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Copyright of Trans/Form/Ação is the property of Trans/Form/Acao 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.)

Titanium oxide pigment industries produce a large amount of undissolved particles called sludge during the sulfate process of ilmenite. The sludge mainly constituted 48% TiO2, 15% SiO2, 11% Fe2O3, 4.5% SO3, and 2% Al2O3. Zirconium, vanadium, magnesium, and calcium oxides are also in small amounts. The presence of sulfur induces an acidic nature to the sludge and reduces its further utilization. Using a simultaneous process to reduce sulfur content and extract important metals is crucial. The paper describes use of acidic sludge to extract titanium to prepare titanium rich alloy. The method involves initial neutralization and reduction roasting followed by magnetic separation. The separated magnetic part was then utilized for aluminothermic reduction by smelting, resulting in titanium-rich alloy. Analytical techniques such as XRD, SEM–EDS and Thermal analysis were conducted during the studies. Titanium-rich alloys having a composition of ~ 51.8% Ti, 22.4% Al, 9.5% Si, and 16.3% Fe were achieved. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Extractive Metallurgy) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group 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.)

Copyright of Nonferrous Metals (Extractive Metallurgy) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group 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.)

Copyright of Nonferrous Metals (Extractive Metallurgy) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group 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.)

Variation of the slag cover surface (SCS) in the oxygen-enriched top-blown molten bath smelting process is critical for the smelting efficiency of a complex Cu–S concentrate. However, capturing these variation characteristics is difficult because of the high temperature inside the molten bath and the dynamic complexity of the smelting process. In this work, machine learning (i.e., U-net algorithm and support vector machine) is combined with a skillful hydraulic model (i.e., gas–liquid two-phase top-blown agitated vessel) and an experimental measurement strategy to quantitatively explore the variation characteristics of the SCS in an oxygen-enriched top-blown molten bath smelting process. Results showed that a minimum of 30 images, with the smallest size being 900 × 600 pixels, was sufficient for the training process. The data accuracy of the training procedure ranged from 93.20% to 96.23% for identifying the SCS at the laboratory scale. The highest average height of 2.23 cm for the SCS occurred under the operational condition, with a flow rate of 160 L/h, a liquid temperature of 60 °C, and a liquid depth of 0.4 m. The chaotic systems of SCS in industry were deterministic. It was found that the proposed strategy could be used to accurately identify the variation characteristics of the SCS in the gas–liquid two-phase top-blown agitated vessel. The variation of the SCS in the industrial process could be roughly grasped by magnifying the height of the SCS obtained from the experimental data in the laboratory. Quantification of the variation characteristics of the SCS is useful to increase the smelting efficiency of the oxygen-enriched top-blown molten bath smelting process. This also provides insights for multiphase measurements in other studies related to efficient utilization of complex Cu–S concentrates. [ABSTRACT FROM AUTHOR]

Spent Pd-Al2O3 catalyst was recovered by the metal smelting method. Cu and Fe were used as collector metals, and the capture process, smelting slag, and Pd-bearing alloy were comprehensively compared. The process condition results show that although the recovery rate of palladium of both capture processes is > 99%, the collection time using Fe smelting method is longer than that using Cu collection. The Si and P contents in Pd-bearing alloy under 1550°C obtained by Fe collection are obviously higher than those by Cu collection, which causes the difficulty in separation of Pd from impurities. The cost of Fe smelting process is much lower than that of Cu smelting process, while the metal Cu alloy can be further reused through subsequent electrolysis separation. Therefore, Cu collection is suggested to be a better collection metal due to the shorter smelting time, possible lower impurity content under higher temperature and more favorable subsequent treatment process. [ABSTRACT FROM AUTHOR]

The blast furnace smelting of vanadium–titanium ore plays a crucial role in the efficient utilization of vanadium-titanium resources. In this research, a detailed numerical simulation study of the temperature, velocity, and concentration fields during the smelting process in a vanadium–titanium blast furnace was conducted. The actual production data from a 1750 m3 vanadium–titanium blast furnace was utilized, combined with softening and dripping parameters and material balance calculations, to develop a two-dimensional blast furnace model. This model was employed to analyze the effects of varying smelting intensities on the internal operating conditions of the furnace. The study found that as smelting intensity increased, significant changes occurred in the temperature fields and CO concentration fields within the furnace, thereby affecting the reduction efficiency of the burdens. Additionally, this research also shows that increasing the proportion of Baima pellets in the furnace will lead to the expansion of the soft melting zone and the upward movement of the soft melting zone. This investigation not only revealed the variations in the internal physical fields of the blast furnace under different operating conditions but also provided theoretical foundations and references for optimizing the design and operation of vanadium–titanium blast furnaces. By comparing the velocity field under different smelting intensities, it was found that the difference was small, which was mainly related to the expansion behavior of the pellets. These findings provide an important scientific basis for further improving the efficiency of blast furnace smelting and reducing costs. [ABSTRACT FROM AUTHOR]

With the advancement of aerospace, military and related industries, there is a persistent escalation in the performance requirements for steel. According to the actual smelting conditions, this study focuses on Ce-containing high-aluminum steel and various refractories as its research subjects. A combination of laboratory experiments and thermodynamic calculations is employed to investigate and compare the evolution mechanism of oxide inclusions in molten steel. The use of Al2O3 refractory results in an increase in [Al] content, whereas both MgO refractory and MgO–MgO·Al2O3 refractory lead to a decrease in [Al] content. Additionally, following the utilization of MgO refractory and MgO–MgO·Al2O3 refractory, the molten steel exhibits the higher [Ce] content than when Al2O3 refractory are employed (t = 30 minutes). Before the introduction of Ce element, the principal oxide inclusions in Al2O3 refractory and MgO-containing refractory are Al2O3 and MgO·Al2O3 inclusion, respectively. After adding cerium-aluminum alloy, [Ce] in the molten steel replaces the element of Al in the Al2O3 inclusion, transforming into CeAlO3, while [Ce] replaces the Mg element in the MgO·Al2O3 inclusion, evolving into Ce–Mg–Al–O, which further reacts to form CeAlO3 and Ce2O2S. Over time, the number density of inclusions first increases then gradually diminishes with various refractories. MgO refractory minimizes the number density of inclusions to 53.05 mm−2. Moreover, the number of small size inclusions in MgO–MgO·Al2O3 refractories is the largest, and inclusions less than 3 μm account for 78.63 pct of the total number. [ABSTRACT FROM AUTHOR]

The direct-to-blister process is considered as a short process, low energy consumption and environmentally friendly pyrometallurgical copper smelting process. In this study, direct-to-blister smelting experiments were conducted on a laboratory scale using high-grade chalcocite as the raw material and employing the SiO2-FeO-CaO slag system. The effects of smelting parameters including Fe/SiO2 ratio, oxygen blowing volume, and smelting temperature on copper recovery were investigated, and the optimal experimental scenario under the SiO2-FeO-CaO slag was ultimately obtained. The results showed that the maximum copper recovery of 96.23 wt.% was realized at the Fe/SiO2 ratio of 1.2 and with CaO addition of 2.8 wt.%. Moreover, the copper losses in the slag and the phases in the slag were analyzed in detail. The results of this paper may provide theoretical guidance for direct-to-blister of high-grade copper concentrates under SiO2-FeO-CaO slag system. [ABSTRACT FROM AUTHOR]

In this study, the solubilities of oxygen in molten Sm--La--O alloys were measured and the equilibrium oxide phases yielded from the alloys when they were in the temperature range of 1473--1673K were identified. Sm2O3 oxide pellets and Sm--La--O alloy were held at a fixed temperature above melting point of the alloy. Then the samples were quenched into water. The oxygen solubility of Sm--La--O alloy was determined by measuring oxygen concentration in the quenched alloy phase using inert gas fusion infrared absorption spectroscopy. The oxygen solubility increased with the increase in temperature and the composition of Sm. The composition and crystal structure of the oxide after quenching were analyzed using scanning electron microscope with energy dispersive X--ray spectroscopy and X--ray diffraction; The results indicated that hexagonal (A--type) or monoclinic (B--type) (La,Sm)2O3 stably existed in the molten alloy at high temperatures. Larger values in Sm/(Sm + La) ratio were identified in the oxide phase than that in the Sm--La--O alloy. [ABSTRACT FROM AUTHOR]

Iron emissions from human activities, such as oil combustion and smelting, affect the Earth's climate and marine ecosystems. These emissions are difficult to quantify accurately due to a lack of observations, particularly in remote ocean regions. In this study, we used long‐term, near‐source observations in areas with a dominance of anthropogenic iron emissions in various parts of the world to better estimate the total amount of anthropogenic iron emissions. We also used a statistical source apportionment method to identify the anthropogenic components and their sub‐sources from bulk aerosol observations in the United States. We find that the estimates of anthropogenic iron emissions are within a factor of 3 in most regions compared to previous inventory estimates. Under‐ or overestimation varied by region and depended on the number of sites, interannual variability, and the statistical filter choice. Smelting‐related iron emissions are overestimated by a factor of 1.5 in East Asia compared to previous estimates. More long‐term iron observations and the consideration of the influence of dust and wildfires could help reduce the uncertainty in anthropogenic iron emissions estimates. Plain Language Summary: Human activities, such as smelting and oil combustion, release smoke and particles into the atmosphere. These particles often contain iron, which not only absorbs sunlight, contributing to atmospheric warming, but also serves as a nutrient for phytoplankton in various ocean regions. However, the precise extent of human‐induced iron emissions remains uncertain due to a lack of comprehensive monitoring data. In this study, we leverage a global data set of iron observations to refine our estimates of iron emissions attributed to human activities. Additionally, we examine other co‐released substances, such as carbon and nickel, to identify specific emission sources of iron. We employ statistical techniques to distinguish human‐caused iron emissions from those originating from natural sources like dust and wildfires. Moreover, we utilize iron oxide observations to constrain emissions originating from East Asia and Norway, which are estimated to originate largely from smelting emissions. Through the analysis of long‐term data sets, we provide lower and upper bounds to human‐caused iron emissions. Furthermore, we investigate the impact of reduced observation numbers and a sparse network on the range of estimated iron emissions. Our findings highlight the critical role of observation quality in accurately assessing iron emissions from human activities. Key Points: Anthropogenic total iron emissions are constrained to a factor of 3 in most global regions using long‐term aerosol observationsThe number of sites, interannual variability, and site selection filter can affect the model‐observation comparison uncertainty by 15%–50%Smelting‐related emissions are constrained to a factor of 1.5 using iron oxide observations from East Asia [ABSTRACT FROM AUTHOR]

• Metal(loid)s content and mobility were correlated to microbial activities. • Microbial activities are sensitive bioindicators for metal-contaminated sites. • Surface and 1 m deep layers reached alarming and serious pollution levels. • Cadmium and possibly arsenic were the main contributors to the environmental risk. • Modified combined pollution risk was based on chemical and toxicological indices. Abandoned chemical smelting sites containing toxic substances can seriously threaten and pose a risk to the surrounding ecological environment. Soil samples were collected from different depths (0 to 13 m) and analyzed for metal(loid)s content and fractionation, as well as microbial activities. The potential ecological risk indices for the different soil depths (ordered from high to low) were: 1 m (D-1) > surface (S-0) > 5 m (D-5) > 13 m (D-13) > 9 m (D-9), ranging between 1840.65–13,089.62, and representing extremely high environmental risks, of which Cd (and probably not arsenic) contributed to the highest environmental risk. A modified combined pollution risk index (MCR) combining total content and mobile proportion of metal(loid)s, and relative toxicities, was used to evaluate the degree of contamination and potential environmental risks. For the near-surface samples (S-0 and D-1 layers), the MCR considered that As, Cd, Pb, Sb, and Zn achieved high and alarming degrees of contamination, whereas Fe, Mn, and Ti were negligible or low to moderate pollution degrees. Combined microcalorimetry and enzymatic activity measurements of contaminated soil samples were used to assess the microbial metabolic activity characteristics. Correlation analysis elucidated the relationship between metal(loid)s exchangeable fraction or content and microbial activity characteristics (p < 0.05). The microbial metabolic activity in the D-1 layer was low presumably due to heavy metal stress. Enzyme activity indicators and microcalorimetric growth rate (k) measurements were considered sensitive indicators to reflect the soil microbial activities in abandoned chemical smelting sites. [Display omitted] [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature 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.)

A sampling campaign was carried out at an industrial nickel flash smelter with the aim of evaluating the trace element distributions along the smelting line from raw materials to high-grade nickel matte and discard slag. The industrial technology was direct-to-nickel matte smelting without conventional Peirce–Smith converters, thus having two different nickel mattes as smelting products and feeds in the refinery: the sulfidic low-iron nickel matte from smelting furnace and the low-sulfur electric furnace matte from slag cleaning. Major and trace element concentrations were obtained from the solidified samples by electron probe microanalysis and laser ablation–inductively coupled plasma–mass spectrometry. Due to the industrial sampling environment, i.e., the slow cooling rate of the samples, not all the trace element concentrations were able to be measured at the lowest detection limits of the techniques used in some of the phases formed after cooling. However, the obtained results and element distribution coefficients were in good agreement with equilibrium values published in the literature. [ABSTRACT FROM AUTHOR]

Copyright of Foundry Technology (1000-8365) is the property of Foundry Technology 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.)

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group 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 first standardized assessment for soil quality at Sb smelting site is developed. • Soil resilience index (SRI) and soil contamination index (SCI) are both evaluated. • Soil quality in Sb smelting site is mainly limited by low level of soil resilience. • The weak soil resilience is caused by relatively low specific microbial abundances. Antimony smelting activities damage the soil and vegetation surroundings while generating economic value. However, no standardized methods are available to diagnose the extent of soil degradation at antimony smelting sites. This study developed a standardized framework for assessing soil quality by considering microbial-induced resilience and heavy metal contamination at Xikuangshan antimony smelting site. The soil resilience index (SRI) and soil contamination index (SCI) were calculated by Minimum Data Set and geo-accumulation model, respectively. After standardized by a multi-criteria quantitative procedure of modified Nemerow's pollution index (NPI), the integrated assessment of soil quality index (SQI), which is the minimum of SRI NPI and SCI NPI , was achieved. The results showed that Sb and As were the prominent metal(loid) pollutants, and significant correlations between SQI and SRI indicated that the poor soil quality was mainly caused by the low level of soil resilience. The primary limiting factors of SRI were Fungi in high and middle contaminated areas, and Skermanella in low contaminated area, suggesting that the weak soil resilience was caused by low specific microbial abundances. Microbial regulation and phytoremediation are greatly required to improve the soil quality at antimony smelting sites from the perspectives of pollution control and resilience improvement. This study improves our understanding of ecological effects of antimony smelting sites and provides a theoretical basis for ecological restoration and sustainable development of mining areas. [Display omitted] [ABSTRACT FROM AUTHOR]

Integrated experimental and thermodynamic modeling study was undertaken to characterize the effect of Al, Ca and Zn on the partitioning of elements between the slag, matte and metal phases in the Pb–Fe–O–S–Si-(Al), (-Ca), and (-Zn) systems in equilibrium with tridymite at 1100–1200 °C. The experimental methodology involved closed system equilibration in sealed ampoules, quenching and electron probe X-ray microanalysis (EPMA) of compositions of phases. FactSage thermodynamic database obtained by combining earlier assessments of sub-systems was used to plan the targeted experiments, and the results of new experiments were used to improve the thermodynamic database. Important effects were revealed for the conditions of the present study: CaO decreases the concentration of Pb and S in slag; Al2O3 has small effect on Pb in slag, but significantly decreases the concentration of S in slag; ZnO has small effect on Pb in slag, but increases the concentration of S in slag. These experimentally measured effects were reproduced by the model.

The Shu Commandery was an important iron production center in southwest China during the Han Dynasty (202 BC‐AD 220). In 2007, archaeologists excavated a Han Dynasty smelting furnace (L1) at the Gushishan site and collected large amounts of smelting remains including slags, furnace bricks, and ores. Scientific analysis of the excavated slags was carried out to ascertain that the Gushishan site was a pig iron smelting site. No flux was used at the Gushishan site, and the site is dated no later than the Eastern Han period. No remains related to iron casting of the Han Dynasty was found at or near the iron smelting sites in southwest China, which indicates a separation between iron smelting and iron casting as characteristics of the industrial layout in this region. [ABSTRACT FROM AUTHOR]

In 2017/2018, two seasons of archaeological surveys were undertaken in Lejja, southeastern Nigeria. The aim of the archaeological field work was to systematically sample the area to locate archaeological sites, scatters of artefacts, features; and to characterize and record these findings. A particular objective was to identify sites with different typological or chronological characteristics and to then select representative examples for further investigation and excavations. This paper thus focuses for the first time; on the general knowledge of the archaeological signatures in addition to iron working that abound at the Lejja site from an archaeological perspective. We aimed to identify sites with evidence of iron production and sites with other characteristics of human habitation to compare inter-site variation. Using ethnoarchaeological studies, archaeological surveys and excavations, sixteen new sites were identified stretching from iron smelting sites to domestic/habitation sites and ancestral sites. We utilized both a systematic transect and an opportunistic approach to locate and map the archaeological sites encountered. The focus of the study was on thirteen key villages in Lejja southeastern Nigeria. Analysis of data shows that there seem to be distinct areas on the landscape for habitation and metal working respectively. However, it is unclear as yet what this distinction represents in terms of social organization, particularly whether they represent one community with different activity sites or two communities with distinct identities or indeed a more complex temporal and spatial patterning. [ABSTRACT FROM AUTHOR]

The current study presents a fundamental understanding of the behavior of different-sized hydrogen bubbles rising in a new slag – metal system featured with a thick upper slag layer and ever-changing slag thickness and slag physical properties in the H2-based smelting process, based on newly developed CLSVOF model simulations. The evolution of bubble shape, bubble rising velocity, and the formation, collapse and detachment of metal liquid film wrapped on the bubble are predicted. The results show that decreasing the slag layer thickness or the slag viscosity delays the detachment of the metal liquid film from the bubble, increases the bubble rising velocity in the metal layer, but make no difference to the bubble terminal rising velocity in the slag layer. As a result, the bubble has shorter rising time in the bath with a higher slag viscosity. The resistance of the slag – metal interface to the bubble decreases with the increase of the bubble diameter, and small bubble therefore passes through the interface more slowly than the large one. In addition, the bubble shape evolution and bubble breakup in the slag layer are complicated with the increase of the slag thickness, bubble diameter and slag viscosity. [ABSTRACT FROM AUTHOR]

The global trend of ore quality degradation, which is occurring in parallel with increased production volumes of primary metals, has led to the necessity of comprehensive processing of raw materials. This involves the concentration and recycling of metallurgical technogenic wastes, which were previously considered unprofitable. In particular, this means the introduction of dump tailings and sludges from holding ponds to concentration, as well as the feeding of matured concentrates, dump, and recycled slags, and in-house low-grade reverts to metallurgical processing. The feed and the product of its concentration demonstrate an increased content of the refractory spinel phase, which has a variable composition. A share of the technogenic feed in charge of head smelting units exceeds 20%. The majority of main smelting units employ autogenous processes, such as flash smelting, liquid bath smelting, and oxygen-flash smelting. The processing of technogenic low-heat feed in autogenous smelting units results in thermal imbalance, loss of melt homogeneity, and, consequently, disrupts the discharge of smelting products, potentially leading to complete shutdown of the unit. Such behavior is typical for both types of autogenous units operated in the Nornickel Polar Division, namely the Vanukov furnace and the flash smelting furnace. The issue of melt heterogeneity and the formation of refractory accretion at problem areas of the flash smelting furnace is widely known and sufficiently investigated in foreign literature as well as by the authors of this paper. However, further investigation is required for the Vanukov furnace, with a particular focus on the formation mechanism of the intermediate layer phase in the melt. This investigation should aim to develop effective mitigation strategies to address the adverse impact of this phase formation. [ABSTRACT FROM AUTHOR]

This paper gives an overview of findings, connected with metallurgical activity, at the Pržanj archeological site near Ljubljana, Slovenia. More than 230 kg of slag and other remains connected with early medieval (from the 5th to the 12th century AD) metallurgical activities was found at the excavation site. The remains were grouped into four categories, i.e., furnace remains, ore, slag and a ferrous product, and analyzed in detail to obtain their chemical composition, microstructural characteristics, and mineral phase composition. The furnace wall remains, identified by their morphology and chemical composition, revealed an intensive iron processing activity at the site. The iron ore at the site was identified as goethite (FeO(OH)), a surprising find in Slovenia where limonite is typically used, and its presence suggests the potential exploitation of local bog iron ore, given the site's geological context. Abundant slag remains at the site, identified by their shape, molten microstructure, and mineral components like wuestite, fayalite, and hercynite, indicated sophisticated smelting practices, including the use of CaO-rich materials to lower the melting temperature, a technique likely preserved from antiquity. Findings of ferrous products at ancient metallurgical sites are rare due to their value, but the discovery of a corroded iron bloom conglomerate at this site, initially mistaken for furnace remains, highlights the challenges in identifying small, corroded ferrous fragments that are often misidentified as ore. The results indicate extensive metallurgical activity at the excavation site, marking it as the first documented early medieval iron smelting production site in Slovenia. [ABSTRACT FROM AUTHOR]

The high-temperature roasting/smelting process of copper and zinc concentrates will cause the mercury in the concentrate to evaporate into the flue gas, and most of the mercury in the flue gas will eventually enter the waste acid in its ionic form. A highly efficient mercury removal agent M201 with long carbon chains and loaded active functional groups can adsorb and disperse fine particles for mercury removal in the system. Through bridging, the linear structure is woven into a network to achieve large-scale capture and dispersion of fine particles and colloidal substances. The recommended operating conditions for developing mercury deep purification technology are as follows: M201 reagent concentration of 50 g/L, 6 mL/L added acid solution, room temperature, mixing time of 5 min, air flotation time of 10 min, ventilation rate of 0.1 L/min, H2SO4 concentration of 33.67 g/L, and the residual mercury content of 2 mg/L (the mercury content reaches 0.01 mg/L after two-stage mercury removal treatment). Meanwhile, the residual arsenic content is 21.9 mg/L. This study shows a better separation of arsenic and mercury and achieves one-step mercury removal. [ABSTRACT FROM AUTHOR]

Infrared thermography (IRT), as a non-contact condition monitoring (CM) technique, measures the temperature distribution of machines and components to detect anomalous thermal behaviour. It is usually considered as a complementarytechnique and nowadays is used in a wide variety of industrial applications. In this paper, two commonly used criteria to assess the condition of machines based on the infrared thermography technique, ie absolute and relative temperature criteria, are represented. Then, the importance of the temperature trend in condition monitoring and fault diagnosis of machines and components is described. The ThermaITrend software, which was developed in the Condition Monitoring Unit, Smelting Department, Sarcheshmeh Copper Complex in Rafsanjan, Iran, is introduced and its most important and unique features are discussed. This software package helps thermographers toorganise thermal images and provides the temperaturetrends of machines and components that are under regular monitoring. Finally, some industrial case studies on the usefulness and applicability of the infrared thermography technique and the ThermaITrend software are reported. [ABSTRACT FROM AUTHOR]

The publication presents the functions of the SLAG software created to recreate historical metallurgical processes. SLAG allows for determining the smelting temperature, the viscosity of the metallurgical melt, and the oxygen and sulfur fugacities during smelting. With software, both liquidus temperature and melt viscosity can be calculated using different models, covering the range of chemical compositions of historical slags as wide as possible. Based on thermodynamic calculations, SLAG allows the performance of O2 and S2 fugacity calculations in the temperature range of 1000–2000 K (727–1727°C). The range of applicability of other properties (viscosity and liquidus temperature) depends only on the limitations of individual models. Using SLAG, it is also possible to create predominance area diagrams (PADs) and diagrams that consider the viscosity's dependence on temperature for slag of a given chemical composition. Based on glass transition temperature (Tg) and melt fragility, it is also possible to reconstruct the conditions that prevailed during the various stages of historical glass manufacturing processes. [ABSTRACT FROM AUTHOR]

The variability of the composition of recycled copper-containing materials requires enhanced control and understanding of slag chemistry in the secondary pyrometallurgical processing, when compared to primary copper smelting. In the black copper route for recycling waste electronic and electrical equipment (WEEE), slags exhibit high concentrations of alumina and zinc oxide. The simplest system governing phase equilibria at the reducing smelting stage of the black copper process is "CuO 0.5 "-ZnO-FeO-FeO 1.5 -CaO-SiO 2 -AlO 1.5. In the present study, slags within this system were equilibrated with liquid copper Cu and solid Fe metallic alloys, quenched and characterized by the Electron Probe X-ray Microanalysis (EPMA). The range of compositions was selected based on the information about the process available in literature. The study focused on the liquidus and proportion of solid spinel in the temperature range from 1100 to 1300 °C. Precise control of the proportion of solids can enhance the stability of refractory materials against corrosive slags while maintaining entrained metal droplets at reasonably low level. Additionally, experimental correlations between the solubility of copper in the oxide liquid and the partial pressure of oxygen were developed for the Zn-free slags in equilibrium with metallic copper at 1200 and 1300 °C. All experimental results were compared to thermodynamic predictions using recent models and FactSage® software. Uncertainties were identified to be used in further model improvement. [ABSTRACT FROM AUTHOR]

The sparation and recovery of tin, zinc and cadmium from tin smelting dust by sulfuric acid leaching--removing arsenic with oxidation hydrolysis--replacing cadmium with zinc powder were studied. And the effects of various factors on the sparation and recovery were investigated. The results show that the leaching rates of Zn and Cd are 93.25% and 89.35%, respectively, and the leaching rates of Sn are less than 0.1% under the conditions of initial sulfuric acid concentration of 15%, liquid volume to solid mass ratio of 3:1, leaching time of 120 min and leaching temperature of 90 °C. When the amount of hydrogen peroxide is 2% and the control end point pH is 5, the mass concentration of As in the leaching solution can decrease to 0.1 mg/L after arsenic removal. Under the conditions of reaction temperature of 60 °C, dosage of zinc powder 1.0 times of the theoretical amount, stirring speed of 250 r/min and reaction time of 30 min, sponge cadmium with cadmium content above 95% is obtained. The process can realize efficient recovery and utilization of valuable metals in tin smelting dust. [ABSTRACT FROM AUTHOR]

Arsenic containing non-ferrous metal and precious metal sulfide ore will produce acidic high concentration arsenic solution in the smelting process, which has the characteristics of high arsenic concentration, complex composition, large changes, strong toxicity and difficult to store, such as direct discharge without treatment, will have a great impact on the environment and human health. In this paper, the principles, advantages and disadvantages of chemical precipitation method, evaporation enrichment method and metal powder method are reviewed, as well as the research progress of each method, so as to provide reference for the development of arsenic removal technology. [ABSTRACT FROM AUTHOR]

Accurate prediction of endpoint carbon at the dynamic control stage in the converter is crucial for achieving smelting targets. Currently, there are two main methods for converter endpoint prediction: the data-driven method and the mechanism-based method. Data-driven methods exhibit high accuracy but are vulnerable to data quality variations and lack interpretability. Mechanism-based methods provide great interpretability but face challenges in precisely identifying key parameters in the mechanism formula. Inspired by the design concept of physics-informed neural networks (PINNs), an integrated data-driven and mechanism-based method for endpoint carbon prediction in BOF (dmPINNs, data-driven and mechanism-based physics-informed neural networks) is proposed, which has four parts: feature extraction, mechanism-based calculation, data-driven prediction, and integrated prediction. We identify key parameters of the mechanism formula through the neural network to obtain the specified formula for each heat and supervise the training process of the neural network through the mechanism formula to ensure interpretability. Experimental results show that, within the ±0.012% error range, the hit rate of endpoint carbon content using dmPINNs improved by 5.23% compared with the traditional data-driven method and has greater robustness with the supervision of the mechanism formula. [ABSTRACT FROM AUTHOR]

Computational fluid dynamics (CFD) software was used to simulate the feeding behavior in a bottom-blown lead-smelting furnace. The results show that when the particle size is less than 30 μm, 20% of the particles are suspended in the gas phase and do not enter the melt pool for smelting, thus resulting in material loss. When the particle size exceeds 75 μm, the particles settle in the metal layer. When the particle size is 40–60 μm, the particles are distributed in the slag and metal phases, and the material is uniformly distributed in the molten pool; additionally, the average velocity of the particles exceeds 1.4 m/s, the average temperature exceeds 960 K, and the particles exhibit better behavior within this range, thus rendering it the optimal range of particle sizes for feeding. [ABSTRACT FROM AUTHOR]

A new approach for the thermal reduction of tin dioxide (SnO2) in the carbon/sodium sulfite (Na2SO3) system is demonstrated. The process of tin smelting was experimentally optimized by adjusting the smelting temperature and amounts of the chemical components used for the thermal reduction of SnO2. The numbers obtained are consistent with the thermodynamic characteristics of the system and molar fractions of reactants derived from the proposed mechanism of the SnO2 thermal reduction process. They reveal that the maximum yield of tin is obtained if masses of C, Na2SO3 and SnO2 are approximately in the ratio 1:2:3 and the temperature is set to 1050 °C. The key role in the suggested mechanism is the thermal decomposition of Na2SO3. It was deduced from the available experimental data that the produced sulfur dioxide undergoes carbothermic reduction to carbonyl sulfide—an intermediate product involved in the bulk reduction of SnO2. Replacing sodium sulfite with sodium sulfate, sodium sulfide and even elemental sulfur practically terminated the production of metallic tin. The kinetic analysis was focused on the determination of the reaction orders for the two crucial reactants involved in the smelting process. [ABSTRACT FROM AUTHOR]

In the process of bottom blowing bath smelting, continuous bubbles are formed and rise in the melt after the bottom blowing gas is ejected. In order to reveal the motion behavior and wake characteristics of continuous bubbles formed during the injection process, the rising process of coaxial double bubbles is studied through numerical simulation, the velocity and deformation characteristics of coaxial double bubbles in the rising process are obtained. Based on the vortex identification reconstruction of the flow field, the characteristics of formation, evolution, and configuration of bubble wake are obtained. The results show that in terms of motion characteristics, the aspect ratio of the upper bubble is always less than 1, and lower bubble has a large span of change: the minimum is 0.85 and the maximum is 1.2. As the two bubbles approach, the aspect ratio of the upper bubble is always less than 1, while the maximum aspect ratio of the lower bubble can reach 1.2. In terms of wake characteristics, the vorticity on the upper bubble surface is larger. When the wake rotation centers of the upper and lower bubbles merge with each other, the instantaneous acceleration of the lower bubble reaches the maximum. [ABSTRACT FROM AUTHOR]

Owing to the complexity of converter reactions and the inevitable fluctuations of raw materials, developing a universal smelting strategy suitable for all converter conditions is challenging. Therefore, this study introduces a multimode smelting strategy based on a novel classification method to categorize molten iron. In this method, the molten iron is classified into four regions based on the comprehensive effects of Si and P contents. Specific smelting strategies are recommended for the molten iron in each region. These strategies include adjustments to slag basicity, charging schemes, and the blowing mode of the lance. These multimode smelting strategies are implemented in actual production. The results indicate satisfactory optimization of production processes, including stable production, cost reduction, and increased efficiency. Consequently, the dephosphorization rate increases by 1.22%, the lime consumption per ton of steel decreases by 2.41 kg t−1, and the average basicity of steel slag decreases by 0.21. This strategy provides preliminary guidance before the initiation of the smelting process to improve efficiency, reduce consumption, and standardize the operations. [ABSTRACT FROM AUTHOR]

The traditional bismuth sulfide concentrate smelting process had the problems of low direct recovery rate of metallic bismuth, low extraction rate of associated valuable metal elements, and SO2 flue gas pollution. In this paper, alkaline smelting has been proposed to realize one-step extraction of metallic bismuth from bismuth sulfide concentrate and immobilization of sulfur in molten salt. The influences of smelting temperature, Na2CO3 addition, and reduced coke dosage on the direct recovery rate of metallic bismuth and sulfur-fixing rate have been investigated in detail. Under the optimum conditions (smelting temperature 900°C, WNa2CO3:WConcentrate = 15%, WCoke:WConcentrate = 10%), the direct recovery rate of metallic bismuth was 95.98% and 99.16% sulfur was fixed in the molten salt. More than 99% Mo and W in the raw material entered into the molten salt, and dissolved in the leach solution in the form of Na2MoO4 and Na2WO4 after water leaching. 20% N235—40% sec-caprylic alcohol—40% sulfonated kerosene organic phase was used as extractant, and 94.48% Mo and 99.49% W were extracted from the organic phase by shaking at 25°C for 10 min with O/A of 1:1. Ammonia was then used for stripping, and the stripping efficiencies of Mo and W reached 96.18% and 93.85%, respectively. [ABSTRACT FROM AUTHOR]

The results of research on the processing of ilmenite concentrate from the Obukhovskoye deposit are presented in this article. As the concentrate has a high chromium content, the study involved converting the iron into metal and the titanium into slag through the addition of soda. Positive results were obtained during the smelting of the ilmenite concentrate, and a one-stage smelting mode was established. This mode involved an increase in the temperature up to 1700 °C, with a heating step of 10 °C/min and using an argon supply. The holding time at this temperature was 30 min, followed by cooling to 700 °C in argon. The optimal parameters for sintering the non-magnetic fraction with soda and leaching the sinter with water and hydrochloric acid solution were also determined. [ABSTRACT FROM AUTHOR]

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The primary aim of this research was to delimitate the final pit in an open pit mine using the 1×5 and 1×9 arch methods of the pseudoflow maximum flow algorithm. To achieve this, Exploratory Data Analysis (EDA), economic, and geomechanical parameters were utilized. Various final pit scenarios were generated by varying the revenue factor. The analysis was conducted using Python 3.11 (Jupyter Notebook) and SGeMS V.3.0 software. The block model comprised 480,000 blocks, each measuring 10×10×10 meters, with a copper grade range from 0 to 1.41%. Specific parameters were employed, including a slope angle of 45°, a base copper price of 3.90 US\$/lb, and smelting, extraction, and crushing-grinding costs of 0.40 US\$/lb, 2.30, and 11.00 US\$/ton, respectively. Twenty final pits were generated for each method, based on a revenue factor from 0.10 to 2.00. The results indicated that both methods are effective for final pit delineation, with the 1×5 method achieving an NPV of 17,855 MUS\$ and a REM of 0.27, and the 1×9 method attaining an NPV of 18,456 MUS$ and a REM of 0.35. It was concluded that the 1×9 arch method is preferable as it yields a higher NPV. This study underscores the importance of methodological selection in the planning of open-pit mines, demonstrating that despite a higher REM, the 1×9 method significantly enhances the NPV, implying substantial economic benefits for the industry. [ABSTRACT FROM AUTHOR]

The technosphere consists of material stocks accumulated by human activities, which can include processing residue, such as slag. Various smelting processes generate slag, and some valuable elements are concentrated in this by-product. In this review, the extraction of critical and strategic metals from non-ferrous slags is discussed. Critical and strategic metals are materials that are vital for the nation's economy and defence, as well as its industries, and have common features, such as expected shortfalls, increasing demand, and few substitutions. There are several definitions, methods, and classifications of critical and strategic elements by different organisations. In this study, reports from seven institutions around the world are summarised, and a list of recommended critical and strategic metals is presented. Non-ferrous slags contain a considerable amount of critical and strategic elements, and research on technology and process development using both pyro- and hydrometallurgical methods is very attractive. When it comes to the extraction of values from slag and the development of technology, it is not only important to consider the economic aspect but also to ensure the processes are low in emissions and energy consumption but high in efficiency and recycling. [ABSTRACT FROM AUTHOR]

This study explored, on a laboratory scale, how matte separates from the gangue in the black top of a PGM smelter. Two PGM concentrates, one with high sulfide content (17.3 mass%, Platreef concentrate) and the other with low sulfide content (1.3 mass%, UG-2 concentrate), were studied in the temperature range of 800°C to 1480°C, which is the temperature gradient across the black top. The results showed that effective matte separation occurs at temperatures when the matte is completely molten, and a substantial amount of liquid silicate phase has formed. The main matte separation mechanism is the coalescence of sulfide prills and their gravitational settling through the continuous path created by the liquid silicate phase. Complete matte separation occurs at lower temperatures in Platreef concentrate (1400°C in Platreef concentrate vs. 1480°C in UG-2 concentrate), due to the higher concentration of liquid silicate phase of lower viscosity, as well as the higher amount of sulfide minerals in this concentrate. PGMs already dissolve and collect in a nickel-iron-based alloy associated with the matte at temperatures as low as 900°C. [ABSTRACT FROM AUTHOR]

Analysis of the current state of production of various types of fused zirconia (monoclinic and stabilized) was conducted. A practical possibility of obtaining stabilized zirconia from baddeleyite concentrate in experimental electric-arc furnace (EDP-600) was established. The obtained process and electrical parameters of smelting are recommended for use when producing fused zirconia from synthetic zirconia and baddeleyite concentrate using commercial electric-arc furnaces (DSP‑1.5, OKB-2126, etc). During carbothermic reduction of zircon concentrate in an electric-arc furnace (EDP-450), silica content in the fused product was decreased by 3 times to 10.9% SiO2. To implement the final stage of the carbothermic technology for obtaining fused zirconia containing at least 95% ZrO2, it is recommended to develop a pilot electric-arc system based on DS-05 electric-arc furnace. [ABSTRACT FROM AUTHOR]

The technology to control the motor speed according to load requirements is variable frequency drive (VFD). The motor fan dust collector operates using a VFD to reduce the speed during idle smelting conditions. In addition to energy efficiency, the power quality of the electrical energy system is important to consider. Nonlinear loads from VFDs cause harmonics in the industry that affect electrical power. Power quality measurement and analysis to determine the harmonic and unbalance values of voltage and current are important for improving power quality. This paper discusses the effect of VFDs on power quality, as a real case study, data from existing VFDs in the steel industry are taken to analyze power quality. A large current harmonic of 45% occurs when the VFD decrease the motor speed during idle smelting operation and drops to 5% when the motor speed returns to full speed during smelting operation on. The average maximum current unbalance value is 10.8% and the voltage unbalance is 0.36%, which is still below the standard maximum limit whether the motor is at full or low speed. [ABSTRACT FROM AUTHOR]

Cost‐effective and zero‐carbon‐emission seasonal/annual energy storage is highly required to achieve the Zero Emission Scenario (ZES) by 2050. The combination of Al production via inert‐anode smelting and Al conversion to electricity via Al−air batteries is a potential option. Although playing an important role in this approach, Al−air batteries, however, suffer from limited specific energy and inefficient collection of the discharge product. Herein, an important progress in addressing these issues is summarized, emphasizing the importance of non‐material, but rather process‐related aspects. First, a recently reported approach allowing controllable collection of discharge product and electrolyte regeneration is presented. Next, the importance of cell design in addressing the obstacles of Al−air batteries is emphasized. Subsequently, the impact of operational parameters on improving electrochemical performance of Al−air batteries is summarized. Last, a perspective on future research directions is proposed. [ABSTRACT FROM AUTHOR]

With the continuous evolution and development, smelting technology has gradually matured. After the tungsten is extracted through the smelting process, a large amount of tungsten smelting slag is piled up, which has a negative impact on human production and life. The composition of tungsten smelting slag is complex, and there is leaching agent remaining on the surface, which is rich in valuable metals, so the selection of suitable process to recover the valuable metals in tungsten smelting slag can not only reduce the solid waste emission, reduce the pollution of soil and water resources, but also improve the resource utilization rate of valuable metals and reduce the cost of tungsten smelting slag treatment. The reduction, environmental protection and resource treatment of tungsten smelting slag are the key parts of carbon emission reduction in the tungsten industry. The recovery of metal tin out of a mixed tungsten smelting slag from treatment of wolframite and scheelite was experimentally studied. In this slag about 87.59% of the tin in the tungsten smelting slag was distributed in the -0.045 mm particle size, which was difficult to sort. The Knelsen vertical centrifugal separator was selected as the roughing equipment, and the optimal conditions for the roughing process were determined by step-by-step optimization experiments, which were 78.15% -0.038 mm of the grinding fineness, 15% of the feed concentration, 90 G/s of separation cone speed, and 2.60 L/min of backflush water flow. In order to further improve the tin grade of the rough concentrate, the four selection methods were compared and tested, and finally with the gravity separation process of "one roughing and one cleaning centrifugal separation, shaking table and centrifugal separation after classification", under the feed concentration 15%, the speed of the separation cone 90 G/s and the backflush water flow rate 2.75 L/min, the tin grade of tin concentrate was 4.03% and the tin recovery was 52.41%, which realized the effective recovery of valuable metal tin in tungsten smelting slag, and provided a certain reference for the reduction and resource utilization of the tungsten smelting slag. [ABSTRACT FROM AUTHOR]

Abstract The study assessed the uniformity of the metallurgical process carried out during the period of Roman influence in Poland. The age of the investigated material was confirmed based on an analysis of the 12C/14C isotope ratio in the charcoal found in slag. The comparison was based on four Holy Cross Mountains (Poland) locations. The evaluation included smelting temperature, viscosity of the metallurgical melt, oxidation–reduction conditions, and slag cooling rate determined based on geochemical (XRF) and mineralogical (XRD, SEM, EPMA) analyses. Despite the distance between individual sampling sites, the conditions in which smelting was carried out were similar for all samples. The liquidus temperature of the analyzed slags was in the range of 1150–1200 °C. Oxidation–reduction conditions were determined through thermodynamic calculations using SLAG software. In the temperature range of 1150–1200 °C, the oxygen fugacity had to be below logP O2 = − 13.20 to − 12.53 atm to reduce iron oxides to metallic iron. The viscosity of the metallurgical melt was calculated and ranged from 0.15 to 1.02 Pa s, indicating a low viscosity. The slag cooling rate determined based on olivine morphology was in the range of > 5 to 300 °C/h. Smelting parameters were compared with other locations in Poland, and similar results were obtained for slags from Masovia and Tarchlice. In the case of one site (Opole), despite the higher maximum value of liquidus temperature, it was indicated that the process could have taken place in similar conditions, and the differences resulted from contamination of the slag with material from the furnace/pit walls.

The study assessed the uniformity of the metallurgical process carried out during the period of Roman influence in Poland. The age of the investigated material was confirmed based on an analysis of the 12C/14C isotope ratio in the charcoal found in slag. The comparison was based on four Holy Cross Mountains (Poland) locations. The evaluation included smelting temperature, viscosity of the metallurgical melt, oxidation–reduction conditions, and slag cooling rate determined based on geochemical (XRF) and mineralogical (XRD, SEM, EPMA) analyses. Despite the distance between individual sampling sites, the conditions in which smelting was carried out were similar for all samples. The liquidus temperature of the analyzed slags was in the range of 1150–1200 °C. Oxidation–reduction conditions were determined through thermodynamic calculations using SLAG software. In the temperature range of 1150–1200 °C, the oxygen fugacity had to be below logP O2 = − 13.20 to − 12.53 atm to reduce iron oxides to metallic iron. The viscosity of the metallurgical melt was calculated and ranged from 0.15 to 1.02 Pa s, indicating a low viscosity. The slag cooling rate determined based on olivine morphology was in the range of > 5 to 300 °C/h. Smelting parameters were compared with other locations in Poland, and similar results were obtained for slags from Masovia and Tarchlice. In the case of one site (Opole), despite the higher maximum value of liquidus temperature, it was indicated that the process could have taken place in similar conditions, and the differences resulted from contamination of the slag with material from the furnace/pit walls. [ABSTRACT FROM AUTHOR]

• Fe oxyhydroxides are the common dominant phase for As, Cd, Pb and Zn. • Paulmooreite is an important mineral host for Pb and As. • The leaching of Pb, Zn, Cd and As exhibit a strong dependence on pH. • Fe oxyhydroxides and secondary insoluble minerals are the solubility-controlling phases. The lack of understanding of heavy metal speciation and solubility control mechanisms in smelting soils limits the effective pollution control. In this study smelting soils were investigated by an advanced mineralogical analysis (AMICS), leaching tests and thermodynamic modelling. The aims were to identify the partitioning and release behaviour of Pb, Zn, Cd and As. The integration of multiple techniques was necessary and displayed coherent results. In addition to the residual fraction, Pb and Zn were predominantly associated with reducible fractions, and As primarily existed as the crystalline iron oxide-bound fractions. AMICS quantitative analysis further confirmed that Fe oxyhydroxides were the common dominant phase for As, Cd, Pb and Zn. In addition, a metal arsenate (paulmooreite) was an important mineral host for Pb and As. The pH-stat leaching indicted that the release of Pb, Zn and Cd increased towards low pH values while release of As increased towards high pH values. The separate leaching schemes were associated with the geochemical behaviour under the control of minerals and were confirmed by thermodynamic modelling. PHREEQC calculations suggested that the formation of arsenate minerals (schultenite, mimetite and koritnigite) and the binding to Fe oxyhydroxides synchronously controlled the release of Pb, Zn, Cd and As. Our results emphasized the governing role of Fe oxyhydroxides and secondary insoluble minerals in natural attenuation of heavy metals, which provides a novelty strategy for the stabilization of multi-metals in smelting sites. [Display omitted] [ABSTRACT FROM AUTHOR]

This study aimed at determining the concentration and possibility of migration of potentially harmful elements (PHEs) in soils and mining and metallurgical waste in the Silesian-Cracow region. Our research was carried out in selected locations of Ruda Śląska, Świętochłowice, Bytom, and in the Olkusz region (Bukowno) in southern Poland. The concentrations of metals (e.g., Ag, Ba, Ca, Cd, Cu, Fe, Mg, Mn, Pb, Sr, Zn), metalloids (As, Sb), and sulphur were determined in 33 soil samples (with a depth range of 0.0–0.3 m) and 12 slag samples. These studies show an increased concentration of metals, metalloids, and sulphur, exceeding the level of regional geochemical background. The research results indicate that the degree of the chemical transformation of soils in the analysed regions of Ruda Śląska, Bytom, and Bukowno is advanced. This highlights the high concentrations of most metals, i.e., arsenic, antimony, and sulphur, in the surface layer of soils (topsoil) due to historic Zn-Pb ore mining and Zn and Fe metallurgy. The presence of both primary and secondary metal sulphides, sulphates, carbonates, oxides/hydroxides, silicates, and aluminosilicates was found in the mineral composition of soils and slags. [ABSTRACT FROM AUTHOR]