Fabrication of Macroporous SiC and SiC/C Monoliths from Arylene-Bridged Polysilsesquioxanes via Carbothermal Reduction

2012 ◽  
pp. 147-162
Author(s):  
George Hasegawa
Keyword(s):  
Carbothermal Reduction

Investigation of the products of carbothermal reduction of yttrium oxide by the hydrolysis method

1984 ◽  
Vol 49 (4) ◽  
pp. 936-943 ◽  
Author(s):  
Bohumil Hájek ◽  
Pavel Karen ◽  
Vlastimil Brožek
Keyword(s):  
Yttrium Oxide ◽  
Carbothermal Reduction ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrolysis Method ◽  
Sample Decomposition ◽  
Products Of Reaction ◽  
Hydrolysis Of ◽  
Lower Carbon

For the investigation of the products of reaction of yttrium oxide with carbon mixed in various proportions, the chemical and X-ray diffraction methods of analysis were combined with the gas chromatographic analysis of the mixture of hydrocarbons and hydrogen formed on the sample decomposition with water. The carboreduction of Y2O3 was examined at relatively low temperatures, convenient for obtaining the reaction intermediates in higher yields. At 1 600 °C and pressures of 10-3 Pa the reduction of a mixture of Y2O3 with carbon in a stoichiometric ratio of 1 : 7 yields YC2 in equilibrium with 20% of Y2OC phase. At lower carbon contents (down to the Y2O3 : C ratio of 1 : 2) tha fraction of the Y2OC phase increases up to approximately 30%. In addition to Y2O3, the reaction mixture contains also Y2C, Y2OC and a phase giving propyne on hydrolysis. The presence of traces of C3 hydrocarbons and small amounts of methane in the product of hydrolysis of the carbide sample prepared by the carbothermal reduction of the oxide can be explained in terms of the occurrence of the Y15C19 phase, probably substituted in part by oxygen, and of the Y2OC phase. The results are compared with those obtained previously for the Sc2O3 + C system.

Preparation of primary Al-Si alloy from bauxite tailings by carbothermal reduction process

2010 ◽  
Vol 20 (1) ◽  
pp. 147-152 ◽  
Author(s):  
Dong YANG ◽  
Nai-xiang FENG ◽  
Yao-wu WANG ◽  
Xiao-lei WU
Keyword(s):  
Carbothermal Reduction ◽  
Reduction Process ◽  
Bauxite Tailings

scholarly journals Feasibility of fly ash as fluxing agent in mid- and low-grade phosphate rock carbothermal reduction and its reaction kinetics

2021 ◽  
Vol 10 (1) ◽  
pp. 157-168
Author(s):  
Biwei Luo ◽  
Pengfei Li ◽  
Yan Li ◽  
Jun Ji ◽  
Dongsheng He ◽  
...  
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Reaction Time ◽  
Carbothermal Reduction ◽  
Industrial Waste ◽  
Phosphate Rock ◽  
Molar Ratio ◽  
Low Grade ◽  
Carbon Excess ◽  
Fluxing Agent

Abstract The feasibility of industrial waste fly ash as an alternative fluxing agent for silica in carbothermal reduction of medium-low-grade phosphate ore was studied in this paper. With a series of single-factor experiments, the reduction rate of phosphate rock under different reaction temperature, reaction time, particle size, carbon excess coefficient, and silicon–calcium molar ratio was investigated with silica and fly ash as fluxing agents. Higher reduction rates were obtained with fly ash fluxing instead of silica. The optimal conditions were derived as: reaction temperature 1,300°C, reaction time 75 min, particle size 48–75 µm, carbon excess coefficient 1.2, and silicon–calcium molar ratio 1.2. The optimized process condition was verified with other two different phosphate rocks and it was proved universally. The apparent kinetics analyses demonstrated that the activation energy of fly ash fluxing is reduced by 31.57 kJ/mol as compared with that of silica. The mechanism of better fluxing effect by fly ash may be ascribed to the fact that the products formed within fly ash increase the amount of liquid phase in the reaction system and promote reduction reaction. Preliminary feasibility about the recycling of industrial waste fly ash in thermal phosphoric acid industry was elucidated in the paper.

Influence of Mo addition on microstructure and mechanical properties of Ti(C,N)-based cermets fabricated by in-situ carbothermal reduction of TiO2

Vacuum ◽  
2021 ◽  
Vol 184 ◽  
pp. 109912
Author(s):  
Zhengkai Yang ◽  
Yong Zheng ◽  
Xiangyu Xu ◽  
Guotao Zhang ◽  
Zheng Ke ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbothermal Reduction ◽  
Microstructure And Mechanical Properties

scholarly journals Ultrafast carbothermal reduction of silica to silicon using a CO2 laser beam

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Seok-Ho Maeng ◽  
Hakju Lee ◽  
Min Soo Park ◽  
Suhyun Park ◽  
Jaeki Jeong ◽  
...  
Keyword(s):  
Carbon Black ◽  
Laser Beam ◽  
Carbothermal Reduction ◽  
Gas Flow ◽  
Crystalline Silicon ◽  
Reduction Process ◽  
Reaction Chamber ◽  
Raman Shift ◽  
Influence Of Process Parameters ◽  
Laser Beam Intensity

AbstractWe report the extraction of silicon via a carbothermal reduction process using a CO2 laser beam as a heat source. The surface of a mixture of silica and carbon black powder became brown after laser beam irradiation for a few tens of seconds, and clear peaks of crystalline silicon were observed by Raman shift measurements, confirming the successful carbothermal reduction of silica. The influence of process parameters, including the laser beam intensity, radiation time, nitrogen gas flow in a reaction chamber, and the molar ratios of silica/carbon black of the mixture, on the carbothermal reduction process is explained in detail.

Synthesis of high‐purity high‐entropy metal diboride powders by boro/carbothermal reduction

2019 ◽  
Vol 102 (12) ◽  
pp. 7071-7076 ◽  
Author(s):  
Da Liu ◽  
Honghua Liu ◽  
Shanshan Ning ◽  
Beilin Ye ◽  
Yanhui Chu
Keyword(s):  
High Purity ◽  
Carbothermal Reduction ◽  
High Entropy

scholarly journals Titanium Carbide Nanocrystals Synthesized from a Metatitanic Acid-Sucrose Precursor via a Carbothermal Reduction

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Hyunho Shin ◽  
Jun-Ho Eun
Keyword(s):  
Process Control ◽  
Titanium Carbide ◽  
Specific Surface ◽  
Surface Area ◽  
Pore Volume ◽  
Carbothermal Reduction ◽  
Crystal Size ◽  
Reduction Process ◽  
Specific Pore Volume ◽  
Metatitanic Acid

A TiC powder is synthesized from a micron-sized mesoporous metatitanic acid-sucrose precursor (precursor M) by a carbothermal reduction process. Control specimens are also prepared using a nanosized TiO2-sucrose precursor (precursor T) with a higher cost. When synthesized at 1500°C for 2 h in flowing Ar, the characteristics of the synthesized TiC from precursor M are similar to those of the counterpart from precursor T in terms of the crystal size (58.5 versus 57.4 nm), oxygen content (0.22 wt% versus 0.25 wt%), and representative sizes of mesopores: approximately 2.5 and 19.7–25.0 nm in both specimens. The most salient differences of the two specimens are found in the TiC from precursor M demonstrating (i) a higher crystallinity based on the distinctive doublet peaks in the high-two-theta XRD regime and (ii) a lower specific surface area (79.4 versus 94.8 m2/g) with a smaller specific pore volume (0.1 versus 0.2 cm3/g) than the counterpart from precursor T.

Effects of processing parameters on ultraviolet emission of In-doped ZnO nanodisks grown by carbothermal reduction

2007 ◽  
Vol 61 (8-9) ◽  
pp. 1767-1770 ◽  
Author(s):  
Po-Fan Lin ◽  
Chih-Yuan Ko ◽  
Wen-Tai Lin ◽  
C.T. Lee
Keyword(s):  
Carbothermal Reduction ◽  
Processing Parameters ◽  
Ultraviolet Emission ◽  
Doped Zno

Y2Si4N6C:Ce3+ carbidonitride green-yellow phosphors: novel synthesis, photoluminescence properties, and applications

2017 ◽  
Vol 5 (24) ◽  
pp. 6061-6070 ◽  
Author(s):  
Jieqiong Wan ◽  
Qian Liu ◽  
Guanghui Liu ◽  
Zhenzhen Zhou ◽  
Rong-Jun Xie
Keyword(s):  
Carbothermal Reduction ◽  
Photoluminescence Properties ◽  
Yellow Phosphor ◽  
Novel Synthesis

The carbidonitride Y2Si4N6C:Ce3+ green-yellow phosphor was synthesized via a novel acid-driven carbonization and carbothermal reduction nitridation method (ADC–CRN).

Preparation and Formation Mechanism of Elongated (Ca,Dy)-α-Sialon Powder via Carbothermal Reduction and Nitridation

2012 ◽  
Vol 95 (6) ◽  
pp. 1871-1877 ◽  
Author(s):  
Juntong Huang ◽  
Heping Zhou ◽  
Zhaohui Huang ◽  
Guanghua Liu ◽  
Minghao Fang ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Carbothermal Reduction ◽  
Sialon Powder
Sign in / Sign up

Export Citation Format

Share Document