Effects of Recycling Ladle Lining Materials on Phase Composition and Microstructure of Al2O3-SiC-C Castable for Iron Runner

2013 ◽  
Vol 652-654 ◽  
pp. 1614-1618
Author(s):  
Yi Cui ◽  
Rong Lin Wang ◽  
Li Ren Wang ◽  
Jing Long Bu ◽  
Qian Wang
Keyword(s):  
Phase Composition ◽  
Flow Pattern ◽  
Internal Structure ◽  
External Surface ◽  
Ladle Lining ◽  
Air Atmosphere

In this experiment, preparation of samples were based on original ratio of bauxite matrix Al2O3-SiC-C castable for iron tap channel, and partial bauxites of size 8-5 mm, 5-3 mm, 3-1 mm and 2O3-MgO-C ladle bricks, respectively. Effects of recycling ladle lining materials on phase composition and microstructure of Al2O3-SiC-C castable for iron runner were investigated by XRD, SEM and EDS. The results showed that new phases SiO2 and (Mg0.804Ca0.196)3Al2(SiO4)3 were formed in the castable at 1450 oC in air atmosphere, and the spherical (Mg0.804Ca0.196)3Al2(SiO4)3 was formed on external surface of recycling Al2O3-MgO-C particle. thereinto, SiC oxidation to formed SiO2 with flow pattern character was key element of the phase (Mg0.804Ca0.196)3Al2(SiO4)3 formation. The more fine and uniform of recycling Al2O3-MgO-C particles, the more spherical (Mg0.804Ca0.196)3Al2(SiO4)3 was formed in recycling Al2O3-SiC-C castable. Internal structure of theirs samples exhibited looser state with content increasing of recycling ladle lining materials.

Study on the Phase Formation of Corundum-Type Mg4Nb2O9 Powders by the Solid-State Process

2012 ◽  
Vol 499 ◽  
pp. 174-177
Author(s):  
Yi Shan Jiang ◽  
Ying Zi Wang ◽  
Ya Ming Chen ◽  
Yun Long Yue ◽  
Hai Tao Wu
Keyword(s):  
Phase Composition ◽  
Solid State ◽  
Phase Formation ◽  
Single Phase ◽  
Magnesium Niobate ◽  
Calcination Temperatures ◽  
Air Atmosphere ◽  
State Process

The corundum-type magnesium niobate, Mg4Nb2O9, powders were synthesized by the conventional solid-state process. The mixtures of MgO and Nb2O5were calcined in the temperature ranging from 500°C to 1200°C for crystallization in air atmosphere. The formation of the Mg4Nb2O9phase was investigated as a function of calcination temperatures by DTA and XRD. The morphology and phase composition were determined via a combination of SEM and EDX techniques. The results showed that the single-phase Mg4Nb2O9could be obtained at 1050°C for 2h with the size of less than 5μm.

scholarly journals Phase equilibria in the MnO-Mn2O3-FeO-Fe2O3-Sb2O3-Sb2O5 System in Air at 1200℃

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
BG Golovkin
Keyword(s):  
Phase Diagram ◽  
Phase Composition ◽  
Phase Equilibria ◽  
Normal Pressure ◽  
X Ray ◽  
Densitometric Analysis ◽  
Temperature Range ◽  
Air Atmosphere ◽  
Different Temperatures ◽  
New Phase

Using the methods of X-ray phase and X-ray Densitometric analysis, the phase equilibria between oxides of manganese, iron and antimony have been investigated in an air atmosphere at temperatures up to 1250? in an air mosphere at normal pressure. The phase diagram of the system at 1200? was built MnO-Mn2O3-FeO-Fe2O-Sb2O3-Sb2O5. A new phase was found Mn12-2x,sup>2+Fe2x2+Sb3+Sb55+O26(0?x?1), with edge compositions FeMn5Sb3O13 and Mn6Sb3O3 (a=8.5003?0.0025Å; b=8.0064?0.0025Å; c=11.5779?0.0025Å; Z = 3; ?obs. = 5.7 g/cm3; ?calc = 5.6991 g/cm3). The phase exists in the temperature range 1180-1230oC and can be obtained by quenching, but always with a large admixture of Mn2Sb2O7 and spinel Mn112+Mn133+Sb93+O44.The reason for this behavior is that air molecules have different temperatures, as a result of which the phase composition of the reaction mixture cannot be strictly related to one temperature, and different phases can be stable at different temperatures.

Structures d'écoulement dans une caisse filonienne : le mécanisme d'intrusion télescopique et le concept d'intra-épontes

1982 ◽  
Vol 19 (12) ◽  
pp. 2387-2399 ◽  
Author(s):  
Francis André ◽  
Claude Gagny
Keyword(s):  
Flow Pattern ◽  
Internal Structure ◽  
Chemical Data ◽  
Rheological Characteristics ◽  
Mineral Distribution ◽  
Flow Models ◽  
Mechanical Differentiation

A detailed study of the internal structure of a dyke has revealed the existence of three facies, separated by magmatic discontinuities termed intrawalls. Chemical data from rocks and minerals, noteworthy for their homogeneity, point to a comagmatic identity for the different facies.Magmatic fabrics and especially intratelluric mineral distribution across the dyke width permit us to propose flow models specific for each facies. From these data it appears that, for a given facies, the flow pattern (and the consequent mechanical differentiation) must be expressed in terms of rheological characteristics of the magma during its emplacement.The data as a whole (chemical, mineralogical, structural petrology) are integrated in a dynamic emplacement model of a single magma through a pipe, according to what we define as a telescopic intrusion model.

Changes in the Crystal Structure of Cement Mortars Subjected to a High Temperature

2019 ◽  
Vol 808 ◽  
pp. 165-171
Author(s):  
Maria Ratajczak ◽  
Michał Babiak ◽  
Piotr Kulczewski
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Compressive Strength ◽  
Phase Composition ◽  
High Temperature ◽  
Internal Structure ◽  
Cement Paste ◽  
Original Research ◽  
Physical Parameters ◽  
Cement Mortars

During the fire, structures of a building are exposed to the effect of a high temperature. As a result, the strength parameters and physical properties of concretes and cement mortars undergo change. Their range depends on the time and temperature of the fire. Describing the changes of the internal structure of concretes and mortars resulting from a fire is important in the fire diagnostics of the structures. The paper presents the results of an original research project, within which there was an attempt to relate changes in mechanical properties of the cement mortars with changes in the crystal structure of cement paste. For this purpose, the authors prepared cement prisms, which were heated at various temperatures that occur during a fire after 28 days of their curing. Then, the samples were subjected to compressive strength tests and tests of a structure and a phase composition using an electron scanning microscope. Scanning microscopy is a precious research method that allows observing surfaces of various materials with magnifications from x50 to even x1000000 at a very big sharpness depth. The tests conducted by the authors showed that the effect of fire and of the gradient of high temperatures on the executed samples causes the deterioration of the cement paste in the form of changes in physico-mechanical properties and in its internal structure. As the temperature increases, the compressive strength of the paste decreases gradually and proportionally. The SEM analysis also showed that the change in the physical parameters of the cement paste is reflected in its phase composition.

scholarly journals XXIII. Observations on the fossil bones presented to the Royal Society by his most Serene Highness the Margrave of Anspach, &c

1794 ◽  
Vol 84 ◽  
pp. 407-417 ◽  
Keyword(s):  
Internal Structure ◽  
Royal Society ◽  
External Surface ◽  
The Other ◽  
Fossil Bones ◽  
The Subject

The bones which are the subject of the present paper, are to be considered more in the light of incrustations than extra­neous fossils, since their external surface has only acquired a covering of crystallized earth, and little or no change has taken place in their internal structure. The earths with which bones are most commonly incrusted are the calcareous, argillaceous, and siliceous, but principally the calcareous; and this happens in two ways; one, the bones being immersed in water in which this earth is suspended; the other, water passing through masses of this earth, which it dissolves, and afterwards deposits upon bones which lie under­-neath.

Phase Equilibria and Elements Partitioning in Zirconolite-Rich Region of Ca-Zr-Ti-Al-Gd-Si-O System

1996 ◽  
Vol 465 ◽  
Author(s):  
O. A. Knyazev ◽  
S. V. Stefanovsky ◽  
S. V. Ioudintsev ◽  
B. S. Nikonov ◽  
B. I. Omelianenko ◽  
...  
Keyword(s):  
Phase Composition ◽  
Phase Equilibria ◽  
The Other ◽  
Cold Crucible ◽  
Rich Region ◽  
Aluminium Titanate ◽  
Air Atmosphere ◽  
Melting Technique ◽  
Mineral Structure

ABSTRACTZirconolite-rich ceramics were produced by the cold crucible melting technique in an air atmosphere, at 1550±50 °C and 1 atm. Four samples with overall composition (in wt.%): 4.9–14.3 CaO; 19.0–41.3 ZrO2; 24.1–42.6 TiO2; 1.3–11.3 Al2O3; 6.8–30.0 Gd2O3, and 1.1–8.5 SiO2 have been studied. Total phases in the ceramics consist of major zirconolite and minor rutile, perovskite, zirconia, aluminium titanate, and glass. The Gd2O3 content in zirconolite reaches up to 31.4 wt.% corresponding to the formula: (Cao4,Gd0.7)Zri.0(Tii4,Alo 5)070. The data on the phase composition agree well with coupled Gd incorporation into the mineral structure. Ca(H) + Ti(IV) = Gd(III) + Al(III), and 2Gd(III) - Ca(II) + Zr(IV). The highest Gd contents observed in the other phases are 25.4 % for zirconia, 12.6 % in glass, 8.8 % in perovskite, and 1.4 % for rutile. The rest of the elements' distribution in the samples are analyzed.

Phase Composition Analysis of Recycled MgO-C Ladle Lining Materials

2013 ◽  
Vol 750-752 ◽  
pp. 2236-2239
Author(s):  
Jian Zhang ◽  
Jing Long Bu ◽  
Li Ren Wang ◽  
Rong Lin Wang
Keyword(s):  
Phase Composition ◽  
Melting Point ◽  
Liquid Steel ◽  
Rapid Development ◽  
Ladle Lining ◽  
Composition Analysis ◽  
Iron And Steel ◽  
Slag Line ◽  
Steel Metallurgy ◽  
The One

With the iron and steel metallurgy, cement, ceramic and other industries making a rapid development, the refractory consumption in our country is quite large. So how to recycle the used refractory materials effectively is more and more important. In this experiment, the phase composition of ladle lining bricks at slag line, rampart and bottom were researched systematically, to determine the phase composition change between the unused and recycled materials. It turned out that the low melting point minerals CaMgSiO4 and Ca3Mg (SiO4)2 formed due to the reaction between MgO and the impurity compositions like SiO2 and CaO from the melted slag and liquid steel. On the one hand, the formation of these low melting point minerals was one of the main reason for the damage of the recycled MgO-C ladle lining bricks. On the other hand, the alkaline magnesium carbon bricks had purification effect for the liquid steel as a result of the content reduction of SiO2 and CaO.

Effect of Aluminium Powder on the Hot Mechanical Properties of Corundum-Silicon Nitride Composites

2011 ◽  
Vol 189-193 ◽  
pp. 3960-3963
Author(s):  
Jun Cong Wei ◽  
Jun Bo Tu
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Silicon Nitride ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Modulus Of Rupture ◽  
Reaction Sintering ◽  
Sintering Process ◽  
Aluminium Powder ◽  
Air Atmosphere

Based on the Al-O-N phase stable diagram and adopting inverse reaction sintering process, corundum-silicon nitride composite refractories were prepared using corundum, silicon nitride, clay and aluminium powder as the main starting materials. The specimens were sintered at 1600 for 3 hours under air atmosphere with different oxygen partial pressure obtained by addition of different amount of aluminium powder. The effects of aluminium powder additions(0, 4wt.%, 8 wt.% and 12 wt.% respectively) on the hot modulus of rupture were investigated .The phase composition and microstructure were tested by means of XRD, SEM and EDAS.The results showed that aluminium would be oxidized, nitrided and displaced as aluminium powder increased during sintering, which reduced the oxygen partial pressure in the specimen. The hot modulus of rupture (HMOR) increased considerably due to large amounts of fibrous sialon formed.

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