Effect of iron ore type on the thermal behaviour and kinetics of coal-iron ore briquettes during coking

Xu, Runsheng; Dai, Bowen; Wang, Wei; Schenk, Johannes; Xue, Zhengliang

doi:10.1016/j.fuproc.2018.01.006

Cited by 65 publications

(34 citation statements)

References 37 publications

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“…The obtained values of the activation energy are compared with the values from FWO and KAS methods, and the possible mechanism reaction for gasification is acquired. Moreover, the preexponential factor can be obtained by the intercept of Equations and …”

Section: Kinetic Modelsmentioning

confidence: 99%

Effect of pyrolysis temperature on pine sawdust chars and their gasification reactivity mechanism with CO₂

Wei

Liu

Ren

et al. 2018

Asia-Pacific J Chem Eng

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The mechanism on CO 2 gasification reactivity of pine sawdust chars (PS chars) obtained from the different pyrolysis temperatures (873, 973, and 1073 K) is studied on the basis of nonisothermal thermogravimetric method. The order of gasification reactivity is PS char-873 > PS char-973 > PS char-1073. The effect of pyrolysis temperature is depicted by microstructure characterization, and the gasification reactivity is analyzed with nonisothermal kinetic models. The microstructure characterizations of chars are characterized by scanning electron micrograph, Brunauer-Emmett-Teller, Fourier transform infrared, and X-ray diffraction. Results show that the microcrystalline structure of biomass char is the dominant factor for the effect of gasification reactivity with the pyrolysis temperature rising. The kinetic models of Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose are applied to describe the kinetics of gasification process.The average values of activation energy are in close agreement with the two methods. Both of the methods prove that F2 mechanism is applicable to the gasification of PS chars at lower pyrolysis temperature and F1 mechanism at higher pyrolysis temperature. Besides, there is a compensation effect between activation energy and preexponential factor in the CO 2 gasification process.

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Section: Kinetic Modelsmentioning

confidence: 99%

Effect of pyrolysis temperature on pine sawdust chars and their gasification reactivity mechanism with CO₂

Wei

Liu

Ren

et al. 2018

Asia-Pacific J Chem Eng

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“…The mass loss rate of samples sintered during reduction is a function of reaction time and temperature, and it can be expressed as [22,23]:…”

Section: Effect Of Sio 2 On the Mechanical Properties Of Calcium Ferritementioning

confidence: 99%

“…The apparent activation energy values of all samples are 167. 23 The relationship between reduction degree and reduction rate of powdered samples with different SiO2 content by non-isothermal thermal analysis is shown in Figure 4. It can be seen from Figure. 3 that when x was over 0.6, the reduction rate of sample 1 was much higher than that of sample 2, although the reduction temperature of sample 1 was lower than that of the rest of samples.…”

Section: Diffusion Modelsmentioning

confidence: 99%

Effect of SiO2 on the Mechanical Property and Reduction of Calcium Ferrite

Yang

Wang

et al. 2019

Metals

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SiO 2 -Fe 2 O 3 -CaO (SFC) is believed to be the transition phase during the SiO 2 -Fe 2 O 3 -CaO-Al 2 O 3 (SFCA) formation process. The effect of SiO 2 on the mechanical property and reduction of the CaO-Fe 2 O 3 -SiO 2 system was inspected in this study. Experiments were carried out under air at 1200 • C with different amounts of SiO 2 mixed with Fe 2 O 3 and CaO. The mechanical properties and reduction of samples were studied. Results indicate that the hardness of samples gradually increases with the increase of SFC content. That may be caused by SiO 2 solid solution in calcium ferrite. The larger the amount and smaller size of acicular calcium ferrites in samples, the greater the fracture toughness. The solid solution of SiO 2 in calcium ferrite is beneficial to decrease the initial reduction temperature. The apparent activation energy values of the samples with the different content of SiO 2 from 0% to 5% are 167. 23, 84.36, 87.90, 96.02, 92.44 and 107.83 kJ·mol −1 , respectively. The microstructure of lump samples after reduction consists of four phases, i.e., CF (CaFe 2 O 4 ), SFC, calcio-wüstite (CW) and Fe. It was not difficult to find the Fe in the samples reduced from CW. Scanning electron micrograph images have revealed that the acicular-like calcium ferrites are more easily reduced than the platy-like ones.

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“…One of the main factors that is easily overlooked is the high‐temperature ash melting characteristics of the PC, and the BF is a gasification shaft furnace equipment for liquid slagging. The blast temperature of the BF is up to 1250°C, and the temperature of the tuyere region is 1600‐1700°C, which has wide adaptability to the melting temperature of coal ash . However, when the ST of coal ash is lower than 1250°C, the PC is easily wrapped by molten ash during the combustion process, affecting the combustion efficiency of the PC, and even leading to slagging before the tuyere or injector.…”

Section: Introductionmentioning

confidence: 99%

Effect of coal blending on ash fusion behavior for blast furnace injection of high calcium bituminous coal

Zhang

Wang

et al. 2019

Energy Science & Engineering

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In order to expand the range of bituminous coal injected into blast furnace, the ash melting behavior and regulation mechanism of bituminous with high calcium and low ash fusion temperature (AFT) were investigated by coal blending. And the mineral transformation behavior in the blended ashes was investigated by X-ray powder diffractometry with normalized reference intensity ratio software and FactSage software. The experimental results manifest that the softening temperature (ST) of coal D is 8°C lower than that of the hot blast temperature. By adequately mixing coal B and coal D, it is easy to meet the requirements of pulverized coal injection.And coal D has become a standard bituminous for blast furnace injection. However, the high content of CaO in the coal S ash makes the AFT much lower than the hot blast temperature, which leads to the reluctance of the steel industry to inject coal S.With the increase of coal B mass ratio, the content of high-melting eutectic matters (3Al 2 O 3 ·2SiO 2 and tridymite) increases at high temperature, while the content of low-melting anorthite, andradite, gehlenite, and grossularite decreases, which leads to the increase of AFTs. The variation in the liquid phase under certain conditions reflects the change in AFT. In summary, by blending with coal B, the ST of blended coals S/B is higher than the hot blast temperature (1250°C), so that coal S can be applied to blast furnace injection. And the injection ratio of coal S in blended coals can reach about 50%. K E Y W O R D Sash fusion behavior, coal blending, high calcium bituminous, mineral transformation, thermal properties How to cite this article: Li Y, Zhang J, Wang G, Qiao J, Wang P, Liang W. Effect of coal blending on ash fusion behavior for blast furnace injection of high calcium bituminous coal. Energy Sci Eng.

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Effect of iron ore type on the thermal behaviour and kinetics of coal-iron ore briquettes during coking

Cited by 65 publications

References 37 publications

Effect of pyrolysis temperature on pine sawdust chars and their gasification reactivity mechanism with CO₂

Effect of pyrolysis temperature on pine sawdust chars and their gasification reactivity mechanism with CO₂

Effect of SiO2 on the Mechanical Property and Reduction of Calcium Ferrite

Effect of coal blending on ash fusion behavior for blast furnace injection of high calcium bituminous coal

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Effect of iron ore type on the thermal behaviour and kinetics of coal-iron ore briquettes during coking

Cited by 65 publications

References 37 publications

Effect of pyrolysis temperature on pine sawdust chars and their gasification reactivity mechanism with CO2

Effect of pyrolysis temperature on pine sawdust chars and their gasification reactivity mechanism with CO2

Effect of SiO2 on the Mechanical Property and Reduction of Calcium Ferrite

Effect of coal blending on ash fusion behavior for blast furnace injection of high calcium bituminous coal

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Product

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Effect of pyrolysis temperature on pine sawdust chars and their gasification reactivity mechanism with CO₂

Effect of pyrolysis temperature on pine sawdust chars and their gasification reactivity mechanism with CO₂