scholarly journals Analysis of possible ways to reduce sulfur content in pig iron

2021 ◽  
Vol 63 (11-12) ◽  
pp. 878-882
Author(s):  
S. V. Myasoedov ◽  
S. V. Filatov ◽  
V. V. Panteleev ◽  
V. S. Listopadov ◽  
S. A. Zagainov
Keyword(s):  
Blast Furnace ◽  
Cast Iron ◽  
Sulfur Content ◽  
Sulfur Removal ◽  
Slag Basicity ◽  
Slag Viscosity ◽  
Pig Iron ◽  
Blast Furnace Smelting ◽  
Coal Fuel ◽  
Slag Yield

One of the ways to increase the energy efficiency and intensity of blast furnace smelting, especially when using pulverized coal fuel, is to increase the hot strength of coke. In the conditions of OJSC NLMK, an oil additive was introduced into the coal charge to improve the coke quality. At the same time, sulfur content in the coke increases, and, consequently, sulfur content in the cast iron increases as well. In this regard, the task of finding ways to improve the desulfurization of cast iron in blast furnace becomes urgent. The main factors determining the desulfurization of cast iron are slag basicity, content of MgO oxide in it, temperature of the smelting products, and the slag viscosity. The purpose of this work was to compare the efficiency of sulfur removal by increasing the slag basicity and MgO content. On the basis of wellknown equations, an algorithm was developed that allows the problem to be solved. It was established that an increase in MgO content in the slag promotes desulfurization of cast iron to a greater extent than a basicity increase. In addition, an increase in MgO content by 1 % is accompanied by an increase in slag yield by 3.0 – 3.5 kg/t of cast iron. At the same time, an increase in basicity by 0.01 leads to an increase in the slag yield by 4 – 5 kg/t of pig iron. Consequently, reducing the sulfur content in pig iron by increasing the slag basicity requires less heat. In terms of the specific consumption of coke, difference in heat demand is 0.4 – 0.5 kg/t of pig iron. It is shown that with an increase in MgO content in the slag, the slag viscosity at a temperature of 1450 °C increases to a lesser extent than with an increase in basicity.

Analysis of hot metal desulfurization methods efficiency during titanomagnetite processing

2020 ◽  
Vol 76 (6) ◽  
pp. 543-549
Author(s):  
V. V. Panteleev ◽  
K. B. Pykhteeva ◽  
M. V. Polovets ◽  
K. V. Mironov ◽  
S. A. Zagainov
Keyword(s):  
Blast Furnace ◽  
Data Analysis ◽  
Sulfur Content ◽  
Slag Basicity ◽  
Slag Viscosity ◽  
Blast Furnaces ◽  
Hot Metal ◽  
Blast Furnace Smelting ◽  
Low Sulfur ◽  
Hot Metal Desulfurization

To make high-quality steel, it is necessary to ensure low sulfur content in the hot metal entering a steelmaking shop. The task to obtain low sulfur metal can be solved either during blast furnace smelting or its ladle desulfurization immediately after tapping out of blast furnace. Under conditions of JSC EVRAZ NTMK, the ladle desulfurization of vanadium hot metal is not applied, since it leads to a loss of vanadium. Is explained by the fat, that calcium oxide forms with V2O5 a strong calcium vanadate (3СаО·V2O5), which makes the process of vanadium recovery during further slag processing more complicated. Therefore the ladle desulfurization is accomplished after devanadation of hot metal. After the devanadation the semi-product has ions of oxygen, which makes it impossible to arrange an effective desulfurization and males it necessary to smelt the hot metal with limited sulfur content. The factors, effecting the process of hot metal desulfurization in a blast furnace, including slag basicity, MgO content in it, temperature of smelting products and slag viscosity, are presented. Dependence of distribution coefficient of sulfur on slag basicity has been shown. Research goal is pig iron desulphurization efficiency estimation by means of MgO increasing in slag. Data analysis findings about smelting products composition over 500 tappings for each of two investigated JSC EVRAZ NTMK blast furnaces have been reported. The aim of the study was comparison of hot metal desulphurization efficiency due to both slag basicity increase and MgO increase in slag. Results of data analysis on smelting products composition of over 500 heats for each of two investigated JSC EVRAZ NTMK blast furnaces have been presented. It was established that a sulfur content decrease in hot metal is achieved more effectively by MgO increase in slag. It has been shown that MgO has better desulfurizing properties, and with an increase of its content in the blast furnace slag, the overall technology for running the blast furnace process improves. It was recommended to increase the consumption of materials containing MgO while maintaining basicity at a constant level. Such a technology will allow to decrease sulfur content in hot metal, as well as will result in the process stabilization providing other conditions being equal.

scholarly journals Development of the model complex of the expert system of control and management of the slag mode in modern mixed blast furnace conditions

2020 ◽  
pp. 30-46
Author(s):  
D.N. Togobitskaya ◽  
A.I Belkova ◽  
D.A. Stepanenko ◽  
N.A. Tsyupa ◽  
Yu.M. Likhachev
Keyword(s):  
Blast Furnace ◽  
Slag System ◽  
Homogeneous State ◽  
Pig Iron ◽  
Blast Furnace Smelting ◽  
Final Slag ◽  
Coal Fuel ◽  
Model Complex ◽  
Slag Melt ◽  
Furnace Smelting

The aim of the work is to develop physicochemical bases for predicting the technological properties of finite blast furnace slags, algorithmic and software for the subsystem for diagnosing the slag regime of blast furnace smelting. Based on experimental data on the properties of natural finite blast furnace slags, predictive models for calculating the viscosity of the final slag at a temperature of 1400-1550 °C were improved by including in the model structure an integrated slag melt index of the parameter Δe, which reflects the individual effect. Using the integral parameters of the slag melt characterizing the charge state of the system Δe and the structure of the slag ρ, an equation was developed to determine the viscosity of the slag at any temperature corresponding to the slag temperature at the cast iron outlet. As a result of analytical research, a predictive model for determining the enthalpy of slag depending on the integral parameters Δe and ρ and the temperature of the melt has been developed. It is shown that the viscosity characterizes the fluidity of the slag and provides desulfurizing and drainage properties. The calculation of the viscosity for the specified production of pig iron by the chemical composition of the slag is carried out according to the basic model of slag in a conditionally "homogeneous" state and taking into account its heterogeneity. This takes into account the presence of macroheterogeneous inclusions formed when using coke with low strength characteristics and due to incomplete combustion of pulverized coal fuel in the blast furnace. The improved models for evaluating the viscosity and enthalpy of the final slag are software implemented in the new version of the «Slag» system for operational control of the slag mode of blast furnaces in Ukraine. Rapid assessment of the slag mode using the «Slag» system as part of the DCS allows you to effectively and at a modern level solve the problems of optimizing the slag mode and the quality of pig iron in modern conditions of blast furnace smelting.

scholarly journals INFLUENCE OF BLOWING PARAMETERS AND SLAG REGIME ON SILICON AND SULFUR CONTENT IN BLAST-FURNACE CAST IRON

2021 ◽  
Vol 1 (38) ◽  
pp. 7-14
Author(s):  
M. Kuznetsov ◽  
G. Kryachko
Keyword(s):  
Blast Furnace ◽  
Cast Iron ◽  
Sulfur Content ◽  
Silicon Content ◽  
Furnace Operation ◽  
Pulverized Coal ◽  
Operating Conditions ◽  
Noticeable Effect ◽  
Silicon Oxides ◽  
Coal Fuel

At two blast furnaces (BF) with a volume of 1386 and 1500 m³, the influence of the parameters of blast and slag modes on the content of silicon and sulfur in cast iron was investigated. The blast mode was evaluated by the consumption of pulverized coal fuel (PCF) and oxygen, the slag mode was evaluated by its basicity CaO / SiO₂. It was found that the injection of pulverized coal into the hearth of 1500 m³ BF in the range of flow rates from 108 to 120 g/m³·s, and in the hearth of 1386 m³ BF in the range from 90 to 110 g/m³·s was accompanied by a decrease in the silicon content in cast iron. The deterioration of the transition of silicon into cast iron with an increase in the consumption of pulverized coal is explained by the complex effect of factors that retard the reduction of its oxides. Extreme relationships were also established between the intensity of melting in terms of oxygen consumption and the silicon content in the cast iron of the furnaces under study. The extreme dependences of the studied variables are due to the dual effect of the melting intensity on the reduction of silicon oxides: a reduction in the time of contact of the metal with furnace gases reduces the possibility of transition of silicon into metal, and an increase in the volume of the silicon reduction zone improves these possibilities. When operating a 1386 m³ furnace on calcium slag in the range of CaO / SiO₂ basicity change from 0.9 to 1.3 without removing the blast furnace operation periods associated with a change in operating conditions, the absence of dependence of the silicon content in cast iron on the CaO/SiO₂ modulus was found/ In its turn this indicated the complexity of factors influencing the reduction of silicon oxides. In the same range of changes in basicity and different operating modes of the furnace, a noticeable effect of basicity on the sulfur content in cast iron was observed, which indicates the decisive role of basicity in the process of blast-furnace desulfurization.

Study of a blast-furnace smelting technology which involves the injection of pulverized-coal fuel, natural gas, and an oxygen-enriched blast into the hearth

Metallurgist ◽  
2006 ◽  
Vol 50 (5-6) ◽  
pp. 235-240 ◽  
Author(s):  
A. N. Ryzhenkov ◽  
S. L. Yaroshevskii ◽  
V. P. Zamuruev ◽  
V. E. Popov ◽  
Z. K. Afanas’eva
Keyword(s):  
Blast Furnace ◽  
Natural Gas ◽  
Pulverized Coal ◽  
Blast Furnace Smelting ◽  
Coal Fuel ◽  
Pulverized Coal Fuel ◽  
Furnace Smelting

Effect of slag basicity on pig iron loss during tapping from the blast furnace

Metallurgist ◽  
1982 ◽  
Vol 26 (8) ◽  
pp. 273-275 ◽  
Author(s):  
G. A. Volovik ◽  
B. F. Marder ◽  
V. I. Kotov ◽  
P. G. Kalashnyuk ◽  
L. V. Fomenko
Keyword(s):  
Blast Furnace ◽  
Slag Basicity ◽  
Iron Loss ◽  
Pig Iron

scholarly journals Effect of Basicity and Al2O3 on Viscosity of Blast Furnace Slag and Thermodynamic Analysis

2021 ◽  
Author(s):  
Jian Zhang ◽  
Zhengjian Liu ◽  
Jianliang Zhang ◽  
Cui Wang ◽  
Hengbao Ma ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Blast Furnace ◽  
Constant Temperature ◽  
Slag Basicity ◽  
Al2o3 Content ◽  
Wave Number ◽  
Slag Viscosity ◽  
Slag Structure ◽  
Slag Temperature

With the increased use of laterite nickel ore, the impact of high Al2O3 slag on blast furnace smelting has gradually increased. In this paper, the effects of slag basicity and Al2O3 content on slag viscosity and enthalpy change under constant temperature conditions was investigated. The changes in slag structure were analyzed by activation energy and Fourier Transform Infrared (FT-IR) spectroscopy. The relationship between slag components and slag temperature and viscosity when slag heat is reduced was investigated. The results showed that the viscosity first slightly decreased and then significantly increased with increasing basicity at constant temperature. With the addition of Al2O3 content, the viscosity of the slag increases. The activation energy increases with increasing slag basicity and Al2O3. With increasing basicity, the [SiO4]4- tetrahedral unit trough depth becomes shallow, the [AlO4]5- asymmetric stretching band migrates to lower wave numbers, and the slag structure depolymerizes. With the increase of Al2O3 content, the trough of [SiO4]4- tetrahedra deepens and the center of the symmetric stretching band moves to a higher wave number. The [AlO4]5- asymmetric stretching band becomes obvious, indicating the complexity of the slag structure. When the heat decreases, the slag temperature increases as the basicity increases, and the slag thermal stability is better at the basicity of 0.95-1.05. As the Al2O3 content increases, the thermal stability of the slag becomes worse.

scholarly journals COMPUTER SYSTEM OF CONTROL OF SLAG MODE IN MODERN blast furnace conditions

2020 ◽  
pp. 373-377
Author(s):  
Daria Tohobytska ◽  
Alla Bielkova ◽  
Dmytro Stepanenko ◽  
Yurii Likhachov ◽  
Oleksandr Skachko
Keyword(s):  
Blast Furnace ◽  
Computer System ◽  
Slag System ◽  
Slag Viscosity ◽  
Melting Points ◽  
Blast Furnace Smelting ◽  
Functional Capabilities ◽  
Slag Regime ◽  
Furnace Slag ◽  
Furnace Smelting

The functional capabilities, methodological foundations and information software of a modernized computer system for controlling the slag regime of blast furnace smelting, developed at the Institute of Ferrous Metallurgy on the basis of fundamental principles in the physicochemical and mathematical modeling of metallurgical melts and systems based on the concept of directional chemical bonding, are considered. The system provides a predictive calculation of the complex of technological properties of the final blast furnace slag: viscosity, melting points, enthalpy, and desorption capacity. Operational assessment of the slag regime using the Slag system as part of the process control system allows efficiently and up-to-date solving the problems of optimizing the slag regime and pig iron quality under unstable blast furnace conditions

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