Insights into the effect of particle size on coal char particle gasification by thermogravimetric analyzer and high temperature stage microscope

Fuel ◽  
2022 ◽  
Vol 313 ◽  
pp. 123010
Author(s):  
Mengjie Liu ◽  
Xiaoming Li ◽  
Xuetao Wang ◽  
Jin Bai ◽  
Lingxue Kong ◽  
...  
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Coal Char ◽  
Thermogravimetric Analyzer ◽  
Char Particle ◽  
Effect Of Particle Size ◽  
High Temperature Stage

Self-propagating high-temperature synthesis of the SiC

1986 ◽  
Vol 1 (2) ◽  
pp. 275-279 ◽  
Author(s):  
Osamu Yamada ◽  
Yoshinari Miyamoto ◽  
Mitsue Koizumi
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Exothermic Reaction ◽  
Experimental System ◽  
Ignition Process ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Effect Of Particle Size ◽  
Constituent Elements ◽  
Heat Released

Self-propagating high-temperature synthesis (SHS), also called combustion synthesis, is useful for fabricating numerous ceramics. In the case of SiC, heat released from the exothermic reaction is not sufficient to completely convert the mixed reactants of constituent elements into SiC in the usual nonadiabatic experimental system. This disadvantage could be overcome by a new ignition process called, the “direct passing method of electric current.” By using this method, stoichiometric fine SiC powder could be obtained rapidly and efficiently with low electric power. This paper also involves the effect of particle size of Si and C initial reactant powders on conversion efficiency into SiC and also on particle size of SiC powder fabricated by this method.

Pulverized coal char combustion: the effect of particle size on burner performance

1998 ◽  
Vol 18 (11) ◽  
pp. 981-989 ◽  
Author(s):  
H.H. Liakos ◽  
K.N. Theologos ◽  
A.G. Boudouvis ◽  
N.C. Markatos
Keyword(s):  
Particle Size ◽  
Coal Char ◽  
Pulverized Coal ◽  
Char Combustion ◽  
Effect Of Particle Size

Effect of particle size on indicator gas emission during high-temperature oxidation of weathered coal

2020 ◽  
Author(s):  
JiaJia Song ◽  
Jun Deng ◽  
JingYu Zhao
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
High Temperature Oxidation ◽  
Spontaneous Combustion ◽  
Combustion Characteristics ◽  
Particle Sizes ◽  
Gas Emission ◽  
Temperature Oxidation ◽  
Weathered Coal ◽  
Effect Of Particle Size

<p>Coal spontaneous combustion is one of the severe nature hazards among nature resources. There are many influence factors which control the development of spontaneous combustion such as particle size, oxygen concentration, etc. Weathering effects alter the spontaneous combustion characteristics of coal. To explore the effect of particle size on gas emission from weathered coal under high temperature oxygen deficiency, the macroscopic spontaneous combustion characteristics of weathered coal with various particle sizes in high temperature oxidation process were studied. The gas concentration of different particle sizes with weathered coal oxidation from normal temperature to 600 °C was tested by the self-built high temperature program experiment system, and the variation law of the indicator gas was analyzed. The results showed that there were different experimental phenomena in each particle size coal sample. The concentration of indicator gas neither increased nor decreased monotonically with the change of particle size. Roughly, 3 mm is the critical particle size in the process of high temperature oxidation of weathered coal. The experimental results provided a pivotal theoretical basis for the early prediction and the scientific prevention of the spontaneous combustion of the weathered coal during the mining process of the open pit and the shallow coal seam.</p>

Dechromization Kinetics of Limonitic Laterite Ores by Alkali-Roasting Method Using Sodium Hydroxide

2011 ◽  
Vol 233-235 ◽  
pp. 798-804
Author(s):  
Qiang Guo ◽  
Jing Kui Qu ◽  
Bing Bing Han ◽  
Guang Ye Wei ◽  
Tao Qi
Keyword(s):  
Activation Energy ◽  
Particle Size ◽  
High Temperature ◽  
Liquid Phase ◽  
Avrami Model ◽  
Phase Reduction ◽  
Laterite Ores ◽  
Effect Of Particle Size ◽  
Roasting Temperature ◽  
Kinetics Of

A novel process was proposed for the activation pretreatment of Cr-containing limonitic laterite ores by NaOH roasting. The dechromization kinetics of the laterite ores and the effect of particle size, NaOH-ore ratio, and roasting temperature on Cr extraction were studied in detail. Experimental results indicate that decreasing the particle size and increasing the NaOH-ore ratio and roasting temperature increase the Cr extraction rate. Approximately 96% Cr in the laterite ores could be extracted under the optimal alkali-roasting conditions. The results also indicate that the Avrami model is suitable for the dechromization process and that the apparent activation energy is calculated 11.12 kJ·mol-1. The 99.5% Cr2O3 was obtained from Na2CrO4 leached in the alkali solution by liquid-phase reduction and then calcining at high temperature.

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