In Situ Synthesis of β-Sialon Powder from Fly Ash

2011 ◽  
Vol 194-196 ◽  
pp. 2179-2182 ◽  
Author(s):  
Bei Yue Ma ◽  
Ying Li ◽  
Li Bing Xu ◽  
Yu Chun Zhai
Keyword(s):  
Fly Ash ◽  
Carbon Black ◽  
Carbothermal Reduction ◽  
Raw Materials ◽  
Reaction Process ◽  
Synthesis Process ◽  
Average Particle ◽  
Nitridation Reaction ◽  
Sialon Powder

β-Sialon powder was synthesized by in-situ carbothermal reduction-nitridation process, with fly ash and carbon black as raw materials. The influence of raw materials composition on synthesis process was investigated, and the phase composition and microstructure of the synthesized products were characterized by X-ray diffraction and scanning electronic microscope. The carbothermal reduction-nitridation reaction process was also discussed. It was found that increasing carbon content in a sample could promote the decomposition of mullite in fly ash and the formation of β-Sialon. The β-Sialon could be synthesized at 1550°C for 6h by heating the sample with the mass ratio of fly ash to carbon black of 100:56. The β-Sialon as-received in this study existed as granular with an average particle size of about 2μm. The carbothermal reduction-nitridation reaction process consisted of the nitridation processes of mullite, SiO2and Al2O3in fly ash as well as the conversion process of X-Sialon to β-Sialon.

Preparation of β-Sialon from Fly Ash by Carbothermal Reduction-Nitridation Reaction

2008 ◽  
Vol 368-372 ◽  
pp. 910-912 ◽  
Author(s):  
Jun Tong Huang ◽  
Ming Hao Fang ◽  
Yan Gai Liu ◽  
Zhao Hui Huang
Keyword(s):  
Fly Ash ◽  
Carbon Black ◽  
Carbon Content ◽  
Carbothermal Reduction ◽  
Single Phase ◽  
Raw Materials ◽  
Synthesis Mechanism ◽  
Nitridation Reaction

Single phase Sialon was synthesized successfully from fly ash by carbothermal reductionnitridation reaction in this paper. The effects of synthesizing temperature (1200°C, 1300°C, 1400°C and 1450°C) and carbon content (stoichiometric content, exceeding 10%, 50% and 100%) on the final production were studied by XRD and SEM. Synthesis mechanism of β-Sialon was also analysized. The results indicated that single phase β-Sialon with z=3 was obtained using fly ash as raw materials and carbon black of stoichiometric content as reducer by carbothermal reduction- nitridation reaction in flow nitrogen at 1450°C for 3h. Temperature and content of carbon had significant effect on the synthesis of β-Sialon.

scholarly journals Facile Preparation of Mesoporous MCM-48 Containing Silver Nanoparticles with Fly Ash as Raw Materials for CO Catalytic Oxidation

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 841
Author(s):  
Dong Tian ◽  
Yonghong Chen ◽  
Xiaoyong Lu ◽  
Yihan Ling ◽  
Bin Lin
Keyword(s):  
Silver Nanoparticles ◽  
Fly Ash ◽  
Co Oxidation ◽  
Surface Composition ◽  
Raw Materials ◽  
Silica Source ◽  
Co Conversion ◽  
Co Catalytic Oxidation ◽  
Adsorption Desorption

An environmentally friendly method was proposed to prepare mesoporous Mobil Composition of Matter No.48 (MCM-48) using fly ash as the silica source. Silver nanoparticles were infiltrated on MCM-48 facilely by an in situ post-reduction method and evaluated as an effective catalyst for CO oxidation. The as-prepared MCM-48 and Ag/MCM-48 nanoparticles were characterized by XRD, N2 adsorption/desorption, and TEM. Investigations by means of XPS for Ag/MCM-48 were performed in order to illuminate the surface composition of the samples. Studies revealed the strong influence of the loading of Ag nanoparticles on catalysts in the oxidation of CO. CO conversion values for Ag/MCM-48 of 10% and 100% were achieved at temperatures of 220 °C and 270 °C, respectively, indicating that the Ag-decorated MCM-48 catalyst is extremely active for CO oxidation.

Fabrication of Porous SiC/SiAlON Composites Using Semi Coke and Fly Ash as Raw Material

2012 ◽  
Vol 724 ◽  
pp. 347-350 ◽  
Author(s):  
Qing Wen Duan ◽  
Rong Zhen Liu ◽  
Hai Yun Jin ◽  
Jian Feng Yang ◽  
Zhi Hao Jin
Keyword(s):  
Fly Ash ◽  
Carbothermal Reduction ◽  
Pore Diameter ◽  
Reduction Method ◽  
Raw Materials ◽  
Nitrogen Atmosphere ◽  
Raw Material ◽  
Coke Content ◽  
Porous Sic ◽  
Median Pore

Porous SiC/SiAlON ceramics were fabricated by carbothermal reduction method from raw materials of fly ash and semi coke in nitrogen atmosphere. The results showed that composites were composed by multi-structure of SiC, Ca-SiAlON and AlN phases. With the increase of semi coke contents, the contents of Ca-Sialon increased. The fracture mode of this material was intergranular. The results also showed that micro area hereditary of semi coke particles was observed in the morphology of this material. The morphology of this material was composed by nanosized SiC and plate like Ca-SiAlON. The median pore diameter was affected by the contents of semi coke and increased with the increase of semi coke content.

A Review on Preparation of Non-Oxides Materials from Fly Ash

2012 ◽  
Vol 531 ◽  
pp. 280-283
Author(s):  
Bei Yue Ma ◽  
Bo Li ◽  
Yu Shi Ding ◽  
Chen Yan ◽  
Ying Li ◽  
...  
Keyword(s):  
Fly Ash ◽  
Carbothermal Reduction ◽  
Reduction Process

The latest development on preparation of SiC-AlN, SiC-mullite and β-Sialon materials using fly ash via in-situ carbothermal reduction process was reviewed. The synthesis mechanisms of SiC based materials and β-Sialon were also discussed.

Fabrication and Analysis of β-Sialon Whiskers from Fly Ash by Carbon Thermal Reduction-Nitridation

2015 ◽  
Vol 723 ◽  
pp. 610-614
Author(s):  
Jing Zhang ◽  
Jiang Long Yu ◽  
Huan Zhao ◽  
Jun Shuai Liu
Keyword(s):  
Fly Ash ◽  
Reaction Time ◽  
Carbon Content ◽  
Reaction Temperature ◽  
Carbothermal Reduction ◽  
Thermal Reduction ◽  
Optimal Temperature ◽  
Nitridation Process ◽  
Best Parameter ◽  
Sialon Powder

β-Sialonwhiskers which the molecular structuralformula of β-Sialonis Si3Al3O3N5(z = 3) were synthesized from fly ash and graphite under appropriate technological conditions by carbothermal reduction–nitridation process. The effects of carbon content, reaction temperature and reaction time on synthesis ofβ-Sialonwere analysed by XRD, SEM techniques. The results proved that, the condition of the carbon content over 80% is the best parameter to promote theβ-Sialon powder production. Compared to other kinds of temperature, 1430 °C is the optimal temperature to promoteβ-Sialon powder generation. Compared to 3h, holding time of 6h is promoting theβ-Sialon powder generation.The main morphology of β-Sialon was rod-like whisker.

Preparation of TiB2 Ultrafine Powders by Carbothermal Reduction

2016 ◽  
Vol 697 ◽  
pp. 58-61
Author(s):  
Jin Cheng Yu ◽  
Li Ma ◽  
Yu Jun Zhang ◽  
Hong Yu Gong ◽  
Li Wei Zhou
Keyword(s):  
Carbon Black ◽  
Carbothermal Reduction ◽  
Reduction Method ◽  
Raw Materials ◽  
Structural Evolution ◽  
Holding Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Boron Source ◽  
Different Content

TiO2, B2O3, H3BO3, B4C and carbon black were used as the raw materials to prepare TiB2 powders by carbothermal reduction method. The influence of different content of carbon black (13.6~14.8 wt%) on products was discussed. The effects of different boron sources and holding time (10~50 min) on the microstructure of TiB2 powders were also investigated. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to study the phase composition and structural evolution of the powder. The final results showed that hexagonal TiB2 crystal grain could be successfully synthesized without impurities when heated at 1700°C for 30 min in Ar atmosphere with the addition of 14.1 wt% carbon black. Submicrometric TiB2 powders range from 0.5 to 1.0 μm could be obtained when B4C was used as the boron source. The increase in holding time contributed to the grain growth and completion of chemical reactions, but could also result in oversintering.

scholarly journals Synthesis of .BETA.-SiAlON Powder by Carbothermal Reduction and Nitridation(3). Reaction Process of .BETA.-SiAlON (Z=3).

1994 ◽  
Vol 41 (2) ◽  
pp. 188-192
Author(s):  
Chitake Yamagishi ◽  
Keizou Tsukamoto ◽  
Tatsuya Shiogai ◽  
Mutsuo Hayashi ◽  
Takayoshi Iseki
Keyword(s):  
Carbothermal Reduction ◽  
Reaction Process ◽  
Sialon Powder

scholarly journals In situ controlled rapid growth of novel high activity TiB2/(TiB2–TiN) hierarchical/heterostructured nanocomposites

2017 ◽  
Vol 8 ◽  
pp. 2116-2125 ◽  
Author(s):  
Jilin Wang ◽  
Hejie Liao ◽  
Yuchun Ji ◽  
Fei Long ◽  
Yunle Gu ◽  
...  
Keyword(s):  
High Activity ◽  
Raw Materials ◽  
Average Particle Size ◽  
Particle Surface ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transition Electron Microscopy ◽  
Reaction Coupling

In this work, a reaction coupling self-propagating high-temperature synthesis (RC-SHS) method was developed for the in situ controlled synthesis of novel, high activity TiB2/(TiB2–TiN) hierarchical/heterostructured nanocomposites using TiO2, Mg, B2O3, KBH4 and NH4NO3 as raw materials. The as-synthesized samples were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray energy dispersive spectroscopy (EDX), transition electron microscopy (TEM), high-resolution TEM (HRTEM) and selected-area electron diffraction (SAED). The obtained TiB2/TiN hierarchical/heterostructured nanocomposites demonstrated an average particle size of 100–500 nm, and every particle surface was covered by many multibranched, tapered nanorods with diameters in the range of 10–40 nm and lengths of 50–200 nm. In addition, the tapered nanorod presents a rough surface with abundant exposed atoms. The internal and external components of the nanorods were TiB2 and TiN, respectively. Additionally, a thermogravimetric and differential scanning calorimetry analyzer (TG-DSC) comparison analysis indicated that the as-synthesized samples presented better chemical activity than that of commercial TiB2 powders. Finally, the possible chemical reactions as well as the proposed growth mechanism of the TiB2/(TiB2–TiN) hierarchical/heterostructured nanocomposites were further discussed.

Minimum Particle Diameter of the Sulfur-Doped Nano-TiO2 Transparent Hydrosol at Room Temperature

2014 ◽  
Vol 587-589 ◽  
pp. 788-791
Author(s):  
Ling Li ◽  
Hua Yan Zhang ◽  
Xiao Wei Li ◽  
Zi Hao Xu ◽  
Sen Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Room Temperature ◽  
Photocatalytic Performance ◽  
Raw Materials ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Synthesis Process ◽  
Average Particle ◽  
Hydrolysis Method ◽  
Particle Size Analyzer

Sulfur-doped nanoTiO2transparent hydrosol with an average particle size of 3.8 nm was synthesized by a novel complexation-controlled hydrolysis method at room temperature and atmospheric pressure by using TiCl4, thiourea, organic carboxylic acid, NH3H2O, D-sorbitol etc. as raw materials. The composition, phase structure, particle size, absorbance spectrum, and photocatalytic performance of samples were characterized by XRD, nanolaser particle size analyzer, ultraviolet-visible spectrophotometer. In addition, the influence of reaction conditions in the synthesis process was also studied. The results indicate that when nanoparticle doped with 0.5% S, and the reflux time was 15 min, the photocatalytic performance of sulfur-doped TiO2hydrosol was best.

The Process Research on VN-Making which Deploy Vanadium Pentoxide Powder, Graphite and Carbon Black in the Lab

2013 ◽  
Vol 668 ◽  
pp. 115-119
Author(s):  
An Gang Ning ◽  
Hua Nan Ding ◽  
Jian Jun Ma ◽  
Han Jie Guo
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Carbon Black ◽  
Vanadium Pentoxide ◽  
Raw Materials ◽  
Process Research ◽  
Reaction Process ◽  
Particle Sizes

This paragraph deploys high temperature non-vacuum methods, and vanadium pentoxide powder, carbon black and graphite is used to make VN. The result shows that the particle sizes of these three raw materials vary greatly. When they are mixed with a certain proportion, the kinetics condition of reaction is greatly improved. when the vanadium pentoxide powder enters agglomeration level(1490°C) after it has been reduced and nitrided, agglomeration time has small effect on the reaction process and chemical composition of product. On the contrary，if the agglomeration time lasts too long, it will generate VC. Therefore, the agglomeration time can be reduced to 2~4 hours.

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