Effect of Roasting Temperature on High Temperature Sintering Process of Different Mass Ratio of CaCO3/ SiO2

2012 ◽  
Vol 454 ◽  
pp. 21-25
Author(s):  
Ying Gao ◽  
Yue Xin Han ◽  
Wenbo Li ◽  
Jie Liu
Keyword(s):  
High Temperature ◽  
Sintering Process ◽  
Mass Ratio ◽  
Roasting Temperature

Effect of Roasting Temperature on High Temperature Sintering Process of Different Mass Ratio of CaCO3/ SiO2

2012 ◽  
Vol 454 ◽  
pp. 21-25
Author(s):  
Ying Gao ◽  
Yue Xin Han ◽  
Wenbo Li ◽  
Jie Liu
Keyword(s):  
High Temperature ◽  
Calcium Carbonate ◽  
Initial Temperature ◽  
Sintering Process ◽  
Mass Ratio ◽  
Remarkable Effect ◽  
Synthetic Product ◽  
Roasting Temperature

Roasting temperature is a significant factor for synthesis of wollastonite by high-temperature roasting. In this paper, experiments were carried out at various temperatures by using quartz and nanometer calcium carbonate mixed in different ratios. The synthetic products under the condition of different roasting temperatures and initial temperatures were characterized by means of XRD. The results indicated that initial temperature had a remarkable effect on the synthetic product during calcination at 1300°C for 2 h when nanometer calcium carbonate and quartz were mixed in such ratios as 2.3:1 and 4:1 by weight.

Microstructural Study of Diamond Deformed Under High Pressure and Temperature

1985 ◽  
Vol 43 ◽  
pp. 230-231
Author(s):  
E. F. Koch
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Lattice Structure ◽  
Diamond Particle ◽  
Polycrystalline Diamond ◽  
Sintering Process ◽  
Ion Milling ◽  
Sintered Compact ◽  
Transmission Electron ◽  
High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

scholarly journals Pressureless Sintering of YIG Ceramics from Coprecipitated Nanopowders

2021 ◽  
Vol 7 (5) ◽  
pp. 56
Author(s):  
Yimin Yang ◽  
Xiaoying Li ◽  
Ziyu Liu ◽  
Dianjun Hu ◽  
Xin Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Calcination Temperature ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Secondary Phase ◽  
Coprecipitation Method ◽  
Pressureless Sintering ◽  
Densification Behavior ◽  
Sintering Process

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.

scholarly journals Sintering densification curve: A practical approach for its construction from dilatometric shrinkage data

2008 ◽  
Vol 40 (2) ◽  
pp. 117-122 ◽  
Author(s):  
K. Maca ◽  
V. Pouchly ◽  
A.R. Boccaccini
Keyword(s):  
High Temperature ◽  
Sintering Temperature ◽  
Practical Method ◽  
Practical Approach ◽  
Powder Technology ◽  
Ceramic Processing ◽  
Sintering Process ◽  
Densification Curve ◽  
Sample Density ◽  
Sintering Shrinkage

This article summarizes the usage of high-temperature dilatometry in ceramic processing and powder technology with special attention on the description of the sintering process. A practical method for transformation of dilatometric shrinkage data into densification curves (the dependence of the sample density on sintering temperature or time) is described in detail. A new automatic procedure to recalculate sintering shrinkage data allowing the plot of the densification curve has been developed, which is presented here.

scholarly journals Modeling of REE and Fe Extraction from a Concentrate from Araxá (Brazil)

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 451 ◽  
Author(s):  
Marisa Nascimento ◽  
Flávio Lemos ◽  
Rogério Guimarães ◽  
Clóvis Sousa ◽  
Paulo Soares
Keyword(s):  
Laboratory Experiments ◽  
Earth Element ◽  
Process Variable ◽  
Optimization Method ◽  
Chemical Processing ◽  
Important Process ◽  
Mass Ratio ◽  
Process Variables ◽  
Acid Processing ◽  
Roasting Temperature

The study aimed to employ a comprehensive methodology for the acid processing of a rare earth element (REE) concentrate obtained from the ore from Araxá (MG-Brazil). The most important process variables have been identified and their levels determined to maximize REE extraction (%RE) and minimize Fe extraction (%Fe). The thermodynamic analysis showed that the roasting temperature (TF) is crucial for the control of Fe solubilization in the aqueous leaching step of the acid processing. A statistic design of laboratory experiments and a process optimization method were applied to address the interaction among the process variables. Experimental results showed that a TF of about 700 °C can significantly reduce the Fe concentration in the aqueous leaching liquor. Mathematical models were proposed to predict the effect of process variable on REE and Fe extraction of the concentrate. A multi-objective technique was employed for optimization of chemical processing and the best conditions were reached for roasting temperature (TF) = 700 °C, acid to sample mass ratio (ACs) = 0.8 and leaching time (tL) = 20 min, which led to %RE = 96.91% and %Fe = 21.69%.

Study of High Temperature Sintering Process on Characteristics of Al2O3–ZrO2–TiO2 Ceramics Systems

2014 ◽  
Vol 3 (1) ◽  
pp. 67-71
Author(s):  
M. J. Abden ◽  
J. D. Afroze ◽  
M. R. Qadir ◽  
M. A. Gafur
Keyword(s):  
High Temperature ◽  
Sintering Process

PREPARATION OF C60 BY DETONATION A MIXTURE OF TRINITROTOLUENE AND GRAPHITE

2012 ◽  
Vol 27 (01) ◽  
pp. 1350004
Author(s):  
XIANFENG WEI ◽  
YONG HAN ◽  
LIU LIU ◽  
XINPING LONG
Keyword(s):  
High Pressure ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Temperature ◽  
High Performance ◽  
Extreme Conditions ◽  
Detonation Pressure ◽  
Detonation Synthesis ◽  
Mass Ratio ◽  
Detonation Products

To explore the practicability of C 60 synthesis under extreme conditions (high pressure and high temperature), trinitrotoluene (TNT), trinitramine (RDX) and graphite mixtures of different proportions were detonated in a vacuum container, and the detonation products were collected for detecting. The results of mass spectroscopy, high performance liquid chromatography showed significant signals of C 60, which proved that C 60 could be synthesized by detonating the mixture of TNT and graphite (in 6:4 and 7:3 mass ratio, respectively), the detonation pressure and temperature were calculated around 13 GPa and 2000 K, respectively. Both experiment results and theoretical analysis showed the importance of detonation pressure and cooling temperature in detonation synthesis of C 60.

Gaseous Fluorides Formation Mechanism in the Roasting Process of the Fluorite-Bearing Iron Concentrate

2013 ◽  
Vol 690-693 ◽  
pp. 3498-3505 ◽  
Author(s):  
Yi Ci Wang ◽  
Jian Liang Zhang ◽  
Jing Wang ◽  
Fang Zhang ◽  
Guo Ping Luo
Keyword(s):  
Thermal Analysis ◽  
Water Vapor ◽  
Formation Mechanism ◽  
Theoretical Basis ◽  
Emission Rate ◽  
Sintering Process ◽  
Iron Concentrate ◽  
Roasting Process ◽  
Fluorine Emission ◽  
Roasting Temperature

The gaseous fluorides formation mechanism in the roasting process of the fluorite-bearing iron concentrate was studied by thermodynamic calculation, differential thermal analysis (DTA) and chemical analysis. The results show that fluorine in the fluorite-bearing iron concentrate begins to escape since 400~500°C, and the emission rate of fluorine significantly increases when the temperature is above 1100°C; in the roasting process of fluorite-bearing iron concentrate, SiO2, K2O, Na2O, MgO, Al2O3 in the gangue and water vapor in roasting atmospher react with CaF2 in fluorite to generate such gaseous fluorides as SiF4, KF, NaF, MgF2, AlF3 and HF; with the increase of roasting temperature, the emission rate of fluorine increases obviously; and the water vapor in roasting atmosphere can improve escaping of fluorine.The results provide a theoretical basis for the improvement of roasting technology to reduce fluorine emission in the roasting or sintering process of Baiyanobo iron concentrate.

Sintering of β-Si3N4 Powder Prepared by Self-Propagating High-Temperature Synthesis (SHS)

2007 ◽  
Vol 546-549 ◽  
pp. 2179-2182 ◽  
Author(s):  
Ling Bai ◽  
Xing Yu Zhao ◽  
Chang Chun Ge
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Bending Strength ◽  
Sintering Process ◽  
Hot Press ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Good Sinter ◽  
The Cost ◽  
Hot Press Sintering

Sintering of the Self-Propagating High-Temperature Synthesis (SHS) of β-Si3N4 powder with 6.67 wt.% Y2O3 and 3.33 wt.% Al2O3 as sintering additives has been emphatically investigated using hot-press sintering process. The relative density of hot-pressed β-Si3N4 reached near to the full densification (99.43%) at 1700°C. The similar micrographs with self-reinforcing rod-like β-Si3N4 grains forming an interlocking structure were observed. The better mechanical properties of hot-pressed Si3N4, such as the hardness (16.73GPa), fracture toughness (5.72 MPa·m1/2) and bending strength (611.72MPa) values, were obtained at 1700°C. The results indicate that good sinter ability can be obtained with the cheaply SHS of silicon nitride powder for preparing silicon nitride materials, which will make the cost of silicon nitride materials lowered.

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