "pure ice" layers. [ABSTRACT FROM AUTHOR]

[Display omitted] • An Al-5Ti-1B alloy was prepared by gas-assisted continuous casting and extrusion (GAC) process. • The Al-5Ti-1B alloy wire prepared by GAC has a fine and uniform microstructure. • Al-5Ti-1B alloy wires prepared by GAC showed fast and high efficiency when refining an industrially pure aluminium. The feasibility of preparing Al-Ti-B alloy wires based on a novel technology of gas-assisted continuous casting and extrusion (GAC) was investigated. Results show that Al-5Ti-1B alloy wire with fine and uniform distribution of the second phase can be prepared by combining the fluoride salt method and the GAC process. When the wire was added into an industrial pure aluminum at 730 °C with an addition of 0.2 wt%, the pure aluminum grains could be refined into equiaxed crystals with an average size of about 140 μm by contacting time of 60 s, which showed the characteristics of rapidity and high efficiency. [ABSTRACT FROM AUTHOR]

Cell-derived exosomes have opened new horizons in modern therapy for advanced drug delivery and therapeutic applications, due to their key features such as low immunogenicity, high physicochemical stability, capacity to penetrate into tissues, and the innate capacity to communicate with other cells over long distances. Exosome-based liquid biopsy has been potentially used for the diagnosis and prognosis of a range of disorders. Exosomes deliver therapeutic agents, including immunological modulators, therapeutic drugs, and antisense oligonucleotides to certain targets, and can be used as vaccines, though their clinical application is still far from reality. Producing exosomes on a large-scale is restricted to their low circulation lifetime, weak targeting capacity, and inappropriate controls, which need to be refined before being implemented in practice. Several bioengineering methods have been used for refining therapeutic applications of exosomes and promoting their effectiveness, on the one hand, and addressing the existing challenges, on the other. In the short run, new diagnostic platforms and emerging therapeutic strategies will further develop exosome engineering and therapeutic potential. This requires a thorough analysis of exosome engineering approaches along with their merits and drawbacks, as outlined in this paper. The present study is a comprehensive review of novel techniques for exosome development in terms of circulation time in the body, targeting capacity, and higher drug loading/delivery efficacies. [ABSTRACT FROM AUTHOR]

Electromagnetic methods can be used to affect the solidification of metallic alloys. Combined alternating and static (DC) magnetic fields can induce pressure waves in liquid metals in a contactless manner, refining grain structure, preventing component segregation, and dispersing added particles. Here, the possibility of using a pulsed magnetic field in combination with a DC magnetic field to improve the solidification structure of metals is investigated. This enables achieving higher pressure amplitude and liquid movement within the whole crucible volume at the same power consumption. This can be a prospective way to achieve a fine-grained and a more homogeneous microstructure of metallic alloys as well as disperse added particles. In this work, analytical description of the phenomena and numerical modeling of the pressure amplitude and melt motion has been performed. A series of experiments have been carried out to demonstrate the effect of such interaction on the solidified metal microstructure. It is found that a combination of pulsed and DC magnetic fields creates strong compression and expansion of the liquid metal. Metals solidified under such interaction exhibit finer grain structure in Sn-Pb alloy and improved TiB2 particle distribution in 6061 aluminum alloy. [ABSTRACT FROM AUTHOR]

Recycling Al scraps is extremely important to achieve carbon neutrality. However, almost all impurity elements cannot be easily removed by oxidation and evaporation once dissolved in molten Al alloy. Therefore, it is necessary to develop an impurity removal process in molten Al. Iron is one of the impurity elements in Al, which easily forms intermetallic compounds with Al. On the contrary, Fe is immiscible with Mg in the liquid state. These facts suggest that the repulsive interaction between Fe and Mg in molten Al alloy enhances the precipitation of such intermetallic compounds as Al3Fe. This study proposed the Fe removal method from molten Al alloy by the precipitation of the Al3Fe inter-metallic compound by adding Mg. Molten Al-Mg alloy was equilibrated with Al3Fe, and the Fe content of molten Al-Mg alloy was investigated. Fe content decreased with increasing Mg content, and this method was proved to be adequate for removing Fe from molten Al-Mg alloy. The standard Gibbs energy change for the precipitation of Al3Fe at 873 K and the activity coefficient of Fe in molten Al-Mg alloy as a function of Mg content and temperature have been derived from the experimental results.... Using the derived values, the removal limit of Fe in molten Al-Mg alloy in the present method was discussed. Fe content can be decreased at higher Mg content and lower temperature, and the lowering limit of Fe is 0.0029 mass percent at the eutectic point of Al-Mg alloy. [ABSTRACT FROM AUTHOR]

Due to its outstanding properties and wide range of applications, high-purity to ultra-high-purity aluminum represents a strategic material for meeting the future challenges of the 21st century. The purification of aluminum towards higher purity levels is usually performed via a combination of three-layer electrolytic refining and fractional crystallization using zone-melting processes. New methods and processes are being researched in the search for more time-saving and less costly options. Metal refining using static crystallization represents one of these new, alternative processes. This work investigated the feasibility of metal refining by means of a static crystallization furnace using aluminum as an example metal. In particular, the effects of the temperature gradient and the cooling rate on the reduction factor of the impurities iron (Fe), silicon (Si), and lead (Pb) were investigated. In addition, the effects of the process parameters on the grain structure formed were investigated, and correlations to the resulting purity level were made. [ABSTRACT FROM AUTHOR]

E-materials become e-waste once they have been discarded without the intent of reuse. Due to its rich content of metals, among which many are Critical Raw Materials (CRMs), e-waste can be considered an urban mine to exploit and valorise. Common metal refining is performed by energy-intensive processes frequently based on the use of fossil fuel. Bio-metallurgy is a promising alternative for e-waste valorisation based on biological routes of specialised microorganisms able to leach solid-containing metals. Because of the physiology of these microorganisms, microbial leaching can be economically feasible, besides being an environmentally sustainable process. Like Bacteria and Fungi, Archaea are also capable of metal leaching activity, though their potential is underestimated. Among them, the extremophiles are the most studied and applied in the field of metal recovery, while mesophilic species are less common but still of high interest. Here we provide the state of industrial application of bio-metallurgy and report on the state of the art of Archaea exploitation in metal recovery from e-waste. Moreover, we give a special highlight to methanogenic archaea, which are able to convert CO2 into methane in order to highlight the potential for the valorisation of CO2-rich industrial streams generated by key processes (i.e., anaerobic digestion, concrete, and steel production) in CH4 for gas grid distribution, while making metals content in e-waste available again as raw material. [ABSTRACT FROM AUTHOR]

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[Display omitted] • A novel roasting method relying on LIB separator was proposed for cathode refining. • Over 93 % Li+ was leached after 2-h separator mediated roasting at 500 °C. • Spent cathode was in situ converted to the desired products, CoO and Li 2 CO 3. • Separator pyrolysis products, C 2 H 4 and CO, dominated the cathode reduction. Developing green and high-efficient pyrometallurgy processes to recycle precious metals from spent lithium-ion batteries (LIBs) is of great importance for resource sustainability and environmental protection. Herein, a novel reduction roasting approach relying on spent LIB separator to refine the spent cathode is proposed. The efficiency of repurposing separator as a reductant for roasting the spent LiCoO 2 cathode and the underlying mechanisms were investigated. After the separator-mediated roasting at 500 °C for 2 h, Li+ leaching efficiency of the cathode reached 93.2 %, >2.6 times higher than those after roasting without reductant (25.2 %) or with benchmark reductant graphite (26.1 %). Under the separator-added roasting condition, the cathode was converted to the desired products, CoO and Li 2 CO 3. Based on the analysis of in-situ reaction using thermogravimetric/differential scanning calorimetry and pyrolysis gas species identification, the separator-mediated reduction roasting of cathode was composed of two stages, i.e., reducing gas generation due to separator pyrolysis, followed by the reducing gas mediated LiCoO 2 reduction. During the process, the generated C 2 H 4 and CO dominated the reduction. The use of co-existing separator to recover precious metals from spent LIBs is an effective and sustainable strategy to maximize the utilization of spent LIBs. [ABSTRACT FROM AUTHOR]

In this study, the effect of A15TilB grain refiners and AllOSr modifiers on the mechanical and corrosion properties of the A360 aluminum alloy was investigated. For this purpose, varying amounts of A15Tİ1B grain refiner and AllOSr modifier were added to the molten A360 alloy and the molten metal was poured into a permanent mold. Subsequently, microstructural investigations, hardness test, tensile strength and corrosion resistance of the samples were examined. The results showed that, the A15Tİ1B grain refiner promotes finergrained and coaxial solidification. The AllOSr modifier, broke down the eutectic particles in the microstructure and caused a more homogeneous distribution in the structure. While the tensile strength and corrosion resistance of the alloy increased both the grain refiner and the modifier added to the A360 alloy, a slight decrease in hardness was observed in the alloys to which only the modifier was added. [ABSTRACT FROM AUTHOR]

Many kinds of refining processes are used in the steelmaking industry. Molten metal contained in the bath of the processes is strongly agitated by gas injection. Meal droplets are carried up into the upper molten slag layer due to the gas-lift effect. Each metal droplet falls and finally returns to the lower metal layer although it is captured for a while at the metal-slag interface due to the interfacial effect. The behavior of molten metals near the interface is closely associated with the refining efficiency and metal loss. The residence time at the interface was investigated in this study. An analytical equation was derived for the residence time and a water model study was carried out to validate the equation. Water and silicone oil were used for the models of molten metal and slag, respectively. [ABSTRACT FROM AUTHOR]

Clad rebar is one of the key structures of marine and construction services. Therefore, it is of great importance to acknowledge the mechanical property parameters of the composite region in the structural integrity evaluation of clad rebar. The different base materials of clad rebar (20MnSiV/316L steel, 35#/316L steel, 45#/316L steel, and 55#/316L steel) are researched in this study. The composite area is further refined, and simultaneously, a refinement model of the composite region of clad rebar is established. In view of the fact that a surface hardness experiment is quite easy to conduct, a proposed method consists of obtaining the mechanical property parameters of materials using the surface hardness test. The mechanical property parameters are acquired; moreover, the relationship between yield stress and surface hardness of the stainless steel clad rebar is set up. We used this method to acquire the mechanical parameters of a composite surface uneven area of clad rebar, and we established a mechanical parameters mathematics model of clad rebar, it is a significant basis for a structural integrity evaluation of cladding materials. [ABSTRACT FROM AUTHOR]

In this paper, the element nitrogen (N) is used to partially replace the element nickel (Ni) in flux-cored wire. A 44%Ni-24%Cr-0.18N nitrogen-containing low-nickel flux-cored wire with excellent corrosion resistance is prepared. The corrosion behavior of nitrogen-containing low-nickel weld cladding and Inconel 625 weld cladding in 40 KCl + 60 MgCl2 (wt%) molten salt at 900 °C is studied. The results show that the selective dissolution of Cr occurs in both weld claddings. The corrosion resistance of the 44%Ni-24%Cr-0.18N nitrogen-containing low-nickel weld cladding is better than that of the Inconel 625 weld cladding. The reason is that added N can react with H+ in molten salt to generate NH 4 + , remove corrosive impurities of MgOH+ in molten salt and change the corrosion environment. N preferentially combines with Cr to form Cr2N, reduces the diffusion precipitation of Cr and improves the corrosion resistance. [ABSTRACT FROM AUTHOR]

Arsenic, one of the most toxic elements, is a byproduct generated from metallurgical processes of arsenic-containing ores. Arsenic can be formed into an arsenic trioxide as a byproduct during the decopperization in electro-refining process when processing high arsenic-bearing copper minerals. However, arsenic trioxide has a very high arsenic mobility, so it requires to be re-dissolved and immobilized into scorodite (FeAsO4▪2H2O). In this study, methanesulfonic acid (MSA) was tested for both arsenic trioxide leaching and scorodite precipitation. Arsenic trioxide leaching tests showed the arsenic extraction of 80% at 21°C in MSA with H2O2 as an oxidant within 6 hours. Meanwhile, arsenic precipitation tests were conducted to achieve above 95% arsenic removal within 6 hours by the formation of scorodite at an initial pH of 0.5 and temperature of 80°C. In addition, coarser scorodite particles were formed in higher temperature and lower solution pH. The optimum condition for scorodite crystallization in MSA medium can be suggested to be at 80°C with the initial pH of 0.5. [ABSTRACT FROM AUTHOR]

Porous materials with high specific surface area, high porosity, and high electrical conductivity are promising materials for functional applications, including catalysis, sensing, and energy storage. Molten salt dealloying was recently demonstrated in microwires as an alternative method to fabricate porous structures. The method takes advantage of the selective dissolution process introduced by impurities often observed in molten salt corrosion. This work further investigates molten salt dealloying in bulk Ni–20Cr alloy in both KCl–MgCl2 and KCl–NaCl salts at 700 ℃, using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction (XRD), as well as synchrotron X-ray nano-tomography. Micro-sized pores with irregular shapes and sizes ranging from sub-micron to several microns and ligaments formed during the process, while the molten salt dealloying was found to progress several microns into the bulk materials within 1–16 h, a relatively short reaction time, enhancing the practicality of using the method for synthesis. The ligament size increased from ~ 0.7 μm to ~ 1.3 μm in KCl–MgCl2 from 1 to 16 h due to coarsening, while remaining ~ 0.4 μm in KCl–NaCl during 16 h of exposure. The XRD analysis shows that the corrosion occurred primarily near the surface of the bulk sample, and Cr2O3 was identified as a corrosion product when the reaction was conducted in an air environment (controlled amount sealed in capillaries); thus surface oxides are likely to slow the morphological coarsening rate by hindering the surface diffusion in the dealloyed structure. 3D-connected pores and grain boundary corrosion were visualized by synchrotron X-ray nano-tomography. This study provides insights into the morphological and chemical evolution of molten salt dealloying in bulk materials, with a connection to molten salt corrosion concerns in the design of next-generation nuclear and solar energy power plants. [ABSTRACT FROM AUTHOR]

The calcium- and strontium- alumo-germanides SrxCa1–xAl2Ge2 (x ≈ 0.4) and SrAl2Ge2 have been synthesized and structurally characterized. Additionally, a binary calcium germanide CaGe has also been identified as a byproduct. All three crystal structures have been established from single-crystal X-ray diffraction methods and refined with high accuracy and precision. The binary CaGe crystallizes with a CrB-type structure in the orthorhombic space group Cmcm (no. 63; Z = 4; Pearson symbol oC8), where the germanium atoms are interconnected into infinite zigzag chains, formally [Ge]2−. The calcium atoms are arranged in monocapped trigonal prisms, centered by Ge atoms. SrxCa1−xAl2Ge2 (x ≈ 0.4) and SrAl2Ge2 have been confirmed to crystallize with a CaAl2Si2-type structure in the trigonal space group P 3 ¯ m1 (no. 164; Z = 1; Pearson symbol hP5), where the germanium and aluminum atoms form puckered double-layers, formally [Al2Ge2]2−. The calcium atoms are located between the layers and reside inside distorted octahedra of Ge atoms. All presented structures have a valence electron count satisfying the octet rules (e.g., Ca2+Ge2− and Ca2+[Al2Ge2]2−) and can be regarded as Zintl phases. [ABSTRACT FROM AUTHOR]

Mixing plays a key role in mass and heat transfer, as well as chemical reactions in various vessels involving agitation. Several studies have confirmed that the mixing time obtained from several monitor locations cannot reflect the mixing time for the whole bath because stirring situation in different locations is variable due to the change of operation schemes. It is proved that some zones with inefficient stirring cannot be monitored by applying a limited amount of probes in physical and mathematical models. This study provides a novel approach to quantify mixing time evaluation considering the tracer variation for the whole bath using a mathematical model. It was found that the mixing time obtained by considering the whole bath is more representative than that of the probe monitor method. Compared with the traditional probe method, about 50 to 70 pct longer mixing times were obtained for different operations by applying the volume track method. In addition, the volume integral of the concerned variable for the whole bath is more representative to determine the developed flow compared to the points monitoring method for a transient simulation. [ABSTRACT FROM AUTHOR]

Contact bubble refinement method is difficult to be applied in secondary refining process, resulting in low refining efficiency of metallurgical melt because of bubbles with large size. Herein, the non-contact forward–reverse rotating electromagnetic field (FRREF) with maximum 8.24 × 104 N/m3 electromagnetic force density is proposed to refine bubbles. The average diameter of bubbles is 3.84 mm, a decrease of more than 50 pct compared to that without the FRREF, which will significantly improve the secondary refining efficiency. [ABSTRACT FROM AUTHOR]

The current study examines the effect of magnetic flux density (MFD) on the morphology of the metal pool and the refinement of eutectic carbides in magnetic controlled electroslag remelting (MC-ESR, M2 high speed steel). When a transverse static magnetic field (TSMF) with a larger MFD was used, it was easier to obtain a shallower metal pool and finer eutectic carbides. These phenomena are explained by the smashing effect of the droplet neck (stronger at higher MFD values) induced by electromagnetic vibration, resulting in smaller/more dispersed droplets and thus a more uniform temperature distribution in the metal pool. Additionally, as MFD increased, the local solidification time (LST) decreased (0 to 140 mT) and the number of inclusions serving as heterogeneous nuclei for eutectic carbide formation increased (0 to 65 mT), resulting in a gradual size reduction of eutectic carbides. However, the refinement of eutectic carbides in MC-ESR must consider the above two factors comprehensively, and the MFD of applied TSMF need not be excessively large. [ABSTRACT FROM AUTHOR]

The present work aimed to develop a predictive model for the end temperature of liquid steel in advance to support the smooth functioning of a vacuum tank degasser (VTD). An ensemble model that combines extreme learning machine (ELM) with a self-adaptive AdaBoost.RT algorithm was established for the regression problem. Based on analyzing the energy equilibrium of the VTD system, the factors were determined for predicting the end temperature of liquid steel. To establish a hybrid ensemble prediction model, an ELM algorithm was selected as the ensemble predictor due to its strong performance and robustness, and a modification of the AdaBoost.RT algorithm is proposed to overcome the drawback of the original AdaBoost.RT by embedding statistical theory to dynamically self-adjust the threshold value. For efficient VTD operations, an ensemble model that combines ELM with the self-adaptive AdaBoost.RT algorithm was established to model the end temperature of liquid steel. The proposed approach was analyzed and validated on actual production data derived from a steelmaking workshop in Baosteel. The experimental results reveal that the proposed model can improve the generalization performance, and the accuracy of the model is feasible for the secondary steel refining process. In addition, a polynomial equation is obtained from the ensemble predictive model for calculating the value of the end temperature. The predicted results are in good agreement with the actual data with <1.7% error. [ABSTRACT FROM AUTHOR]