Effects of particle distribution of matrix on microstructure and slag resistance of lightweight Al 2 O 3 –MgO castables

Yang, Zhenliang; Huang, Ao; Gu, Huazhi; Zhang, Mei‐Jie; Lian, Pengfei

doi:10.1016/j.ceramint.2015.09.167

Cited by 24 publications

(22 citation statements)

References 15 publications

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“…On the other hand, care should be taken not to use more micropowders in castables, as this can also cause dilatancy that affects the green strength, and at higher temperatures (during sintering), it can cause larger pores and microcracks on the boundaries between the aggregates and matrix. It is clear that these microcracks are due to the separation of fine powders from the aggregates due to excess shrinkage [17,41,42]. Otroj and Daghighi [40] reported that small-diameter particles (<100 μm) with large specific surface areas (>1 m 2 /g) play an important role in bonding systems, in which adding nanoalumina particles results in the production of refractory castables with lower porosity and smaller pore sizes leading to higher strength.…”

Section: Particle Size Distributionmentioning

confidence: 99%

Reasons for crack propagation and strength loss in refractory castables based on changes in their chemical compositions and micromorphologies with heating: special focus on the large blocks

Kazemi

2019

Journal of Asian Ceramic Societies

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Section: Particle Size Distributionmentioning

confidence: 99%

Reasons for crack propagation and strength loss in refractory castables based on changes in their chemical compositions and micromorphologies with heating: special focus on the large blocks

Kazemi

2019

Journal of Asian Ceramic Societies

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“…To address this issue, recent studies have shown that the thermal conductivities of refractories can be reduced by using microporous aggregates instead of dense aggregates. [12][13][14][15][16][17][18][19][20][21] For example, a new lightweight periclase-spinel refractory was prepared by using microporous aggregates instead of dense aggregates, and the thermal conductivity was reduced by 18.8% at 1000°C. 13 Therefore, it is of great significance to develop microporous MgO-Al 2 O 3 refractory…”

Section: Introductionmentioning

confidence: 99%

Microstructures and strengths of microporous MgO‐Al₂O₃ refractory aggregates using two types of magnesite

Chen

Yan

Dai

et al. 2020

Int J Applied Ceramic Tech

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Six microporous MgO-Al 2 O 3 refractory aggregates were prepared with Al(OH) 3 and two different types of magnesite powders via an in-situ decomposition pore-forming technique. One magnesite powder contained more CaO (Magnesite C), the other one contained more SiO 2 and Al 2 O 3 impurities (Magnesite SA). Effects of magnesite powder type and content (11 wt.%, 36 wt.% and 77 wt.%) on the phase compositions, microstructures and mechanical strengths of the prepared microporous aggregates were investigated by X-ray diffractometry (XRD), mercury porosimetry measurements, and scanning electron microscopy (SEM), etc. With the addition of 11 wt.% and 77 wt.% magnesite, the type of magnesite had only a small effect on the microporous corundum-spinel and periclase-spinel aggregates, while great influence on the microporous spinel aggregates was observed with 36 wt.% addition. This was mainly because of the sintering process with liquid phase. The best microporous MgO-Al 2 O 3 refractory aggregates, which had an apparent porosity of 39.1%, a median pore size of 3.38 μm and a compressive strength of 66.3 MPa, were prepared by using 36 wt.% Magnesite C. This work has practical significance for the efficient utilization of magnesite and the development of energy-saving lightweight MgO-Al 2 O 3 refractories. K E Y W O R D S in-situ decomposition pore-forming technique, magnesite powders, microporous MgO-Al 2 O 3 refractory aggregates, microstructures, properties Department of Education's Scientific Research Plan (Grant No. D20181106) for financially supporting this work.

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“…The introduction of pores can reduce the thermal expansion and shrinkage during the temperature changes, enhancing the thermal spalling resistance of the lining materials. Generally, lightweight refractories with low thermal conductivity coefficient, good thermal‐shock, and corrosion resistance are composed of microporous aggregates with apparent porosity of up to 45% 3,4 . During the service process of high temperature industrial furnaces, the lining refractories with low thermal conductivity show a better thermal insulation performance in furnace 5,6 …”

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of microporous magnesia‐based refractory

Hou

Luo

Xie

et al. 2020

Int J Applied Ceramic Tech

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In recent years, there was a huge demand for basic lightweight insulation materials in the metallurgical industry, especially magnesia‐based refractories with low thermal conductivity. Therefore, the preparation of microporous magnesia‐based refractory products through the synthesis of lightweight aggregate and the different grain compositions to meet the supply of light basic refractories is discussed in this paper. The microstructure, pore size distribution, phase composition, coefficient of thermal expansion, thermal conductivity and sintering properties of the microporous magnesia‐based refractory products sintered at 1600°C were characterized. The results indicated that the original salt pseudomorph produced by the thermal decomposition of magnesite fine powder (porogenic agent) provides a uniform microporous structure for the synthesis of lightweight aggregates. The microporous morphology of the periclase phase was controlled by adjusting the content of the porogenic agent. The average pore size of microporous magnesia‐based refractory ranged from 1.5 to 4.2 μm, and the apparent porosity increased from 29.88% to 32.46%. In the same time, the thermal conductivity increased from 0.037 to 0.217 W/(m K), indicating that the introduction of homologous porogenic agents could produce lightweight alkaline refractories with high porosity and low thermal conductivity.

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Effects of particle distribution of matrix on microstructure and slag resistance of lightweight Al 2 O 3 –MgO castables

Cited by 24 publications

References 15 publications

Reasons for crack propagation and strength loss in refractory castables based on changes in their chemical compositions and micromorphologies with heating: special focus on the large blocks

Reasons for crack propagation and strength loss in refractory castables based on changes in their chemical compositions and micromorphologies with heating: special focus on the large blocks

Microstructures and strengths of microporous MgO‐Al₂O₃ refractory aggregates using two types of magnesite

Preparation and characterization of microporous magnesia‐based refractory

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Effects of particle distribution of matrix on microstructure and slag resistance of lightweight Al 2 O 3 –MgO castables

Cited by 24 publications

References 15 publications

Reasons for crack propagation and strength loss in refractory castables based on changes in their chemical compositions and micromorphologies with heating: special focus on the large blocks

Reasons for crack propagation and strength loss in refractory castables based on changes in their chemical compositions and micromorphologies with heating: special focus on the large blocks

Microstructures and strengths of microporous MgO‐Al2O3 refractory aggregates using two types of magnesite

Preparation and characterization of microporous magnesia‐based refractory

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Microstructures and strengths of microporous MgO‐Al₂O₃ refractory aggregates using two types of magnesite