scholarly journals Prospects for using boron in metallurgy. Report 1

2021 ◽  
Vol 64 (7) ◽  
pp. 471-476
Author(s):  
V. I. Zhuchkov ◽  
O. V. Zayakin ◽  
A. A. Akberdin
Keyword(s):  
Cast Iron ◽  
Boron Oxide ◽  
Sulfur Removal ◽  
Steel Production ◽  
Liquid Phase Sintering ◽  
Blast Furnace Smelting ◽  
Technical And Economic Indicators ◽  
Kinetics Of ◽  
Metallurgical Processes

On the basis of literature and our own data, the effect of boron on characteristics of all stages of metallurgical processes (from sintering, smelting of cast iron and ferroalloys, to steel production) and on the properties of the resulting slag and metal was studied. To intensify the pellets hardening at the stage of liquid-phase sintering and to improve their metallurgical properties, it is sufficient to have 0.20 – 0.35 % of boron oxide in them. According to the laboratory studies, the presence of boron oxide in pellets increases their compressive strength by 1.5 – 1.7 times and hot strength by 3 – 4 times. While studying the mechanism and kinetics of sulfur removal, it was shown that the presence of boric anhydride significantly intensifies processes of pellets desulfurization. Their intensive progress goes to the zones of lower temperatures of 1050 – 1100 °С. To increase the sinter strength characteristics, it is possible to add B2O3 to the charge. The introduction of 0.44 % of B2O3 does not affect the sinter abrasion. The content of fines (0 – 5 mm) in comparison with the base sample is reduced by 1.5 times. The use of boron pellets in blast-furnace smelting makes it possible to increase the basicity of the final slag from 1.10 to 1.16. In this regard, the sulfur distribution coefficient increases from 48 to 74. The sulfur content in cast iron decreases by 0.005 %. The possibility of using boron and its compounds to improve the technical and economic indicators of production and the quality of pellets, sinter and cast iron is shown on the base of the presented theoretical, laboratory-experimental and industrial data.

scholarly journals Integrated influence of melting parameters of rail steel on rail products quality and technical and economic indicators of the production

2018 ◽  
Vol 61 (11) ◽  
pp. 876-883
Author(s):  
A. A. Umanskii ◽  
L. V. Dumova
Keyword(s):  
Cast Iron ◽  
Sulfur Content ◽  
Surface Defects ◽  
Rail Steel ◽  
Economic Indicators ◽  
Metal Charge ◽  
Linear Decrease ◽  
Solid Iron ◽  
Technical And Economic Indicators

Analysis of literature and production data has shown that despite the significant improvement in quality of domestic rail products, achieved in the last decade due to fundamental technical re-equipment of rail production, there is a problem of increased rejection of rails for surface defects. Based on studies of influence of rail steel chemical composition on quality of rails produced by «EVRAZ ZSMK», there was established a significant effect of increasing copper content in the range of 0.07 - 0.15 % and of sulfur - in the range of 0.006 - 0.011 % in E76KhF steel to increase rejection caused by rail surface defects. Mechanism of the influence of these elements concentration in rail steel on finished rails quality was revealed. Decisive influence of ratio of pig iron and scrap in metal charge on copper and sulfur content in rail steel was evidenced - higher rate of cast iron in metal charge within 20 - 50 % contributes to decrease of copper concentration and increase of sulfur content. To justify optimal composition of the charge for rail steel melting in regard to rail products quality and technical and economic indicators of production, study of the effect of cast iron (liquid and solid) to scrap ratio in metal charge on basic parameters of furnaces’ operation was conducted. As a result, it was found that with an increase in share of both liquid and solid iron in metal charge, there are linear decrease in specific electricity consumption, increase in specific oxygen consumption according to parabolic law and a linear decrease in manganese content in furnace output. The obtained dependences of melting duration on ratio of charge components in metal charge indicates presence of prominent minimum, when using liquid iron in the range of 35 - 40 %, and when using solid iron - in the range of 30 - 35 %. Based on the regression equations, statistical model was constructed for the influence of metal charge composition on technical and economic performance of the melt charge in rail steel smelting, in which optimization parameters are: total cost, depending on the metal stock composition and performance of the shop for suitable billets produced by continuous casting. Application of the obtained model allows to develop reasonable recommendations on the optimal proportion of iron in the metal for current level of prices for materials and energy used in electric smelting, taking into account changes in the shop productivity.

The Model of Temperature Field and Chemical Heterogeneity of Solidifying Ductile-Cast-Iron Roller

2011 ◽  
Author(s):  
Jana Dobrovska ◽  
Frantisek Kavicka ◽  
Karel Stransky ◽  
Bohumil Sekanina
Keyword(s):  
Temperature Field ◽  
Cast Iron ◽  
Structural Heterogeneity ◽  
Ductile Cast Iron ◽  
Chemical Heterogeneity ◽  
The Matrix ◽  
Working Rollers ◽  
Length Of Life ◽  
Kinetics Of

The quality of the working rollers used for rolling rails of different profiles is determined by the chemical and structural composition of the material of the rollers and the production technology. It is therefore necessary to find and ensure optimal relationships between the matrix structure and the resultant values of the mechanical properties of the rollers in order to maximize the length of life. The requirements introduced here cannot be ensured without perfect knowledge of the course of solidification, cooling and heat treatment of the cast rollers as well as the kinetics of the temperature field of the casting and mould. The kinetics of the solidification has a measurable and non-negligible influence on the chemical and structural heterogeneity of the investigated type of cast-iron. Tying on to the results of the model of the temperature field of the cast rollers, an original methodology was developed for the measurement of chemical microheterogeneity.

Temperature Field and Solidification Structure of a Ductile-Cast-Iron Roller

2013 ◽  
Vol 592-593 ◽  
pp. 197-200
Author(s):  
František Kavička ◽  
Jana Dobrovská ◽  
Karel Stránský ◽  
Bohumil Sekanina ◽  
Josef Stetina
Keyword(s):  
Temperature Field ◽  
Cast Iron ◽  
Structural Heterogeneity ◽  
Ductile Cast Iron ◽  
Solidification Structure ◽  
Heat Flows ◽  
Working Rollers ◽  
Original Application ◽  
Kinetics Of

The quality of the working rollers from ductile-cast-iron used for rolling rails is determined by the chemical and structural composition of the material of the rollers and the production technology. The requirements of the quality cannot be ensured without perfect knowledge of the course of solidification, cooling and heat treatment of the cast rollers as well as the kinetics of the temperature field of the casting and mould. An original application of ANSYS simulated the forming of the temperature field of the entire system comprising the casting, the mold and ambient. In the experimental investigation of temperature field, an original methodology for the measurement of the distribution of temperatures and heat flows in the roller-mould system had been developed and verified in the operation. The kinetics of the solidification has a measurable and non-negligible influence on the chemical and structural heterogeneity of the investigated type of ductile-cast-iron. Tying on to the results of the model of the temperature field of the cast rollers, an original methodology was developed for the measurement of chemical microheterogeneity. The chemical and structural heterogeneity of the cast roller is therefore a significant function of the method of melting, modification and inoculation and the successive procedures of risering, casting and crystallization after cooling.

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.

scholarly journals Modern view on steel desulfurization

2021 ◽  
Vol 100 (4) ◽  
pp. 33-44
Author(s):  
O.S. Vodennikova ◽  
◽  
P.V. Holovkov ◽  
Keyword(s):  
Cast Iron ◽  
Sulfur Removal ◽  
Steel Production ◽  
Steel Making ◽  
Desulfurization Process ◽  
Current Production ◽  
Solid Slag ◽  
The Cost ◽  
Steel Treatment ◽  
Steel Works

Modern technological schemes of steel production do not allow to achieve low (< 0.01 % S) and ultra-low (<0.005 % S) sulfur content on the production of in the metal directly. That is why out-of-furnace steel treatment is often used to remove sulfur. Desulfurization process of steel depends on the chemical composition of the slag, the time of its formation in the ladle, metal oxidation, conditions of mixing of steel in a ladle, additional technological operations and ladle metal processing. Methods are widely used for desulfurization of steel treatment of steel with solid slag-forming mixtures, synthetic slag, lime-aluminous slag, silico-calcium and other powdered materials. Modern approaches to the process of steel desulfurization in conditions steel production are analyzed in the Study. In particular, the Ukrainian (on the example of PJSC ‘Azovstal Iron & Steel Works’ and PJSC ‘Dneprovsky Integrated Iron & Steel Works named after Dzershinsky’) and foreign (on the example of PJSC ‘Severstal’ and PJSC ‘Magnitogorsk Iron & Steel Works’) experience of desulfurization under oxygen converter production. The use of technological complexes ‘Installation of pig iron desulfurization steel making unit’ and ‘Cast iron desulfurization installation steel making unit is ‘oven-bucket’ installation’ provides a deeper desulfurization of steel, the possibility of optimizing the cost of steel production, expands range of scarce products and eliminates a number of restrictive conditions that complicate current production. The analysis of steel C80D desulfurization process is given in the conditions of JSC ‘Moldova Steel Works’, in which partial sulfur removal occurs in an arc steel making furnace, and the ultra-low content is achieved by creating a highly basic refining slag in the process out-of-furnace processing of steel. The study of the kinetics of the desulfurization process of 20GL steel in the conditions of JSC ‘Tashkent Mechanical Plant’ with the use of solid slag-forming mixtures and modification of steel with rare-earth metals is analyzed. The issue of desulfurization of electric steel in the conditions of OJSC ‘Byelorussian Steel Works’ with injection of powdered materials through the installation ‘Velko’ during out-of-furnace processing of steel is considered. Keywords: steel desulfurization, desulfurizer reagent, degree of desulfurization, cast iron desulfurization installation, out-of-furnace processing of steel, ‘‘oven-bucket’’ installation.

scholarly journals Increasing the efficiency of blast-furnace smelting by improving the quality of iron ore materials

2019 ◽  
pp. 43-60
Author(s):  
A.S. Nesterov ◽  
L.I. Garmash
Keyword(s):  
Blast Furnace ◽  
Cast Iron ◽  
Chemical Composition ◽  
Coke Consumption ◽  
Iron Ore ◽  
Raw Materials ◽  
Blast Furnace Smelting ◽  
Blast Furnace Dust ◽  
Sinter Mixture

It is noted in the work that when mastering the technology of pulverized coal injection (PUT) at the metallurgical enterprises of Ukraine, it is necessary to intensify work, including research, in the direction of improving the quality characteristics of the sinter, the stability of its chemical composition and strength parameters. The analysis of the quality of iron ore raw materials used in sintering production in Ukraine and foreign countries is carried out. The requirements of international and domestic standards for the quality of raw materials and fuels, providing for the injection of large quantities of firearms into the furnace, are given. A methodology for determining the quality of raw materials developed in the HMI is described. The results of a study of the quality of iron ore raw materials according to the developed method are presented. Based on the analysis of the results of the research, requirements were developed for the quality of granular iron ore wastes and their rational amount in the composition of the sinter charge, and the process for the production of granules was developed. Recommendations have been developed on the use in the sinter mixture of a part of the granular components of secondary waste, which allowed to increase the content of secondary resources in the mixture. As a result, the chemical composition of the sinter was stabilized, its strength was improved, the yield of sinter of the second grade was reduced, the removal of blast furnace dust and coke consumption were reduced. Improving the quality of the sinter and the rational distribution of charge materials over the cross-section of the top of the blast furnace allows for self-renewal of the protective skull, to reduce the removal of top dust by 4.3 kg / t of cast iron, and to reduce coke consumption by 19.6 kg / t of cast iron. The developed measures make it possible to increase the competitiveness of products, even at the additional cost of preparing the sinter mixture for sintering.

Features of the Reducibility of Titanomagnetite Iron Ore Materials

2020 ◽  
Vol 400 ◽  
pp. 176-185
Author(s):  
A.N. Dmitriev ◽  
R.V. Alektorov ◽  
Galina Yu. Vitkina ◽  
S.A. Petrova ◽  
Yury A. Chesnokov
Keyword(s):  
Titanium Dioxide ◽  
Blast Furnace ◽  
Iron Ore ◽  
Economic Indicators ◽  
Blast Furnace Smelting ◽  
Ore Preparation ◽  
Before And After ◽  
Technical And Economic Indicators ◽  
Furnace Smelting

The reducibility of titanomagnetite iron ore materials (agglomerate, pellets) with various TiO2 contents are studied. The mineralogical features of agglomerate and pellets before and after reduction are investigated. Calculations of technical and economic indicators of blast furnace smelting using iron ore materials with different TiO2 contents are carried out. It is shown that an increase in the content of titanium dioxide in pellets and agglomerate (with an increase in the amount of concentrate introduced into them) does not change the quality of iron ore preparation for blast furnace smelting.

STUDYING THE KINETIC CHARACTERISTICS OF THE EXTRACTION OF ANTHOCYANINS FROM THE SQUEEZE OF KRASNOSTOP ZOLOTOVSKY

2020 ◽  
Author(s):  
M.A. Egyan ◽  
Keyword(s):  
Reaction Rate ◽  
Sugar Content ◽  
Extraction Process ◽  
Efficiency Coefficient ◽  
Kinetic Characteristics ◽  
Reaction Rate Constants ◽  
Solids Content ◽  
Kinetics Of ◽  
Process Speed

The article shows studies characterizing the quality of the squeeze: the mechanical composition of the squeeze is determined, the structural moisture of each component is determined, the sugar content in the formed process of sedimentation of the juice and its acidity are determined refractometrically. The kinetics of anthocyanins extraction was determined in two ways, the solids content in the extract was calculated, and the reaction rate constants of the extraction process and the efficiency coefficient of ultrasonic amplification of the extraction process speed were calculated.

A model to predict the kinetics of mass loss in wood during thermo-vacuum modification

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ottaviano Allegretti ◽  
Ignazia Cuccui ◽  
Nasko Terziev ◽  
Laerte Sorini
Keyword(s):  
Mass Loss ◽  
Treatment Process ◽  
Linear Trend ◽  
Thermal Modification ◽  
Thermal Treatments ◽  
Temperature Profiles ◽  
Relative Area ◽  
Heat Power ◽  
Kinetics Of

AbstractMass loss (ML) of wood caused by thermal degradation is one of the most important features of the thermal treatments and referred to as an indicator of intensity and quality of the process. The ML is proportional to the quantity of the effective heat power exchanged during the treatment process, represented by the area of the temperature profile versus time during the process. In this paper a model for the ML prediction based on the relative area was discussed. The model proposed an analytical solution to take into account the non-linear trend of ML when plotted versus temperature and time as observed in isothermal experiments. The model was validated comparing calculated and measured final ML of samples treated during thermal modification tests with different temperature profiles. The results showed that the relative area calculated in a transformed time-temperature space improves the correlation with the measured ML.

Study on the Behavior of the Cast-Iron Bonded Grinding Wheel to Machining Properties of Hard and Brittle Materials

2007 ◽  
Vol 24-25 ◽  
pp. 229-232
Author(s):  
S.L. Ma ◽  
Wei Li ◽  
Cong Rong Zhu ◽  
J. Zhang ◽  
H.C. Ye
Keyword(s):  
Grain Size ◽  
Cast Iron ◽  
Tungsten Carbide ◽  
Surface Quality ◽  
Ground Surface ◽  
Grinding Wheel ◽  
Different Grain Size ◽  
Grinding Efficiency ◽  
Machining Properties

Tungsten carbide which is a hard and brittle material was ground by cast-iron bonded diamond wheel with ELID (Electrolytic In-Process Dressing) technique, for the purpose of getting high efficiency, super-precision machining. Three kinds of cast-iron bonded diamond wheels with different grain size were adopted to get different grinding efficiency and surface quality of workpieces. The grinding properties of cast-iron bonded grinding wheels with different grain size and the ground surface quality of tungsten carbide are discussed in this paper. The experiment results indicate that, under the same feeding amount, the grinding efficiency of the wheel with bigger grain size is higher, and it could make the dimension accuracy of the workpiece controllable, but the wheel with smaller grain size could get better ground surface quality. The two grinding phases are decided by the ratio between the size of abrasive grain and the thickness of the oxide layer on the grinding wheel.

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