scholarly journals Use of magnesian fluxes of the Khalilovo deposit in sinter production

2019 ◽  
Vol 62 (7) ◽  
pp. 548-556
Author(s):  
A. N. Shapovalov ◽  
E. V. Ovchinnikova ◽  
V. B. Gorbunov

The article describes the magnesian fluxes properties of the Khalilovo deposit with different proportions of magnesite and serpentine. The results of laboratory experiments on the effect of these fluxes with various magnesite contents on the parameters of sintering process of the Kursk magnetic anomaly ores at JSC “Ural Steel” are presented. The use of experimental magnesian fluxes of the Khalilovo deposit increases the sinter strength, yield and sinter productivity. With the use of experimental fluxes instead of Bakal siderite, an increase in the sinter yield of 3  –  5  %  (rel.) can be reached. In addition, the sinter productivity increases from 1.04 to 1.08  –  1.15  t/(m2·h), that is, by 4  –  10  %  (rel.). The use of experimental magnesian fluxes increases the sinter strength: the tumbler index (+5  mm) increases by an average of 4  –  6  %  (abs.), and the abrasion index (–0.5  mm) decreases by 0.6  –  0.8  %  (abs.). Improving the strength characteristics of the sinter using magnesian fluxes of the Khalilovo deposit is due to the formation of “reinforcing” ferritic binder, as well as due to homogenization of the solidifying melt and its crystallization in the form of glass phase of the rankinite composition, which together limit the formation of β-Ca2SiO4 . The results of experimental sintering have confirmed the possibility of using experimental fluxes in the sintering production at sinter plant of JSC “Ural Steel” without changing the production technology. The rational variant for JSC “Ural Steel” is 50  % of magnesite of Khalilovo deposit in sinter rawmix. Replacement of the Bakal siderite in the production of sinter with 2  % of MgO on the magnesian flux of the Khalilovo deposit with 50  % of magnesite provides an increase in yield by 4  –  5  %, an increase in sinter strength by 5  –  6  % and an increase in sinter productivity by 8  –  10  % while keeping the iron content at the level of the “base” period.

Author(s):  
G. E. Isaenko ◽  
D. A. Kovalev ◽  
N. S. Meshcheryakov ◽  
V. G. Mikhailov ◽  
D. S. Kim

Effectiveness of blast furnaces operation in many respects depends on metallurgical properties of agglomerate, in particular, iron content in the sinter and its basicity. At the same time, it is accepted that usage of iron ore concentrates with iron content more than 66–67% for sinter production results in decreasing of its strength. As a result of the planned modernization of the technological sections of the concentration plant JSC “Stoilensky GOK”, iron content in the concentrate will be increased to 68–70%. It makes it actual to accomplish comprehensive studies of metallurgical properties of the sinter while increasing iron content in the raw material. Results of the study of sinter properties presented, the sinter being obtained with utilization of iron concentrate with iron content 66.6 % (base), 68.0 and 69.2 % (exp. 1 and exp. 2 correspondently). The iron ore mixture for all the stages was the same and consisted of iron ore concentrate – 78.3%, sintering ore – 8.0%, lime – 5.5% and sintering additives (sludge, dust, scale) – 8.2%. The sintering mixtures composition for all the study stages differed only by fluxes and iron ore mixture consumption. 18 test sintering operations at three values of basicity 1.6, 1.8 and 2.0 units were accomplished. It was established that increase of iron content in the concentrate and basicity of the sinter results in improving of the sintering process indices, increase of the vertical sintering rate, sintering machines productivity, recovery and the sinter cold strength. Increase of the sinter basicity and its production with increased content of iron results in improving RDI indices at low temperature reducing. Results of the study of porosity indices and metallurgical properties of the sinter presented, in particular the collapsibility during reducing and temperature interval softening-melting presented. The advisability of concentrate with increased iron content utilization in the iron ore mixture shown.


2015 ◽  
Vol 60 (4) ◽  
pp. 2895-2900 ◽  
Author(s):  
M. Fröhlichová ◽  
D. Ivanišin ◽  
A. Mašlejová ◽  
R. Findorák ◽  
J. Legemza

The work deals with examination of the influence of the ratio between iron ore concentrate and iron ore on quality of produced iron ore sinter. One of the possibilities to increase iron content in sinter is the modification of raw materials ratio, when iron ore materials are added into sintering mixture. If the ratio is in favor of iron ore sinter, iron content in resulting sintering mixture will be lower. If the ratio is in favor of iron ore concentrate and recycled materials, which is more finegrained, a proportion of a fraction under 0.5 mm will increase, charge permeability property will be reduced, sintering band performance will decrease and an occurrence of solid particulate matter in product of sintering process will rise. The sintering mixture permeability can be optimized by increase of fuel content in charge or increase of sinter charge moisture. A change in ratio between concentrate and iron ore has been experimentally studied. An influence of sintering mixture grain size composition, a charge grains shape on quality and phase composition on quality of the produced iron sinter has been studied.


2021 ◽  
Vol 1045 ◽  
pp. 17-31
Author(s):  
Lina Kieush ◽  
Andrii Koveria ◽  
Zuo Qiao Zhu ◽  
Maksym Boyko ◽  
Artem Sova ◽  
...  

The use of biomass as fuel might solve several technological and environmental issues and overcome certain challenges of sinter production. In particular, as revealed by comprehensive analyses, biomass can be used as fuel for iron ore sintering. In this study, we investigate the use of some raw and pyrolysis-processed biomass pellet types, namely wood, sunflower husks (SFH), and straw, for iron ore sintering. In the experiments, the pyrolysis temperature was set to 673, 873, 1073, and 1273 K, and the proportion of biomass in the fuel composition was set to 25%. It was established that the addition of biofuels to the sintering blend leads to an increase in the gas permeability of the sintered layer. The analysis of the complex characteristics of the sintering process and the sinter strength showed the high potential of wood and sunflower husk pellets pyrolyzed at 1073 and 873 K, respectively, for iron ore sintering. The analysis of the macrostructure of the sinter samples obtained using biomaterials revealed that with higher pyrolysis temperatures; the materials tend to have greater sizes and higher amounts of pores and cracks. The composition analyses of the resultant sinters revealed that with higher temperature, the FeO content of the sinters tends to increase.


2020 ◽  
Vol 867 ◽  
pp. 25-31
Author(s):  
Fakhreza Abdul ◽  
Sungging Pintowantoro ◽  
Ari Maulidani

The depletion of sulfide nickel ore and the growing of stainless steel demand each year cause the use of low-grade laterite nickel ore continues to increase. Due to very low nickel content, there is no optimal process to extract them. One of the alternative processes being developed now is the sintering-blast furnace process which produces Nickel Pig Iron (NPI). This research was conducted by sintering limonitic laterite nickel ore using charcoal as fuel and limestone as a flux. This research aims to analyze the effect of charcoal mass variation on Ni content, sinter strength, and the yield on the sintering process of limonitic laterite nickel ore. Charcoal and limestone demand calculated using energy balance and mass balance, then varied charcoal mass to feed material. Feed materials are fed in the furnace, heated at a temperature of 1200oC with 4 hours holding time. Next, the sinter yield was calculated. EDX, XRD, and Drop tests were also performed to determine Ni content, sinter compounds, and strength. The highest Ni content was 3.66% which was obtained by adding 9.9 kg charcoal. The highest sinter strength and yield also obtained by adding 9.9 kg charcoal (72.30% and 86.44%, respectively). Mayor phases which formed on sinter with 9.9 kg charcoal addition is nickel-iron oxide.


Author(s):  
Y. Kouh Simpson

It is well known that A1203 can reach near-theoretical density by a liquid-phase sintering process in which an amorphous glass phase containing SiO2, CaO and Al2O3 helps density Al2O3. Understanding the faceting behavior of Al2O3 in the presence of such a glass phase is important since the movement of the facets and the type of facets that form during the liquid-phase sintering process determine the final microstructure of the grain boundaries that ultimately control the properties of Al2O3 compacts. As a part of a larger study on the role of impurities in the sintering process of Al2O3 compacts, a new investigation has been carried out to examine the nature and the type (e.g. facet planes) of the crystalline Al2O3, / amorphous glass interface in systematic experiments in which densification aids such as SiO2, CaO and MgO are reacted with single crystal Al2O3. Substantial anisotropy, both from an energy consideration and a kinetics consideration, in the Al2O3/ glass interface is to be expected, and has been observed in this investigation.


2009 ◽  
Vol 147-149 ◽  
pp. 896-901
Author(s):  
Ahmet Atasoy ◽  
M. Tümer

In the present work, laboratory experiments were carried out on the sintering of silicone nitride powder without any sintering additives. Silicone nitride powder was produced at own laboratory conditions by carbothermal reduction-nitriding of silica of which was presented elsewhere. It consists of mainly -Si3N4 (83%) and -Si3N4 (17%) phases with a small amount of minor constituents. Before compaction procedure, the powder was ball milled for 2 h and then 2 gr. of the sample was compacted uniaxially at a pressure of 25 MPa. The green compact was placed into furnace in a graphite crucible. The sintering process was carried out in a programmable muffle furnace at 1700 °C and held for 1 h. with a 20 °C/min. heating rate. The sintered compacts were analyzed using X-ray, SEM, SEM-EDS techniques. The results showed that the formation of liquid phase can accelerate the densification of the compact. The densification of the pure SIALON can be increased by adding of sintering aids that accelerates the formation of liquid phases in the sample. The densified sialons give better hardness and thermal properties of the sample. It was well demonstrated that for the densification of sialons large amount of liquid phase forming oxides are needed to add to initial composition. It is also suggested that there is linear relationships between densification and amount of liquid phase formed in the compact.


2018 ◽  
Vol 115 (6) ◽  
pp. 604
Author(s):  
Xiao-zhe Wang ◽  
Dong-hui Liu ◽  
Jian-liang Zhang ◽  
Zheng-Jian Liu

The research status of the iron ore’s high temperature behaviors in the sintering process was reviewed in this paper. The influencing factors of the high temperature behaviors and their effects on the sinter performances were discussed, and the prospects of the optimization of ore proportioning based on the iron ores’ basic characteristics were also proposed. It is suggested that the melting behavior and infiltration behavior of the sintering liquid should be further investigated. Moreover, the limiting links of the sinter quality for different iron ores sintering should be analyzed by combining the basic characteristics and the production technology of the industrial sintering processes. Given priority to the low fuel ratio and the sinter quality, the complementary principles of the iron ores basic characteristics and mathematical models should be used in the optimization of ore proportioning.


2021 ◽  
Vol 72 (4) ◽  
pp. 2-14
Author(s):  
Marian Niesler ◽  
Janusz Stecko ◽  
Sławomir Stelmach

The article presents the results of tests carried out at Łukasiewicz – IMŻ, in cooperation with the Institute for Chemical Processing of Coal, on the use of biochar from coniferous wood as a substitute fuel in the iron ore sintering process. It was found that, considering productivity, fuel consumption and properties of the obtained sinter, the content of the tested biochar should not exceed 10 wt% in total fuel. When using the tested biochar, the content of FeO in the sinter decreased. The sinter was characterised by better ISO T strength than when using only coke breeze. At the same time, the grindability of the ISO A sinter decreased with the increase in the content of the biochar in the total fuel. The use of the tested biochar can have a very positive effect on both the sinter strength and its reducing properties.


2020 ◽  
Author(s):  
Baofu Qiu ◽  
Xiaoming Duan ◽  
Zhuo Zhang ◽  
Chen Zhao ◽  
Bo Niu ◽  
...  

Abstract BN/La-Al-Si-O composite ceramics were fabricated by hot-pressed sintering using h-BN, La2O3, Al2O3 and amorphous SiO2 as the raw materials. The effects of sintering temperature on the microstructural evolution, bulk density, apparent porosity, and mechanical properties of h-BN composite ceramics were investigated. The results indicated that La-Al-Si-O liquid phase was formed during sintering process, which provided an environment for the growth of h-BN grains. With increasing sintering temperature, the cristobalite phase precipitation and h-BN grain growth occurred at the same time, which had the significant influence on the densification and mechanical properties of h-BN composite ceramics. The best mechanical properties of BN/La-Al-Si-O composite ceramics were obtained under sintering temperature of 1700 °C, and the elastic modulus, flexural strength, and fracture toughness were 80.5 GPa, 266.4 MPa and 3.25 MPa·m1/2, respectively.


2021 ◽  
Vol 4 (1) ◽  
pp. 45-50
Author(s):  
Judit Pázmán ◽  
Jánosné Fehér ◽  
Viktor Gonda ◽  
Balázs Verő

Abstract Aluminum alloys en AW-8006 with three different Fe:Mn ratios were studied. In the experiments, the temperature of the intermediate soft-annealing between the cold rolling processes and the final soft-annealing at the end of the production technology were varied. The processed samples were subjected to tensile testing and hardness measurements. The effect of chemical composition, based on the test results, showed that for samples without intermediate softening, only the increase of iron content has a significant effect on the yield stress, and the change of iron content refined the final grain structure compared to the reference material.


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