Papers by Keyword: Blast Furnace

Abstract: The paper presents results of an improvement to the mathematical system of the two-dimensional equilibrium balance model of the blast furnace process (IMMDP). This improvement was made in terms of transition to three-dimensional modelling of both the furnace space and temperature fields, degrees of reduction, concentration potentials, etc. The model incorporates the azimuthal coordinate dependence of parameters, facilitating enhanced realism in furnace operation by accounting for the circumferential non-uniformity of blast and natural gas distribution over the blast furnace lances. This is particularly pertinent for the assessment of hydrogen gas utilization in support of international climate initiatives. The three-dimensional model facilitates data visualization, enhancing operator clarity. To this end, Python scripts have been developed to visualize both parameter distributions in selected planes and iso-surfaces in three-dimensional space. The data for visualization was obtained by interpolating the results of calculations performed using a two-dimensional model onto a regular grid. Resulting visualization enables the observation of the spatial distribution of the primary parameters of blast furnace operation (gas dynamics, heat exchange, reducing) on the monitor screen, thereby facilitating enhanced comprehension of its operation and optimized control process.

Abstract: Gas-liquid two phase flow of blast furnace taphole stream into the main trough is studied through computational fluid dynamics (CFD) method. Tapping process of blast furnace with different taphole angles is simulated by volume of fluid model of CFD. The velocity and region of taphole stream into flow within the main trough is analyzed. It is concluded that the tophole case with bigger angle is conducive to slag-metal separation in the main trough.

Abstract: Firing of various basicity pellets and sintering of Kachkanar concentrates were evaluated on a pilot plant. Mineral analysis was carried out for fired pellets and those reduced in a derivatograph in gas with composition close to that of blast furnace gas. Structure and metallurgical property dependence of pellets and agglomerate on their basicity was studied. Failure mechanism of fluxed pellets was considered. Blast furnace smelting process was developed for Kachkanar iron ore raw material with various fluxing degree, consisting of low-basic pellets, and high basic agglomerate characterized by low failure characteristics at reduction and ensuring high gas permeability in blast furnace top. Optimal values of agglomerate basicity, carbon content in burden and ferrous oxide in agglomerate, ensuring its high reducibility and adequate reduction degree index, were determined. Optimal ratio of pellets and agglomerate in a blast furnace, which implementation contributes to improved furnace performance, was detected.

Abstract: In the shaft metallurgical units (blast furnace, Corex, Finex and Midrex installations) the powder is generated within the process with charge materials as its source or it is introduced into the unit within the process procedure. Accumulation of small particles inside the furnace is diversified and depends on the applied process procedure. Noticeable disruptions of the flow might occur at large degree of dustiness. The article presents the results of model investigation of gas flow resistance and the powder holdup during two-phase flow (gas + powder) through the descending packed bed. The aim of the research was to determine the conditions of the descending bed suspension in the following systems: sinter + coal powder and blast furnace pellets + coal powder. Air was used as a gas. The study results were the basis for defining the conditions in which bed suspension of the model systems occurs. It was found that in case of sinter + coal powder system the most intensive powder holdup in the bed occurs together with the optimal conditions for bed movement distortions.

Abstract: We have studied the influence of oxidation-reduction reactions on the structure and strength behavior of the Kachkanar fluxed pellets both in their initial condition and during reduction. It has been discovered that at heating rates and temperatures found in industrial units the roasted pellets that are not oxidized to a full extent and are characterized by zonal structure do not meet the requirements imposed for the blast-furnace smelting raw materials. To develop a process that would ensure high metallurgical properties, we have analyzed the hematite dissociation reaction. It was found that the temperature and the content of slag-forming oxides influence this reaction. A sinter pot was used to carry out the research and determine metallurgical properties of partially dissociated pellets. The obtained results helped to develop a process to dissociate hematite at lower temperatures with calcium ferrosilicate melt. Such pellets are reduced at the temperatures of over 700^оС, which prevents their destruction in blast furnaces.

Abstract: A mathematical model of the overall material and thermal balance of the ferromanganese smelting in blast furnaces of JSC "Satka Iron Smelting Works" is presented. Completeness of chemical reactions was taken into account in calculations based on thermodynamic analysis and technological data. Data on the thermochemical properties of substances; on the thermal effects of chemical reactions; on the degree of carbon graphitization in coke; on the heats of formation of metallic and slag solutions; on the thermochemical characteristics of ferromanganese, slag and gas phase were systematized and corrected. Heat losses for a particular type of blast furnaces are taken into account. The mathematical model is implemented in the computer program environment Lazarus. Test calculations of material and heat balances of ferromanganese blast furnace smelting were carried out. The calculation results correspond to the technological data. The developed software allows you to manage quickly the production process, to predict the optimal composition of charge materials for obtaining a product of a specific composition without experimental smelting. The software is used in the "consultant" mode at the JSC "Satka Iron Smelting Works".

Abstract: Daily average slag and the corresponding hot metal samples were collected from blast furnace No.3 (1033m³ useful volume) of the Egyptian Iron and Steel Company (EISCO) charged with 100% self- fluxing sinter over a period of two months (from July to August 2015). The analyses of slag and metal were used to investigate the effects of temperature and basicity, defined as CaO/SiO_2, on manganate capacity and manganese distribution between slag and metal.

Abstract: Improving thermal conductivity of carbon blocks is one of the most important developing trends for carbon blocks. In this work, artificial graphite and nickel nitrate catalyst were introduced into carbon blocks with an attempt to improve thermal conductivity of carbon blocks and their effect on microstructure and properties of carbon blocks were systematically studied by means of X ray diffraction (XRD), scanning electron microscopy (SEM) and laser thermal conductivity meter. The results revealed that artificial graphite possessed lower oxidation activation energy than electrically calcined anthracite, and thus, higher reactivity, which could accelerate the formation of SiC whiskers in carbon blocks and have a positive effect on thermal conductivity of carbon blocks. Moreover, it was interestingly noted that one dimensional nano-carbon was catalytically formed at 1000 °C and lots of Sialon phases were formed at 1400 °C when nickel nitrate catalyst was further added in carbon blocks containing artificial graphite. These in-situ ceramic phases formed in carbon blocks constructed high thermal conductive network and reduced the interface thermal resistance, thus improving the thermal conductivity of carbon blocks significantly.

Abstract: The problem of an assessment of the monitoring of lining condition in the Blast Furnace hearth during its campaign today has no unambiguous solution. Various techniques for the diagnostics have their own merits and demerits [1]. In this paper, characteristics of the diagnostic methods based on the measurements of temperatures in the lining, heat transfer of the cooling system and acoustic effects are considered. Various techniques can be combined and formulated into a uniform package of the strongest measures.

Abstract: This work reviews the issues of modeling of the operating modes for a blast furnace and identification of areas of unimprovable solutions on a set of indicators of cast iron output, coke consumption, and thermal state. These areas define the boundaries of potential opportunities for achieving high values of quality of the blast-furnace processes on a set of real-life operating modes of a blast furnace. They also indicate the reserves of coke consumption reduction and output enhancement, which might be implemented by optimal choice of a blast furnace operating mode and which enable the reasonable choice of the operating mode of a blast furnace based on the potential opportunities for increasing the output, minimizing coke consumption for the specified coke quality and the specified requirements to the furnace thermal state.