The Effect of Synthesis Temperature and Gallium Oxide Additive on the Structure and Phase Composition of Magnesium Aluminate Spinel Powder

2018 ◽  
Vol 58 (6) ◽  
pp. 683-686
Author(s):  
M. O. Senina ◽  
E. V. Zhurba ◽  
D. O. Lemeshev ◽  
N. A. Popova
Keyword(s):  
Phase Composition ◽  
Gallium Oxide ◽  
Synthesis Temperature ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Oxide Additive ◽  
Spinel Powder

Performance Studies on In Situ Spinel Solid Solution Bonded Periclase Refractories

2014 ◽  
Vol 633 ◽  
pp. 245-248
Author(s):  
Xin Lin ◽  
Yong Li ◽  
Yan Jing Li ◽  
Jun Jie Zhang ◽  
Chang He Gao ◽  
...  
Keyword(s):  
Solid Solution ◽  
Phase Composition ◽  
Performance Studies ◽  
Magnesium Aluminate ◽  
Spinel Solid Solution ◽  
Magnesium Aluminate Spinel ◽  
Crushing Strength ◽  
Cold Crushing Strength ◽  
Shock Resistance

Specimens were prepared using iron-rich magnesia (3~1 mm、≤1 mm) and high purity magnesia (≤0.088 mm) as the main starting materials, adding tabular alumina at different size (3~2、2~1、≤1 mm) and content:3%、6%、9%、12%、15% to discover the influence of tabular alumina on sample performance. Phase composition and microstructure were also analyzed. The results show that specimen with content of 6% of corundum possessed the best comprehensive performance:apparent porosity 17%, bulk density 2.95 g·cm-3, cold crushing strength 74 MPa, refractoriness under load 1700 °C, heat shock resistance of up to 18 times. The formations of magnesium aluminate spinel and hercynite solid solution were enhanced by Fe ion at high temperatures in the iron-rich magnesia-corundum system at the presence of iron oxides, which are able to largely dissolved in periclase.

Studies on correlation of surface properties, colloidal shaping and transparency of magnesium aluminate spinel powder

2020 ◽  
Vol 252 ◽  
pp. 123372
Author(s):  
Papiya Biswas ◽  
Swathi Manivannan ◽  
Y. Srinivasa Rao ◽  
Roy Johnson
Keyword(s):  
Surface Properties ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Spinel Powder

Effect of TiO2 on Mechanical Properties and Microstructure of Magnesium Aluminate Spinel Refractories

2011 ◽  
Vol 284-286 ◽  
pp. 638-641
Author(s):  
Jun Cong Wei ◽  
Xiao Cui Han ◽  
Chun Hui Gao ◽  
Jian Kun Huang ◽  
Jun Bo Tu
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Titanium Dioxide ◽  
Phase Composition ◽  
High Temperature ◽  
Physical Properties ◽  
Room Temperature ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel

MgO-Al2O3-TiO2 composite refractories were prepared by using magnesium aluminate spinel (MgAl2O4) and titanium dioxide as main starting materials and being sintered at high temperature. The influences of titanium dioxide additions on the room temperature physical properties, phase composition and microstructure were investigated. The phase composition and microstructure were tested by means of XRD and SEM. The results revealed that with increasing TiO2 content, the densification of the composites first increased sand then decreased and maximized at 4% TiO2 loading. This showed appropriate amount of TiO2 could contribute to the sintering of the composites due to the solid solution of TiO2 in magnesium aluminate spinel.

scholarly journals THE EFFECT OF Mg-Al Wt% FOR PHASE FORMATION OF SPINEL MgAl2O4 PRODUCED BY METAL DISSOLVED METHOD

2020 ◽  
Vol 12 (1) ◽  
pp. 21
Author(s):  
Chairatul Umamah ◽  
Suminar Pratapa ◽  
Herman Jufri Andi
Keyword(s):  
Raw Materials ◽  
Relative Weight ◽  
Weight Fraction ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Qualitative And Quantitative ◽  
Mixing Method ◽  
Quantitative Analyses ◽  
Spinel Mgal2o4 ◽  
Spinel Powder

<p class="Abstract">Synthesis of magnesium aluminate spinel powder (MgAl<sub>2</sub>O<sub>4</sub>, abbreviated as MA) were prepared by the liquid mixing method. The synthesis of MA involved Mg powders with various weight compositions (4.8; 10; 20; 30; 40; and 60%) and Al powders (95.2; 90; 80; 70; 60 and 40%) as the raw materials, which were independently dissolved in 37% HCl to form MgCl<sub>2</sub> and AlCl<sub>3</sub> solutions. Both solutions were then mixed and stirred for 5 hours and dried to a temperature of about 100-105°C to produce powders with different weight compositions. Each powder resulted from drying was characterized using DTA-TGA, and then calcined at 650 °C; 750 °C and 850 °C for 1 hour. The calcined powder was characterized by XRD to qualitative and quantitative analyses using Rietica. It was found that MA samples contained only MgAl<sub>2</sub>O<sub>4</sub> and MgO as the impurity phase. The relative weight fraction of MgAl<sub>2</sub>O<sub>4</sub> increased up to 99% for 95.2 wt% Al. Using an extrapolative approach to determine the Mg-to-Al composition, nearly pure MA, as high as 99%, was achieved at 95.2% Al and 4.8% Mg.</p>

Phase Composition, Microstructure and Mechanical Properties of Aluminous Cements Containing Magnesium Aluminate Spinel

2011 ◽  
Vol 492 ◽  
pp. 467-471
Author(s):  
Jin Hong Li ◽  
Ling Xin Tong ◽  
Wen Cai Zhou
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Phase Composition ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Curing Time ◽  
Sintering Process ◽  
Microstructure And Mechanical Properties ◽  
New Type ◽  
Aluminous Cement

A new type aluminous cement containing magnesium aluminate (MA) spinel was prepared from mixtures of limestone, magnesian and bauxite at different ratios by sintering process. The phase composition, microstructure and mechanical properties of aluminous cements containing magnesium aluminate spinel were investigated in this paper. According to the XRD results, the magnesium aluminate spinel (MA),calcium monoaluminate (CA) and calcium bialuminate (CA2) are the primary phases of the obtained aluminous cements with a small quantity of calcium silicoaluminate (C2AS) and remained alumina (Al2O3). The results of SEM indicate that the MA mainly exist in the shape of octahedron with the length of about 2-5 μm, and it is agglomerated with the tabular or flaky-shaped CA among the obtained aluminous cements. In addition, the compressive strength of castables containing obtained aluminous cements increase obviously with the content of CA rising or the curing time increasing.

Gelcasting of Magnesium Aluminate Spinel Powder

2009 ◽  
Vol 92 (2) ◽  
pp. 350-357 ◽  
Author(s):  
Ibram Ganesh ◽  
Susana M. Olhero ◽  
Paula M. C. Torres ◽  
José M. F. Ferreira
Keyword(s):  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Spinel Powder

Effect of HIP on the Properties and Microstructure of Transparent Polycrystalline Spinel

2007 ◽  
Vol 336-338 ◽  
pp. 1200-1202 ◽  
Author(s):  
Mu Yun Lei ◽  
Cun Xin Huang ◽  
Jia Lin Sun
Keyword(s):  
Grain Size ◽  
Optical Properties ◽  
Hot Pressing ◽  
Hot Isostatic Pressing ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Sintering Aid ◽  
Average Transmittance ◽  
Before And After ◽  
Spinel Powder

In this paper, transparent polycrystalline magnesium aluminate spinel was fabricated by hot pressing ultra fine high purity spinel powder using LiF as the sintering aid in vacuum, then hot isostatic pressing (HIPing) the sintered body to improve the optical properties of the sample. The transmittance and the strength of the samples before and after HIPing were measured; morphologies of the fracture surface of the samples before and after HIPing were observed. Following hot pressing, the grain size of the sample is small; the transmission values are low and may varied at different sites in the same sample. After HIPing, the strength of the sample decreased, the grain size increased obviously, and the transmittance and the uniformity of transmittance increased significantly. The panel of transparent spinel up to 200 mm in diameter and 8 mm thick was fabricated by this method; the average transmittance of the spinel is above 80% in the range between 2 μm and 5 μm .

A Novel Way to Synthesis Magnesium Aluminate Spinel Powders by Polymer Gel Reaction

2012 ◽  
Vol 512-515 ◽  
pp. 600-603 ◽  
Author(s):  
Jiang Feng Tong ◽  
Da Ming Chen
Keyword(s):  
High Purity ◽  
Single Phase ◽  
Raw Materials ◽  
Spinel Phase ◽  
Ultrafine Powder ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Polymer Gel ◽  
Mullite Phase ◽  
Spinel Powder

In this paper, a fine pure Magnesium aluminate spinel powder was synesised by Gel solid reaction,using Al(NO3)36H2O and Mg(NO3)26H2O as raw materials under given condition. The precursor was formed by polymer gelling.The phase changed according to heating temperatures from 700°C to 900°C.The single phase of Magnesium aluminate spinel was obtained by calcining the precursor at temperatures higher than 900°C. The phase changing process and relationship among calcination parameters, phase composition and image of particle are studied to determine the optimal conditions for the synthesis of fine Magnesium aluminate spinel powder. The powder obtained was characterized by XRD,TEM etc. The results of analysis showed that the ultrafine powder is of spinel phase, high purity, good dispersion.This process for preparing fine Magnesium aluminate spinel powder was very simple and inexpensive.The results of analysis showed that the ultrafine powder was of mullite phase, high purity, good dispersion, and the particle were homogeneous.

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