Decarburization Reaction Research Articles

Continuous [C] Content Prediction Model in Molten Steel of the All-Scrap Electric Arc Furnace

The continuous [C] content prediction model in molten steel of the all-scrap electric arc furnace was established through the explicit finite difference method combined with numerical simulation based on the thermodynamics and kinetics of the decarburization reaction. Initially, a method to figure out the average [C] content of mixed input scrap was proposed, which provided a basis for subsequent calculations. Furthermore, scrap melting rate, mixing side-blowing / bottom stirring, and oxygen blowing intensity adjustment of oxygen lance had been considered as the three key elements. Decreasing scrap melting time was beneficial to improving the EAF efficiency because it accounts for 80% of the total operation time. The research found that the scrap melting rate was mainly affected by the solid-liquid phase heat transfer and [C] content transfer, and the heat transfer played a dominant role. Applying mixing side blowing / bottom stirring could lead to an improvement in the mass transfer coefficient of the decarburization reaction, and the value was increased from the range of 0.0059 s-1-0.021 s-1 by using single side-blowing to the range of 0.0079 s-1-0.023 s-1. The mass transfer coefficient could be enhanced by the oxygen intensity adjustment of oxygen lances when mixing side blowing / bottom stirring was used. This was a benefit of deeper jet impact zones on the molten steel surface caused by high oxygen flow. After the model was applied to an industrial site, the prediction accuracy of the endpoint [C] content within the error range of ±0.02% and ±0.01% reached 91.2% and 85.7%, respectively.

Direct regeneration of spent LiFePO4 materials via a green and economical one-step hydrothermal process

The rapid development of electronic devices, electric vehicles and mobile energy storage devices, has increasingly emphasized the shortage of lithium resources for us in lithium-ion batteries are developing rapidly. The key to the disposal of spent lithium-ion batteries is to carry out green and efficient regeneration. Herein, we propose a one-step hydrothermal process for the direct regeneration of spent LiFePO4. To reduce the Fe3+ in the spent LiFePO4, the hydroxyl group was oxidized to an aldehyde group via a decarburization reaction, with DL-malic acid utilized as a low-cost and environmentally friendly reducing agent. The effects of various different Li concentrations, hydrothermal times and hydrothermal temperatures on the performance of regenerated LiFePO4 were investigated. The results revealed optimal electrochemical performance under a Li concentration of 1.2 mol L−1, a hydrothermal time of 6 h, and a hydrothermal temperature of 100 °C. The cycling stability of LiFePO4 regenerated under these conditions considerably improved. The initial discharge specific capacity and the discharge specific capacity of the regenerated LFP after 200 cycles were 138.4 mAh g−1 and 136.6 mAh g−1. All coulomb efficiencies of the regenerated LFP were above 97.2 %, and the capacity retention rate was 98.7%. This developed method can therefore be considered a green and feasible means for regeneration of LiFePO4.

Effect of Surface Oxide on Decarburization Reaction in the Austenitic Steel S304HCu

In the present work, the high-temperature decarburization of the austenitic stainless steel S304HCu in Ar–4%H2–xH2O at temperatures between 1000 and 1150 °C was investigated. The focus was on determining parameters that influence the decarburization rate during heat treatment. Thermogravimetric experiments were performed with simultaneous measurements of CO release from the sample using a mass spectrometer. The variation of the experimental parameters included the composition of the atmosphere during pre-oxidation and decarburization, the temperature and the sample thickness. The results indicate that the loss of carbon from the specimen occurs faster through reaction of Cr2O3 with C from the steel compared to the reaction of C at the steel surface with H2O, provided that in the former case CO can easily evaporate. The overall decarburization process is governed by competing reactions; the destruction of chromium oxide by C and the formation of oxide scale by water vapour. The relative rates of these two reactions determines whether decarburization will occur or whether formation of a protective oxide stops the release of CO, the latter being promoted at lower temperatures and high water vapour contents. A dense, sufficiently thick chromia scale retards the onset of decarburization but does eventually not stop the carbon loss. Indications were found that the destruction of a pre-formed chromia scale by carbon involves a two-step process whereby presence of hydrogen is important.

Insight into internal oxidation mechanism of hot rolled Si–Mn added high strength steel: Pure iron layer formation

In order to reveal special morphology formation mechanism of surface continuous Fe layer, through the vacuum sealing heat treatment experiment, the scale transformation process and the mechanism of oxygen pressure reduction in the coiling process of hot rolled steel are obtained. After discussion, it is considered that the surface pure Fe produced by heat treatment under the condition of vacuum sealing of C–Mn–Si steel sheet is due to the internal oxidation of Mn and Si in the substrate and decarburization reaction, and finally lead to the decomposition of oxide scale, resulting in the special structure of surface pure Fe, intermediate oxide scale and internal oxidation.

A Metallurgical Dynamics-Based Method for Production State Characterization and End-Point Time Prediction of Basic Oxygen Furnace Steelmaking

Basic Oxygen Furnace (BOF) steelmaking is an important way for steel production. Correctly recognizing different blowing periods and abnormal refining states is significant to ensure normal production process, while accurately predicting the end-point time helps to increase the first-time qualification rate of molten steel. Since the decarburization products CO and CO2 are the main compositions of off-gas, information of off-gas is explored for BOF steelmaking control. However, the problem is that most of the existing research directly gave the proportions of CO and CO2 as model input but barely considered the variation information of off-gas to describe the production state. At the same time, the off-gas information can be expected to recognize the last blowing period and predict the end-point time earlier than the existing methods that are based on sub-lance or furnace flame image, but little literature makes an attempt. Therefore, this work proposes a new method based on functional data analysis (FDA) and phase plane (PP), defined as FDA-PP, to describe and predict the BOF steelmaking process from the metallurgical dynamics viewpoint. This method extracts the total proportion of CO and CO2 and its first-order derivative as dynamics features of steelmaking process via FDA, which indicate the reaction velocity and acceleration of decarburization reaction, and describes the evolution of dynamics features via PP. Then, the FDA-PP method extracts the features of phase trajectories for production state recognition and end-point time prediction. Experiments on a real production dataset demonstrate that the FDA-PP method has higher production state recognition accuracy than the classical phase space, SVM, and BP methods, which is 87.78% for blowing periods of normal batches, 90.94% for splashing anomaly, and 81.29% for drying anomaly, respectively. At the same time, the FDA-PP method decreases the mean relative prediction error (MRE) of the end-point time prediction for abnormal batches by about 10% compared with the SVM and BP methods.

Real-Time Prediction Model of Carbon Content in RH Process

In the Ruhrstahl–Heraeus (RH) vacuum degassing process, we propose a real-time prediction model for the carbon content in molten steel, and show that the decarburization endpoint can be accurately determined using this model. Firstly, we applied a novel off-gas analyzer that can measure the carbon oxide concentration produced in the decarburization reaction faster and more accurately. Next, we generate decarburization curves using the off-gas components measured by the new analyzer. The decarburization curve describes the carbon content profile well during operation, and shows good agreement with the actual carbon content. In order to predict the carbon content during operation in real time, we create an artificial neural network (ANN) using the decarburization curves and operation data. By comparing the endpoint carbon content measured at the end of the operation with the predicted values, we confirmed the excellent predictive performance of the ANN model. Finally, we show that it is possible to accurately determine the decarburization endpoint using the prediction model. We expect that the proposed real-time prediction model can increase the productivity of the RH process.

Preparation of Calcined Kaolin by Efficient Decarburization of Coal-Series Kaolinite in a Suspended Bed Reactor

The reaction process, mechanism, and kinetics of the decarbonation of coal-series kaolinite (CSK) were investigated using the thermal analysis (TG)–infrared spectrum analysis (IR) coupling method. A pilot test was performed using a suspended calcination system. Further, the carbon content, phase composition, whiteness, oil-absorbed value, and micromorphology of calcined kaolin were characterized. Results showed that the decarburization reaction of CSK was a two-step reaction that mainly occurred in the ranges of 593 °C–836 °C. The mechanism of the decarburization reaction was a phase-boundary reaction (unreacted-core shrinking model) with an activation energy of 214.56 kJ/mol. Calcination at 900 °C or 950 °C for ~3.3 s in a suspension reactor resulted in the decarburization rate of CSK becoming >99.9%. The whiteness of calcined kaolin was mainly positively associated with the decarburization rate, and increasing the calcination temperature aided in increasing the whiteness. The oil-absorbed value of calcined kaolin was positively correlated with the specific surface area. Insufficient or over-calcination decreased the oil-absorbed value of calcined kaolin products. The calcined kaolin product with a whiteness of 89.3% and an oil-absorbed value of 76.1 g/100 g was obtained via suspension calcination process, which meets the requirements of calcined kaolin for paper-making.

Numerical Simulation of Decarburization Reaction with Oxygen Blowing During RH Refining Process

A mathematical model for the decarburization coupling with the fluid flow in the RH refining process was established. The decarburization reaction at three sites was considered, including the surface of injection lifting gas bubbles, the gas–liquid interface in the vacuum chamber and the interior of the molten steel bath. The effect of the flow pattern on the transfer of carbon and oxygen in the molten steel was obtained. The decarburization inside the molten steel bath in the vacuum chamber contributed the most, accounting for 55.9 pct of the total decarburization. The gas–liquid interface in the vacuum chamber and the surface of bubbles injected from the up-leg snorkel contributed approximately 32.5 and 11.6 pct, respectively. The oxygen blowing through the top of the vacuum chamber promoted the decarburization of RH refining whenever the oxygen was injected. When the oxygen was injected at the beginning of the decarburization process, the contribution of the decarburization at the top surface of the molten steel in the vacuum chamber to the total decarburization increased from 11.6 to 28.3 pct.

Electrochemical study on molten iron-carbon electrodes in slag and their decarburization by slag/metal reaction

An electrochemical study on molten iron-carbon electrodes in slag and their decarburization during anodic polarization was performed at 1600 °C to obtain information relevant to steelmaking. Carbon concentration was varied from 4.5 to 0.2 wt% to cover the range of interest between pig iron tapped from blast furnaces and steel tapped from oxygen converters or electric arc furnaces. Impedance spectra were measured at the rest potential and at applied direct current biases, and results were fitted to a faradaic decarburization reaction proceeding through two adsorbed intermediates. At the rest potential, carbon significantly increases faradaic activity at the metal/slag interface as evidenced by a strong increase in exchange current and interfacial capacitance with carbon activity. The apparent standard heterogeneous rate constant of the anodic decarburization half-cell was determined using the dependence of exchange current on carbon activity. During electrochemical decarburization, interfacial capacitance decreases significantly which is consistent with changes in surface concentrations of intermediates. Using a comprehensive kinetic model, surface concentrations of intermediate adsorbed species were determined during anodic polarization in the Tafel region. Results from impedance spectroscopy were compared with those obtained by gas chromatography during constant-current decarburization.

Interaction between CO–Ar–Molten Steel Flow and Decarburization Reaction in Rheinstahl–Heraeus

Computational fluid dynamics (CFD) is an effective tool to investigate the transfer phenomena in Rheinstahl–Heraeus (RH), which is a multifunctional vacuum refining reactor with various chemical reactions. However, the reported mathematical models, which are based on the assumption of steady Ar–molten steel flow, ignore the CO gas generated by the chemical reaction between carbon and oxygen in RH. Herein, Based on the algebraic slip model, a two‐way coupling model (T‐WCM) is developed to explore the unsteady fluid flow (CO–Ar–molten steel) and mass transfer phenomena during decarburization chemical reaction. The measured data from the water model experiment and the industrial experiment are used to validate the numerical results. The carbon mass concentration predicted by T‐WCM is closer to the result from industrial experiment than that predicted by one‐way coupling model (O‐WCM). The mole number of CO gas is about 3 times that of argon gas injected into RH, and the stirring effect of CO gas leads to a more complicated multiphase flow, enhances the mass transfer and prompts the reaction rate. Therefore, the gas–liquid flow and decarburization process in RH can be described more precisely only when CO gas is considered by T‐WCM.

Thermodynamic and experimental study on CO2 injection in RH decarburization process of ultra-low carbon steel

In this work, carbon dioxide (CO2) was investigated as a lifting gas in the Ruhrstahl–Heraeus (RH) decarburization process of ultra-low carbon steel. The main challenge was to determine whether the local carburization reaction leads to the carburization of molten steel with ultra-low carbon content. Thermodynamic analysis of the reaction of the Fe-C-O melt with CO2 demonstrated that compared with traditional Ar injection, the decarburization rate can be improved during the early stage of the decarburization process. This occurs because oxygen that is present not only in molten steel but also produced by CO2 dissociation can react with dissolved carbon to remove the carbon from molten steel. However, it is difficult to determine whether the decarburization rate can be influenced during the later stage by injecting CO2. This is because the carburization reaction at the surface of CO2 bubbles in the up-snorkel and the decarburization reaction at other reaction sites can occur simultaneously. Industrial test results demonstrated that compared with Ar injection, the decarburization rate was not significantly affected by CO2 injection at the early stage, whereas it was reduced during the middle and later stages. Nevertheless, the average carbon content in molten steel after the RH treatment with CO2 injection was only 2.6 ppm higher compared with that in Ar injection. Therefore, Ar can potentially be replaced by CO2 in the RH decarburization process of ultra-low carbon steel based on economic and environmental considerations.

Physico-chemical bases and mathematical modeling of degassing processes in out-of-furnace steel processing

The object of research is the processes of vacuum treatment of liquid steel after its release from the steelmaking unit. The purpose of the work is to study the processes of degassing of liquid steel under vacuum and optimize the conditions for reducing the gas saturation of the metal. The research method is the use of a dynamic mathematical model, developed taking into account the provisions of process limitation by diffusion links of the metal - gas phase boundary transfer. Mathematical models of degassing of metal in ladles with argon purge have been developed, taking into account the distribution of gases from metal according to three articles - in CO bubbles, in argon bubbles and through the open surface of the metal. In all variants of change of technological parameters blocking of a considerable part of a surface of a section of a metal - gas phase by a stream of oxygen is observed. This is because oxygen flows are about an order of magnitude higher than hydrogen flows. At change of technological parameters there is a process of self-regulation of redistribution of streams of hydrogen and oxygen. This is primarily due to the large deviation of the reaction of CO formation from equilibrium. When replacing argon in the purge gas with nitrogen, the behavior of CO and hydrogen in the bubbles during vacuum treatment of the metal remains almost the same. The basis of the products of the decarburization reaction is CO. As oxygen is removed from the metal, the CO content in the purge gas bubbles decreases, and due to this, the hydrogen and nitrogen content increases. The content of CO and hydrogen in the bubbles of the purge gas does not depend on the ratio of argon and nitrogen in the vacuum treatment. The optimal ratio of the purge mixture can be changed depending on the grade of steel being smelted. Comparison of calculated and experimental data indicates a fairly high adequacy of the model in kind

Kinetics of Dehydroxylation and Decarburization of Coal Series Kaolinite during Calcination: A Novel Kinetic Method Based on Gaseous Products.

The analysis of gaseous products reveals the characteristics, mechanisms, and kinetic equations describing the dehydroxylation and decarburization in coal series kaolinite. The results show that the dehydroxylation of coal series kaolinite arises from the calcination of kaolinite and boehmite within the temperature range of 350–850 °C. The activation energy for dehydroxylation is 182.71 kJ·mol−1, and the mechanism conforms to the A2/3 model. Decarburization is a two-step reaction, occurring as a result of the combustion of carbon and the decomposition of a small amount of calcite. The temperature range in the first step is 350–550 °C, and in the second is 580–830 °C. The first step decarburization reaction conforms to the A2/3 mechanism function, and the activation energy is 160.94 kJ·mol−1. The second step decarburization reaction follows the B3 mechanism function, wherein the activation energy is 215.47 kJ·mol−1. A comparison with the traditional methods proves that the kinetics method utilizing TG-FTIR-MS is feasible.

CFD study on the effect of the oxygen lance inclination angle on the decarburization kinetics of liquid steel in the EAF

In Electric Arc Furnace (EAF) steelmaking the main chemical reaction is the decarburization reaction. This reaction is promoted by the injection of oxygen using supersonic or coherent jets and further chemical reaction with dissolved carbon in liquid steel at high temperatures. A 3D mathematical model to describe the effect of the injection angle, oxygen gas flow rate and number of lances on the decarburization kinetics of molten steel, in the absence of the top slag layer has been developed. The model has been validated using experimental data reported in the literature. The model shows that the decarburization kinetics is promoted by decreasing the injection angle from the horizontal, condition that improves both bath movement and reaction kinetics. These findings suggest that current injection angles in industrial EAF’s can be decreased in order to improve the decarburization rate. The main mechanism is the effect of the gas jet on the motion of the liquid. Taking into consideration that decreasing the injection angle from the horizontal promotes splashing, the numerical model predictions are employed to suggest alternative solutions in order to reach high decarburization rates.

Effect of oxidizing slag on the decarburization of ultra-low-carbon steel during the ruhrstahl-heraeus vacuum process

In this study, the effect of oxidizing slag on the decarburization of ultra-low carbon steel during the RH vacuum process was investigated. Based on the experimental results under different operating conditions, it was concluded that high oxidazibility in the top slag could enhance the decarburization rate, particularly in the rapid decarburization stage during the first 4 min of the vacuum process. The highly efficient decarburization for liquid steel depends on two parts of oxygen source. Internal oxygen source is the free oxygen in the liquid steel, and the external oxygen source is the FeO that existed in the RH slag or formed due to the re-oxidation of the splashed scrap and steel skull on the wall of the vacuum chamber. The external oxygen sources participated in decarburization reaction, and promoted the mass transfer of oxygen from the slag to molten steel in the early stage of the vacuum process to further improve the decarburization rate. The decarburization mechanism considering the influence of the oxidizing slag was proposed to explain the reaction sites at different stages of RH decarburization.

Corrosion mechanism of MgO‐C bricks used as linings in a vanadium extraction converter

AbstractTo extend the service life of MgO‐C bricks used as linings in vanadium extraction converters, their corrosion mechanism was investigated using stationary immersion and rotary crucible methods at 1673 K. The effects of oxides in vanadium slag were studied using the slag invasion method. The results showed that a decarburization layer was formed but was not effectively sintered under vanadium extraction conditions, resulting in it having a loose structure and poor binding strength. When slag‐splashing technology was applied to protect the converter, the decarburization layer and slag‐splashing layer easily fell off due to scouring by the molten pool. Consequently, the poor strength of the decarburization layer was the main reason for the poor anti‐erosion performance of the MgO‐C bricks and the weak effect of slag‐splashing technology. In addition, higher contents of SiO2 and TiO2 in vanadium slag could form low melting point compounds and increase the thickness of the decarburization layer, thereby accelerating the MgO‐C brick corrosion rate. Higher contents of FeO in the vanadium slag not only formed low melting point compounds but also caused a decarburization reaction with the MgO‐C bricks. However, with increases of V2O3 in the slag, the formation of high melting point compounds decreased the corrosion rate and corrosion depths.

A facile pathway to prepare molybdenum boride powder from molybdenum and boron carbide

AbstractMolybdenum boride is an ideal hard and wear‐resistant material. In this study, a new method is proposed for preparing molybdenum boride, by which Mo first reacts with B4C to generate the mixture of molybdenum boride and C, and then the product is decarburized by molten Ca to generate CaC2. Pure molybdenum boride could be obtained after acid leaching to remove the by‐product CaC2. According to the experimental and thermodynamic calculation results, it is concluded that the single‐phase MoB could be successfully prepared, while Mo2B, Mo2B5, and MoB4 could not be synthesized by this method. Moreover, it was found that the particle size of finally prepared MoB is determined by particle size of raw Mo powder. The residual carbon content of the product could be decreased to 0.10 wt% after first reaction at 1673 K for 6 hours and then decarburization reaction at 1673 K for 6 hours.

Average carbon content change during gas-solid decarburization of 2 mm iron sheet with a high carbon content

The average carbon content after decarburization is an important criterion in judging the feasibility of the solid-state steelmaking process. To investigate the change mechanism of the average carbon content, the gas-solid decarburization of 2 mm iron sheet in weak oxidizing atmosphere (Ar + H2 + H2O) at 1293, 1353, and 1413 K is studied. The influences of decarburization time and temperature are considered. Increasing both the temperature and time can enhance decarburization. The gas-solid decarburization reaction of 2 mm iron sheets is nearly a first-order reaction, and the activation energy of the decarburization reaction is 144.9 kJ/mol. It was found that the diffusion of carbon from the interior of the sheet to the reaction interface is the rate-controlling step. The relationship between decarburization time, temperature, and average carbon content is precisely described by an empirical formula. A new segmented heating method is developed. With this new method, 0.28 mass% C sheets can be produced from 4.15 mass% C sheets with thickness of 2 mm in 70 min.

Computational Fluid Dynamics Simulations for Understanding and Optimizing the AOD Converter

Computational fluid dynamics (CFD) has constantly evolved in the last decades and nowadays play an important role in the design and development of modern steelmaking converters. Although the flow inside the converter is highly complex and comprises many physical phenomena, like chemical reactions, heat transfer, and the flow of gas bubbles in the liquid melt, it is possible to capture major effects for the design of new converters with modern simulation tools. It is well known that the decarburization reaction is strongly influenced by the partial pressure of CO. To ensure a low partial pressure of CO, a flat bath design with low bath height shows advantages. On the other hand, the bath height needs to be sufficient to ensure enough time for the reactions of the rising gas plume with liquid melt as well as proper mixing. Primetals Technologies has used extensive numerical simulations to compare various bath geometries for a 120 t AOD to improve bath mixing and the interaction between slag and steel phase. As a result, an optimized flat bath geometry could be found, which was an intermediate configuration between deep bath and flat bath design that ensures both high mixing efficiency for the reduction phase and low partial pressure for the decarburization phase. In this paper the most important aspects of numerical modelling of the flow and mixing inside an AOD converter are described, followed by a detailed comparison of different vessel geometries and presentation of an optimized version.

CHARACTERIZATION OF METAL KINGS IN SLAG AFTER DESULFURIZATION CAST IRON ACCORDING TO THE REAGENT CO-INJECTION SCHEME

The results a study of the distribution by fractions and composition of metal drops removed from the cover slag formed along the ladle desulfurization of hot metal according to the reagent co-injection scheme in the conditions of the converter shop of Dneprovsky Metallurgical Plant PJSC are presented. It is proposed to classify metal drops according to size and shape by groups «A», «B» and «C». Drops are assigned to group «A», mostly of irregular shape, which are formed mainly due to bursts of metal in the zone of the «eye» on the surface of the metal bath and are larger than10 mm; to group «B» – drops of spherical shape with a size of 2.5 ...10 mmand to group «C» – drops of both spherical and irregular shape with a size of less than2.5 mm, respectively. A characteristic size distribution of drops was established, which, for the conditions of co-injection lime and magnesium, amounted to: 0.5 ...2.5 mm– 10 ... 16%; 6 ...8 mm– 10 ... 20%; >10 mm– 30 ... 45%, respectively. It was found that with a decrease in the diameter of the drops from2.5 mmor less, there is a trend towards an increase in the sulfur content in the latter, and the sulfur content in the fraction <0.5 mmreaches, and in most cases, exceeds this figure for the coating slag. The substantiation of a high degree influence physicochemical state of the coating slag on the conditions for the transition sulfur from slag to metal droplets in its volume is given. It was established that both the dimensions and the total mass metal drops in the coating slag substantially depend on the thickness of the slag coating layer, which is formed during processing, the diameter gas-metal bubbles that pop up and collapse at the slag-metal and gas-slag boundaries, the degree of turbulization bath and size «eye» on the surface of the bath. Schemes formation and accumulation metal drops group «B» in the slag layer are proposed. In accordance with the first scheme, with increasing viscosity coating slag more than 0.3 Pa.s metal drops in the slag are crushed. In accordance with the second, the formation groups of drops is ensured by grinding metal drops «A» group, which are carried out into the space above the surface of the bath, as a result of the explosion latter during the course their decarburization reaction with the release CO. A scheme is proposed for the transition sulfur from coating slag into metal droplets, which consists in the following. As it rises to the interfacial boundaries, the surface bubbles is covered with a metal shell, which contains surface-active sulfur, which, in addition, diffuses from the volume metal to the surface bubble. If the bubble floats to the “slag-metal” boundary, and the slag is dry, heterogeneous, then the bubble with a metal film on the surface is destroyed with the formation of liquid metal droplets saturated with MgS, and the slag, respectively, is enriched with sulfur. Depending on the physicochemical state slag, both rounded or oval drops and irregular particles are formed. Within the «eye», at the intersection gas-metal boundary, the metal shell from the surface bubbles at the moment their destruction is ejected at different angles into the surrounding space, is crushed and forms metal droplets group «A», which under certain conditions are decarburized with destruction, followed by subsidence on the surface slag and the formation groups drops «B» and «C». Moreover, depending on the period of desulfurization, the metal shell and the metal droplets formed from it contain various amounts sulfur in the slag. Thermodynamic calculations confirmed the possibility of a spontaneous reaction formationFeSin the slag over the entire temperature range ladle desulfurization hot metal under the conditions co-injection lime and magnesium.