To ascertain the thermodynamic conditions for the enrichment of vanadium in V-bearing steelmaking slag and V-bearing black shale, the effects of alumina content and basicity on the formation of phases and distribution of vanadium in CaO-SiO2-FeOt-MgO-Al2O3-V2O3-P2O5 slag system at 1573 K (1300 °C) were investigated by adopting the high-temperature quenching method. The phases formed in the samples

The continuous casting of Ti-alloyed Al-killed steels traditionally experiences clogging in the tundish, impeding stable operation. We studied the microstructures and mode of formation of such clogging deposits in tundish skulls recovered after long cast series. We sampled the steel skull along the whole tundish bottom from under the ladle shroud (impact zone) up to the tundish well and nozzle. The

This paper presents a brief review of the history of titanium smelting and the current trends in related research and development. Presently, both electrolytic and metallothermic reduction processes utilizing various feed materials such as titanium oxide are widely studied. However, many challenges remain to be addressed before realizing the practical application of smelting processes utilizing oxide

Carbonization of TiO2, which is a process typically used to synthesize TiC, consumes a huge amount of energy. Low-temperature synthesis of TiC from carbon-infiltrated TiO2 has been investigated in this study to develop an energy-saving process. Porous TiO2 was first obtained by hydrochloric acid leaching of ilmenite (FeTiO3) ore. Then, carbon-infiltrated TiO2 was prepared from the porous TiO2 using

Great merits have been identified for the continuous production of copper, and different continuous converting (CC) processes are developed and increasingly used for copper making. For the CC process, the equilibria of multiple phases including iron silicate slags, spinel, gas, blister, and white metal phases are clarified under a high-level P(SO2) 0.4 atm in the temperature range of 1523 K to 1573 K

The transient trajectory taken for a system striving toward equilibration has consequences on the rate of processes and on the chemical and physical state of products in metallurgical processes. A case study approach to recent advancements in liquid steel processing is given. A combination of techniques and knowledge developed is given as a targeted showcase of the authors’ contributions to the understanding

To improve the properties of castings, a new technique to observe the fluid flow and study the motion of oxygen-bearing inclusions has been developed. This new technique, Positron Emission Particle Tracking (PEPT), enabled a single radioactive tracer particle, moving inside a liquid metal casting, to be tracked with an accuracy of some millimeters, depending on the properties of the liquid metal and

The studies on the thermodynamics of P in silicon solution are significant for phosphorus removal in silicon purification technology. The activity interaction coefficient of Fe to P (\( \varepsilon_{\text{P}}^{\text{Fe}} \)) in a ternary system of Si-P-Fe at temperatures of 1623 K, 1673 K, and 1693 K was determined experimentally by the same activity method. The dissolution of P and Fe in the ternary

Gas-atomized powders are commonly used in additive manufacturing, specifically laser powder bed fusion, due to their high flowability during recoating. Morphological changes can occur in particles that are irradiated by the laser during additive manufacturing, but are not incorporated into the melt pool. These irradiated particles will affect the rheology of the recycled powder in subsequent builds

The partial roasting of high-arsenic copper concentrates at 973 K/998 K (700 °C/725 °C) under controlled atmosphere can remove > 95 pct of the arsenic contained in the concentrates, leaving a calcine with 52 to 68 wt pct bornite, 10 to 13 wt pct chalcopyrite and 2 to 5 wt pct magnetite, with 8 to 24 wt pct remnant chalcocite. The mineralogic composition of the calcine obtained is consistent with the

In industrial applications, filter materials are often chosen according to cost as well as their processing and thermomechanical properties, but rarely in terms of their behavior during filtration, which is largely due to there being insufficient information available on the influence of filter materials and surface quality on filtration behavior. In this study, the manufacture of functionalized Al2O3

The service life of roller bearings is extremely sensitive to large and hard nonmetallic inclusions (NMIs), requesting the highest standards in their production. To determine the metallurgical possibilities, the effect of Al2O3 contents between 0 and 33 pct in the remelting slag was investigated by remelting a roller bearing steel in an experimental electroslag remelting (ESR) plant. Thereby, changes

Thermal properties of green Söderberg electrode pastes were measured up to 1073 K (800 °C) using the transient plane source method. Comparison was made to measurements on an electrode material baked beforehand to 1473 K (1200 °C). For the green pastes, thermal conductivity was found to decrease up to 673 K (400 °C) at the onset of baking. After about 873 K (600 °C), thermal conductivity of the material

According to the composition variation during the initial period of basic oxygen steelmaking, ice-quenched samples of the CaO-SiO2-FexO system were prepared, and the viscosity and structure of molten slag were further analyzed by a rotary viscometer and Raman spectroscopy, respectively. The results showed that Si4+ existed as Q0, Q1, Q2 and Q3 units. The O2− ions led to the depolymerization of [SiO4]

POSCO’s advanced CASting Technology (PoCAST) is an innovative molten mold flux feeding technology which has been developed to ensure quality of continuously-cast Twinning-Induced Plasticity (TWIP) steel and Ultra-low carbon steels (ULCSs). Stable qualities of ULCS slabs could be achieved by reducing mold flux entrapments by optimizing the range of slag pool depth; this result matches well with entrapment

CaO-SiO2-Al2O3-MgO-Na2O (CSAMN), as a basic system, has been extensively studied and widely applied in the field of mold flux. The thermal conductivity parameter of melt film as a critical indicator affects the heat transfer during the continuous casting process. However, many details of the CSAMN thermal conductivity still remain unclear. Herein, the thermal conductivity of the molten CSAMN system

The mixing behavior of compositional modifiers into viscous liquid BOF slag was studied using fluid flow modeling under industrially relevant conditions. The Volume of Fluid-Large Eddy Simulation-Discrete Phase Model was used to simulate the gas-solid particle-liquid slag turbulent flow. The area fraction of the particle migration zone was calculated to quantify the mixing process. The results show

Fluorspar (CaF2) has been widely used to control the physicochemical properties of slag in steelmaking processes. However, it is very important to reduce the CaF2 consumption because it causes various environmental problems. In the current study, therefore, the effect of industrial waste materials such as red mud (RM) and ferromanganese slag (FMS) on the desulfurization behavior of molten steel was

Ferrous calcium silicate (FCS) slags are reported to have high potential for use in the copper converting process. However, no phase equilibrium study has been carried out under a simulated converting gas atmosphere in the presence of SO2. In this study, under accurately controlled P(SO2) 0.4 atm and P(O2) 10−6 atm, the phase equilibria of FCS slags in a liquid/spinel/white metal/gas system were investigated

The effects of preexisting MnO·SiO2 and FeO inclusions on the size and morphology of Al2O3 were investigated. Two-stage deoxidation with Mn and Si followed by Al and single-stage Al deoxidation at [O] levels of 287 ppm [O], 612 ppm [O], and 1071 ppm [O] were performed. The results showed heterogeneous nucleation and growth of Al2O3 onto MnO-SiO2 and FeO inclusions that were present in the steel before

New experimental data are reported on the liquidus and sub-liquidus phase equilibria in the FeO-Fe2O3-CaO-SiO2 system in air. The study was undertaken using equilibration/quenching and microanalysis techniques enabling the compositions of the liquid and solid phases in equilibrium at temperature to be accurately measured. The limits of stability and associations of the primary phase fields of hematite

Iron-based alloy overlays are widely utilized in industry to extend the service life of components subjected to wear and corrosion attack. Welding is an overlay process commonly employed because of its low cost and high efficiency. The microstructure of an as-welded chromium carbide overlay and a new Fe-Cr-C-B overlay containing multiple alloying elements has been characterized by optical microscopy

The effects of supersaturation and steel composition on the morphology of Al2O3 inclusions were investigated. Thermodynamic calculations with Factsage 7.0® were used to predict the degree of supersaturation and select the starting aluminum and oxygen amounts for the experiment. Deoxidation experiments were performed by melting the charge material and using specially designed samplers to study the local

This study evaluates the carbothermal microwave reduction of low-grade banded hematite jasper iron ore for the preparation of potential feedstock for the alternative iron-making process. The coal sample act as transparent material to microwave irradiation at low temperature, however, above 600 °C, an exponential rise in temperature with a heating rate of ~ 220 °C/min was achieved. In contrast, charcoal

Submerged arc welding under high heat input has been conducted on EH36 plate employing two series of CaF2-SiO2-CaO-fused fluxes. The effects of CaO and SiO2 on element transfer between slag and weld metal are systematically evaluated using thermodynamics. It is concluded that the substitution of CaF2 by CaO is an environmentally friendly approach to suppress the transfer of Si to weld metal and decrease

Spent pot-lining (SPL) and red mud (RM) are the two major solid wastes of the aluminum industry. In this study, an innovative method has been proposed for co-treatment of SPL and RM to reuse carbon and recover metal (iron, aluminum and sodium) by a reductive roasting-leaching-magnetic separation process (RRLMS process). Moreover, the transformation behaviors of fluoride, cyanide and sulfur present

The ironmaking blast furnace (BF) is an energy-intensive process, requires a considerable amount of carbon-related materials such as coke, coal, or natural gas, and releases enormous amounts of greenhouse gas (GHG). The oxygen enrichment operation is one promising technology to reduce the carbon footprint in the ironmaking process. However, the oxygen enrichment ratio (OER) varies significantly in

To purify crude ZnCl2, which can be recovered by selective chlorination of electric arc furnace dust, vacuum distillation utilizing evaporation separation of volatile ZnCl2 was investigated. Experimental results indicated that vacuum distillation at 700 K or 800 K could effectively separate ZnCl2 and FeCl2. The ZnCl2-rich deposit in the low-temperature zone was contaminated with PbCl2 after a long

A thermodynamic and kinetic model is proposed to explain the formation of bornite, chalcopyrite, and magnetite during partial roasting of enargite-containing copper concentrates. The proposed mechanism involves solid–solid–gas and solid–gas reactions between chalcocite, pyrrhotite, gaseous sulfur, and oxygen. Bornite formation could be explained through a mechanism of simultaneous formation of bornite

In the present work, the dynamics of a downward gas injection into a liquid metal bath is studied using a numerical modeling approach, and validated with experimental data. As in a top-submerged-lance (TSL) smelter, gas is injected through the lance into the melt. By this means, the properties of the liquid are closer to the actual industrial process than the typically used water/glycerol–air/helium

To clarify the effects of Si concentration, temperature, and time on melting of the silicon steel, three silicon steels with different Si concentrations were used to conduct an experimental investigation of the melting of scrap cylinders under natural convection. Thermodynamics and kinetics of scrap cylinder melting were revealed and analyzed based on the experimental results. Carbon diffusion between

The effects of adding 5 to 25 wt pct of ilmenite ore to hematite ore sinter were investigated employing a horizontal tube furnace to clarify the phase development. The temperature was raised nonisothermally at 10 °C/min to 1150 °C in an Ar atmosphere. When the target temperature was reached, 1 L/min of air was injected to allow combustion of the carbon in the pellets. The development of the phases

Furnace tapping is a critical operation on pyrometallurgical furnaces known for unpredictable performance in many cases. A reduced order mathematical model capable of predicting tapping rates of both slag and metal is presented. The model accounts for separate liquid phases and particle bed resistance to flow. The model is compared for consistency against results from both a water-model experiment

The effects of the amphoteric and basic oxides alumina and lime on the phase equilibria of copper matte and silica-saturated slags were investigated at 1300 °C and \( P_{{{\text{SO}}_{ 2} }} \) = 0.1 atm in a controlled CO-CO2-SO2-Ar gas atmosphere using a high-temperature isothermal equilibration technique followed by rapid quenching. The equilibrium phase compositions were obtained by Electron Probe

Although alumina-based inclusions in Al-killed steel have been widely investigated, few studies focus on non-metallic inclusions in Si-killed steel. Most high-carbon steel, which is expected to have higher potential for the formation of alumina, is deoxidised by silicon to avoid alumina-based inclusions. Many types of high-carbon steel such as free-cutting steel and grinding media for the mining industry

The heat transfer processes and the molten metal bath kinetics of the electric arc furnace are governed by the changes in the arc length and voltage. Thus, information on the electric arc behavior with respect to the voltage is important for accurate computation of the furnace processes and adjustment of the industrial furnace parameters. In this work, the length-voltage characteristics of electric

Abstract A new twin-roll casting (TRC) process to produce Cu/Invar/Cu clad strips, which have greater application potential, is proposed. The symmetrical cast-rolling zone is divided into two asymmetrical parts by introducing the substrate strip in the middle. The thermal-flow coupled simulation was conducted, and it realized the coupling analysis of casting roll, molten pool, and substrate strip.

In this study, the mechanism of reduction of hematite-magnetite concentrate (HMC) by graphite-calcium carbonate reductant mixture at about 1000 °C was investigated. The initial and middle stages of the reduction process (up to 63 pct) were mainly affected by the heat transfer inside the crucible. It was concluded that in the middle to final stages of the reduction process, the gaseous diffusion of

Four different Cu-rich polymetallic concentrates (additionally comprising Zn, Pb and impurity elements As, Sb) from various deposits in Sweden are examined, in particular for the sintering tendency during roasting in inert atmosphere. Experiments performed in a laboratory-scale roasting setup between 200 °C and 700 °C in intervals of 100 °C revealed that significant sintering initiates from 500 °C

Theories on fluidity of alloys based on the solidification mode are not satisfactory in describing fluidity of alloys under high-pressure die casting (HPDC) conditions. To understand the flow-choking mechanisms under HPDC conditions, microstructure in the fluidity test coupons made using a 125-ton HPDC machine was characterized. Pre-solidified dendrites (PSDs), or externally solidified crystals (ESCs)

A drainage model of a multi-taphole hearth of a (large) blast furnace operated by alternate tappings has been developed. The model, which is based on a simplified treatment of the pressure losses in the dead man, taphole entrance and taphole, can estimate the liquid levels and outflow rates of the two liquid phases in quasi-stationary and dynamic states. The sensitivity of the results to changes in

The multiphase flow, initial solidification and solute diffusion and their interactions in a mold region of 380 × 280 mm2 casting bloom under different installation positions of in-mold electromagnetic stirring (M-EMS) were analyzed and compared by a multi-physical model. The results showed that the simulated electromagnetic field and solute carbon distribution in initial solidified shell are basically

The converting of copper matte after the smelting process is one of the main steps in the copper-making industry. This work used microstructural analyses of samples collected at different stages of converting and thermochemical calculations to study a real converting batch in a Peirce-Smith converter at Atlantic Copper. The transformation of matte and slag produced during the converting was studied

The incongruent reactions between Zr-Cu melts and WC solid were studied. Mo was used as a tracer to track the movement of “heavy” W atoms during the incongruent reaction. In separate experiments, dense polycrystalline plates and porous preforms of W0.9Mo0.1C were reacted with Zr2Cu and Zr14Cu51 melts at 1200 °C, 1300 °C and 1600 °C for 15 minutes. The microstructure of the reactive interfaces was studied

Spark plasma extrusion is a new process that has recently shown superiority over spark plasma sintering for powder consolidation. This paper represents the first investigation of novel spark plasma extrusion (SPE) of titanium (Ti) powder. Extrusion temperature (above and below the β-transus) and initial Ti powder type were found to have a pronounced effect on the developed microstructures and properties

The low hydration activity and volumetric instability of steel slag (SS) limits its application as a binding material. SS contains approximately 30 pct of a divalent metal oxide solid solution (RO phase). According to the XRD results of the RO phase extracted from SS, RO phases (MgO·xFeO) with different compositions were synthesized to study their hydration activity and expansibility. The hydration

A model of flotation was developed and applied to alumina in the aluminum electrolysis cell. The conditions of flotation for alumina on the cryolitic bath surface were determined for disc and sphere geometries. The contact angle between alumina and cryolitic bath, which had not been found in the literature, was measured and it was found to be around 30 deg. Experiments with compressed alumina discs

A three high planetary mill is used to produce bismuth-containing stainless-steel bars with high production efficiency. However, due to the influence of bismuth metal properties, the selection of processing parameters must be optimized to avoid the generation of cracking in the bar core. To solve this contradiction and find a suitable processing zone, the thermal simulation experiment of bismuth-containing

The present study proposed, for the first time, an evaluation method to predict the generation rate of aluminum dross in melting or holding furnaces during mechanical stirring of molten aluminum through water model experiments and numerical simulation. In the experiments, a gas–liquid interface reaction between CO2 gas and NaOH solution was exploited as a model reaction between the aluminum melt and

A sample of limonitic nickel ore was characterized by XRD, SEM-EDS, and ICP-OES techniques. The Rietveld refinement method showed that the main mineral constituent of this sample is goethite (55.8 pct). Thermal analysis experiments were performed and the determination of the goethite content in the sample could be confirmed by the mass loss associated to the dehydroxylation of this mineral at temperature

The activity coefficient of CoO in SiO2-saturated MnO-SiO2 slag was measured using metal-slag-gas equilibrium experiments under controlled oxygen potentials (10−12 to 10−10 atm) at 1623 K. The solubility of CoO in the slag increased with increasing oxygen potential and cobalt content in the alloy. The activity coefficient of cobalt oxide, γCoO, referred to solid CoO, can be described as: γCoO = 1.65

The effect of CaO fluxing on slag morphology was investigated during the reduction of FeO in electric arc furnace slag by aluminum black dross (ABD). Macro- and microscopic observations, by evaluating entrapped gas bubbles and reduced iron droplets related to gas evolution, apparent slag morphologies, and vertical section of slag at different initial CaO contents and reaction times, confirmed that

The anode potential has been shown to be highly dependent on anode geometry and orientation in the Hall–Héroult process. This work is an experimental laboratory scale study of the effect of anode geometry and orientation on bubble formation and detachment for four different anode designs: horizontal (surface facing downwards), inverted horizontal (surface facing upwards), vertical, rod (with both vertical

It is necessary to study crystallization from glass (devitrification) for non-reactive F-free CaO-Al2O3 based mold fluxes; this is especially important for the development of mold fluxes for continuous casting of high aluminum steels. To the knowledge of the authors, there is no report in the literature regarding devitrification of F-free mold fluxes based on the CaO-Al2O3-B2O3-Na2O-Li2O system. Therefore

A novel austenite aging steel coating was prepared by laser cladding to improve the elevated-temperature wear performance of AISI H13 steel. The wear tests at 400 °C to 600 °C were performed for the austenite aging steel coating and H13 steel. Their elevated-temperature wear performances were comparatively studied; the wear mechanisms under various loads at 400 °C to 600 °C were clarified. The novel

During the mass recycling of spent lithium-ion battery (LIB) packs, the packs that have not been disassembled are heat-treated to remove organic substances; further, the valuable metals obtained in the burnt product are recovered in the leaching process. Numerous methods have been reported for the efficient recovery of valuable metals in the leaching process; however, the material balance of the constituents

In this work, the thermal studies of ultrafine and nanocrystalline core–shell structures of Ti(Mo)C and Ti(Mo)C-Co formed in the process of plasma chemical synthesis according to the plasma condensation scheme in a low-temperature nitrogen plasma were performed. The oxidation processes of all phase components in the core–shell structures, determined during the high-resolution transmission electron

The effects of hydrogen gas on the reduction rate of ore and reactivity of coke were estimated by using the Boris type movable reaction furnace shaft inner reaction simulator (SIS). The temperature profile was controlled to reproduce the shaft region in the actual blast furnace, and the gas composition was self-controlled inside the reaction tube. The apparent gas utilization ratio was also affected

Monitoring the meniscus velocities of molten steel in continuous casting molds is critical for revealing the velocity field in the whole mold and consequently for process control and final product quality, however, the realization of contactless online measurement in an actual metallurgy environment is a highly challenging task. In this paper, we develop a special Lorentz force velocimetry (LFV) device

The specific focus of this study is on the boehmite–water interaction during attrition milling of a boehmite prepared by thermal dehydroxylation of gibbsite. Various characterization studies confirm the formation of a new phase, bayerite (an Al-trihydroxide polymorph) during milling of boehmite with water as the dispersant. Bayerite is a more stable (thermodynamically) phase than boehmite. By forming