scholarly journals Effect of Thermodynamic Melt Formation Characteristics on Liquid Phase Fluidity of Iron Ore in the Sintering Process

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 404 ◽  
Author(s):  
Shengli Wu ◽  
Heping Li ◽  
Weili Zhang ◽  
Bo Su
Keyword(s):  
Liquid Phase ◽  
Iron Ore ◽  
Sintering Temperature ◽  
Mixed Phase ◽  
Al2o3 Content ◽  
Phase Content ◽  
Sintering Process ◽  
Test Device ◽  
Sintering Characteristics ◽  
Factsage Software

The liquid phase fluidity of iron ore is a vital index of fundamental sintering characteristics. In this paper, FactSage software and a visible microsintering test device were used to research the influence of the thermodynamic melt characteristics on the liquid phase fluidity under fixed CaO content conditions. The results show that the laws governing liquid phase fluidity of iron ore are significantly different with a fixed alkalinity and fixed CaO content of the sample. The liquid phase content at the sintering temperature is the most important thermodynamic melt formation characteristic affecting the liquid phase fluidity. In addition to the liquid phase content, other minerals also have a greater impact on liquid phase fluidity. Decreasing the viscosity of the liquid phase improves the liquid phase fluidity of the iron ore, and the effect of the SiO2 content of the iron ore on the mixed phase viscosity is greater than that of the Al2O3 content.

scholarly journals The Mechanism of the Effect of Al2O3 Content on the Liquid Phase Fluidity of Iron Ore Fines

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 931 ◽  
Author(s):  
Heping Li ◽  
Shengli Wu ◽  
Zhibin Hong ◽  
Weili Zhang ◽  
Heng Zhou ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Mineral Composition ◽  
Phase Formation ◽  
Iron Ore ◽  
Al2o3 Content ◽  
Calcium Ferrite ◽  
Sintering Process ◽  
Liquidity Index ◽  
Iron Ore Fines

The sintering process is significantly important for the ironmaking in China because of the large amount of sinter consumed. Al2O3 is an important element determining the quality and quantity of sinter. However, different conclusions have been made regarding the effects of Al2O3 on the amount and fluidity of the liquid phase formed in the sinter phase. Therefore, it is necessary to examine the effects of Al2O3 content on the amount and fluidity of the liquid phase. The present work investigated the effects of different Al2O3 contents of iron ore fines on the liquid phase formation, mineral composition, and consolidation strength. The results showed that a small amount of Al2O3 increased the amount of calcium ferrite, making the liquid phase formation easier. As the Al2O3 content in iron ore fines increased, the liquidity index decreased continuously, while the fluidity and the consolidation strength of the sintered body were directly related to the content squared. The quality of the sinter is optimal when the Al2O3 content of the iron ore fines is about 2 wt % (the SiO2 content is 4 wt %).

Effects of Compound Silicate Gangue on Mineral Composition and Microstructure of Sinter Produced by Baiyunebo Iron Ore Concentrates

2011 ◽  
Vol 194-196 ◽  
pp. 201-206
Author(s):  
Guo Ping Luo ◽  
Sheng Li Wu ◽  
Yi Ci Wang ◽  
Guang Jie Zhang ◽  
Zhi Zhong Hao ◽  
...  
Keyword(s):  
Mineral Composition ◽  
Iron Ore ◽  
Glassy Phase ◽  
Optical Microscope ◽  
Calcium Ferrite ◽  
Melting Time ◽  
Sintering Process ◽  
Test Device ◽  
Lower Melting Point ◽  
Mineral Compositions

The effects of compound silicate gangue on mineral composition and microstructure of sinter produced by Baiyunebo iron ore concentrates was studied by using mini-sintering test device and optical microscope. The result showed that compound silicate gangue has lower melting point, wider melting temperature range, longer melting time and melts easily to form glassiness during the sintering process. It can promote the solution of CaO and CaF2 in glassy phase, which affects viscosity and fluidity of glassy phase as well as the homogeneity of sinter microstructure. The compound silicate gangue intensely inhibits the generation of complex calcium ferrite and cuspidine as well. The major mineral compositions of sinter are hematite and glassy phase. The sinter exhibits multi-cavities and grainy structure when SiO2 exists entirely in the form of compound silicate gangue.

Physical, Mechanical and Electrical Properties of W-20 wt.% Cu Composite Produced by Liquid Phase Sintering Process

2014 ◽  
Vol 879 ◽  
pp. 21-26
Author(s):  
Fauzi Ismail ◽  
Mohd Asri Selamat ◽  
Norhamidi Muhamad ◽  
Abu Bakar Sulong ◽  
Nurzirah Abdul Majid
Keyword(s):  
Particle Size ◽  
Liquid Phase ◽  
Electrical Properties ◽  
Microstructure Evolution ◽  
Sintering Temperature ◽  
Cold Isostatic Pressing ◽  
Liquid Phase Sintering ◽  
Sintering Process ◽  
Composite Powders ◽  
Mechanical And Electrical Properties

In this study, the effect of sintering temperature on the properties of tungsten-copper (W-Cu) composite produced by liquid phase sintering (LPS) process has been investigated. W-20 wt.% Cu composite powders with particle size less than 1 μm was prepared by cold compaction and followed by cold isostatic pressing. The green specimens were then sintered under nitrogen based atmosphere in the temperature range of 1100°C to 1300°C. The sintering studies were conducted to determine the extent of densification and corresponding to microstructure changes. In addition, the properties of the sintered specimens such as physical appearance, microstructure evolution, mechanical and electrical properties were presented and discussed.

Research on Influence Law of Fuel Structure for Low-FeO Sintering

2011 ◽  
Vol 201-203 ◽  
pp. 1802-1805
Author(s):  
Miao Lian Bian ◽  
Sheng Li Wu ◽  
Qing Feng Wang
Keyword(s):  
Liquid Phase ◽  
Solid Fuel ◽  
Iron Ore ◽  
Experimental Results ◽  
Coke Breeze ◽  
Partial Substitution ◽  
Liquid Volume ◽  
Sintering Process ◽  
Bonding Phase ◽  
Sintering Condition

Micro–sintering equipment was applied to simulate sintering process of iron ore. FeO content of sinter-samples under different fuel structures was measured, and then the effect of fuel structure on fluidity of liquid phase and strength of bonding phase were analyzed in this paper. The proper fuel structure was finally discussed under low FeO sintering condition. The results show that: when anthracite was adopted as partial substitution of coke breeze as part of solid fuel, FeO of sinter reduces and self-strength of bonding phase increases. Although fluidity of liquid phase reduces, the fluidity index it is still above 0.8, which can meet the liquid volume needed for sintering. When CDQ powder is used as part of solid fuel, FeO of sinter also reduces, but fluidity of liquid phase and self-strength of bonding phase reduce a little due to its low combustibility. Taking experimental results and practical production together into account, it can be concluded that proper fuel structure that meets low FeO sintering should be “70% coke+30% anthracite”.

Additive Sintering Process in Aluminum Nitride Ceramics

1991 ◽  
Vol 249 ◽  
Author(s):  
H. Makihara ◽  
N. Kamehara
Keyword(s):  
Thermal Conductivity ◽  
Phase Diagram ◽  
Liquid Phase ◽  
Sintering Temperature ◽  
Early Stage ◽  
Sintering Process ◽  
Residual Oxygen ◽  
Nitride Ceramics ◽  
Calcium Compounds ◽  
Oxygen Impurities

ABSTRACTCalcium compounds and yttrium compounds are frequently used as additives to densify AlN ceramics[l,2]. They react with oxygen impurities, such as A1203 in the raw AlN powder and in aluminate forms. A phase diagram is helpful in deciding the amount of additives to add, but the AlN sintering process doesn't come to equilibrium. We investigated the differences between sintering AlN with CaCO3 and with Y2O3.With CaCO3 added, the calcium-aluminate liquid phase evaporates from the sintered AlN body at high sintering temperatures. The AlN thermal conductivity doesn't increase above a sintering temperature of 1700°C because residual oxygen substitutes into the AlN grains. With Y2O3 added, AlN sinters below 1850°C, as predicted by a phase diagram. With a large amount of Y2O3 added, 5 wt%, thermal conductivity doesn't depend on residual oxygen. This is because yttrium doesn't evaporate from the sintered AlN body and residual oxygen substitutes into AlN grains at an early stage of the AlN sintering.

The Influence of AST Doping on the Dielectric Properties of MgTiO3-Based Ceramics Fabricated by Soild-State Sintering

2013 ◽  
Vol 634-638 ◽  
pp. 2378-2382
Author(s):  
Chun Yuan Luo ◽  
Jing Xiao Liu ◽  
Fei Shi ◽  
Ji Wei Wu ◽  
Chao Qian ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Liquid Phase ◽  
Dielectric Loss ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Sintering Process ◽  
Solid State Sintering ◽  
Doped Zno

AST-doped ZnO-MgTiO3-SrTiO3ceramics were prepared using a solid-state sintering process. The effects of AST (Al2O3-SiO2-TiO2) on the dielectric properties of MgTiO3-based ceramics were investigated. The results indicate that AST-doped MgTiO3-based ceramics could be obtained after 1205~1280°C sintering for 3 h. The XRD results indicate that the obtained MgTiO3-based ceramics contain high percentage of MgTi2O5 phase and the percentage increased with the increase of AST content. It was found that the occurred liquid-phase sintering by adding AST glass could effectively lower the sintering temperature and decrease the dielectric loss of MgTiO3-based ceramics. A minimum tanδ of 1.5×10-4 associated with εr=19.0 was achieved for 6.0 wt% AST-doped samples sintered at 1255°C.

EFFECTS OF B2O3 ADDITION ON SINTERING BEHAVIOR AND MICROWAVE DIELECTRIC PROPERTIES OF Mg4Ta2O9 CERAMICS PREPARED BY THE SOL–GEL METHOD

2016 ◽  
Vol 23 (01) ◽  
pp. 1550090 ◽  
Author(s):  
J. D. GUO ◽  
J. X. BI ◽  
H. T. WU
Keyword(s):  
Dielectric Properties ◽  
Liquid Phase ◽  
Detrimental Effect ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Phase Effect ◽  
Microwave Dielectric ◽  
Sintering Characteristics

Sintering characteristics and microwave dielectric properties of Mg4Ta2O9–5[Formula: see text]wt% B2O3 ceramics were investigated. With the sintering temperature increasing in the range of 1100[Formula: see text]C–1350[Formula: see text]C, the apparent density, [Formula: see text] and [Formula: see text] values increased firstly and then saturated at 1250[Formula: see text]C with excellent microwave properties: [Formula: see text], [Formula: see text][Formula: see text]GHz and [Formula: see text][Formula: see text]ppm/[Formula: see text]C. Compared to the pure MT ceramics, the B2O3 additives effectively decreased the sintering temperature of MT ceramics and had no detrimental effect on the properties of the MT ceramics due to the liquid phase effect.

scholarly journals Influence of sintering temperature on raw and beneficiated clay “Klokoti”

2012 ◽  
Vol 44 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Marina Jovanovic ◽  
Tatjana Volkov-Husovic
Keyword(s):  
Grain Size ◽  
Chemical Composition ◽  
Glassy Phase ◽  
Sintering Temperature ◽  
Phase Content ◽  
Sintering Process ◽  
Characteristic Temperatures ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
Scanning Electron

The raw clay ?Klokoti? from middle Bosnia was beneficiated by method of wet separation which results in removing fraction over 20 ?m. The raw clay was characterized by chemical composition, grain size distribution and characteristic temperatures on heating microscope. The beneficiated clay was characterized by chemical composition and characteristic temperatures. The phase composition of raw and beneficiated clay was observed by RDA while the microstructure was monitored on scanning electron microscope (SEM). The sintering process was performed at 1100?C, 1250?C, 1320?C and 1400?C with two hours holding time at the highest temperature. The obtained results indicate a big content of coarse quartz in raw clay and gradually increase of crystalline mullite content with increasing temperature of sintering. Beneficiated clay at higher temperature of sintering produces larger glassy phase content, which is result of larger fluxing content in its composition. It is also observed that from beneficiated clay by sintering at 1250?C crystallize the most mullite along with minimum porosity and the lowest glassy phase content.

Creating Dense, Constrained Ce0.9Gd0.1O1.95 Films at Low Temperature for SOFC Applications

2007 ◽  
Vol 1023 ◽  
Author(s):  
Jason D. Nicholas ◽  
Lutgard C. De Jonghe
Keyword(s):  
Liquid Phase ◽  
Low Temperature ◽  
Grain Boundary ◽  
Sintering Temperature ◽  
Vacancy Concentration ◽  
Lithium Salts ◽  
Lithium Nitrate ◽  
Sintering Characteristics

AbstractWe have investigated the effect of various dopants on the sintering characteristics of Ce0.9Gd0.1O1.95 (CGO) and found that 99% dense electrolyte pellets can be produced at the record low temperature of 800°C (as opposed to the 1400°C typically needed) by sintering Ce0.9Gd0.1O1.95 with as little 3mol% lithium. Our studies indicate that doping the CGO surface with lithium nitrate, as opposed to using alternative lithium salts, produces the largest decrease in sintering temperature. Unlike other dopants that lower the sintering temperature by altering the near grain boundary vacancy concentration, lithium lowers the sintering temperature through the formation of an intergranular liquid phase. This liquid phase allows fully dense, completely constrained CGO films to be produced on inert substrates at temperatures as low as 950°C.

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