Effect of citric acid on the hydration process of colloidal silica-bonded magnesia gunning materials

Cai, Manfei; Liang, Yonghe; Yin, Yansheng; Nie, Jianhua

doi:10.1016/j.ceramint.2019.05.055

Cited by 8 publications

(3 citation statements)

References 30 publications

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“…Magnesia refractory is widely used in key parts such as the converter, ladle and tundish, which are of great significance for smelting clean steel [ 1 , 2 , 3 , 4 , 5 ]. However, the hydration of magnesium oxide can cause cracks due to the density mismatch between magnesium oxide (ρ = 3.5 g/cm 3 ) and its hydroxide (ρ = 2.4 g/cm 3 ), which damages the integrity of the material and limits its industrial application as a refractory material [ 6 ]. At present, the mechanism of the hydration of MgO at the molecular level is still not clear, which restricts the solutions to the hydration problem of MgO [ 7 , 8 , 9 , 10 , 11 ].…”

Section: Introductionmentioning

confidence: 99%

A First-Principles Study on the Hydration Behavior of (MgO)n Clusters and the Effect Mechanism of Anti-Hydration Agents

et al. 2022

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Magnesia-based refractory is widely used in high-temperature industries; its easy hydration is, however, a key concern in refractory processing. Understanding the hydration mechanism of MgO will help in solving its hydration problem. Herein, the hydration behavior of (MgO)n (n = 1–6) at the molecular level and the effect mechanisms of several anti-hydration agents on the hydration of (MgO)4 were investigated with first-principles calculations. The results indicated that the following: (1) The smaller the (MgO)n cluster size, the more favorable the hydration of MgO and the tendency to convert into Mg(OH)2 crystal; (2) Anti-hydration agents can coordinate with the unsaturated Mg atom of (MgO)4 to form a bond, increasing the coordination number of Mg, thus reducing its activity when reacting with H2O; (3) The greater the number of −COOH groups and the longer the chain length in the anti-hydration agents, the better its effect of inhibiting the hydration of MgO. These findings could enhance the understanding of the mechanism of hydration of MgO and provide theoretical guidance for the design of novel anti-hydration agents.

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Section: Introductionmentioning

confidence: 99%

A First-Principles Study on the Hydration Behavior of (MgO)n Clusters and the Effect Mechanism of Anti-Hydration Agents

et al. 2022

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“…15,16 However, the hydration reaction of MgO and the resultant gelatinization is too fast in alkaline media at room temperature; thus, acidic media are often used to suppress the hydration reaction of MgO. 17,18 To lower chemical reactivity of MgO and ensure the flowability of aqueous Al 2 O 3 suspensions with MgO addition in alkaline media, in the present work, MgO was pre-calcined at 800 • C for 2 h and then used as a gelling and consolidating agent; thus, the hydration reaction of the calcined MgO in alkaline media could be effectively regulated and hardly affects the viscosity of the Al 2 O 3 -MgO-water suspension at room temperature. Furthermore, MgO addition can significantly suppress the abnormal growth of Al 2 O 3 grains during sintering and thus improve microstructure and mechanical strength of Al 2 O 3 ceramics.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, MgO, a cementitious material, could undergo hydration reaction and produce magnesium hydroxide (Mg(OH) 2 ) 15,16 . However, the hydration reaction of MgO and the resultant gelatinization is too fast in alkaline media at room temperature; thus, acidic media are often used to suppress the hydration reaction of MgO 17,18 . To lower chemical reactivity of MgO and ensure the flowability of aqueous Al 2 O 3 suspensions with MgO addition in alkaline media, in the present work, MgO was pre‐calcined at 800°C for 2 h and then used as a gelling and consolidating agent; thus, the hydration reaction of the calcined MgO in alkaline media could be effectively regulated and hardly affects the viscosity of the Al 2 O 3 –MgO–water suspension at room temperature.…”

Section: Introductionmentioning

confidence: 99%

Preparation and properties of porous Al₂O₃‐based ceramics by gel casting using MgO as a gelling and consolidating agent

Piao

Tang

et al. 2022

Int J Applied Ceramic Tech

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Low-cost and environment-friendly MgO was used as a new gelling and consolidating agent to fabricate porous Al 2 O 3 -based ceramics via a gel casting routine. Effects of 800 • C calcined additions of MgO (.5, 1.0, 1.5, and 2.0 wt%, respectively) on open porosity (OP), pore size distribution, gas flux, and microstructure of the porous ceramics were investigated deliberately. The experimental results showed that 800 • C calcined MgO exhibits excellent gelling and consolidating performance at 80 • C, mainly owing to the hydration reaction between MgO and H 2 O and thus results in high-quality porous Al 2 O 3 -based ceramics without deformation and cracking. The Al 2 O 3 -water suspensions with different MgO additions have good flowability at room temperature. Moreover, water absorption, open porosity, and gas flux of the as-prepared porous ceramics increase remarkably with rising of MgO addition. Furthermore, MgO addition significantly suppresses the abnormal growth of Al 2 O 3 grains, and thus the microstructure of the porous Al 2 O 3 -based ceramics becomes more uniform. This technique of gel casting using MgO as a new gelling and consolidating agent offers an alternative routine for a large-scale production of porous ceramics.

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3D Printed nanocomposite optical ceramics with temperature-resistant high infrared transmittance

Wang,

Fan,

et al. 2024

Additive Manufacturing

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Effect of citric acid on the hydration process of colloidal silica-bonded magnesia gunning materials

Cited by 8 publications

References 30 publications

A First-Principles Study on the Hydration Behavior of (MgO)n Clusters and the Effect Mechanism of Anti-Hydration Agents

A First-Principles Study on the Hydration Behavior of (MgO)n Clusters and the Effect Mechanism of Anti-Hydration Agents

Preparation and properties of porous Al₂O₃‐based ceramics by gel casting using MgO as a gelling and consolidating agent

3D Printed nanocomposite optical ceramics with temperature-resistant high infrared transmittance

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Effect of citric acid on the hydration process of colloidal silica-bonded magnesia gunning materials

Cited by 8 publications

References 30 publications

A First-Principles Study on the Hydration Behavior of (MgO)n Clusters and the Effect Mechanism of Anti-Hydration Agents

A First-Principles Study on the Hydration Behavior of (MgO)n Clusters and the Effect Mechanism of Anti-Hydration Agents

Preparation and properties of porous Al2O3‐based ceramics by gel casting using MgO as a gelling and consolidating agent

3D Printed nanocomposite optical ceramics with temperature-resistant high infrared transmittance

Contact Info

Product

Resources

About

Preparation and properties of porous Al₂O₃‐based ceramics by gel casting using MgO as a gelling and consolidating agent