Application In Steel Industry Research Articles

Quality assessment of needle coke used in the production of graphite electrodes for metallurgical furnaces

Needle coke is a special kind of carbon material that has a developed anisotropic fibrous structure, high current conductivity in the fiber direction and low coefficient of linear thermal expansion. This material has found a wide application in steel industry where it is used for the production of graphite electrodes of the SHP (50–75 kA) and UHP (up to 100 kA) grades designed for high-power electric arc furnaces. This paper describes the results of assessing the quality of the needle coke that is commercially used at El 6 for the production of carbon and graphite products. The quality of the material was analyzed based on two groups of techniques: spectral analysis (SEM and optical microscopy, XRD, Raman spectroscopy) and analysis of physical and chemical properties (CTE, real density, sulfur, ash, moisture, electrical resistivity). A study and a comparative analysis were carried out using seven samples of calcined petroleum and pitch needle cokes. Six of them are used commercially (imported) and one was produced in laboratory conditions from Russian raw materials. The study confirmed that a better needle coke structure tends to form from petroleum coke versus pitch coke. Using the results of spectral analysis, the studied samples of needle cokes were classified into three groups based on their morphology and structure, which correlates with the results of the analysis that looked at their physical and chemical properties. The combination of research and data processing techniques presented in the paper ensures a comprehensive analysis of the studied needle coke and suggests that the material in view can be used in the production of graphite electrodes.The authors would like to thank Evgeny S. Gorlanov, deputy director of the Research Center for the Problems of Processing Mineral and Man-Made Resources at Saint Petersburg Mining University, and Andrey L. Kvanin, who oversees research and engineering projects at El 6, for their valuable advice and assistance in preparing this paper.This research was carried out as part of the State Assignment 0792-2020-0010 by the Ministry of Education and Science of the Russian Federation: Elaborating the innovative technologies of processing heavy hydrocarbons into environmentally friendly motor fuels and new carbon materials with controllable macro- and microstructures of the mesophase”.

Modern concepts of refractory materials application in production of steel and cast iron

Refractory lining is an integral part of metallurgical facilities and requires constant perfection. Examples of successful interaction of specialists-steelmakers, companies-manufacturers of refractories and engineering companies on increasing efficiency of refractories application in steel industry presented. The wide application of drying and heating stations of steel ladles, EAFs, BOFs was noted because of using refractory gunned castable at their current repairs. The growth of unmolded refractory share in the BF production was shown. At the stoves repair technology of guniting and shotcreting is widely used. Transfer to application of modern concrete at lining of shoots, ramming mixtures and repairs with application of liquid concrete addition resulted in a decrease of labor­ intensiveness of repair work, accelerated the process of repair and considerably decreased specific consumption of refractory materi­als. Nevertheless, within a predictable period, despite of increase of unmolded refractories application, it is expected that the molded refractories would take the main share of the refractory market in the steelmaking. Creation of partial load conditions in a metallurgical facility is an important factor for increasing lining resistivity. Slag foaming in EAF screens radiation from electrodes in the process of the furnace running. Blowing of the final slag (preliminary enriched by magnesium oxide in case of necessity) forms a scull on the working surface of the BOF lining, thus preventing intensive contact of the refractory lining with steel melt and slag. Modem technologies of instrumental control the lining state of metallurgical facility within the period of its running considered, which allowto accomplish operation of hot repair at particular arears of the lining, avoiding overconsumption of the repair material. It was noted that apart from the task of decreasing specific expenses for refractory materials, the customers most often estimate the indirect costs, cover of loss and obtaining additional profit due to increase of metal production because of increase of overhaul period and decrease of time of lining repair. This is the purpose of cooperation of specialists of refractories manufacturers and metallurgical plants.

Performance assessment of thermophotovoltaic application in steel industry

The potential for using Thermophotovoltaic (TPV) generators as an alternative for recovering energy losses in steel production industry is assessed. A mathematical model for the assessment of the performance of TPV application in the iron and steel industry has been developed. In order to support the mathematical model, a sample TPV apparatus in laboratory scale based on an IR emitter has been designed and assembled. The key modeling parameters of TPV generator include: the open circuit voltage, the short circuit current density and fill factor of the TPV cell. These parameters have been considered in the model as functions of several variables such as: the emitter (hot steel slab) temperature, the cell temperature, the distance between the cells and emitter, the spectral response and the cell energy gap. The External Quantum Efficiency (EQE) as an important indicator of the cell׳s spectral response is included in the model. Moreover, the variation of the emitter temperature has been considered. Several tests have been carried out for different values of the cell-emitter gap. It has been found that when the GaSb cells are used for energy recovery, a minimum temperature of 873°C is required. The upper limit of the emitter temperature is usually determined in steel production process associated with hot rolling process which has a temperature around 1250°C. Finally, the total efficiency of the system was obtained to 4.12%, when GaSb cell with temperature of 27°C and slab emitters with temperature of 1257°C are used. The results of the simulation of the model in a casting process at the Mobarakeh Steel Complex have shown a potential of energy recovery of 26.987MJ per year.

Effect of M-EMS on in-mould transient flow during continuous casting

Electromagnetic braking (EMB) and electromagnetic stirring (EMS) are widely used to increase the efficiency in continuous casting process of steel. In particular, in-mould applications (M-EMS) allow decreasing the free surface fluctuation, controlling the velocity field and decreasing the turbulence of the flow. Since laboratory-scale tests are not fully representative of the process and industrial measurements are both expensive and difficult to carry out, numerical simulation is a strong tool to study and optimize these electromagnetic applications in steel industry. These simulations cannot fully model the process because the problem results to be strongly multiphysical and the simulation of all the phenomena involved would lead to huge computational costs, which is one of the main limits in the current situation. For this reason, this work aims at starting searching a coupling algorithm which could guarantee both computational efficiency and accuracy of the final results.

A parallel immune algorithm for traveling salesman problem and its application on cold rolling scheduling

Parallel computing provides efficient solutions for combinatorial optimization problem. However, since the communications among computing processes are rather cost-consuming, the actual parallel or distributed algorithm comes with substantial expenditures, such as, hardware, management, and maintenance. In this study, a parallel immune algorithm based on graphic processing unit (GPU) that originally comes to process the computer graphics in display adapter is proposed. Genetic operators and a structure of vaccine taboo list are designed, and the internal memory utility of GPU structure is optimized. To verify the effectiveness and efficiency of the proposed algorithm, various middle-scale traveling salesman problems (TSP) are employed to demonstrate the potential of the proposed techniques. The simulation examples demonstrate that the developed method can greatly improve the computing efficiency for solving the TSP, and the results are more remarkable when the scale of TSP becomes higher. Furthermore, the derived algorithm is verified by a practical application in steel industry that arranges the cold rolling scheduling of a batch of steel coils.

Data-based process monitoring, process control, and quality improvement: Recent developments and applications in steel industry

The issue of how to improve product quality and product yield in a brief period of time becomes more critical in many industries. Even though industrial processes are totally different in appearance, the problems to solve are highly similar: how to build a reliable model from a limited data, how to analyze the model and relate it to first principles, how to optimize operating condition, and how to realize an on-line monitoring and control system and maintain it. In this paper, statistical process monitoring and control methodologies are briefly surveyed, and our application results in steel facilities are presented. The achievements of the present work are as follows: (1) the development of a new method that can cope with qualitative quality information and relate operating conditions to product quality or product yield, (2) the simultaneous analysis of multiple processing units including a converter, a continuous caster, a blooming process, and rolling processes, and (3) the successful application results in the steel industry.

High Power Laser Applications in Steel Industry.

High Power Laser Applications in Steel Industry.