scholarly journals Study of blast furnace heat filterability through coke filling

Author(s):  
A. Yu. Chernavin ◽  
V. A. Kobelev ◽  
D. A. Chernavin ◽  
G. A. Nechkin

Increase of gas permeability of burden materials column lower part is one of the way of blast furnace heat intensification. Filterability of intermediate slag through coke filling determines the gas permeability of the lower zone and the blast furnace heat running. To study the filterability a methodology was elaborated and implemented, which enabled to estimate reliably the iron ore raw materials behavior in the blast furnace at high temperatures. By laboratory studies influence on the filterability of BF slag melt was determined, when MgO, MnO and CaO adding to the burden, depending on the oxides mineralogical composition. The positive influence of magnesium oxide on the slag filterability has an extreme character, at that the sinter basicity has a considerable influence. The mineral form of magnesium-containing additives introduced into the burden substantially influenced the filterability on heat products in blast furnace. Replace ofsiderite and dolomite by other magnesium-containing materials facilitates to improving of slag filterability through coke filling. Additional input of manganese in the form of manganese limestone or manganese-containing ferritic-calcium flux is an effective mean to improve filterability of sinter smelting products through coke filling. Transfer to hot metal smelting from fluxed pellets and sinter will facilitate heat products filterabilityincrease thanks to close physical andchemical properties of BF burden components in respect of smelting and slag filtering through coke filling.

2018 ◽  
Vol 916 ◽  
pp. 179-183
Author(s):  
Vit Cerný ◽  
Jindrich Melichar ◽  
Jan Fleischhacker ◽  
Rostislav Drochytka

Autoclaved aerated concrete is an ecological building material with suitable properties and long-time tradition. The research of secondary raw materials usage and technology optimization is needed in order to increase the efficiency and sustainability of its production. It is important to focus on development of mineralogical composition while studying the influence of input materials and the parameters of hydrothermal synthesis on the properties of final product. This is especially important in case of tobermorite formation as the bearer of strength in the structure. Main focus of this paper is applicability of fly ash (silica component) and admixture of energo-gypsum (sulfate component) in production of lime-ash composite in hydrothermal conditions. The research was focused on autoclaving of samples at temperature of 170°C in three various isothermal sustains. Final samples were analyzed by XRD and SEM in order to proof the influence of input materials. Results show that 5% admixture of energo-gypsum had positive influence on tobermorite formation.


Author(s):  
D.A. Kassim ◽  
A.K. Tarakanov ◽  
V.P. Lyalyuk ◽  
P.I. Otorvin ◽  
A.A. Gusev

Purpose: Compare the results of blast furnace smelting efficiency, when chang-ing the qualitative characteristics of the sinter and coke, and the calculated param-eters of the blowing regime of melting. Methodology: Analysis of technical and economic performance of blast furnaces during periods of work on the agglomerate with different metallurgical characteris-tics and different diameter of the tuyeres. Findings: The experience of blast furnaces with a volume of 2,700 and 2,000 m3 confirmed a known fact of the dependence of furnace efficiency and coke consump-tion not only through the quality of charge materials, but also through the distribu-tion of the gas flow along the furnace section. Originality: The technological analysis of the results of the operation of blast furnaces with the volume of 2700 and 2000 m3 with a change of the quality of the sinter and pellets in combination with the change of the blowing regime parame-ters was performed. On the basis of the performed analysis, it was confirmed the expediency of increasing the gas permeability of the charge by improving the quali-ty of the raw materials while increasing the total mechanical energy of the com-bined gas-blast and hearth-gas, which are responsible for the length of the com-bustion zone and the depth of penetration of the gas flow to the center of the blast furnace. Practical value: Alternation of tuyeres of different diameters along with the im-provement of the quality characteristics of charge materials, additionally contrib-utes to the enhancement of the positive effect due to the expansion of the combus-tion zones in the furnace hearth. And if in this case the total mechanical energy of the mountain gas rises and the depth of penetration of the furnace gas to the fur-nace axis increases, the effect of using high-quality raw materials can be maxim-ized. Keywords: agglomerate, coke, blowing, tuyeres, gas permeability, quality, total energy.


2021 ◽  
Vol 900 (1) ◽  
pp. 012032
Author(s):  
R Papesch ◽  
K Macalova ◽  
J Charvat ◽  
T Dvorsky ◽  
V Vaclavik

Abstract The aim of the work is to find a suitable way of treatment of steel ladle slag for subsequent use as a partial replacement of the binder component in cement composites. The goal is based on the raw materials policy of the Czech Republic. Within this work is solved the issue of possible use of steel slag as the largest by-product of steel production. The work is focused on a specific ladle slag from ladle furnaces, by which are equipped the modern steel plants. Ladle slag is similar in chemical composition to Portland cement. However, its mineralogical composition should be taken into account in relation to its expansion reactions and lower hydraulic activity. One of the goals is the research of effect of particle size in cement-slag mixtures. The slag was ground for research on two different specific surfaces - coarsely in a vibrating mill and finely in a ball mill. The research within the experimental part of the work verified the positive influence of ladle slag on the properties of fresh and hardened mortar mixtures. Tensile bending strengths and compressive strengths are for some mixtures with ladle slag even higher than the strengths of the reference mixtures.


2020 ◽  
Vol 299 ◽  
pp. 681-686
Author(s):  
Boris Yur'ev ◽  
Vladimir A. Gol'tsev ◽  
Vyacheslav Dudko

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.


2019 ◽  
Vol 70 (11) ◽  
pp. 3835-3842
Author(s):  
Mihai Dumitru Tudor ◽  
Mircea Hritac ◽  
Nicolae Constantin ◽  
Mihai Butu ◽  
Valeriu Rucai ◽  
...  

Direct use of iron ores in blast furnaces, without prior sintering leads to a reduction in production costs and energy consumption [1,2]. Fine-grained iron ores and iron oxides from ferrous wastes can be used together with coal dust and limestone in mixed injection technology through the furnace tuyeres. In this paper are presented the results of experimental laboratory investigations for establishing the physic-chemical characteristics of fine materials (iron ore, limestone, pulverized coal) susceptible to be used for mixed injection in blast furnace. [1,4]. The results of the experimental research have shown that all the raw materials analyzed can be used for mixt injection in blast furnace.


Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 657
Author(s):  
José María Encinar ◽  
Juan Félix González ◽  
Sergio Nogales-Delgado

On account of the continuous decrease in oil reserves, as well as the promotion of sustainable policies, there is an increasing interest in biomass conversion processes, which imply the search for new raw materials as energy sources, like forestry and agricultural wastes. On the other hand, gasification seems to be a suitable thermal conversion process for this purpose. This work studied the thermogravimetry of the steam gasification of charcoal from heather (Calluna vulgaris) in order to determine the kinetics of the process under controlled reaction conditions. The variables studied were temperature (from 750 to 900 °C), steam partial pressure (from 0.26 to 0.82 atm), initial charcoal mass (from 50 to 106 mg), particle size (from 0.4 to 2.0 mm), N2 and steam volumetric flows (from 142 to 446 mL·min−1) and catalyst (K2CO3) concentration (from 0 to 10% w/w). The use of the shrinking core model and uniform conversion model allowed us to determine the kinetic parameters of the process. As a result, a positive influence of catalyst concentration was found up to 7.5% w/w. The kinetic study of the catalytic steam gasification showed activation energies of 99.5 and 114.8 kJ·mol−1 and order of reactions (for steam) of 1/2 and 2/3.


2014 ◽  
Vol 1052 ◽  
pp. 392-395 ◽  
Author(s):  
Li Xia He

High Ti-bearing blast furnace (BF) slag is the smelting waste of vanadium titano-magnetite. It has great production but low utilization. The high Ti-bearing BF slag is used in building materials industry, which recycles waste material, saves resources and energy, benefiting environmental protection and achieving sustainable development of resources. Study on the recycling of high Ti-bearing BF slag will be an important subject of our researches in future.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yasin Erdoğan

Handere clay deposits were discovered at Adana in Turkey. These clay units primarily consist of uncoloured claystone, pebbly sandstone, sandstone, siltstone, and mudstone marl and include gypsum lenses and clay levels of various thicknesses in places. The physicochemical properties of these clays have been investigated by different techniques including Scanning Electron and Elemental Analysis (SEM and EDS), mineralogical analyses, chemical and physical analyses, X-ray diffraction (XRD), thermogravimetric differential thermal analysis (TG-DTA), and Atterberg (Consistency) Limits Test. The mineralogical composition deduced from XRD is wide (smectite + palygorskite + illite ± feldspar ± chlorite ± quartz ± calcite ± serpentine) due to the high smectite contents (≈85%). SEM studies reveal that smectite minerals are composed of irregular platy leaves and show honeycomb pattern in the form of wavy leaves in places. The leaves presenting an array with surface edge contact are usually concentrated in the dissolution voids and fractures of volcanic glass. Organic matter content and loss on ignition analysis of raw materials are good for all the studied samples. In summary, Handere clays can be used as building materials in bricks, roof tiles, and cement and as a binder.


Author(s):  
I. F. Iskakov ◽  
G. A. Kunitsyn ◽  
D. V. Lazarev ◽  
А. А. Red`kin ◽  
S. A. Trubitsyn ◽  
...  

To use effectively internal raw material base, JSC “Ural Steel” accomplished I category major overhaul of the blast furnace No. 2. The main purpose of the overhaul was to design a rational profile which could ensure an ability to operate with a charge containing 95 % of Mikhailovskii GOK (mining and concentrating plant) pellets having basicity of 0.5 by CaO/SiO2. The blast furnace No. 2 having useful volume of 1232 m3, was constructed by design of Danieli Corus, the Netherlands, and was blown in on December 30, 2020. In the process of guarantee tests, step-by-step increase of Mikhailovskii GOK pellets (Fetotal = 60.5 %, CaO/SiO2 = 0.5) content in the charge iron ore part was being accomplished from 55 to 95.1%. Charging of the blend containing pellets in the amount of 55% of iron ore part, was done by charging system 4OOCC + 1COOCC (Ore - Coke) with filling level 1.5 m. Under conditions of pellets part increase in the blend, the charging system was changed to decrease their content at the periphery, to increase it in the ore ridge zone and make it intermediate between periphery and the ore ridge. At the pellets share in the iron ore raw materials 0.75 the charging system was used as the following: 3OOCC + 1COOC + 1COOCC, while at the content 95.1% the following charging system was used: 2COOC + 2COOC + 1COOCC. It was noted that in the period of guarantee tests the furnace running was smooth. The average silicon content in the hot metal was 0.70% at the standard deviation 0.666. Sulfur content in the hot metal did not exceed 0.024%, the blowing and natural gas consumption figures were 2100 m3/min and 11000 m3/min correspondently, oxygen content in the blowing 26.5%, hot blowing and top smoke pressure figures were 226.5 and 109.8 KPa correspondently. The productivity of the furnace was reached as high as 2358 t/day at the specific coke rate 433 kg/t of hot metal. After guarantee tests completion, the pellets content in the iron ore part was decreased gradually from 95 down to 50%. The decreasing was made by 5% in every 6 hours of operation. Application of the mastered technology of the blast furnace No. 2 with the increased share of pellets will enable to stably supply the blast furnaces No. 1, 3 and 4 by iron ore raw materials in the proportion of 30-35% of pellets and 65-70% of sinter.


2015 ◽  
Vol 51 (2) ◽  
pp. 143-151 ◽  
Author(s):  
K.X. Jiao ◽  
J.L. Zhang ◽  
Z.J. Liu ◽  
Y.G. Zhao ◽  
X.M. Hou

A type of carbon composite brick was produced via the microporous technique using natural flack graphite, ?-Al2O3 and high-quality bauxite chamotte (Al2O3?87 mass%) as raw materials with fine silicon powder as additive. The composition and microstructure of the obtained carbon composite were characterized using chemical analysis, XRD and SEM with EDS. The high temperature properties of thermal conductivity, oxidization and corrosion by molten slag and hot metal of the composite were analyzed. Based on these, the type of carbon composite brick worked in a blast furnace hearth for six years was further sampled at different positions. The protective layer was found and its chemical composition and microscopic morphology were investigated. It is found that the carbon composite brick combines the good properties of both the conventional carbon block and ceramic cup refractory. The protective layer near the hot face consists of two separated sublayers, i.e. the slag layer and the carbon layer. A certain amount of slag phase is contained in the carbon layer, which is caused by the reaction of coke ash with the refractory. No obvious change in the chemical composition of the protective layer along the depth of the sidewall is found. This work provides a useful guidance for the extension of the lifetime of blast furnace hearths.


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