MODELING OF DISTRIBUTION COEFFICIENTS OF CHARGE ELEMENTS BETWEEN FINISHED PRODUCTS OF BLAST FURNACE SMELTING IN MODERN CONDITIONS

The results of using the developed methodology for predicting the distribution coefficients of the charge elements between the products of blast-furnace smelting based on the calculation of the integral parameters of the charge and the temperature-blowing regime for modern operating conditions of one of the blast furnaces in Ukraine are presented. The proposed approach differs from traditional methods of considering the distribution coefficients of charge elements as constant values and provides a predictive calculation of the chemical composition of cast iron and slag depending on specific charge and technological conditions when solving the problem of a reasonable choice of the composition of the blast furnace charge.

HIGH-PERFORMANCE METHOD OF PRODUCTION OF POWDER FRICTIONAL PRODUCTS ON FE-BASIS WITH HIGH TECHNOLOGICAL AND OPERATIONAL PROPERTIES

Physical and technological bases of DHP-PFM method for production of dry friction powder friction articles on Fe-base with high technological and operational indices for a wide range of practical use have been developed. The DHP-PFM method is that the dynamic hot pressing (DHP) provides production of the new powder frictional materials (PFM) through an underlayer from carbonyl iron between frictional material and a basis (framework) with electroplated nickel coating. Friction lining compaction is made of charge of ФМК-79 type and has high hardness and low porosity. Processes of the choice of composition of furnace charge, formation of structure and properties of new powder frictional materials on Fe-to a basis are investigated. The method is characterized by high productivity, energy saving, simplified technology and provides the possibility to use existing technological equipment for making structural powder products. Method of DHP-PFM manufacturing of dry friction powder friction linings can be used for manufacturing of friction units of transmissions of light track machines with high specific power. The friction material received by this method from furnace charge of FMK-79 type can be used as unified for such frictional units as the main friction clutch, an onboard friction clutch, tape and disk brakes.

Improvement of iron ore pellets metallurgical properties by their fluxing by lime

Fluxed iron ore pellets, obtained by application of raw limestone are widely used in the iron ore share of blast furnace charge. Decomposition of the raw limestone in the process of the pellets burning requires considerable energy. The purpose of the work was to study quality variation of raw and burned pellets, as well as metallurgical properties variation, caused by substitution of limestone by burned and slaked lime. Physical simulation of the pelletizing process and pellets burning process was done. In the process of the experiment simulation of total and partial substitution of limestone by lime as well as with partial substitution of limestone by slaked lime was accomplished. Diagrams of plasticity and strength of raw and burned pellets at various shares of limestone, burned and slaked lime presented. It was shown that the strength during reducing RDI-1 (ISO 4696-1) has a tendency to increase when application of lime. Increase of Index RDI+6,3 value accounted for 3.6% (abs.) at application of quicklime and slaked lime correspondently. Index RDI−3,15 value decreased by 1.06% (abs.) and 0.88% (abs.) and that of index RDI−0,5 – by 0.75% (abs.) and 0.8% (abs.) at application of quicklime and slaked lime correspondently. It was assumed that application of slaked lime can contribute to bentonite share decrease and thus to total iron content increase. It was established that application of lime enables to decrease heat consumption for pellets burning. Application of slaked lime instead of limestone in the process of pellets production results in an increase of their strength during reducing and compression strength. This effect enables to reach a higher efficiency in the process of such pellets usage in blast furnace charge or in the process of their metallization, comparing with the usage of pellets fluxed by limestone.

TECHNOLOGY FOR MAKING OF 12Х18Н10Т ALLOY IN INDUCTION-ARC FURNACES

A technology for making structural cryogenic steel 12Х18Н10Т from industrial waste has been developed. For it an induction plant was used which consists of two FS-series induction-arc furnaces. Problems of furnace charge preparation were considered: the fractional composition, oxidation, content of harmful impurities and a charging way. It made possible to ensure pot resistance and to decrease the melting period. Recommendations to decrease meniscus height on the melt surface are given.

Innovated Technologies of Recycling of Metallic Wastes – Modification of Existing Industrial Processes

This paper describes interesting operational experiments have been performed in the scope of the project where the process of melting deoxidation was used under improvised conditions of cold blast cupola furnace. The goal was to find out metallurgical effects of added selfreducing briquettes prepared from steel sludge into cupola furnace charge and above all to verify the grade of deoxidation of oxides of iron at keeping output quality of cast metal. Present state of research and development of technologies of iron production in the area of commercial exploitation of these technologies is not in such a position that we could realistically assess their efficiency, investment costs and economic impacts. Moreover, an unequivocal requirement on minimization of CO2 emissions, mainly by its recycling, is here more and more promoted.