Search

The nitrogen content and solidification structure of the 1Mn18Cr18N ingots produced by the customized laboratory‐scale vacuum induction melting furnace and the pressure electroslag remelting furnace (PESR) with novel composite electrode under different pressure and the same power consumption are compared and studied. The results show that there are perfectly uniform radial chromium and nitrogen profiles during the PESR process. The nitrogen uptake reaction in the PESR process with composite electrode takes place on the liquid metal film on the electrode. Nitrogen uptake could be improved by increasing the nitrogen partial pressure. In addition, the basin depth at a pressure of 0.1 and 1.22 MPa is about 41 and 38 mm, the angle of the grains with respect to the vertical axis is 35° and 31°, respectively. The flat metal basin profile resulted from the thermal resistance at the slag–mold interface decreasing with increasing pressure. Primary and secondary dendritic arm spacing (PDAS and SDAS) variations exhibit an increasing and subsequently decreasing the trend as they move further away from the center in a horizontal direction. Both PDAS and SDAS decrease with increasing pressure from 0.1 to 1.22 MPa. [ABSTRACT FROM AUTHOR]

Spent automotive catalysts (SACs) are the most important secondary resource for platinum group metals (PGMs). Due to the complex physicochemical properties and low concentration of SAC, it is very difficult to recover Pt, Pd, and Rh. The technology of using smelting iron to recover PGMs has the advantages of a simple process and large-scale production. The rheological behavior of slag is an important influencing factor in the recycling process. In this paper, the principle of slag design is proposed, and CaO/SiO2 mass ratio and B2O3 content are used as parameters to adjust the composition of the slag. The viscosity of slag was measured by the rotation axis method, and the structure of the slag was characterized by FTIR and Raman spectroscopy. The influence on the rheological properties and structure of slag was studied to optimize the smelting process. The optimized composition of the slag is 5.10 wt.%CaO-43.86 wt.%SiO2-9.40 wt.%Al2O3-5.64 wt.%MgO-6.00 wt.%B2O3. In the reduction melting experiment, the recovery rate of PGMs reached 99.8%. This, furthermore, avoids the generation of ferrosilicon (FeSi), providing a reference for the effective recovery of PGMs. [ABSTRACT FROM AUTHOR]

The titanium distribution ratio ( L Ti ) between ferrosilicon (FeSi) melt and the CaO-SiO2-Al2O3 slag was measured at 1773 K (1500 °C). FeSi-slag equilibration was carried out using various slag compositions. The L Ti was presented against the Vee ratio (pct CaO/pct SiO2 = C/S) between 0.3 and 1.2, and Al2O3 content from 5 to 20 mass pct. The L Ti exhibited minima at about C/S=0.7(±0.1) at a fixed Al2O3 content. In a C/S < 0.7 regime, i.e., relatively acidic melts, Ti4+ ions were considered as network forming [TiO4]-tetrahedron unit in the aluminosilicate framework. However, in a C/S > 0.7 regime, i.e., relatively basic melts, Ti4+ ions were considered to form the [TiO5]-pyramid structure unit compensated by Ca2+. When adding Al2O3 into the basic melts over 10 mass pct, [AlO4]-tetrahedrons take Ca2+ ions for charge compensation, resulting in a decrease of stability of [TiO5] unit because of Ca2+ depletion. At a greater than 10 mass pct Al2O3 content in the basic melts, Ti4+ replaced Al3+ to form the [TiO4]-tetrahedron unit, decreasing the activity coefficient of TiO2 in the slag. [ABSTRACT FROM AUTHOR]

Industrially, the silicon requirement of liquid steel is often met with ferrosilicon (FeSi) instead of high‐purity silicon addition. FeSi, a silicon‐rich alloy, contains impurities typically inherited from its manufacturing stage. Therefore, FeSi addition results in the formation of complex inclusions in the liquid steel. Herein, a detailed inclusion characterization of the samples obtained from the melting experiments for a wide range of silicon concentrations has been carried out to examine the effect of FeSi impurities. Pure silica inclusions evolve to silica‐ and/or alumina‐based Si–Al–(Ti)–O–(TiN) complex inclusions with the increasing addition of FeSi to the steel melt. Reduction of silica by aluminum or titanium, the presence of titanium in the steel melt, and/or TiN inclusions formed at the periphery of oxide inclusions restrict the growth of oxide inclusions, resulting in small‐sized (average) oxide inclusions. The underlying mechanism of such complex (Si–Al–Ti–O–N)‐based inclusions has been explained with the aid of microstructural characterization and thermodynamic calculations. Moreover, the steel–crucible (alumina) interface has also been investigated for inclusion deposits and crucible–steel interaction. [ABSTRACT FROM AUTHOR]

Automotive catalysts containing Platinum Group Metals (PGMs) are valuable secondary raw materials for refineries. Hydrometallurgical processing of catalysts is ineffective due to the low PGMs content—0.15–0.3%. Therefore, such raw materials are melted into an iron collector containing 1.5–5% PGMs. However, when leaching a collector containing 10–20% Si in both HCl and H2SO4, the recovery of PGMs does not exceed 40%. The latter indicates incomplete destroying of the PGM-encapsulating ferrosilicon matrix. To completely destroy the ferrosilicon matrix, it is proposed to carry out the leaching process in a mixture of HCl and HF. In this case, the extraction of Fe into solution and Si into the gas phase (in the form of SiF4) exceeds 90%. This should be sufficient to completely destroy the ferrosilicon matrix and release PGMs. The current work presents the results of studies of the leaching kinetics of the iron collector containing ferrosilicon in a mixture of HCl and HF using the Shrinking Core Model (SCM). It was found that the greatest positive effect on Fe extraction into solution is exerted by HCl concentration and temperature, while Si release into the gas phase is only influenced by HF concentration. In addition, during the destroying of ferrosilicon, FeF2 is formed and deposited on the surface of the material in the form of thin-film conglomerates. This leads to diffusion difficulties and a gradual decrease in the intensity of the iron collector leaching 30 min after the start of process. After 120 min, there may be a decrease in Fe recovery into solution. [ABSTRACT FROM AUTHOR]

Abstract The article presents the results of research carried out using a water model of a refining ladle for the Fe–Si ferroalloys treatment. These studies were aimed at improving the efficiency of refining and homogenization of liquid Fe–Si ferroalloy in the refining ladle by using a new method of blowing gas through a system of nozzles installed at the bottom of the ladle. The obtained results allowed to determine the proper location of the plug at the bottom of the refining ladle and the possibility of using combined blowing. The tests were carried out for a refining ladle with a capacity of 3 m3 using a physical model on a linear scale of 1:3. The gas flow rate used in the model corresponded proportionally to the value previously used in industrial practice and amounted to 26.8 l/min. Experiments were performed for both combined blowing applications and through a purging plug at the bottom of the ladle. In the case of combined blowing, the volume of the gas stream was divided into two blowing sources (lance and purging plug). As a result of laboratory tests, one of the variants was selected and tested in industrial conditions. These studies confirmed the improvement in the efficiency of refining treatment of the FeSi alloy in terms of reducing the carbon and aluminum content in the alloy.x

This article presents the results of thermodynamic and experimental studies on the joint processing of a mixture of Shalkiya deposit zinc–lead sulfide ore and its concentration tailings in the presence of coke and magnetite. Using the HSC-6.0 software package, it was established by thermodynamic modeling that the silicon-containing products of the SiO2 reduction in the system under consideration are FeSi, Si, Fe3Si, Fe5Si3, FeSi2, FeSi2.33, and SiOg, which, based on the starting reduction temperature, form an increasing series: Fe3Si (1200 °C); Fe5Si3, Si (1400 °C); and SiOg, FeSi2, FeSi2.33 (1500 °C). The smelting of the zinc–lead sulfide ore and concentration tailings mixture in the case of replacing 55% of the iron contained in the magnetite concentrate with steel shavings iron allowed us to produce FeSi45 ferrosilicon (41.9%–42.1% Si), with the extraction of 85% of the silicon in it, and sublimates containing 26.03% zinc and 13.47% lead, with the extraction of 97% of the zinc and 99% of the lead in them. In comparison with the initial ore-tailings mixture, the resulting sublimates are 11.83 times richer in zinc. [ABSTRACT FROM AUTHOR]

Death of vascular smooth muscle cells (VSMC) induced by reactive oxygen species (ROS) may occur as ferroptosis, contributing to atherosclerotic plaque instability and rupture. Although it is involved in ROS-induced VSMC death, the role of nuclear transcription factors erythroid 2 related factor 2 (NRF2) in ferroptosis remains unclear. This study was designed to determine the coupling between NRF2 and antioxidant ferroptosis suppressor protein 1 (FSP1) in ROS-induced VSMC ferroptosis. We exposed mouse aortic VSMCs to hydrogen peroxide (H 2 O 2), and cell death was characterized by increased NRF2 expression and inhibition of FSP1 expression. The results demonstrated that VSMC exposure to H 2 O 2 emerged as the characteristic of ferroptosis·H 2 O 2 promoted the expression and nuclear translocation of NRF2 and downregulated FSP1 expression. These data imply a novel and important role for NRF2/FSP1 in ferroptosis for treating VSMCs ferroptosis-associated diseases. [Display omitted] • Hydrogen peroxide induces VSMCs ferroptosis. • Hydrogen peroxide promoted the expression of NRF2, down-regulating the expression of FSP1. • Hydrogen peroxide induces ferroptosis in VSMCs by NRF2/FSP1 axis. [ABSTRACT FROM AUTHOR]

Voacangine, a naturally occurring alkaloid, has been testified to display beneficial effects on a variety of human diseases, but its role in ischemic stroke is unclear. The impacts of voacangine on oxygen–glucose deprivation/reoxygenation (OGD/R)‐tempted hippocampal neuronal cells are investigated. The bioinformatics analysis found that voacangine is a bioactive ingredient that may have good effects on ischemic stroke. KEGG pathways analysis found that voacangine may regulate ischemic stroke through modulating the PI3K‐Akt‐FoxO signaling pathway. Voacangine could mitigate OGD/R‐tempted cytotoxicity in HT22 cells. Voacangine mitigated OGD/R‐tempted oxidative stress in HT22 cells by diminishing reactive oxygen species level and enhancing superoxide dismutase level. Voacangine mitigated OGD/R‐tempted ferroptosis in HT22 cells. Voacangine promoted activation of the PI3K‐Akt‐FoxO signaling in OGD/R‐induced HT22 cells. Inactivation of the PI3K‐Akt‐FoxO signaling pathway reversed the protective effects of voacangine against OGD/R‐tempted oxidative stress, cytotoxicity, and ferroptosis in HT22 cells. In conclusion, voacangine protects hippocampal neuronal cells against OGD/R‐caused oxidative stress and ferroptosis by activating the PI3K‐Akt‐FoxO signaling. Voacangine has been shown to have beneficial effects on several human diseases, but its role in ischemic stroke has not been elucidated. In this study, we have identified the neuroprotective effects of voacangine against oxygen‐glucose deprivation/reoxygenation (OGD/R)‐induced damage through bioinformatics and in vitro cell experiments. Mechanistically, voacangine protected hippocampal neuronal cells against OGD/R‐caused oxidative stress and ferroptosis by activating the PI3K‐Akt‐FoxO signaling. [ABSTRACT FROM AUTHOR]

Yttrium (1 mol %) -doped 0.49BiFeO3-0.20Pb(Mg1/3Nb2/3)O3-0.31PbTiO3 ceramic at the morphotropic phase boundary was synthesized by a solid-state reaction via columbite precursor technique. X-ray diffraction (XRD) and FESEM analysis confirmed a perovskite phase in the P1m1 space group with a homogeneous microstructure sintered at 920 °C. Rietveld refinement yield lattice parameters a = 3.95984 Å, b = 3.93828 Å, c = 4.04466 Å, α = 90.000°, β = 89.970°, γ = 90.000°. Studies of dielectric permittivity and ferroelectric hysteresis at room temperature shows Y doping impact, exhibiting low dielectric loss and a saturated hysteresis loop. The synthesized sample remains fatigue-free over 104 cycles, with a high value of converse piezoelectric coefficient of d33* ̴ 723 pm/V. Weak ferromagnetism is observed in the magnetic hysteresis loop (M-H) at room temperature, suggesting potential applications in ferroelectric-based technologies. [ABSTRACT FROM AUTHOR]

[Display omitted] • G-FA and F-FA were vitrified together based on their compositional complementarity. • Clean vitrified slag was obtained at 1300 °C without water-washing and any additives. • Cr, Ni, Cu could be recovered as Fe-Cr-Ni-Cu alloy. • FA was efficiently reutilized as three separated phases. The increasing application of municipal solid waste incineration (MSWI) emphasises the need for MSWI fly ash (FA) safe treatment. Based on the compositional complementarity of FA from grate furnaces (G-FA) and fluidised bed incinerators (F-FA), we proposed a co-reduction process to treat G-FA and F-FA together for producing vitrified slag and ferroalloys. The clean vitrified slag and Fe-Cr-Ni-Cu alloy were obtained with the mass ratios of 1:9 ∼ 6:4 (G-FA:F-FA) at 1300℃, which is about 300℃ lower than the conventional G-FA vitrification. The metals Zn, Cd, and Pb were mostly volatilised into the flue gas for potential recovery from the secondary FA. The thermodynamic SiO 2 -Al 2 O 3 -CaO ternary system demonstrated that an optimal mass ratio of the two complementary FA types contributes to the system shifting to the low-temperature melting zone. The co-reduction process of G-FA and F-FA could be a promising option for FA beneficial reutilization with environmental advantages. [ABSTRACT FROM AUTHOR]

In the steelmaking industry, the kind of silica and carbon sources utilized in the ferrosilicon manufacturing process have a big impact on the operation's stability, energy usage, and cost. Biomass resources have gained attention due to their potential to replace existing materials to produce activated carbon as it is the best way to preserve the environment. Thus, this study focused on the synthesis of ferrosilicon from coconut char as a reductant at different reduction times (30, 60, 90 and 120 minutes). The coconut char was prepared by physical activation method via pyrolysis process at 450 °C within 2 hours under a nitrogen atmosphere. X-ray Diffraction (XRD), Xray fluorescence (XRF), and Optical Microscope (OM) were used to characterize the activated carbon from coconut shells. CHNS analysis found an increment of about 65% in carbon content after pyrolyzed, which could potentially be used as a reductant in ferrosilicon synthesis. Next, the ferrosilicon synthesis study was conducted in a muffle furnace at a reduction temperature of 1200 °C with a flow rate of 10 °C/min for 30, 60, 90, and 120 minutes of reduction times. Phase transformation of reduced samples at different reduction times was analyzed by X-ray Diffraction (XRD). XRD pattern found that at 120 minutes reduction times, the iron silicon peak is observed as the morphology analysis showed a presence of metallic grey particles which represent the existence of iron silicon. The possibility of converting the biomass into an alternate supply that was discovered in ferrosilicon synthesis also would minimize the landfill waste. [ABSTRACT FROM AUTHOR]

SiAlON ceramics is a unique material used in various applications. Producing porous SiAlON material from available industrial waste by combustion is of great interest. In this work, a porous SiAlON composite was synthesized by the combustion of a mixture of aluminum ferrosilicon powder and aluminosilicate hollow microspheres in nitrogen. Aluminosilicate hollow microspheres were used as a pore-forming agent. The addition of aluminosilicate hollow microspheres to aluminum ferrosilicon powder increased the total porosity from 34.1 to 90.3%, the open porosity from 16.4 to 88.2%, and the maximum pore size from 53 to 413 μm in the final product. The porosity of the synthesized samples was predominantly open. [ABSTRACT FROM AUTHOR]

[Display omitted] Despite development in nanozymes for cancer treatment, challenges in their synthesis and structural optimization for peak catalytic activity persist. A multifunctional enzyme-like nanoparticle using a controllable synthesis that offers a clear structure–activity relationship was developed. The nitrogen-doped mesoporous carbon nanospheres (MCNs) with iron coordination were produced via an in-situ iron-catalyzed pyrolysis, which allowed for precise adjustment of iron content. Not only do Fe/MCN exhibit high graphitization for enhanced photothermal conversion but also feature co-doping with both single atoms and atom clusters, enhancing their enzyme-like activities. These activities included oxidase, peroxidase, catalase, and glutathione oxidase, leading to synergistic effects in chemodynamic, photodynamic therapies, and hypoxia alleviation. Additionally, Fe/N-MCNs induced potent immunogenic cell death, aided by ROS, ferroptosis, and ferroptosis-sensitized photothermal therapy. Fe/N-MCN also provided excellent photoacoustic and magnetic resonance imaging capabilities, establishing a multifaceted platform for the treatment of breast cancer and the inhibition of postoperative recurrence and metastasis. [ABSTRACT FROM AUTHOR]

Some key experiments are carried out to determine the solubility of N in Fe–Si liquid solutions at various compositions, temperatures, and N2 pressures using the sampling method. The Fe–Si–N system is thermodynamically modeled using the CALculation of PHAse Diagrams (CALPHAD) approach for the first time based on critical evaluation of all available experimental data. In the present thermodynamic modeling, the liquid and solid solutions of the Fe–Si–N system are described using the modified quasichemical model and compound energy formalism, respectively. In particular, the Gibbs energies of liquid, FCC_A1, and BCC_A2 solutions are carefully determined to resolve the discrepancies among existing experimental data. The solubility product of β‐Si3N4(s) in Si steels and ferrosilicon alloys, activity coefficients, and interaction parameters of N in liquid and solid Fe–Si–N solutions are determined over a wide temperature range. As an application of the database, the N solubility in Si steels and phase constitution of nitrided ferrosilicon alloys in a wide composition, temperature, and N2 pressure ranges are predicted. [ABSTRACT FROM AUTHOR]

This article proposes a novel Si3N4-based five-ring hexa-circular photonic crystal fiber (PCF) that shows a remarkably high nonlinear coefficient (NLC) and birefringence (Br). Several distinctive optical features, including birefringence, nonlinearity, effective area, numerical aperture, confinement loss, dispersion, etc., are investigated utilizing the COMSOL Software. The simulation analysis demonstrates that a zero-crossing dispersion for Y- polarization and an extremely high Br and NLC of 0.22 and 2687.51 W - 1 Km - 1 are reached at the wavelength of 1.55 μ m . The proposed PCF, having extremely high Br and NLC properties, can be useful for prospective future applications in the areas of supercontinuum generation, nonlinear optics, polarization-maintaining, and so on. [ABSTRACT FROM AUTHOR]

Driven by the rising demand for glass, metals, and plastics in industrial and household sectors, there was a substantial increase in waste and by-products generated. This study presents a method for repurposing waste glass, mill scale, and plastics as raw materials for ferrosilicon alloy production. This process entails reducing SiO2 and Fe2O3 using carbon derived from polystyrene/polypropylene mixtures. The glass, scale, and carbon powders were blended to achieve a C/O molar ratio of 1 (Blends A to F). The thoroughly mixed samples were then shaped into pellets and subsequently heated at 1550 °C in a tube furnace for 60 min. Ferrosilicon was successfully synthesized, with the reaction generating numerous metal droplets along with a slag layer in the crucible. The metallic yield for Blends A to F ranged from 16.65 wt% to 21.39 wt%, with the highest yield observed in Blend D. The bulk metal primarily consists of the FeSi phase, with Blend D exhibiting the highest Si concentration of 13.51 wt% and the highest hardness of 649.55 HV. Mechanism steps for ferrosilicon formation may vary with carbon dissolution rates. This work supports fossil fuel reduction and carbon neutrality, benefiting zero wastes practice and promoting sustainable material processing. [ABSTRACT FROM AUTHOR]

In this study, existing and promising methods of processing fine fractions and dust of aspiration systems for the production of ferroalloys were analyzed. The technological properties of high-carbon ferrochrome screenings and dust of the ferrochrome crushing aspiration system of the Aktobe Ferroalloy Plant as raw materials for the production of low-carbon ferrochrome briquettes using the vacuum-thermal method were studied. The contents of basic and impurity elements, including gas-forming ones, were determined. The oxygen content in the dust reached 4.2 and 0.12% in the screening. The average size of aspiration dust particles was 9.6 μm, whereas that of the ferrochrome screenings was 1.44 mm. In the dust and screening samples, the main phase was Cr7C3, and graphite was present in the dust sample. During thermal analysis, the dust sample completely melted at 1453 °C, and a liquid phase was not observed when ferrochrome was heated. At 1340 °C, the formation of iron silicide was noted. With increasing temperature, the concentrations of carbon and chromium carbide decreased. From thermodynamic calculations, recommendations were given on the parameters of vacuum-thermal decarburization of high-carbon ferrochrome. The results of preliminary experiments confirmed the possibility of removing carbon from screenings and aspiration dust. From samples containing 9.04–9.11% carbon, ferrochrome with a content of 0.10% carbon could be obtained. At the next stage of our work, we plan to work out in detail the parameters affecting the vacuum-heat treatment of ferrochrome. We assume that ferrochrome with a carbon content of 0.00x% can be obtained. [ABSTRACT FROM AUTHOR]

Due to the frequent occurrence of extreme weather and severe environmental pollution, food security and human survival are at risk. Silicon, a key element in plant nutrition and environmental remediation, has a variety of applications in combatting various forms of abiotic and biotic stress and fostering healthy plants and soils. To establish a silicon-based defense barrier for plants, we firstly summarized and grouped the mechanisms of silicon functioning in plants: 1) molecular regulation and overall strengthening, 2) physical barrier and apoplastic obstruction, and 3) energy conservation. Additionally, the types and applications of silicon-based materials as soil remediation materials and fertilizers were discussed. Then, the challenges to build up such a barrier were analyzed in terms of silicon absorption and transportation, deposition and aggregation, and perception and regulation. An "external + internal" strategy was proposed to accelerate the establishment of a silicon-based barrier to enhance plants' resistance to extreme weather and environmental pollution, including high temperatures, drought, ultraviolet radiation, salt, heavy metals, nutrient deficiencies, new pollutants, and biotic stress. Finally, this paper emphasized the contribution of silicon barrier to healthy Soil-Plant-Atmosphere system that eventually benefit human health. This paper highlights the current understanding and future perspectives of silicon-related research in Soil-Plant-Atmosphere system, providing a reference for the application of silicon-based materials in environmental and agricultural fields. [ABSTRACT FROM AUTHOR]

This paper deals with the possibility of smelting quasi-high-entropy alloys (QHEAs) with the partial use of ferroalloys in the charge instead of pure metals. The Cantor alloy (CoCrFeMnNi) was used as the base alloy and the comparison sample, into which niobium was introduced in the amount of 14 to 18% by weight. The structure, hardness, strength, and tribological properties of prototypes were studied. The results obtained showed, on the one hand, the possibility of using ferroalloys as charge components in the smelting of QHEAs and, on the other hand, the positive effect of niobium in the amount of 14–17% on the strength and wear resistance of the alloy. Increasing the niobium content above 18% leads to its uneven distribution in the structure, consequently decreasing the strength and wear resistance of the alloy. The structure of the studied alloys is represented by a solid solution of FCC, which includes all metals, and the niobium content varies widely. In addition, the structure is represented by the phases of implementation: niobium carbide NbC 0.76–1.0, manganese carbide Mn7C3, and a CrNi intermetallic compound with a cubic lattice. [ABSTRACT FROM AUTHOR]

This paper presents a practical approach to the production of certified reference materials (CRMs) for ferrosilicon magnesium alloys. These new CRMs are predicted to be used in fast X-ray fluorescence spectrometry (XRF) analysis, which does not require sample digestion and does not result in the production of acidic sewage and emissions, contrary to the classical and instrumental techniques currently used in laboratories. Four new certified reference materials (CRMs) were developed to fill the gap in the reference materials market and ensure fast and traceable analyses. The materials were produced with an industrial process and then homogenized and mixed to achieve the required compositions and level of homogeneity. The homogeneity was determined using specially developed analytical methods and confirmed statistically by ANOVA. Additionally, the results of the tests show the short- and long-term stabilities of the new materials. The certified values for specific element contents were determined in interlaboratory tests. All results were assessed statistically for outliers. The results from three or more independent and different analytical methods were used for the calculations. In parallel homogeneity, the stability, and characterization standard uncertainties were calculated and used in the estimation of the final expanded uncertainties of the certified values. Finally, four new CRMs were assisted with the proper certificates according to ISO standards. [ABSTRACT FROM AUTHOR]

The performance and quality of steel products are significantly impacted by the alloying element control. The efficiency of alloy utilization in the steelmaking process was directly related to element yield. This study analyses the factors that influence the yield of elements in the steelmaking process using correlation analysis. A yield prediction model was developed using a t-distributed stochastic neighbor embedding (t-SNE) algorithm, a whale optimization algorithm (WOA), and a long short-term memory (LSTM) neural network. The t-SNE algorithm was used to reduce the dimensionality of the original data, while the WOA optimization algorithm was employed to optimize the hyperparameters of the LSTM neural network. The t-SNE-WOA-LSTM model accurately predicted the yield of Mn and Si elements with hit rates of 71.67%, 96.67%, and 99.17% and 57.50%, 89.17%, and 97.50%, respectively, falling within the error range of ±1%, ±2%, and ±3% for Mn and ±1%, ±3%, and ±5% for Si. The results demonstrate that the t-SNE-WOA-LSTM model outperforms the backpropagation (BP), LSTM, and WOA-LSTM models in terms of prediction accuracy. The model was applied to actual production in a Chinese plant. The actual performance of the industrial application is within a ±3% error range, with an accuracy of 100%. Furthermore, the elemental yield predicted by the model and then added the ferroalloys resulted in a reduction in the elemental content of the product by 0.017%. The model enables accurate prediction of alloying element yields and was effectively applied in industrial production. [ABSTRACT FROM AUTHOR]

The article presents the results of studies on the use of the high-silicon phosphorites (51,8 % of Ca3(PO4)2, 25,6 % of SiO2) for the co-production of ferrosilicon, calcium carbide and gaseous phosphorus. The studies included the electric smelting a charge in an arc furnace and using the second-order rotatable designs. The conditions of producing FeSi45 ferrosilicon (51,2-54,2 % of coke, 12,5-18,4 % of steel shavings) and FeSi25 ferrosilicon (53-58 % of coke, 39,7- 40 % of steel shavings) with extraction of 65-67,8 % of silicon into the alloy were determined. The second product of the process is technical calcium carbide with a capacity of 129-167 l/kg, in which from 44,8 to 64,1 % of calcium is extracted. At least 99,3 % of phosphorus during the electric smelting is sublimated. [ABSTRACT FROM AUTHOR]

[Display omitted] • The porous Si obtained from industrial ferrosilicon is low-cost. • The mechanism of dual immobilization from TiO 2 and carbon double shells protected PSi is investigated. • The graphene matrix provides a stable 3D conductive network to accelerate the charge transfer and Li+ diffusion. • The composite demonstrates outstanding electrochemical performance and structural stability. Smart surface coatings have been proven to be an effective strategy to significantly enhance the electronic conductivity and cycling stability of silicon-based anode materials. However, the single/conventional coatings face critical challenges, including low initial Coulomb efficiency (ICE), poor cyclability, and kinetics failure, etc. Hence, we proposed a dual immobilization strategy to synthesize graphene supported anatase TiO 2 /carbon-coated porous silicon composite (denoted as PSi@TiO 2 @C/Graphene) using industrial-grade ferrosilicon as lithium storage raw materials through the simple etching, combined with sol–gel and hydrothermal coating processes. In this work, the dual immobilization from the "confinement effect" of the inner TiO 2 shell and the "synergistic effect" of the outer carbon shell, improves the kinetics of the electrochemical reaction and ensures the integrity of the electrode material structure during lithiation. Furthermore, the introduction of the graphene substrate offers ample space for dispersing and anchoring the Si-based granules, which in turn provides a stable 3D conductive network between the particles. As a result, the PSi@TiO 2 @C/Graphene electrode delivers high reversible capacity of 1605.4 mAh g−1 with 93.65% retention at 0.5 A g−1 after 100 cycles (vs. 4th discharge), high initial Coulomb efficiency (82.30%), and superior cyclability of 1159.9 mAh g−1 after 250 cycles. The above results suggest that the particle structure has great potential for applications in Si-based anode and may provide some inspiration for the design of other energy storage materials. [ABSTRACT FROM AUTHOR]

This publication presents the chemical compositions of carbon reducers used in the production of ferroalloys, with particular emphasis on the content of Al, Ca, Mg, Mn, Cr, Ti, P, or S in their mineral substances. A certain amount of these elements is transferred to the produced alloys, creating inclusions and precipitations in the metal structure. Most of them are undesirable and adversely affect the final effect of the production process. The work includes sample images of the microstructure of alloys, the chemical compositions of the samples at the test point, and diffragrams. On the basis of the obtained metallographic data, technological observations are made, especially of the crushing process and the amount of grain fractions obtained. [ABSTRACT FROM AUTHOR]

Most common ferroalloys are produced mainly by carbothermal reduction of high-grade ores or concentrates, which results in large CO2 emissions. Hydrogen is a promising alternative to coke and coal, which are reducing agents in the carbothermal process. Hydrogen production is becoming increasingly cheaper, and in the future, it may become available for extensive industrial applications. The advantage of using hydrogen is due to its ability to reduce many different oxides, which are the sources of metals in ferroalloy production, at lower temperatures than using carbon-based reducing agents. Hydrogen is the most promising, and its use is presently possible in the production of ferrotungsten, ferromolybdenum, and ferronickel. [ABSTRACT FROM AUTHOR]

The influence of a dispersed powder filler obtained by thermal synthesis from a mixture of 65% titanium hydride, 30% ferrosilicon, and 5% technical carbon powders, on the main physicomechanical properties of a polymer composite based on ED-20 epoxy diane oligomer, is investigated. The content of the filler varied in the range from 5 to 40 mass%. The introduction of the filler into the polymer composition leads to a noticeable increase in the main mechanical characteristics of the composite. Its maximum values at the dispersed component content of 10%, ensure an increase in bending strength in 1.6 times, and an impact toughness in 1.7 times compared to the original matrix. A further increase in the dispersed filler content in the composite composition to 20–40% leads to a decrease in fracture stresses, the level of which, however, still exceeds the strength of the original matrix phase. Composites with 5% filler demonstrate maximum values of adhesive strength and minimum values of residual stresses. When the content of dispersed filler increases by more than 5–10%, the formation of the dispersed particles conglomerates the number and size of which increase with the increase in the powder concentration in the mixture is observed in the composite structure. [ABSTRACT FROM AUTHOR]

The article presents the results of studies on the use of the high-silicon phosphorites (51,8 % of Ca3(PO4)2, 25,6 % of SiO2) for the co-production of ferrosilicon, calcium carbide and gaseous phosphorus. The studies included the electric smelting a charge in an arc furnace and using the second-order rotatable designs. The conditions of producing FeSi45 ferrosilicon (51,2-54,2 % of coke, 12,5-18,4 % of steel shavings) and FeSi25 ferrosilicon (53-58 % of coke, 39,7- 40 % of steel shavings) with extraction of 65-67,8 % of silicon into the alloy were determined. The second product of the process is technical calcium carbide with a capacity of 129-167 l/kg, in which from 44,8 to 64,1 % of calcium is extracted. At least 99,3 % of phosphorus during the electric smelting is sublimated.

The paper presents the results of studying the use of iron ore concentrate as a component of the charge for briquetting finely dispersed dust generated during the production of ferrosilicon. Experiments were carried out on introducing iron ore concentrate into the mixture in the amount of 3 to 10 %. Liquid glass and water were used as a binder. It was shown that the use of 5-7 % by weight of iron ore concentrate with the iron and silicon content of about 65 % and 26 %, respectively, led to increasing strength and density of the briquette by an average of 20 % compared to the same characteristics of briquettes obtained without adding iron ore concentrate. It should be expected that improving such briquette characteristics as strength and density will provide higher safety of the product during transportation and loading and better conditions during deoxidation and alloying, which ultimately ensures an improved steel quality. [ABSTRACT FROM AUTHOR]

The paper presents the results of studying some properties and structure of a quasi high-entropy alloy (QHEA) of the CoCrFeMnNi system melted with the use of ferroalloys. The paper presents the results of a study of some properties and structure of a quasi-high-entropy alloy of the CoCrFeMnNi system, smelted using low-carbon ferromanganese and ferrochrome. Chemical composition, strength and microhardness have been studied. The structure contains a small number of inclusions of silicate nature. The experimental alloy demonstrated properties close to the level of properties of a similar alloy melted with the use of pure metals by 5-fold remelting. The results obtained showed the possibility of partial replacement of pure metals with ferroalloys when smelting of QHEAs, which will positively affect their cost. [ABSTRACT FROM AUTHOR]

Automotive catalysts containing Platinum Group Metals (PGMs) are valuable secondary raw materials for refineries. Hydrometallurgical processing of catalysts is ineffective due to the low PGMs content—0.15–0.3%. Therefore, such raw materials are melted into an iron collector containing 1.5–5% PGMs. However, when leaching a collector containing 10–20% Si in both HCl and H2SO4, the recovery of PGMs does not exceed 40%. The latter indicates incomplete destroying of the PGM-encapsulating ferrosilicon matrix. To completely destroy the ferrosilicon matrix, it is proposed to carry out the leaching process in a mixture of HCl and HF. In this case, the extraction of Fe into solution and Si into the gas phase (in the form of SiF4) exceeds 90%. This should be sufficient to completely destroy the ferrosilicon matrix and release PGMs. The current work presents the results of studies of the leaching kinetics of the iron collector containing ferrosilicon in a mixture of HCl and HF using the Shrinking Core Model (SCM). It was found that the greatest positive effect on Fe extraction into solution is exerted by HCl concentration and temperature, while Si release into the gas phase is only influenced by HF concentration. In addition, during the destroying of ferrosilicon, FeF2 is formed and deposited on the surface of the material in the form of thin-film conglomerates. This leads to diffusion difficulties and a gradual decrease in the intensity of the iron collector leaching 30 min after the start of process. After 120 min, there may be a decrease in Fe recovery into solution.

Targeted synthesis of oxynitride composites is implemented by means of organizing coupled processes. Interaction of ferrosilicon with nitrogen during combustion is considered as the main (inducing) process. The phase composition of the products of the coupled processes is determined by the chemical and phase compositions of the components added to ferrosilicon before performing self-propagating high-temperature synthesis. The influence of the basic products of the synthesis on the burning rate, fraction of nitrogen, phase composition, and morphology of synthesis products is considered. Chemical stages of ferrosilicon interaction with additives of natural minerals (zircon, ilmenite, and shungite) and aluminum in a nitrogen medium are demonstrated. The phase composition is determined by chemical transformations in a combustion wave. It is found that addition of aluminum leads to reduction or elimination of the Si2N2O phase in synthesis products with an increase in the aluminum fraction and obtaining composites based on the Si3N4 (SiAlON) solid solution. The microstructure of combustion products is presented by aggregates (5–10 m) composed of small faceted crystals, shapeless structures, and crystal flakes. Oxynitride composites with an open porosity value of 51.0–68.8% are obtained. [ABSTRACT FROM AUTHOR]

This paper deals with the electromagnetic characterization of a laminated toroidal ferromagnetic core made through additive manufacturing, specifically using the laser powder bed fusion process. The continuing demand for increasingly efficient, lightweight, and higher performance electric machines is creating huge challenges in the design and realization of new electric motor solutions. The constant improvements in additive manufacturing technologies have prompted researchers to investigate the possibility of adopting these production techniques for the manufacture of high-value electric motors. For these reasons, this paper investigates the ferromagnetic characteristics of an additively manufactured core made with FeSi6.5 powder. The BH curve and the specific iron losses of the processed material have been measured so that they can be compared with a commercial lamination, and have the possibility of carrying out more precise finite element simulations. [ABSTRACT FROM AUTHOR]

Zinc dust having a high ZnO content can be obtained after the preliminary treatment of zinc-bearing dust generated by the iron and steel industry by using a rotary kiln. However, this material has a high concentration of chloride salts that can affect the hydro-metallurgical extraction of metallic zinc. The present study used a vacuum distillation-vacuum thermal reduction process to recover zinc metal from this dust. This process first separated chloride and PbO by vacuum distillation and then extracted metallic zinc via the vacuum silicothermic reduction of ZnO. The results show that high-purity ZnO was prepared by vacuum distillation using the original zinc dust as a raw material. Both alkali metal chlorides and PbO in the dust could be removed with greater than 99 % efficiency by vacuum distillation at 1000 °C. Following this step, the slag contained more than 80 wt% Zn but less than 0.01 wt% chlorine and PbO. The vacuum thermal reduction process used the slag obtained from distillation as the raw material together with ferrosilicon alloy as a reducing agent. ZnO was reduced above 1000 °C and the recovery of this oxide exceeded 99 % using a reduction temperature of 1200 °C, reduction time of 2 h, and ferrosilicon mass ratio of 0.27. The main phase in the slag after reduction was SiO 2 and the ZnO concentration was below 1 wt%, indicating a purity greater than 99 %. This method can realize the separation, recovery, and reuse of zinc-bearing dust to maximize the value-added utilization of this resource. [ABSTRACT FROM AUTHOR]

This study investigates the deformation characteristics of SiO2–MnO–(CaO–Al2O3)‐type inclusions in silicon manganese deoxidized steel from continuous casting to rolling. The results reveal that the inclusions contain 60–80% SiO2, 10–35% MnO, and a combined CaO and Al2O3 content of <20%. SiO2 precipitates inside the inclusions during the continuous casting and rolling processes, which results in the formation of pure SiO2/SiO2–MnO–(CaO–Al2O3) dual‐phase inclusions in the remaining components owing to the increase in the MnO content to 15–40%. According to the experimental results of melting rate measurement and thermodynamic calculation using FactSage8.1, the SiO2–MnO–(CaO–Al2O3) phase has a high proportion of liquid components at 1100–1360 °C and exhibits good deformation properties during the breaking down and rolling processes. When the total content of CaO, Al2O3, and MgO in the SiO2–CaO–Al2O3–MgO–MnO inclusions reaches 30–50%, SiO2 precipitation is inhibited during the continuous casting to rolling process. Through the addition of metal manganese and carbon powder during the pre‐deoxidation process, followed by alloying with ferrosilicon and metal manganese, and then the addition of acidic synthetic slag for slag formation, the proportion of SiO2/SiO2–MnO–(CaO–Al2O3) dual‐phase inclusions in the casting billet is increased from 12% to >60%. [ABSTRACT FROM AUTHOR]

The article presents the results of thermodynamic prediction and electric smelting of Shalkiya sulfide zinc-lead-bearing ore in the presence of magnetite and coke. Using the HSC-6.0 software package, it was found that under equilibrium conditions in the presence of Fe3O4 and carbon, the reduction and formation of gaseous zinc from ZnS (according to ΔG° = 0) occurs at a temperature of 1205.7 °C, and the formation of ferroalloy at the interaction of the sulfide ore with magnetite and carbon begins at 1200 °C. About 58% of silicon is extracted into the ferroalloy at 1800-1900 ℃; almost all zinc and 83-88% of lead turns into a gaseous state. Electric smelting of the sulfide ore in the presence of magnetite concentrate and coke makes it possible to obtain the FS45 grade ferrosilicon (42-43% of Si); the silicon extraction degree was 84-88%. At the same time, 97.3% of lead and 99.2% of zinc are extracted into the sublimates. The developed method for processing zinc sulfide ores allows us to increase the degree of raw materials' comprehensive use due to the extraction of not only zinc and lead, but also silicon. The technology can be used to process raw materials containing zinc, lead and silica, such as zinc ore concentration tailings. [ABSTRACT FROM AUTHOR]

Increasing the serviceability of industrial components intended for the petrochemical industry is possible through their superficial saturation with silicon (silicon cementation). Obtaining a silicon-rich surface coating results in a considerable increase in corrosion resistance, refractoriness, and wear resistance. One of the most economically convenient options for silicon cementation is pack siliconizing in powdery solid media. This paper presents the possibility of pack siliconizing that contains ferrosilicon (FeSi75C) and a thermite mixture (SiO2 + Al) as active, silicon-providing components, in P265GH grade steel, which is frequently used in the petrochemical industry. The aim of the study was to determine the most suitable active component of the two that were analyzed and at the same time identify the processing conditions in which the siliconized coating has the greatest thickness, is free of porosity, and is in direct contact with the support. The use of experimental programming methods allowed the optimization of the operation to obtain the optimal solution. It was concluded that the thermite mixture is not compatible with pack siliconizing because it results in a superficial saturation predominantly composed of aluminum. When ferrosilicon is used as the active component, it determines the particularly intense formation kinetics of the non-porous siliconized coating with its maximum thickness being reached at high processing temperature values (over 1100 °C) with a proportion of 60% FeSi75 and, simultaneously, with the lowest possible proportion of ammonium chloride (max. 3%), which is the surface activation/cleaning component. [ABSTRACT FROM AUTHOR]

Abstract—To reduce the losses of ferrosilicon during heavy-medium separation, it is necessary to increase its corrosion and mechanical resistance with the obligatory preservation of magnetic properties. To form ferrosilicon powder with the specified physical and mechanical characteristics that meet the technological process requirements, an automated heat treatment process control system is designed. The formed nitrided layer thickness is found to be controlled by the holding time and temperature. The total processing time is 3 h, and the temperature can vary in the range 900–1000°C. At higher temperatures, intense growth of silicon nitride crystals occurs. [ABSTRACT FROM AUTHOR]

The paper shows the results of studies in searching for a binder for briquetting finely dispersed dust (FDD) of ferroalloy production of the Kazakhstan content. The fractional composition and shape of FDD particles were studied. Liquid glass and caustic soda were used as a binder. The research results showed the possibility of using liquid glass as a binder. Experimental briquettes have sufficiently high compressive strength and drop strength, which implies the possibility of their transportation and loading.

Driven by the rising demand for glass, metals, and plastics in industrial and household sectors, there was a substantial increase in waste and by-products generated. This study presents a method for repurposing waste glass, mill scale, and plastics as raw materials for ferrosilicon alloy production. This process entails reducing SiO2 and Fe2O3 using carbon derived from polystyrene/polypropylene mixtures. The glass, scale, and carbon powders were blended to achieve a C/O molar ratio of 1 (Blends A to F). The thoroughly mixed samples were then shaped into pellets and subsequently heated at 1550 °C in a tube furnace for 60 min. Ferrosilicon was successfully synthesized, with the reaction generating numerous metal droplets along with a slag layer in the crucible. The metallic yield for Blends A to F ranged from 16.65 wt% to 21.39 wt%, with the highest yield observed in Blend D. The bulk metal primarily consists of the FeSi phase, with Blend D exhibiting the highest Si concentration of 13.51 wt% and the highest hardness of 649.55 HV. Mechanism steps for ferrosilicon formation may vary with carbon dissolution rates. This work supports fossil fuel reduction and carbon neutrality, benefiting zero wastes practice and promoting sustainable material processing.

The article presents the results of thermodynamic prediction of a new process of interaction of chrysotile-asbestos waste with calcium carbide and aluminium (III) oxide with the co-producing gaseous magnesium and calcium aluminosilicate. The study was carried out by the thermodynamic modelling method using the HSC-6.0 Chemistry software package developed by the Finnish metallurgical company Outokumpu, and the optimal parameters of the process under study were determined by means of the second-order rotatable experiment planning designs with the computer construction of a 3D model of changing the technological parameters. Based on the results obtained, it was established that the interaction products in the system under consideration are Mg(g), CaSiO3, 2CaO·Al2O3·SiO2, FeSi, SiC, SiO(g), Fe, Fe3Si, CO(g). The equilibrium distribution degree of the elements in the system is largely dependent on temperature and calcium carbide, which, from a thermodynamic point of view, is more reactive to MgO than FeSi2. An increase in the calcium carbide content in the charge reduces the transition degrees of calcium and silicon into the silicates (2CaO·Al2O3·SiO2 and CaSiO3), increases the transition degrees of aluminium into 2CaO·Al2O3·SiO2 and silicon into SiC and SiO(g). Up to 1640 °C, an increase in the amount of calcium carbide reduces the transition of silicon into the alloy, and at the higher temperature, on the contrary, it increases. In the temperature range of 1636–1700 °C at a pressure of 0.1 bar, to achieve high extraction degrees of the elements from the chrysotile-asbestos production waste, such as 80.0–90.6% of magnesium into gas, 80–84.3% of calcium, 74.3–76.8% of silicon and 81,6-87,4% of aluminium into the silicate melt, the process should be carried out in the presence of 28–31.5% of calcium carbide. Silicon, passing to a small extent into the alloy, forms nickel-alloyed (2.8–3.1% of Ni) FeSi25 ferrosilicon. The silicate melt mainly consists of 2CaO∙Al2O3·SiO2 (72,9%) and CaSiO3 (10.6%).