Recycling of mullite from high-alumina coal fly ash by a mechanochemical activation method: Effect of particle size and mechanism research

Ji, Haiyan; Mi, Xue; Tian, Qiangkun; Liu, Chunli; Yao, Junxia; Ma, Shuhua; Zeng, Guisheng

doi:10.1016/j.scitotenv.2021.147100

Cited by 32 publications

(7 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Figure 1, there was a large amount of mullite and quartz phase in fly ash as raw material. And most of the mullite in fly ash existed in the form of acicular, short stick or particles 26 . But, elongated mullite was formed through the development of mullite according to SEM of the product in this study.…”

Section: Discussionmentioning

confidence: 66%

See 1 more Smart Citation

Preparation of high strength and low thermal conductivity mullite refractories based on reconstruction of fly ash

Wan

Sang

et al. 2022

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

The preparation of refractories with both low thermal conductivity and high strength are continuously pursued in industrial furnaces. In this work, mullite refractories with low thermal conductivity and high strength were developed using fly ash as main raw material, and the influence of the quantity of fly ash and sintering temperature on the structure and properties of mullite refractories were investigated. The results show that mullite refractories with low thermal conductivity and high strength could be prepared by using fly ash in large proportion; the thermal conductivity of the samples decreased with the addition of the fly ash and increased with the increase of sintering temperature; the cold compressive strength and modulus of rupture of samples all are enhanced with the increase of sintering temperature, which is attributed to the formation of more elongated mullite by the reconstruction of fly ash at high temperature. For the mullite refractory using 65.04 wt% fly ash treated at 1600 • C, the thermal conductivity was .732W/(m⋅k) at 1000 • C, and the cold compressive strength and modulus of rupture could reach 143.5 ± 5.7 MPa and 47.0 ± 4.1 MPa respectively. It can be considered to use as a prospective work lining in industrial furnaces to meet energy saving requirements.

show abstract

Section: Discussionmentioning

confidence: 66%

“…And most of the mullite in fly ash existed in the form of acicular, short stick or particles. 26 But, elongated mullite was formed through the development of mullite according to SEM of the product in this study.…”

Section: Discussionmentioning

confidence: 73%

Preparation of high strength and low thermal conductivity mullite refractories based on reconstruction of fly ash

Wan

Sang

et al. 2022

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

show abstract

“…There is also an economical way to extract mullite from fly ash. Ji et al 133 used mechanochemical activation-desiliconization process to remove the amorphous phase in high alumina fly ash (HAFA), which increased the mass ratio of Al 2 O 3 /SiO 2 and formed a mullite phase. HAFA is mainly composed of spherical particles.…”

Section: Mullite (Al 2 O 3 -Sio 2 ) Ceramic Powdermentioning

confidence: 99%

Mechanochemical synthesis of nanostructured and composite oxide ceramics: From mechanisms to tailored properties

Zhang,

Xu,

Zhang

et al. 2023

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

Mechanochemical synthesis is a technology formed in the 1950s. By applying mechanical energy, mechanochemical synthesis stimulates chemical reactions, causing structural and phase changes and enabling difficult or otherwise impossible reactions to occur. Mechanochemical reactions are relatively safe, clean and efficient. At present, the synthesis of oxide ceramic materials by mechanochemical methods has attracted widespread attention. In the production of oxide ceramic materials, the characteristics of ceramic powder have a certain influence on the molding, sintering, microstructure, and mechanical properties of subsequent ceramics. In this paper, the research progress of mechanical chemistry in the synthesis of nanostructures and composite oxide ceramic powders is reviewed. The effects of process parameters such as ball milling time, speed, atmosphere, grinding media, additives, and ball‐to‐powder ratio on reaction kinetics, phase formation, and powder properties are summarized. In addition, challenges and opportunities for ceramic powder synthesis are also discussed.

show abstract

“…High-alumina coal fly ash (HACFA), a characteristic secondary resource available in China, contains 40–50 wt% Al 2 O 3 and mainly consists of crystalline mullite, amorphous SiO 2 , and amorphous Al 2 O 3 . Mullite whiskers in HACFA are coated with amorphous SiO 2 and Al 2 O 3 , forming a core-shell structure [ 24 ]. Consequently, HACFA is a promising material for mullite support.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Oxidation Activity of NO over Mullite-Supported Amorphous Manganese Oxide Catalyst

et al. 2023

Self Cite

View full text Add to dashboard Cite

Nitric oxide (NO) can pose a severe threat to human health and the environment. Many catalytic materials that contain noble metals can oxidize NO into NO2. Therefore, the development of a low-cost, earth-abundant, and high-performance catalytic material is essential for NO removal. In this study, mullite whiskers on a micro-scale spherical aggregate support were obtained from high-alumina coal fly ash using an acid–alkali combined extraction method. Microspherical aggregates and Mn(NO3)2 were used as the catalyst support and the precursor, respectively. A mullite-supported amorphous manganese oxide (MSAMO) catalyst was prepared by impregnation and calcination at low temperatures, in which amorphous MnOx is evenly dispersed on the surface and inside of aggregated microsphere support. The MSAMO catalyst, with a hierarchical porous structure, exhibits high catalytic performance for the oxidation of NO. The MSAMO catalyst, with a 5 wt% MnOx loading, presented satisfactory NO catalytic oxidation activity at 250 °C, with an NO conversion rate as high as 88%. Manganese exists in a mixed-valence state in amorphous MnOx, and Mn4+ provides the main active sites. The lattice oxygen and chemisorbed oxygen in amorphous MnOx participate in the catalytic oxidation of NO into NO2. This study provides insights into the effectiveness of catalytic NO removal in practical industrial coal-fired boiler flue gas. The development of high-performance MSAMO catalysts represents an important step towards the production of low-cost, earth-abundant, and easily synthesized catalytic oxidation materials.

show abstract

Recycling of mullite from high-alumina coal fly ash by a mechanochemical activation method: Effect of particle size and mechanism research

Cited by 32 publications

References 37 publications

Preparation of high strength and low thermal conductivity mullite refractories based on reconstruction of fly ash

Preparation of high strength and low thermal conductivity mullite refractories based on reconstruction of fly ash

Mechanochemical synthesis of nanostructured and composite oxide ceramics: From mechanisms to tailored properties

Catalytic Oxidation Activity of NO over Mullite-Supported Amorphous Manganese Oxide Catalyst

Contact Info

Product

Resources

About