Physical and Numerical Modeling of the Slag Splashing Process

The influence of technological factors on the process of slag splashing was analyzed in the paper. The problems were solved in several stages using our own and commercial calculation programs and laboratory tests. Based on the performed calculations and simulations, factors affecting the slag splashing were determined. It was observed that the high efficiency of the process can be achieved by optimizing numerous technological parameters, e.g., flow parameters, pressure, and temperature of the nitrogen stream, height and angle of the lance position, as well as slag height into which the gas stream enters and MgO consumption. In addition, the chemical and mineralogical composition of the slag and its physicochemical parameters should be also considered. The obtained results of numerical simulations of slag splashing in the oxygen converter coincide with the results of experiments carried out using the physical model of oxygen converter. This means that the simulations well represent the real course of the slag splashing process for the studied variants.

MODELING THE MELTING OF SCRAP METAL OF DIFFERENT DENSITY IN A BOF SMELTING

The results of mathematical modeling process of melting scrap metal in the bath of an oxygen converter are presented. The influence relative amount of scrap metal in the charge of oxygen-converter smelting and its density on dynamics bath temperature during melting, slag oxidation and liquid metal yield was studied. It is shown that due to change in the shape of scrap metal during its melting, the classical approach to determining the reactive surface area of ​​the latter needs to be clarified.Mathematical descriptions of scrap metal melting in converter smelting by linear dependence and using fourth degree polynomials, which take into account the influence of initial and current carbon concentration in the bath, are offered. The influence of density and fraction of scrap metal, which is a part of metal charge, on duration of its melting in bath of oxygen converter, content iron oxides in slag, temperature mode process and yield liquid metal is investigated. It is shown that increasing mass of scrap metal in the metal charge to 40%, in the absence of its preheating, significantly changes the appearance both the oxidation curves of carbon and the dynamics of the bath temperature in the initial period melting.The latter may be due to the preservation active surface area of ​​scrap metal as its mass changes. Additional heat consumption for melting an increased amount preheated («cold») scrap metal leads to a decrease in the temperature of the liquid bath, which confirms the feasibility using the technology melting with preheating an increased amount of scrap.It is shown that from the point of view ensuring the rational course of converter smelting it is expedient to use equal shares heavy and lightweight scrap metal, regardless of the share latter in the metal charge. In the case using, under the considered conditions, «cold» scrap metal, the maximization yield of liquid metal is provided at the amount scrap up to 22% of the total mass metal charge.

Application of the shotcreting method to restore the working layer of the lining of steel-pouring ladles of the oxygen-converter shop of PJSC MMK

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Development of Supplements Prevention System in Oxygen Converter Process in Order to Increase the Economic Efficiency of Steel Melting

The article analyzes the work of the oxygen-converter shop of PJSC «ArcelorMittal Kryvyi Rih». It is shown that almost half of the total number of blowing supplements (~ 44%) is carried out by temperature. In order to improve the conditions of steel smelting and reduce resource costs, calculations were performed and new technological solutions were found in steel smelting to reduce the number of additives. The study of real smelters demonstrated the need for corrective operations in the smelting of steel using scrap metal of different types. Scrap smelts have a clear relationship between the amount of scrap in the charge and the temperature of the melt in the first dump. The addition of «goat» scrap to the charge has a number of uncontrolled effects on the process due to significant fluctuations in the chemical composition of this type of metal charge. An economic analysis with introducing the developed control mechanism over the course of steel smelting into the software system for conditions PSJC «ArcelorMittal Kryvyi Rih» was performed.

MATHEMATICAL MODEL AND ALGORITHM FOR CALCULATION OF THERMAL STATE OF A REGENERATOR ACCUMULATING CONVERTER GAS HEAT OF COMBUSTION AND HEATING AIR FOR A RECOVERY BOILER

The heat of combustion of the converter gas, which is periodically formed in the oxygen-converter production at the metallurgical plant, is proposed to be used for alternate heating of the checkerwork of two regenerators (such as сowpers), and their alternate cooling by a continuous flow of air heated to a high temperature, and directed to the recovery boiler to generate steam. A mathematical model is presented that allows evaluating the thermal state of the regenerator, the temperatures of the heating gases and the heated air in the modes of heating and cooling the regenerator checkerwork. An algorithm for numerical calculation of the temperature fields of the regenerator checkerwork, gases and air is presented.