Synthesis of Pure Magnesium Aluminate Spinel (MgAl2O4) from Waste Aluminum Dross

ahmed, Benkhelif; Elkolli, Meriem

doi:10.1007/s12649-022-01677-1

Cited by 14 publications

(8 citation statements)

References 69 publications

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“…The transfer of mass from the particle boundaries to their necks caused sample shrinkage and the disappearance of pores. 31,32 After sintering at 1560 • C, a smaller grain size was observed, as shown in Figure 7(D). The pores between the particles significantly decreased in size with increasing sintering temperature.…”

Section: Microstructures Of Sintered Samplesmentioning

confidence: 83%

Effect of hollow spheres on the properties of lightweight periclase‐magnesium aluminate spinel refractories

Liu

Zhang

Wang

et al. 2023

Int J Applied Ceramic Tech

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This study presents new lightweight periclase-magnesium alumina spinel refractories for the working lining of cement rotary kilns in which magnesium alumina spinel hollow spheres are used to replace conventional dense fused magnesiaaluminate spinel aggregates. The effects of adding spinel hollow spheres on the physical properties, mechanical strength, thermal conductivity, and slag resistance of the samples were explored. The results showed that compared with the sample prepared with dense aggregates, the sample prepared with hollow spheres had a 10.3% higher cold compressive strength, 44.1% higher modulus of rupture (MOR), and lower bulk density. Additionally, with increasing hollow spheres content, the thermal conductivity decreased from 3.79 W/(m⋅K) to 2.53 W/(m⋅K), and the high-temperature MOR increased from 2.82 to 4.09 MPa. The highest residual strength ratio was 90.73% (15 wt.% hollow spheres), which is 1.17 times that of the sample prepared without hollow spheres. Moreover, microstructure and energy dispersive spectroscopy of crucible specimens after corrosion by cement clinker showed that specimens with 15 wt.% hollow sphere additions had a better slag resistance. Introducing hollow spheres reduced the thermal conductivity of the refractories, providing a new strategy for improving the heat insulation performance of kiln linings.

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Section: Microstructures Of Sintered Samplesmentioning

confidence: 83%

Effect of hollow spheres on the properties of lightweight periclase‐magnesium aluminate spinel refractories

Liu

Zhang

Wang

et al. 2023

Int J Applied Ceramic Tech

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“…96 Recently, a similar work of synthesis of pure MgAl 2 O 4 from waste aluminum dross by the combination of leaching, coprecipitation, and calcination methods was reported by Benkhelif and Kolli. 97 The aluminum dross was chemically leached using H 2 SO 4 solution followed by MgO powder addition (8 wt.%) and precipitation using NH 4 OH solution (pH level was maintained at 9), which upon calcination at 1450 • C led to microstructural transformations yielding almost completely pure spinel (>98%) with an average particle size of 550 nm. 97 Synthesis of spinel nanocrystallites by coprecipitation method was investigated by Viswanathan et al 98 using Mg(NO 3 ) 2 ⋅6H 2 O and Al(NO 3 ) 3 ⋅9H 2 O with ammonia as the precipitating agent.…”

Section: Synthesis Of Mas By Coprecipitation Routementioning

confidence: 99%

“…97 The aluminum dross was chemically leached using H 2 SO 4 solution followed by MgO powder addition (8 wt.%) and precipitation using NH 4 OH solution (pH level was maintained at 9), which upon calcination at 1450 • C led to microstructural transformations yielding almost completely pure spinel (>98%) with an average particle size of 550 nm. 97 Synthesis of spinel nanocrystallites by coprecipitation method was investigated by Viswanathan et al 98 using Mg(NO 3 ) 2 ⋅6H 2 O and Al(NO 3 ) 3 ⋅9H 2 O with ammonia as the precipitating agent. The spinel-forming precipitate precursor upon filtering, washing, and calcination at 600-1200 • C revealed complete spinel formation at 600 • C, and only spinel phase was observed until 1000 • C. However, at 1200 • C, there was a slight deviation from stoichiometry due to the presence of excess alumina due to exsolution (α-Al 2 O 3 ) along with spinel phase.…”

Section: Synthesis Of Mas By Coprecipitation Routementioning

confidence: 99%

“…The precipitates were then filtered off, washed, and dried for 48 h. Spinel phase was observed upon calcination at 600°C, whereas complete spinellization occurred at 1000°C/5 h with an average particle size of 17 nm 96 . Recently, a similar work of synthesis of pure MgAl 2 O 4 from waste aluminum dross by the combination of leaching, coprecipitation, and calcination methods was reported by Benkhelif and Kolli 97 . The aluminum dross was chemically leached using H 2 SO 4 solution followed by MgO powder addition (8 wt.%) and precipitation using NH 4 OH solution (pH level was maintained at 9), which upon calcination at 1450°C led to microstructural transformations yielding almost completely pure spinel (>98%) with an average particle size of 550 nm 97 .…”

Section: Introductionmentioning

confidence: 96%

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Synthesis of magnesium aluminate spinel—An overview

Baruah

Bhattacharyya

Sarkar

2023

Int J Applied Ceramic Tech

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Magnesium aluminate spinel (MAS) is a remarkable ceramic material known for its unique combination of beneficial properties. But due to volume expansion associated with spinel formation, and the high cost of production, MAS was not commercially successful till last century. However, environmental friendliness and superior properties have helped MAS to substitute magnesia-chrome refractories and are commercially acceptable with time. From an industrial perspective, solid-oxide reaction route or conventional oxide mixing route is the most popular method used for the synthesis of MAS. Although there have been myriad other common routes-coprecipitation, sol-gel, auto-ignition, molten technique, and so forth to produce spinel, solid-oxide reaction route is still the principal route from the industrial point of view owing to its ease of bulk production and low cost of production for refractory applications. This report attempts to accumulate the information on different synthesis techniques used for the synthesis of MAS for easy and ready reckoning.

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“…AlN is a kind of functional ceramic belonging to diamond nitride, which has excellent thermal, mechanical, and electrical properties, including high thermal conductivity (theoretical value 320 W/(m•K)), linear expansivity (4.8 × 10 −6 /K) comparable to silicon (Si), and outstanding electrical insulation (volume resistivity > 1012 Ω•m) [11]. The AlN in aluminum dross tends to be unstable overall due to its formation conditions, structural composition, and refinement difficulty [12]. Under wet or water-exposure conditions, it releases pungent ammonia gas, causing consequences such as imbalance in material performance and changes in solution pH during the utilization process [13].…”

Section: Introductionmentioning

confidence: 99%

Effects of Hydrolysis Parameters on AlN Content in Aluminum Dross and Multivariate Nonlinear Regression Analysis

Wang

et al. 2022

Coatings

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Aluminum dross, as a hazardous waste product, causes harm to the environment and humans, since the AlN it contains chemically reacts with water to produce ammonia. In the present study, a formula for modifying the AlN content in aluminum dross is proposed for the first time, by investigating the components of aluminum dross and changes in their respective contents during the hydrolysis process. Meanwhile, the effects of such hydrolysis parameters as time, temperature, and rotational speed on the hydrolysis rate of aluminum dross are explored. Furthermore, regression analysis is performed on the hydrolysis parameters and objective functions. The results show that as the reaction time increases, the variation in AlN content in aluminum dross decelerates gradually after modification. The hydrolysis rate is the fastest in the initial 4 h, which essentially stagnates after 20 h. The rise in temperature can significantly accelerate the AlN hydrolysis in aluminum dross, while the rotational speed has a non-obvious effect on the hydrolysis rate of AlN in aluminum dross. Regression analysis and secondary simplification are performed on the hydrolysis parameters and the modified AlN content, revealing that the relative error between the theoretical and experimental values is ≤ ±9.34%. The findings of this study have certain guiding significance for predicting and controlling modified AlN content in aluminum dross during hydrolysis.

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Synthesis of Pure Magnesium Aluminate Spinel (MgAl2O4) from Waste Aluminum Dross

Cited by 14 publications

References 69 publications

Effect of hollow spheres on the properties of lightweight periclase‐magnesium aluminate spinel refractories

Effect of hollow spheres on the properties of lightweight periclase‐magnesium aluminate spinel refractories

Synthesis of magnesium aluminate spinel—An overview

Effects of Hydrolysis Parameters on AlN Content in Aluminum Dross and Multivariate Nonlinear Regression Analysis

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