The Influences of Addition of MgCO3 on the Properties of the Magnesia Prepared Using Magnesite

2018 ◽  
Vol 281 ◽  
pp. 230-235
Author(s):  
Wang Nian Zhang ◽  
Li Wang ◽  
Ni Deng
Keyword(s):  
Grain Size ◽  
Bulk Density ◽  
Raw Materials ◽  
Apparent Porosity ◽  
X Ray Diffraction ◽  
Linear Change ◽  
Change Rate ◽  
X Ray ◽  
Before And After ◽  
Calcination Method

Micropowder MgCO3 was added into magnesite as raw materials to prepare magnesia using a two-step calcination method. The sample magnesite was characterized use X-ray diffraction (XRD) and scanning electron microscopy (SEM). Experimental results showed that the sample insulated at 1600° C for 3 hours before and after sintering presented a linear change rate of 15.6 % in the case of without adding micropowder MgCO3, the prepared magnesia had a bulk density of 2.31 g/cm3 and apparent porosity of 32.8 %, while MgO grain size was 3.11 μm. In the case of adding 8 % micropowder MgCO3, the sample magnesite before and after sintering showed a linear change rate of 17.9 %. The bulk density, apparent porosity of prepared magnesia were 2.46 g/cm3 and 28.1 % respectively, while the grain size of MgO was 5.15 mm.

Preparation and Properties of Sintering Brick from Iron Tailings

2012 ◽  
Vol 512-515 ◽  
pp. 1023-1027
Author(s):  
Ran Fang Zuo ◽  
Gao Xiang Du ◽  
Le Fu Mei ◽  
Wei Juan Guo ◽  
Jing Hui Liao
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Bulk Density ◽  
Raw Materials ◽  
Loss On Ignition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Freeze Thaw ◽  
Scanning Electron

The main objective of this paper was to investigate the addition of iron tailing sintering brick production, in the presence of clay, coal refuses and bentonite. Mixtures containing raw materials of sintering brick and iron tailings were prepared at different proportions (up to 55 wt %), fired at 980°C. Freeze/thaw durability, drying and firing shrinkages were investigated as well as the loss on ignition, bulk density and compressive strength of the fired samples. Their mechanical and microstructure properties were also investigated by differential thermal analysis (DTA/TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that compressive strengths of the brick samples are higher than that required by the standards MU15 of GB5101-2003, up to 21.79Mpa with 40% iron tailings corresponding to its higher bulk density completely. Moreover, the results showed that it has such advantages as no lime blowing, uniform color, good freeze/thaw resistance and slight universal frost.

scholarly journals Characterization of cordierite-mullite ceramics prepared from natural raw materials

2013 ◽  
Vol 6 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Abdulmula Ali Albhilil ◽  
Martin Palou ◽  
Jana Kozánková
Keyword(s):  
Thermal Shock Resistance ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mercury Intrusion ◽  
Before And After ◽  
Shock Resistance ◽  
Quenching Method ◽  
Mullite Ceramics

Abstract Series of six cordierite-mullite ceramics were synthesized via solid state reaction at various temperatures from 1250 °C for pure cordierite to 1500 °C for pure mullite. Then the samples were submitted to the test of thermal shock resistance based on cycling heating-quenching procedure. X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Mercury intrusion porosimeter (MIP) have been used to characterize the samples before and after cycling heating-quenching method. Sample 6 was broken after 35 heating-quenching cycles, while the five other reminded stable. The refractoriness of samples is found to be higher than that of commercial ones. XRD shows that heating-quenching procedure has led to crystallization of cordierite and mullite phases. Apart from sample 6, the pore structure is stable with slight consolidation. The microstructure images confirm the results of XRD and MIP showing crack in sample 6 only, but compact and larger particles resulting from crystal growth in other samples due to the repeated action of heating.

scholarly journals Hydroxyapatite Extracted from Waste Fish Bones and Scales via Calcination Method

2015 ◽  
Vol 773-774 ◽  
pp. 287-290 ◽  
Author(s):  
N. Mustafa ◽  
Mohd Halim Irwan Ibrahim ◽  
Rosli Asmawi ◽  
Azriszul Mohd Amin
Keyword(s):  
Chemical Reaction ◽  
Fish Bone ◽  
Powder Size ◽  
X Ray Diffraction ◽  
Calcination Process ◽  
X Ray ◽  
Calcination Temperatures ◽  
Hydroxyapatite Powder ◽  
Before And After ◽  
Calcination Method

A hydroxyapatite is known as one of vital materials and common use in biomedical field and concentrated in clinical area. In relation to the above, the development of hydroxyapatite powder becomes an attractive research lines due to simplify in produce it. Thus in this paper the researcher stress out about Hydroxyapatite powder gained from the natural sources or so called as the waste of Tilapia bone and scales. The raw bones of and scale were undergo to crushing process to form in powder size (0.2 mm) then analysed by X-ray Diffraction (XRD) to identified the mineralogy of raw bone. Moreover the powder of fish bone and scales also go through to Scanning Electron Microscope (SEM) machine to analyse the microstructure of the powder while EDS act as device to determine the chemical composition of the sample powder. Sample powder then forward calcination process at selected temperature range to as a cheaper method in obtained hydroxyapatite raw sources. The range of calcination temperatures are between 800°C to 1000 °C. The sample preparation were analysed in both condition before and after calcination process by using XRD, SEM and EDS. The HAP crystalline composition of tilapia bones for raw powder and at 800 °C are similar with HAP pattern (JDS 00-009-0432) and the chemical reaction is Ca5(PO4)3(OH) then at temperature 900 and 1000 similar to HAP pattern (JDS 00-055-0592) with chemical reaction equal to Ca10(PO4)6(OH)2.

Laser Recrystallization of InP Films on Oxidized Si Substrate

1985 ◽  
Vol 53 ◽  
Author(s):  
Li Xiqiang ◽  
Zhu Weiwen ◽  
Lin Chenglu ◽  
Wang Weiyuan ◽  
Tsou Shihchang
Keyword(s):  
Grain Size ◽  
Laser Power ◽  
Beam Diameter ◽  
Electrical Characteristics ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray ◽  
Si Substrates ◽  
Laser Recrystallization ◽  
Before And After

ABSTRACTThe InP films with thickness of 1-2 µm and resistivity of 10-10−3Ω-cm were sputtered on oxidized Si substrates heated at about 300°C to form as InP SOI. Using X-ray diffraction, ED, TEM, Hall and RBS, we have investigated the grain size, compositions, thermal stability and electrical characteristics of InP SOI before and after CW Ar+ laser recrystallization. The sputtered InP SOI films appear as polycrystalline and its grain size increases with increasing of irradiated laser power from 5.8 to 7.0 W at a beam diameter of 70 µm. After irradiation at 7 W the single crystal ED patterns are obtained, the mobility and carrier concentrations amount to 103cm2/Vs and 1017cm−3, respectively, and the compositions are stoichiometric.

Effect of Z Values on the Microstructure and Mechanical Properties of Post-sintered Reaction Bonded β-SiAlON

2017 ◽  
Vol 36 (5) ◽  
pp. 453-458 ◽  
Author(s):  
Yanjun Li ◽  
Donghua Liu ◽  
Han Jin ◽  
Donghai Ding ◽  
Guoqing Xiao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Bulk Density ◽  
Grain Growth ◽  
Bending Strength ◽  
Raw Materials ◽  
Apparent Porosity ◽  
Reaction Bonding ◽  
Microstructure And Mechanical Properties ◽  
Before And After

Abstractβ-SiAlON materials with different Z values (Z=0.5–3) were fabricated by a reaction bonding combining post-sintering route using raw materials of Si, Al2O3, AlN, etc. The reaction bonded β-SiAlON (RB-β-SiAlON) were post-sintered at 1,750 °C for 6 h. Apparent porosity, bulk density, bending strength and Vicker’s hardness of the samples before and after post-sintering were tested. XRD results showed that the phase composition of both RB-β-SiAlON and post-sintered RB-β-SiAlON (PSRB-β-SiAlON) were β-SiAlON. For RB-β-SiAlON, the apparent porosity was decreased with the increase of Z values, while the strength and hardness was increased accordingly. After the post-sintering procedure, nearly full densified PSRB-β-SiAlON was obtained and the mechanical properties were significantly improved. The bending strength and Vicker’s hardness of the PSRB-β-SiAlON (Z=0.5) achieved 510 MPa and 16.5 GPa, respectively, which were as 2.7 and 6.7 times high as those of the corresponding RB-β-SiAlON. However, the strength and hardness of PSRB-β-SiAlON decreased with the increase of Z value due to the grain growth.

Synthesis of Titanium Carbonitride Powders by Reactive Ball Milling of Titanium, Graphite and Urea

2014 ◽  
Vol 1004-1005 ◽  
pp. 69-72
Author(s):  
Jin Feng Sun ◽  
Kun Quan ◽  
Ji Sheng Sun ◽  
Yong Qiang Meng
Keyword(s):  
Grain Size ◽  
Ball Milling ◽  
Milling Time ◽  
Rotation Speed ◽  
Raw Materials ◽  
Titanium Carbonitride ◽  
X Ray Diffraction ◽  
X Ray

Titanium carbonitride (TiCN) nanocrystaline powders were syntheiszed by reactive ball milling of titanium, graphite and urea. GN-2 ball milling was used and the rotation speed was 600rpm. The ratio of ball to material was 30:1, the milling time was from 10 hours to 50 hours. The powders milled for different time were analyzed by X-ray diffraction. The results show that TiCN powders can be synthesized by milling 10 hours, although some raw materials remained. After milled for 50 hours, the raw materials can reactive completely to form TiCN and the grain size of the TiCN powder was about 7 nm.

Effect of SiC on Microstructures and Properties of Clay Foam Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 620-622
Author(s):  
Jian Guang Bai ◽  
Guang Liang Liu ◽  
Jian Feng Yang
Keyword(s):  
Compressive Strength ◽  
Bulk Density ◽  
Moisture Absorption ◽  
Raw Materials ◽  
Sintering Behavior ◽  
Powder Size ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Foam Ceramic

A foam ceramic was prepared using clay, SiC, Fe2O3, feldspar and other raw materials as main starting material in a furnace at 1140~1170oC for 15~25min. Effects of silicon carbide’s content and powder size on the bulk density, moisture absorption rate and compressive strength were studied, and the fracture surface morphology was observed and analyzed using Scanning Electron Microscope (SEM) and X-ray diffraction analysis (XRD). The results show that SiC powder reacted with Fe2O3, Fe3O4, CO2, iron, SiO2 and form foam. The sintering behavior and properties of the foam ceramics are influenced by the content and particle size of SiC, when the content of SiC is as high as 8%, and the mass ratio of grain size is 1:1, the foam ceramics with the rate of moisture absorption is 0.05%, the bulk density is 0.32g/cm3, and compressive strength is than 2.2MPa.

Preparation and Structural Characterization of CMC/MMT Nanocomposite

2010 ◽  
Vol 177 ◽  
pp. 606-609
Author(s):  
Chuan Xin Zhai ◽  
Yan Li ◽  
Xiang Dong Ma ◽  
Shi Zhong Wei ◽  
Liu Jie Xu
Keyword(s):  
Raw Materials ◽  
Diffraction Peak ◽  
Atomic Scale ◽  
X Ray Diffraction ◽  
Sodium Carboxymethylcellulose ◽  
Solution Intercalation ◽  
X Ray ◽  
Transmission Electron ◽  
Before And After

Using montmorillonite (MMT) and sodium carboxymethylcellulose (CMC) as raw materials, CMC/MMT nanocomposites were prepared by the solution intercalation technique. The microstructures of MMT before and after being intercalated were characterized by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). The results of XRD showed that when the adding amount of CMC increased from naught to 70wt%, the structures of MMT have no change basically; when the adding amount of CMC increased to 80wt%, the decrease of MMT (001) was significant; when the adding amount of CMC reached to 90wt%, the diffraction peak of (001) disappeared, which indicated that the layers of MMT have been exfoliated along (001) and the CMC/MMT intercalated structure has been obtained. The observations by HRTEM showed that the shapes of MMT are layer aggregation or agglomerated particles. The MMT added with 90wt% CMC has changed into intercalated structure with alternating MMT and CMC order mainly, and the intercalated structure was characterized at the atomic scale.

Effect of NH4Cl Flux on Structural and Luminescent Properties of CaS: Eu2+ Phosphors

2014 ◽  
Vol 989-994 ◽  
pp. 755-758
Author(s):  
Yun Jie Zhang ◽  
Jie Zhao ◽  
Da Jian Wang ◽  
Jian Ma
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Raw Materials ◽  
Luminescent Properties ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Structure Morphology ◽  
Scanning Electron

CaS:Eu2+phosphors were prepared by two steps method at a relatively low temperature (1050°C) using NH4Cl as a flux. The influences of NH4Cl flux concentrations on the crystal structure, morphology and photoluminescent properties of CaS:Eu2+phosphors were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL), respectively. XRD analysis shows that when the raw materials added with the NH4Cl flux, the crystal structure was not changed .The SEM images indicate that increase of the NH4Cl flux enlarged the grain size of the phosphor particles. The luminescence intensity of CaS:Eu2+was enhanced with adding NH4Cl flux and up to the maximum emission intensity when the addition of NH4Cl flux is 1wt%.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

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