Fusion Characteristics of Ash Residues from Lignite Gasification

2012 ◽  
Vol 512-515 ◽  
pp. 2147-2151
Author(s):  
Feng Hai Li ◽  
Jie Jie Huang ◽  
Yi Tian Fang ◽  
Ming Jie Ma ◽  
Yang Wang
Keyword(s):  
High Temperature ◽  
Fluidized Bed ◽  
Sintering Temperature ◽  
Mineral Matter ◽  
Fusion Temperature ◽  
Fusion Point ◽  
Ash Fusion Temperature ◽  
Temperature Analyzer ◽  
Point Detector ◽  
Mineral Type

Fusion characteristics of ash residues from Xiaolongtan lignite pressurized fluidized-bed gasification were investigated with ash fusion point detector and sintering temperature analyzer. The results show that the sintering temperature (Ts) and ash fusion temperature (AFT) of three ashes residues decrease from gangue ashes to agglomerate to slag, which result from the differences of mineral type and content in three ash residues, and the decrease of the total basic constituents increases the AFT. The formations of three ash residues during gasification are the interactions among mineral matter and their transformations under high temperature.

Fusibility Characteristics of Slag from Fluidized-Bed Gasification of Jincheng Anthracite

2013 ◽  
Vol 805-806 ◽  
pp. 1317-1320
Author(s):  
Feng Hai Li ◽  
Zhen Zhu Li ◽  
Ming Jie Ma ◽  
Jie Jie Huang ◽  
Yi Tian Fang
Keyword(s):  
Fluidized Bed ◽  
Slag Formation ◽  
X Ray Diffraction ◽  
Fusion Temperature ◽  
X Ray ◽  
Base Content ◽  
Ash Fusion Temperature ◽  
Total Base ◽  
Mineral Compositions ◽  
Distribution Plate

To investigate fusibility characteristics of slag from Jincheng Anthracite (JC) pressurized ash agglomerate fluidized bed (AFB) gasification of Jincheng Anthracite (JC), the slag samples were examined by an ash fusion temperature (AFT) analyzer, scanning electron microscope (SEM), and X-ray diffraction (XRD). The results show that the AFTs of three kinds of slag are lower than that of JC greatly, and the AFTs of three kinds of slag decrease from the slag formed that on the central tube (SC) to distribution plate (SD) to inner face (SI), as a result of the increase of total base content and the differences in their mineral compositions accordingly. Not all slag during AFB gasification are composed of molten mineral matters. This can be explained that the phenomena that the slag formation during fluidized-bed gasification when the operating temperature is below the AFTs of coal.

Ash Composition Influence on Fusibility of Coal Ash

2013 ◽  
Vol 448-453 ◽  
pp. 3009-3012
Author(s):  
Na Gao ◽  
Sheng Hua Liu ◽  
Yan Hong Guo
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Mineral Composition ◽  
General Trend ◽  
Coal Ash ◽  
Xrd Analysis ◽  
Fusion Temperature ◽  
Basic Oxide ◽  
Ash Composition ◽  
Ash Fusion Temperature

The coal of Zichang was selected as the sample coal, the physical properties of the ash is analyzed with ICP-AES. The ash fusion temperature was researched by adding different basic oxide contents. The results show that the general trend is decrease firstly, and then increase when adding basic oxides. Blended ash fusion temperatures do not change linearly with blending ratios and ash fusion will decrease when adding the contents of CaO, Na2O and MgO, but the effect is different. Na2O is best and CaO is second. Mineral composition and type at addition oxides were determined by XRD analysis. Some combinations of component coals mineral produce eutectic minerals at high temperature;It can explain the reason of oxides decrease the ash fusion. Vitreous minerals are formed to explain increase the fusion temperature.

Electron Microscopy of Silicon Nitride-Based Ceramics

1991 ◽  
Vol 49 ◽  
pp. 926-927
Author(s):  
Gareth Thomas
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Silicon Nitride ◽  
World Wide ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
High Temperature Strength ◽  
Sintering Additives ◽  
Glass Forming ◽  
Dense Product

Silicon nitride and silicon nitride based-ceramics are now well known for their potential as hightemperature structural materials, e.g. in engines. However, as is the case for many ceramics, in order to produce a dense product, sintering additives are utilized which allow liquid-phase sintering to occur; but upon cooling from the sintering temperature residual intergranular phases are formed which can be deleterious to high-temperature strength and oxidation resistance, especially if these phases are nonviscous glasses. Many oxide sintering additives have been utilized in processing attempts world-wide to produce dense creep resistant components using Si3N4 but the problem of controlling intergranular phases requires an understanding of the glass forming and subsequent glass-crystalline transformations that can occur at the grain boundaries.

Transient operating regimes modeling in low-power boilers of a high-temperature fluidized bed

2020 ◽  
Vol 919 ◽  
pp. 052042
Author(s):  
A V Bondarev ◽  
S V Sarkisov ◽  
V N Tarasov ◽  
V A Vakunenko ◽  
N A Biryukov
Keyword(s):  
High Temperature ◽  
Low Power ◽  
Fluidized Bed ◽  
Operating Regimes

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 A Model for Predicting Arsenic Volatilization during Coal Combustion Based on the Ash Fusion Temperature and Coal Characteristic

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 334
Author(s):  
Bo Zhao ◽  
Geng Chen ◽  
Zijiang Xiong ◽  
Linbo Qin ◽  
Wangsheng Chen ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Power Plants ◽  
Combustion Temperature ◽  
Published Data ◽  
Fusion Temperature ◽  
Equilibrium Calculation ◽  
Arsenic Distribution ◽  
Ash Fusion Temperature ◽  
Close Relationship ◽  
Coal Type

Arsenic emission from coal combustion power plants has attracted increasing attention due to its high toxicity. In this study, it was found that there was a close relationship between the ash fusion temperature (AFT) and arsenic distribution based on the thermodynamic equilibrium calculation. In addition to the AFT, coal characteristics and combustion temperature also considerably affected the distribution and morphology of arsenic during coal combustion. Thus, an arsenic volatilization model based on the AFT, coal type, and combustion temperature during coal combustion was developed. To test the accuracy of the model, blending coal combustion experiments were carried out. The experimental results and published data proved that the developed arsenic volatilization model can accurately predict arsenic emission during co-combustion, and the errors of the predicted value for bituminous and lignite were 2.3–9.8%, with the exception of JingLong (JL) coal when combusted at 1500 °C.

The Influence of Bi2O3 on SiO2-Al2O3-B2O3-RO Glass Propertiesarts

2014 ◽  
Vol 887-888 ◽  
pp. 86-89
Author(s):  
Ying Liang Tian ◽  
Jing Zhang ◽  
Shi Bing Sun ◽  
Ji Ye Fan
Keyword(s):  
Electrical Resistivity ◽  
High Temperature ◽  
Expansion Coefficient ◽  
Bismuth Oxide ◽  
Sintering Temperature ◽  
Oxide Content ◽  
Basic Composition ◽  
Wide Range ◽  
Melt Annealing ◽  
Annealing Method

In the paper, regarded SiO2-Al2O3-B2O3-RO system as basic composition, high-temperature glass glaze was prepared successfully by using Bi2O3 in place of Al2O3, and traditional melt annealing method was adopted .The influence of Bi2O3 on expansion coefficient, sintering temperature, electrical resistivity was investigated by DIL-2008, SJY sintering imager, Keythley2410. The results show that the sintering temperature of glass glaze has a wide range, which can reach 270°C, so it is easy to sinter; with the increasing of bismuth oxide content, expansion coefficient of glass glaze gradually increases, whereas sintering temperature and electrical resistivity continuously decreases.

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