Effects of CaO Additives on the Phase Evolution of ZrO2-SiC Composites from Zircon by Carbothermal Reduction

2014 ◽  
Vol 602-603 ◽  
pp. 105-109
Author(s):  
Ze Lin Wu ◽  
Ming Hao Fang ◽  
Zhao Hui Huang ◽  
Yan Gai Liu ◽  
You Guo Xu ◽  
...  
Keyword(s):  
Phase Composition ◽  
Composite Materials ◽  
Carbothermal Reduction ◽  
Reduction Process ◽  
Phase Evolution ◽  
Synthesis Temperature ◽  
Raw Material ◽  
Natural Zircon ◽  
Synthetic Temperature ◽  
Sic Composites

In this study, Ca2+ stabilized ZrO2-SiC composite materials were prepared via carbothermal reduction, using natural zircon ore as raw material, CaO as additive, and black carbon as the reducing agent. The effects of synthesis temperature and CaO content on the phase composition of the products were investigated by XRD. The microstructure and micro-area chemical analysis of the products were characterized by SEM and EDS. The results indicate that: (1) Ca2+ stabilized ZrO2-SiC composite materials could be prepared from natural zircon ore with CaO addition between 1500°C and 1600°C for 4 hours by carbothermal reduction process. (2) The synthetic temperature has an important influence on the phase composition of the carbothermal reduction products of zircon. The production of m-ZrO2 and t-ZrO2 got obviously enhanced with increasing temperature from 1500°C to 1600°C. (3) At the same synthetic temperature, Ca2+ stabilized ZrO2 got enhanced with increasing adding amount of CaO. The optimized synthesis condition of Ca2+ stabilized cubic-ZrO2/SiC composite materials is sintering at 1600°C for 4 hours with adding 40 mol% CaO as additive.

Synthesis of Ti(C,N) Powder via CRN Method from Rutile/Carbon Mixtures

2012 ◽  
Vol 512-515 ◽  
pp. 32-35
Author(s):  
Kai Chen ◽  
Zhao Hui Huang ◽  
Ming Hao Fang ◽  
Yan Gai Liu ◽  
Xin Ouyang
Keyword(s):  
Reaction Temperature ◽  
Carbothermal Reduction ◽  
Phase Evolution ◽  
Nitrogen Pressure ◽  
Synthesis Temperature ◽  
Granular Structure ◽  
Raw Material ◽  
Molar Ratio ◽  
Tin Content ◽  
N Powder

Ti(C,N) powder was prepared via carbothermal reduction nitridation (CRN) using rutile and carbon black as the raw material. The phase evolution and the reaction mechanism during the CRN synthesis of Ti(C,N) were investigated, and the effect of reaction temperature and C/TiO2molar ratio on the phase composition and x value in TiC1–xNxwas analyzed. The XRD and SEM results show that: Ti(C,N) powder was synthesized at 1500°C for 4h with the C/TiO2molar ratio of 2.2, under the nitrogen pressure of 0.2MPa. Irregular granular structure and the growth stripes were observed in the final products. The growth of Ti(C,N) grains in CRN process was followed by the gas-solid mechanism.The phase compositions of the products were quite dependent on the reaction temperature and the C/TiO2molar ratio. The TiN content in Ti(C,N) decreased with the increase of reaction temperature. TiC1–xNxpowder with different x values can be synthesized by optimizing the experiment conditions including the synthesis temperature and the C/TiO2molar ratio.

Preparation of Sialon/Si3N4-SiC Composite Refractories Using Kyanite Tailings

2016 ◽  
Vol 697 ◽  
pp. 467-471 ◽  
Author(s):  
Ming Hao Fang ◽  
Zhao Hui Huang ◽  
Yan Gai Liu ◽  
Xin Min ◽  
Li Na Zhang
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Cross Section ◽  
Compression Strength ◽  
Carbothermal Reduction ◽  
Bending Strength ◽  
Synthesis Temperature ◽  
Composite Powders ◽  
Excess Carbon ◽  
Sic Composites

Sialon-SiC composite powders were synthesized from kyanite tailings through the carbothermal reduction nitridation (CRN) technique. Using Sialon-SiC composites to substitute Si3N4 composites via the CRN technique synthesize Sialon/Si3N4-SiC composite refractories. The phase composition, cross section morphology, and the substituent amount of Sialon-SiC composites impact on refractories mechanical properties were investigated, respectively. The optimized synthesis temperature for the CRN reaction was found to be 1550 °C for 4 h with the excess carbon 20%. The substituent amount of Sialon-SiC was 25%, the mechanical properties of Sialon/Si3N4-SiC composite refractories reached optimal performance, which bending strength value was 41.8 MPa and compression strength value was 61.6 MPa.

scholarly journals Recycling of Alkaline Batteries via a Carbothermal Reduction Process

Batteries ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 35 ◽  
Author(s):  
Selçuk Yeşiltepe ◽  
Mehmet Buğdaycı ◽  
Onuralp Yücel ◽  
Mustafa Şeşen
Keyword(s):  
Carbothermal Reduction ◽  
Reduction Process ◽  
Economic Benefits ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Alkaline Batteries ◽  
Primary Battery ◽  
Battery Recycling ◽  
Steel Container ◽  
Manganese Monoxide

Primary battery recycling has important environmental and economic benefits. According to battery sales worldwide, the most used battery type is alkaline batteries with 75% of market share due to having a higher performance than other primary batteries such as Zn–MnO2. In this study, carbothermal reduction for zinc oxide from battery waste was completed for both vacuum and Ar atmospheres. Thermodynamic data are evaluated for vacuum and Ar atmosphere reduction reactions and results for Zn reduction/evaporation are compared via the FactSage program. Zn vapor and manganese oxide were obtained as products. Zn vapor was re-oxidized in end products; manganese monoxide and steel container of batteries are evaluated as ferromanganese raw material. Effects of carbon source, vacuum, temperature and time were studied. The results show a recovery of 95.1% Zn by implementing a product at 1150 °C for 1 h without using the vacuum. The residues were characterized by Atomic Absorption Spectrometer (AAS) and X-ray Diffraction (XRD) methods.

Synthesis of O'-SiAlON/SiC Ecomaterials by Using Non-Traditional Resources: Yangtze River Sand

2009 ◽  
Vol 610-613 ◽  
pp. 267-273 ◽  
Author(s):  
Hong Shun Hao ◽  
Li Hua Xu ◽  
Ming Liu ◽  
Xiao Meng Zhang ◽  
Jian Ying Yang ◽  
...  
Keyword(s):  
Carbothermal Reduction ◽  
Yangtze River ◽  
Mass Fraction ◽  
Sintering Temperature ◽  
Ph Value ◽  
Orthogonal Design ◽  
Raw Material ◽  
Sem Images ◽  
River Sand ◽  
Sic Composites

O'-SiAlON/SiC ecomaterials were synthesized by using the Yangtze River sand that containing abundant Si and Al elements as the major raw material with minor additives through the carbothermal reduction nitridation route combined with colloidal process. This study realized the conversion of ecomaterials from non-traditional resources, Yangtze River sand. Orthogonal design was adopted to optimize the colloidal process parameters. The green compact with the largest bulk density was obtained when the solid volume loading is 50%, the addition mass fraction of SL is 0.8%, the addition mass fraction of CMC is 0.05%, the ball milling time is 10 h, the pH value is 9 and particle size distribution is multi-peak in the colloidal process. The effects of reduction agent, flowing rate of N2, sintering temperature during carbothermal reduction nitridation process on the microstructure of as-fabricated SiAlON materials were explored. The XRD results indicated that when sintering temperature is 1450°C, maintaining time is 6 h, flowing rate of N2 is 1.0 L/min and carbon black is selected as reduction agent, O-SiAlON/SiC composites was successfully synthesized. The SEM images showed the densificated microstructure and uniform grains with the short column shape.

Preparation of C/SiC Composites by SLA-Intergrated Liquid Silicon Infiltration Method

2010 ◽  
Vol 152-153 ◽  
pp. 1146-1150 ◽  
Author(s):  
Jie Jin ◽  
Shen Hao Wang
Keyword(s):  
Phase Composition ◽  
Electron Microscope ◽  
Phenolic Resin ◽  
Raw Material ◽  
Reactive Infiltration ◽  
Statistical Comparison ◽  
Sic Ceramic ◽  
Ceramic Components ◽  
Sic Composites ◽  
Infiltration Method

Phenolic resin was used as the raw material, formed a mold for complex-shaped component by rapid-prototyping. It was composed of SiC, C and Si. The sample hardness was analyzed through statistical comparison. The phase composition of C/SiC composite was investigated by XRD and microstructures of C/SiC ceramic components were observed with scaning electron microscope. The ceramic components obtained at 1500 by reactive infiltration of Si into porous C-template. The porous structure formed by photecurable resin and starch powders pyrolysis could effectively prevent the C-template from cracking and reduce the stress. It also facilitate penetrating Si to the C-template to form SiC.

Synthesis of Al2OC Ceramic Powder by a Carbothermal Reduction Process

2014 ◽  
Vol 881-883 ◽  
pp. 1017-1020
Author(s):  
Shuang Shuang Ding ◽  
Peng Cui ◽  
Hong Xi Zhu ◽  
Cheng Ji Deng ◽  
Chao Yu
Keyword(s):  
Carbothermal Reduction ◽  
Raw Materials ◽  
Heating Temperature ◽  
Ceramic Powder ◽  
Reduction Process ◽  
Synthesis Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Argon Flow ◽  
Micro Morphology

A12OC ceramic powder was successfully synthesized via a carbothermal reduction method using Al2O3, B2O3 and activated carbon powders as raw materials. The effects of synthesis temperature on the phase transformation and micro-morphology of A12OC were investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the content of A12OC in the products was increased with the increasing heating temperature. The optimized process for preparing A12OC was heating the mixtures at 1700 °C for 2 h in argon flow. A12OC particles synthesized at 1700 °C were hexagon plate-like with thickness of 5 μm and size of about 50 μm. Keywords: A12OC, synthesis, microstructure

Effect of Three Catalysts on Synthesis of Silicon Carbide Whiskers with Silica Fume

2011 ◽  
Vol 284-286 ◽  
pp. 496-499
Author(s):  
Xin Wei Li ◽  
Dian Li Qu ◽  
Zhi Jian Li ◽  
Feng Wu ◽  
Na Xu
Keyword(s):  
Silicon Carbide ◽  
Phase Composition ◽  
Carbon Black ◽  
Black Carbon ◽  
Silica Fume ◽  
Carbothermal Reduction ◽  
Synthesis Temperature ◽  
Catalyst Synthesis ◽  
Silicon Carbide Whiskers ◽  
Better Than

Silicon carbide whiskers were prepared by carbothermal reduction. Materials are silica fume and carbon black, Si, Fe2O3, Si-Fe as catalyst, the phase composition and microstructure of compound products were investigated by XRD and SEM, effect of synthesized temperature, kind of catalysts, amount of catalyst were discussed. The results showed that: Silicon carbide whiskers were synthesized by silica fume and black carbon, add catalyst, synthesis temperature is 1550°C. Synthesis effect of silicon carbide whiskers with Si is better than Si-Fe and Fe2O3. Adding amount of Si is 2%, synthesized rate of silicon carbide whiskers is high, it is straight, length is 10~15μm, diameter is 0.1~0.3μm.

Phases Transformation of Boron Mud during Carbothermal Reduction Process

2011 ◽  
Vol 492 ◽  
pp. 415-418
Author(s):  
Xiao Chao Li ◽  
Zhao Hui Huang ◽  
Yang Gai Liu ◽  
Ming Hao Fang
Keyword(s):  
Phase Transformation ◽  
Firing Temperature ◽  
Carbothermal Reduction ◽  
Industrial Waste ◽  
Reduction Process ◽  
Raw Material ◽  
Partial Reduction ◽  
Graphite Content ◽  
Compound Powder ◽  
Boron Mud

By using the industrial waste boron mud as raw material, graphite as reductant, coke particles as burying materials. During carbothermal reduction process, the Mg-Fe forsterite phase in boron mud row materials can transformed into forsterite and Fe2O3 at 1550°C and 1600°C for 3 h, and the Fe3C can be generated from the partial reduction of Fe2O3 with graphite, The main phase in samples calcined under 1650°C for 3 h contained forsterite, Fe2O3, Fe3C and β-SiC. The compound powder of Mg2SiO4 and β-SiC was prepared through the carbothermal reduction process. The effects of different graphite proportion (theoretical proportion, exceeding 10%, 50% and 100%) and firing temperature (1550°C, 1600°C and 1650°C) on the phase transformation and microstructure of the products were investigated by XRD, SEM and EDS. The results show that β-SiC powders were obtained at 1650°C for 3 h when graphite content was theoretical.

scholarly journals Carbonitriding reactions of diatomaceous earth: phase evolution and reaction mechanisms

2006 ◽  
Vol 71 (6) ◽  
pp. 677-683 ◽  
Author(s):  
Branko Matovic ◽  
Aleksandra Saponjic ◽  
Snezana Boskovic
Keyword(s):  
Reaction Mechanisms ◽  
Carbothermal Reduction ◽  
Diatomaceous Earth ◽  
Phase Evolution ◽  
Raw Material ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
X Ray ◽  
Oxide Powders ◽  
Effective Source

The possibility of using diatomaceous earth as Si precursor for low temperature synthesis of non-oxide powders by carbothermal reduction-nitridation was studied. It was found that carbonitriding reactions produce phases of the Si-Al-O-N system. Already at 1300 ?C, nanosized non-oxide powders were obtained. The comparatively low reaction temperatures is attributred to the nano-porous nature of the raw material. The evolution of crystalline phases proceeded via many intermediate stages. The powders were characterized by X-ray and SEM investigations. The results showed that diatomaceous earth can be a very effective source for obtaining non-oxide powders.

Sign in / Sign up

Export Citation Format

Share Document