Slag Viscosity Research Articles

Effect of Carbon Black Content and Firing Atmosphere on the Properties and Microstructure of Al2O3-SiC-C Castables

Al2O3-SiC-C (ASC) castables containing spherical asphalt are widely utilized in high-temperature metallurgical furnaces because of their good abrasive resistance and slag resistance; however, the release of hazardous benzopyrene during the pyrosis process in spherical asphalt is detrimental to the environment and to the health of furnace workers. Herein, nontoxic nano carbon black (CB) was selected as the carbon source for ASC castables, and the effects of the CB amount and sintering atmosphere on the properties of ASC castables were investigated in this work. The results show that on increasing CB from 0.5% to 2%, the cold strength of the samples after firing in the reducing atmosphere increased, the residual strength increased, and the slag penetrated depth decreased; the reasons can be ascribed to nano CB being able to fill the pores to reduce the apparent porosity of the castables. Furthermore, SiC whiskers were formed at elevated temperatures and generated a network structure, which was beneficial in improving their properties. When CB was 1%, the cold modulus of the rupture of the samples after firing in the oxidizing atmosphere and reducing atmosphere were higher (about 20 MPa), the retained strength ratio of the samples pre-fired in the reducing atmosphere was the highest (85.4%), the hot strength at 1400 °C of the samples tested in the oxidized atmosphere was the highest (5.3 MPa), and the slag resistance of the samples measured in the oxidizing atmosphere was the best. The castables heat-treated in the air atmosphere possessed higher hot strength and slag resistance; the reasons can be attributed to the formed SiO2 derived from the oxidation of SiC, which reacted with Al2O3 to form mullite, creating a strengthening effect and decreasing the porosity and increasing the viscosity of slag, thereby improving the hot strength and slag resistance.

Properties evaluation of electric smelting furnace slag: Viscosity and sulfide capacity under different FeO content

This study investigated the viscosity and sulfide capacity of electric smelting furnace (ESF) slag (CaO-SiO2-6wt.%MgO-10 wt%Al2O3-FeO) with a basicity of 0.8 through cylinder rotating method and gas-slag equilibrium experiments. Additionally, the high-temperature structure of the slag was analyzed using FTIR and Raman spectroscopy. The results showed that as the FeO content increased from 1 wt% to 9 wt%, the viscosity of the ESF slag gradually decreased, with a more pronounced reduction observed when the FeO content exceeded 5 wt%. The increase in FeO content led to a reduction in the initial liquidus temperature, resulting in the formation of a greater amount of liquid phase at lower temperatures. Furthermore, FeO released O2− ions at high temperatures, which depolymerized the silicate network structure, thereby reducing the viscous flow resistance. These dual effects of FeO contributed to the decrease in slag viscosity. In addition, the sulfide capacity of the slag increased with rising FeO content, and the activity order of sulfides in the slag was FeS > CaS > MgS. This was because Ca2+ ions were largely consumed for charge compensation within the silicate structure in the low-basicity slag. Based on these findings, during the ESF furnace smelting process, the desulfurization step should preferably be conducted at the front end of the reduction process.

Hydrogen affection on softening and melting behaviours of high alumina sinter in gas-injection blast furnace

As the Al2O3 content increasing in iron ore, some problems presented in blast furnace (BF) processing, such as worsened burden permeability and slag viscosity. Injection of H2 may improve the permeability and reduce the CO2 emission of BF, because of its less density and higher reduction potential when temperature is higher than 820 °C. Therefore, the influence of H2 concentration on the softening and melting behaviour of high alumina sinter is a worth investigate topic. In this article, the high alumina sintering samples with Al2O3 content of 2.11 wt% are investigated in a specially designed experimental apparatus capable of continuously changing pressure on the burden. The results show that the softening temperature range of the samples is expanded and their melting temperature range is reduced with the increasing of H2 concentration from 0 vol% to 20 vol% in reduction gas. But the overall change on softening-melting temperature range is just from 280 °C to 310 °C, which is relatively small comparing with other references reported results. The addition of H2 promotes the reduction of FeO and is conducive to separate between the iron phase and slag phase before the charge droplet formation, which facilitates the aggregation and precipitation of metallic iron in soften state. Simultaneously, higher H2 concentration leads to more pronounced improvements in the permeability of the high alumina burden.

Viscosity of titanium slag in separating electric melting of a metallized mixture of perovskite and ilmenite concentrates

To assess the possibility of joint processing of ilmenite (FeTiO3) and perovskite (CaTiO3) concentrates using a duplex process involving solid-phase reduction of iron (metallization) and subsequent separating melting into pig iron and titanium slag, the properties of slag melts were studied. The crystallization beginning point (liquidus temperature) and the corresponding viscosity of titanium slag depend on its chemical composition. The increase in titanium oxides content results in increase of these properties, while the presence of iron and calcium oxides leads to their decrease. During the joint processing of ilmenite (IC) and perovskite (PC) concentrates, the CaO content in the slag can be adjusted by changing their PC/IC ratio, and the FeO fraction is determined by the degree of iron metallization during the preliminary reduction roasting of a concentrate mixture with a carbon reducing agent. To select the optimal PC/IC ratio the temperature dependences of the viscosity of model oxide melts of the TiO2–FeO–CaO–Al2O3–MgO system, similar in composition to the slags formed as a result of melting mixtures of perovskite and ilmenite concentrates within the range of PC/IC ratios equaling to 0.6÷1.4, and the metallization degree from 75 to 95% were determined. According to the results obtained, within the entire range of studied compositions and temperatures, the viscosity of slag melts does not exceed 0.8 Pa·s. That is to say, such slags will be sufficiently fluid at the tapping point if the melt temperature is higher than liquidus temperature — the crystallization beginning point. Increasing the PC/IC ratios when decreasing the metallization from 95 to 75%, results in a monotonous decrease in liquidus temperature and its corresponding viscosity from 1490 оC and 0.79 Pa·s up to 1270 оC and 0.17 Pa·s, respectively. It is recommended to use a charge containing equal mass fractions of concentrates (PC/IC equal to 1) at the consumption of carbon reducing agent based on metallization of 85% iron. In this case, slags with a relatively low iron oxide content (3.1%) will be fluid (0.38 Pa·s), and have liquidus temperature of 1400 оC which will allow carrying out top and bottom melt at operating temperatures of 1500–1550 оC.

Mathematical model of molten iron and slag flow in the hearth

The stable hearth discharge is crucial for the operation of a blast furnace (BF). This study established a mathematical model for hearth discharge based on Bernoulli's principle, which considers the blast pressure, kinetic energy of molten iron and slag, gravitational potential energy, the pressure loss of molten iron and slag flowing through the deadman and taphole. It is found that the sharp increase of molten iron and slag flow is probably due to the fracture of the mud, while the sharp decrease of molten iron and slag flow is probably due to the blockage of the taphole by coke. This paper also studies the effect of operating parameters on the hearth discharge. With the increase of taphole plug time, the production rate and slag viscosity, the tap-end time will increase. With the increase of deadman voidage, the tap-end time will be shortened. The correctness of the mathematical model was verified by the actual flow rate of slag and molten iron.

Structure and dynamic viscosity of CaO–SiO2 and CaO–SiO2–B2O3 model slag systems

Correlation dependencies between the dynamic viscosity of slag and its structural parameters were studied to determine an optimal basicity of silicon smelting slag under the addition of boron oxide to eliminate slagging of the bottom of ore-smelting furnaces. Experimental studies were conducted on CaO–SiO2 and CaO– SiO2–B2O3 model slags obtained at 1600°С. Raman spectroscopic analysis was carried out using a Horiba JobinYvon HR800UV analyzer (France). Theoretical calculations of slag viscosity were performed using Urbain and Mills models. During the experiments, the key structural parameters of slag systems varied within the following limits: the experimental Raman spectrum deconvolution function from 1.41 to 2.45 and optical basicity from 0.58 to 0.68. The obtained experimental and theoretical data were related by mathematical dependencies. It was found that the dynamic viscosity of slag can be promptly determined by Raman spectroscopy on the basis of mathematical models. The dependence obtained shows that slag viscosity decreases upon an increase in the number of bridging oxygen atoms in the silicate anion structure. Notably, this decrease in slag viscosity is observed up to the value of the experimental Raman spectrum deconvolution function of ~1.55-1.60 or slag optical basicity of 0.60–0.62. When B2O3 is added, the viscosity undergoes a further decrease. In practice, for CaO–SiO2 slag systems, the use of boroncontaining flux as a liquefying agent is reasonable at CaO/SiO2 = 0.61–0.63 while maintaining the content of B2O3 in the slag at a level of 1%. The two models (classical and modified) proposed by Urbain were established to be more suitable for theoretical calculation of viscosity in CaO–SiO2 and CaO–SiO2–B2O3 systems. Mills’ model is not suitable for these purposes, since the correlation coefficients in the corresponding mathematical model are not sufficiently large. Further research in this direction is required in order to establish appropriate dependencies of slag viscosity on its structural parameters at different temperatures.

Corrosion behavior of co-gasification slag of furfural residue and coal on alumina-silica refractories

Gasification of furfural residue with coal can realize its efficient and clean utilization. But the high alkali metal content in furfural slag is easy to cause the corrosion of gasifier refractory. Two gasification coals with different silica alumina ratio and a furfural residue were selected in the study. The effects of furfural residue additions on corrosion of silica brick, corundum brick, high alumina brick and mullite brick were investigated by using XRD, SEM-EDS and Factsage Software, and the corrosion mechanism was analyzed. With increasing furfural residue addition, the permeability of the slags to high-aluminium-bearing refractories first decreases and then increases, while the permeability on silica brick shows a slight decrease trend. Leucite (KAlSi2O6) with high-melting temperature is generated from the reaction of K2O and SiO2 in slag with Al2O3 in refractories after furfural residue is added, which hinders the infiltration of slag in refractories. Kaliophilite (KAlSiO4) of low-melting point is formed when K2O content increases, and this contributes to the infiltration of slag in refractories. The acid-base reaction between slag and silica brick is distinctly occurred, more slag reacts with SiO2 in the silicon brick, resulting in a decrease in the amount of slag infiltrating into the silicon brick as furfural residue is added. The corrosion of silica brick is mainly caused by the acid-base reaction, while the corrosion of three alumina based refractory bricks of corundum, mullite and high alumina brick is determined by slag infiltration. A linear correlation between the percolation rate and slag viscosity is established, the slag permeability increases with decreasing viscosity, resulting in stronger permeability for the high Si/Al ratio slag with lower viscosity.

Comparison of corrosion behavior of primary/modified nickel slag with semi‐rebonded periclase‐chromite refractory

AbstractSemi‐rebonded periclase‐chromite refractories are commonly utilized in the working lining section of the molten pool in oxygen‐enriched top‐blowing furnaces for nickel production. Its resistance to nickel slag corrosion determines the safety and service life of the melting furnace. The composition of nickel slag influences the corrosion resistance of semi‐rebonded periclase‐chromite refractories. By comparing and analyzing specimens corroded by primary and modified nickel slag, the influence mechanism of w(CaO)/w(SiO2) variations on corrosion resistance of semi‐rebonded periclase‐chromite refractories was clarified. The results show that a spinel isolation layer is preferred to form at a lower w(CaO)/w(SiO2) ratio (< 0.576) and enhance the corrosion resistance of semi‐rebonded periclase‐chromite refractories. As the ratio increases, the slag viscosity falls and the corrosion products contain larger levels of Ca3Cr2Si3O12 and Ca3MgSi2O8, which prevent the creation of the isolation layer and establish a conduit for Ca2+ and Si4+ transport and reaction into the interior of the refractory.

Effects of CaF2 and La2O3 on the phase structure of rare earth in CaO–SiO2–La2O3–CaF2 slags

The rare earth in the rare earth slag can be separated and enriched by heating and melting the rare earth slag and then slowly cooling crystallisation. In this process, it is of great significance to study the effect of chemical composition on the crystallisation of rare earth phase in slag and the effect of slag viscosity on crystal growth. The rare earth slag melt samples were prepared according to the main chemical composition of rare earth slag by using an analytical pure reagent. The effects of CaF2 and La2O3 contents on the phase structure and morphology of rare earth phase in CaO–SiO2–La2O3–CaF2 slags were studied by SEM-EDS and XRD. The relationship between the viscosity of the slag and the crystal growth behaviour was studied by measuring the melt viscosity with the cylinder rotation method. The results show that the rare earth in CaO–SiO2–La2O3–CaF2 slags exists in the form of CaLa4(SiO4)3O. The change of CaF2 and La2O3 content has no effect on the structure of rare earth phase, but the size of rare earth crystal phase changes obviously. With the increase of CaF2 and La2O3 content, the size of rare earth crystal phase increases gradually. CaF2 and La2O3 can reduce the viscosity transition temperature of slag melt and increase the crystallisation temperature range of rare earth phase to promote crystal growth.

Effect of MgO/CaO Ratio on Viscosity and Phase Structure of Chromium-containing High-titanium Blast Furnace Slag

Effect of MgO/CaO Ratio on Viscosity and Phase Structure of Chromium-containing High-titanium Blast Furnace Slag

Effect of Cs2O-containing refining slag on the purity of ultra-clean steel for ultra-fine saw wire

The influence of Cs2O-containing refining slag on the purity of steel for ultra-fine saw wire has been studied in this article. The result indicated that a small amount of Cs2O can significantly improve the capability of low-basicity refining slag to purify molten steel. In detail, the number and size of inclusions decreased dramatically when Cs2O was added to the refining slag. Additionally, the composition of most inclusions is controlled within the low melting point region. However, it will reduce the capability of low-basicity refining slag to purify molten steel if the content of Cs2O exceeds 10 wt%. Cs2O changes the ability of low-basicity refining slag to remove inclusions by changing the slag's viscosity and microstructure. The viscosity of refining slag increased gradually with the mass fraction of Cs2O in the slag increasing, and the disparity of viscosity values between different experimental groups increased sharply with temperature decreasing. Furthermore, the viscosity curve of Cs2O-containing slag developed a turning point, that is, the speed of viscosity increasing raised sharply at the turning point, while this phenomenon cannot be found in a normal experiment group without Cs2O. The detection results of the Raman spectrum show that the three-dimensional network of slag increased greatly with the content of Cs2O in the slag increasing gradually.

CLSVOF simulations of H2 bubble rising through liquid metal bath covered with a thick slag layer

Abstract 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.

Predicting viscosity for steelmaking slag: A stacking regression approach

The viscosity of steel slag plays a pivotal role in steelmaking, impacting various aspects of the steelmaking operation and product quality. This paper introduces a novel approach for predicting the viscosity of turndown slag from a basic oxygen furnace using a stacking regression model. The stacking model in this approach incorporates four base models: multiple linear regression (LR), random forest (RF), k-nearest neighbour (KNN) and AdaBoost (ADB), while random forest is selected as a meta-model. The selection of meta-models is done through a systematic framework provided for identifying suitable meta-models in a stacking model. Similarly, the framework also demonstrated the workflow for constructing and evaluating a series of stacking models with different configurations. On the evaluation of 20 stacking models (including two and three-layers), the optimal configuration is found to be LR + KNN with R2 value of 0.993 and the shortest training time. Additionally, a correlation analysis of slag viscosity with composition and temperature is done, which will help the operators of steel melting shops in optimize the steelmaking process based on the required slag viscosity. Ultimately, this study emphasizes the efficacy of optimal-configured stacking regression models in industrial applications, achieving both maximum accuracy and minimal computational time.

Research on viscosities and structural characteristics of coal slags with various Al2O3 contents

AbstractThe corrosion of the alumina‐based refractory in coal slags would increase the Al2O3 contents of the coal slag and the influences of that on coal slag performances need to be further considered. The effects of Al2O3 on viscosities and structures of SiO2‐MgO‐CaO‐Fe2O3‐(10–22 wt%)Al2O3 coal slags were investigated in this work. The viscosity of the coal slag increased first with increasing the content of Al2O3 from 10 wt% to 14 wt% and further declined with the addition of Al2O3 content to 22 wt%. The role of Al2O3 in the present coal slag was identified. Al2O3 mainly behaved as an acidic oxide in coal slags when the Al2O3 content was less than 14 wt%, which polymerized the slag structure and increased the viscosities, and with further addition of Al2O3 to 22 wt%, a part of Al2O3 behaved as network modifiers due to the deficiency of enough metal cations for charge compensation, which could simplify the slag networks and reduce the viscosity. The variations of slag viscosities were consistent with the change tendencies of structures analyzed by spectra techniques.

Effect of TiO2 on the structural properties and viscosity of CaO-SiO2-8.25 %MgO-15 %Al2O3-TiO2 slags

As a raw material for ironmaking, vanadium-bearing titanomagnetite will leads to an increase in the TiO2 content of blast-furnace slag and deteriorates the metallurgical properties of the slag. In this study, the effect of TiO2 content on the viscosity of CaO-SiO2–8.25 %MgO-15 %Al2O3-TiO2 slag system at fixed w(CaO)/w(SiO2) ratio of 1.2 was investigated, and Raman spectroscopy focusing on the relationship between the structure of high TiO2-bearing blast furnace slag and viscosity was performed. The findings showed that under the experimental condition, the viscosity of slag decreases with the increase of TiO2 content over a range of 20 to 35 %. The melting temperature of slag increases first and then decreases after w(TiO2) is higher than 30 %. The viscous-flow activation energy of slag decreases with the increase of TiO2 content, which has a concomitant variation corresponding with the results of the effect of TiO2 on viscosity. The analysis of Raman spectroscopy results reveals that the blast-furnace slag system is dominated by [SiO4]4- network structure. As the TiO2 content increases, more and more Ti4+ enters the silica-oxygen tetrahedral network structure, disrupting the Si-O-Si bond to form the [TiO4]4- structural unit and a small portion of the [TiO6]8- structural unit. The NBO/Si value of the Si4+ in the tetrahedron unit as an index for the degree of depolymerization of slags increased from 1.62 to 2.60 as the TiO2 content increased, the slag structure was gradually simplified and the slag viscosity was gradually decreased.

Effect of MgO content and CaO/Al2O3 ratio on melting temperature and viscosity of CaF2–CaO–Al2O3–MgO slag for electroslag remelting

During electroslag remelting (ESR), high MgO contents are typically added to CaF2–CaO–Al2O3 slag to control magnesium content in iron- and nickel-based alloys. The melting temperature and viscosity of ESR slag are pivotal for energy consumption, production efficiency, smooth operation, and ingot quality. However, there is currently a notable scarcity of research on the melting temperature and viscosity of CaF2–CaO–Al2O3–MgO slag with high MgO levels. Thus, the melting temperatures and viscosity of CaF2–CaO–Al2O3–MgO slags with varying MgO contents and CaO/Al2O3 (C/A) ratios were investigated. The results show that as the MgO content increases from 7.83 % to 13.18 %, the final precipitation content of the MgO phase significantly increases, resulting in an increase in the melting temperature from 1306 °C to 1319 °C. With the increase in the C/A ratio from 0.86 to 1.16, the precipitation completion temperatures of the Ca12Al14F2O32 and MgO phases significantly decrease and the MgAl2O4 phase transforms into the CaO phase. Hence, the melting temperature decreases from 1329 °C to 1314 °C. Further increasing the C/A ratio to 1.40, the final precipitation content of the CaO phase increases, resulting in a decrease in the melting temperature from 1314 °C to 1282 °C. Moreover, as the MgO content and C/A ratio increase, the slag viscosity exhibits different change trends within various temperature ranges. This depends on which of the depolymerization of the slag structure and the precipitation and clustering of the MgO phase has a greater effect on the slag viscosity.

Effect of B2O3 on the viscosity, structure and crystalline phase of CaO–MgO–Al2O3–SiO2–MnO-based high alumina slags

The effects of B2O3 on viscosities, structures and phase transitions of CaO–MgO–Al2O3–SiO2–MnO-(0-8.0 wt%)B2O3 slags were investigated in this work. From the viscosity experimental results, the slag viscosities declined and the Eη decreased from 205.19 to 175.95 kJ/mol with the addition of B2O3 in slags from 0 to 8.0 wt%. From the structure analysis by using FTIR and XPS, B2O3 entered into the silicate network to increase the slag polymerization degree, while the formation of simple two-dimensional BO3 trihedral units could significantly decline the symmetry and stability of the structure. The effects of decreasing the network stability and forming low-melting eutectics were more dominated than the effects of increasing the structure polymerization degree, which could reduce the slag viscosity. Furthermore, adding B2O3 could decrease the slag initial precipitation temperature and change the primary crystal phase of the slag from melilite to spinel. The comprehensive effects of reducing the slag structure stability and decreasing the influence of solid phase on viscosity eventually resulted in the improvement of the slag fluidity.

Thermodynamics property and structure evolution of the TiO2-containing molten slag with different CaO/SiO2 ratio and TiO2 content

The influences of temperature and compositions (TiO2 and CaO/SiO2) on thermodynamics properties and structural evolutions of TiO2-CaO-Al2O3-MgO-SiO2 slags were investigated in this work. The slag viscosities increased with decreasing the temperature and declined with adding TiO2. With the raising of CaO/SiO2 ratio, the viscosity decreased under high temperatures, while it increased with the temperature further decreased lower than 1420 °C. The enthalpy change of the slag increased with raising the temperature as well as the TiO2 content and reduced with the CaO/SiO2 ratio increasing. Both the liquidus temperature and break point temperature of the slags decreased with adding TiO2 and increased with raising the CaO/SiO2 ratio. Temperature had a significant effect on slag structure evolutions, which decreased the slag polymerization degree. With adding TiO2 and CaO/SiO2 ratio in slags, the slag structure stability was weakened by increasing the amount of simpler silicate and TiO6 units and reducing the proportion of complex Ti-O units. Both the temperature and compositions (TiO2 and CaO/SiO2) depolymerized the slag structure to decline the viscosity.

Щодо взаємодії і захоплення металевих крапель доменним шлаком

The mechanism of capture of metal drops by the slag melt was investigated using blast furnace slag as an example. The role of the viscosity of the blast furnace slag in reducing iron loss at the output from the blast furnace is shown. Reducing the viscosity of slags contributes to the rapid settling of small drops of cast iron in the slag volume. It is noted that the CaO/SiO2 ratio is an important parameter that changes the viscosity of blast furnace slag. To ensure the minimum viscosity of blast furnace slag, it is necessary to establish the optimal chemical composition of the slag, in particular the CaO/SiO2 ratio. A study of the temperature dependence of the viscosity of blast furnace slag melts was carried out using the method of estimating the content of the solid phase in the melt during its cooling. Calculations of the volume fraction of the solid phase for blast furnace slags were performed. An increase in the CaO/SiO2 ratio in slags leads to an increase in their crystallization ability. The microstructure and chemical composition of individual phases of a blast furnace slag sample were studied using scanning electron microscopy (SEM). It was established that the experimental slag contained at least three phases. The main (matrix) phase was an amorphous phase, which contained mainly SiO2 and Al2O3. The volume of the matrix phase contained interspersions of the crystalline phase of different sizes, which mainly included CaO and SiO2. In the volume of the crystalline phase, a metallic phase was found, which consisted mainly of Fe and Mn and had a regular rounded shape. The mechanism of capture of a metal droplet by slag is described. The metal drop serves as a frame (center) for the nucleation of the crystalline phase in the slag volume, as its surface energy decreases at the "metal drop - slag" interface. An increase in the mass of the crystalline phase around the metal drop leads to an increase in its lifting force and capture of the metal drop. Keywords: blast furnace slag, viscosity, metal loss, crystallization, scanning electron microscopy.

Effect of basicity on the structure and viscosity properties of HIsmelt slag: A molecular dynamics simulation

ABSTRACT HIsmelt is an emerging and potentially promising non-blast furnace ironmaking process, and the characteristics of its slag are crucial to the smelting process. Currently, there is no atomic-scale research on the slag of the HIsmelt process. In this work, molecular dynamics simulations were employed to investigate the effect of basicity on the structure and viscosity properties of the HIsmelt CaO-SiO2-Al2O3-FeO slag system at 1773 K. The slag structure was characterised by calculating structural parameters, including radial distribution function, coordination number, oxygen type, and bond angle distribution. Furthermore, the viscosity of the slag system was estimated by using the self-diffusion coefficient and compared with mathematical models. The results indicate that basicity has a negligible impact on the short-range ordering of aluminosilicates in the HIsmelt slag system. As slag basicity increases from 0.4 to 1.8, the concentration of bridging oxygen decreases, non-bridging oxygen increases, and the [SiO4]4+ and [AlO4]5+ network structures undergo depolymerisation in the system. Additionally, the self-diffusion coefficient of atoms increases, and the slag viscosity exhibits a declining trend with increasing basicity. In the basicity range of 0.8 −1.8, the current MD simulations align with the results of the previous models.