scholarly journals Final flotation waste kinetics of sintering at different heating regimes

2016 ◽  
Vol 48 (2) ◽  
pp. 197-208
Author(s):  
Mira Cocic ◽  
Mihovil Logar ◽  
Branko Matovic ◽  
Snezana Devic ◽  
Tatjana Husovic-Volkov ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Fluorescence Analysis ◽  
Ceramic Materials ◽  
Copper Extraction ◽  
Heating Regime ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pyrometallurgical Processing ◽  
Kinetics Of

In the copper extraction, especially during the process of flotation enrichment and the pyrometallurgical processing, the waste materials that represent huge polluters of environment are being generated. In order to examine the application of Final flotation waste (FFW) in the manufacturing of new materials from the glass-ceramic group phase and mineral composition were examined as well as thermal properties. FFW kinetics of sintering has been tested at different dyamics (1?C/min, 29?C/min and 43?C/min), in order to find the optimum conditions for sintering with a minimum amount of energy and time consumption. The samples were examined using: X-ray diffraction, X-ray fluorescence analysis, SEM (Scanning Electron Microscopy) and thermal microscopy. The best results for the production of glass ceramic materials were obtained during the sintering at heating regime of 29?C/min.

Crystallization and Mechanical Properties of Glass-Ceramic from Silicon Slag

2014 ◽  
Vol 953-954 ◽  
pp. 1643-1648
Author(s):  
Hang Li ◽  
Li Qiang Liu ◽  
Min Jing ◽  
Zhi Gang Wang ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Mechanical Performance ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Talcum Powder ◽  
X Ray ◽  
Glass Ceramic Materials ◽  
Spherical Grains

The glass-ceramic materials were produced from silicon slag with the addition of talcum powder and TiO2 by melting them in an electrically heated furnace and subsequent heat treatment at various temperatures and time. The microstructure and crystallization behaviors of glass–ceramics have been investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). With the increase of silicon slag content, the sequent precipitate phase is: krinovite Na (Mg1.9Fe0.1)Cr (SiO)3O, pseudobrookite Fe2TiO5 and anorthite Ca (Al2Si2O8), enstatite ferroan MgFeSi2O6, and albite Na (AlSi3O8). The shape of crystals was spherical grains. The glass–ceramic sample obtained from 70% silicon slag had the excellent mechanical performance including flexural strength of 200.45 MPa and Vickers micro hardness of 909.72 MPa.

scholarly journals GLYCEROLYSIS USING KF/CAO-MGO CATALYST: OPTIMISATION AND REACTION KINETICS

2020 ◽  
Vol 82 (5) ◽  
Author(s):  
Luqman Buchori ◽  
Mohammad Djaeni ◽  
R. Ratnawati ◽  
Diah Susetyo Retnowati ◽  
H. Hadiyanto ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Gas Chromatography Mass Spectrometry ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Base Catalysts ◽  
Cooking Oil ◽  
Surface Method ◽  
Kinetics Of ◽  
Glycerolysis Reaction

Monoglycerides can be produced through glycerolysis using a heterogeneous catalyst. The purpose of this study is to analyse the optimum conditions for the production of monoglycerides from glycerol and cooking oil using KF/CaO-MgO base catalysts and to investigate the kinetics of the monoglyceride glycerolysis reaction. The response surface method (RSM) was used to determine the favourable conditions by varying the catalyst amount (X1) between 0.1, 0.2 and 0.3% (w/w); the reaction temperature (X2) between 210, 220 and 230°C and reaction time (X3) between 2, 3 and 4 hours. Gas chromatography-mass spectrometry (GC-MS) was used to determine the monoglycerides, while catalysts were characterised by X-ray diffraction (XRD) and the Brunauer-Emmett-Teller method (BET). The results showed that, among the three factors examined, temperature shows the most control over this glycerolysis reaction. The most favourable conditions are X1 = 0.19% (w/w), X2 = 208.37°C and X3 = 3.20 hours, which provide a monoglyceride yield of 41.58%. The constants for the reaction kinetics of the monoglyceride formation, k1 and k2 are 1.04189 and 0.88965 hour-1, respectively.

Crystallization Kinetics of Iron Rich Glass-Ceramic Obtained from Waste of Steel Industry

2014 ◽  
Vol 775-776 ◽  
pp. 244-249 ◽  
Author(s):  
André Luís Luza ◽  
Débora Cristina Niero Fabris ◽  
Edivelton Soratto Gislon ◽  
Morgana de Medeiros Machado ◽  
Oscar Rubem Klegues Montedo
Keyword(s):  
Crystallization Kinetics ◽  
Glass Ceramic ◽  
Absorption Spectrometry ◽  
Differential Analysis ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
Heat Treated ◽  
Wet Ground ◽  
Kinetics Of

The main objective of this work was to study the crystallization kinetics of glass-ceramic obtained from steel waste. Two compositions were melted at about 1350 °C. The obtained frits were dried and re-melted. Each composition was then wet ground, dried, and chemically characterized (X-ray fluorescence and atomic absorption spectrometry), structurally (X-ray diffraction), and thermally (thermal differential analysis). Then the powders were compacted and the samples were dried and heat treated in a kiln between 690 and 890 °C. After, the crystallized bodies were ground and the crystalline phases were identified by X-ray diffraction. Results showed that the main formed crystalline phases were magnetite, hematite, Fe2.95Si0.05O4, and CaAl2Fe4O10. The activation energies obtained by the Kissinger method were between 348 and 423 kJ.mol-1, whereas the Avrami parameter was obtained between 0.76 and 1.1 indicating surface crystallization.

scholarly journals Method of X-Ray Diffraction Data Processing for Multiphase Materials with Low Phase Contents

2019 ◽  
Vol 64 (9) ◽  
pp. 870 ◽  
Author(s):  
A. D. Scorbun ◽  
S. V. Gabielkov ◽  
I. V. Zhyganiuk ◽  
V. G. Kudlai ◽  
P. E. Parkhomchuk ◽  
...  
Keyword(s):  
Diffraction Data ◽  
Glass Ceramic ◽  
Noise Level ◽  
Ceramic Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multiphase Materials ◽  
Glass Ceramic Materials ◽  
Amorphous Glass ◽  
Diffraction Patterns

Amorphous, glass, and glass-ceramic materials practically always include a significant number (more than eight) of crystalline phases, with the contents of the latter ranging from a few wt.% to several hundredths or tenths of wt.%. The study of such materials using the method of X-ray phase analysis faces difficulties, when determining the phase structure. In this work, we will develop a method for the analysis of the diffraction patterns of such materials, when diffraction patterns include X-ray lines, whose intensities are at the noise level. The identification of lines is based on the search for correlations between the experimental and test lines and the verification of the coincidence making use of statistical methods (computer statistics). The method is tested on the specimens of a-quartz, which are often used as standard ones, and applied to analyze lava-like fuel-containing materials from the destroyed Chornobyl NPP Unit 4. It is shown that the developed technique allows X-ray lines to be identified, if the contents of separate phases is not less than 0.1 wt.%. The method also significantly enhances a capability to determine the phase contents quantitatively on the basis of lines with low intensities.

Effect of Gradual Substitution of CaO by SrO in Glass-Ceramic Materials of the System SiO2 - Al2O3 - CaF2 - RO (R = Ca, Mg, Sr)

2012 ◽  
Vol 1373 ◽  
Author(s):  
M. Garza-García ◽  
J. López-Cuevas ◽  
C.A. Gutiérrez-Chavarría ◽  
N. Piedad-Sánchez ◽  
E. Camporredondo-Saucedo ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Vickers Microhardness ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Substitution Level ◽  
Glass Ceramic Materials ◽  
Ceramic Samples ◽  
Crystallization Fraction

ABSTRACTThe density, Vickers microhardness and crystallization fraction of glass-ceramic materials synthesized from parent glasses are determined in which CaO is gradually substituted by SrO. The chemical composition (in mol.%) of the parent glasses is 54SiO2-(23-X)CaO-12MgO-5Al2O3-6CaF2-XSrO, where X is the employed CaO substitution level (X = 0, 3, 6 and 9 mol.%, with X = 0 corresponding to the reference material). In order to determine the type of crystallization occurring in the glass-ceramic samples, as well as the crystalline phases formed in them, these are characterized by both Scanning Electron Microscopy (SEM/EDS) and X-Ray Diffraction (XRD). Independently of the CaO substitution level employed, the glass-ceramics show the formation of a solid solution corresponding to diopside-type pyroxene, with chemical formula Ca(Mg,Al)(Al,Si)2O6, as a single crystalline phase. The synthesized glass-ceramic materials with the reference composition show the highest Vickers microhardness and crystallization fraction, as well as the lowest density.

scholarly journals Sinter recrystalization and properties evaluation of glass-ceramic from waste glass bottle and magnesite for extended application

10.30544/223 ◽  
2016 ◽  
Vol 22 (4) ◽  
pp. 285-302
Author(s):  
As'mau Ibrahim Gebi ◽  
Shehu Aliyu Yaro ◽  
Malik Abdulwahab ◽  
Mamuda Rayyan Dodo
Keyword(s):  
Particle Size ◽  
Flexural Strength ◽  
Glass Ceramic ◽  
Sintering Temperature ◽  
Ceramic Materials ◽  
Glass Frit ◽  
X Ray Diffraction ◽  
Glass Bottle ◽  
X Ray ◽  
Glass Ceramic Materials

In a bid to address environmental challenges associated with the management of waste Coca cola glass bottle, this study set out to develop glass ceramic materials using waste coca cola glass bottles and magnesite from Sakatsimta in Adamawa state. A reagent grade chrome (coloring agent) were used to modify the composition of the coca cola glass bottle;  X-ray fluorescence(XRF), X-ray diffraction (XRD) and Thermo gravimetric analysis (TGA) were used to characterize raw materials, four batches GC-1= Coca cola glass frit +1%Cr2O3, GC-2=97% Coca cola glass frit+ 2% magnesite+1%Cr2O3, GC-3=95% Coca cola glass frit+ 4%magnesite+1%Cr2O3, GC-4=93%Coca cola glass frit+ 6%magnesite+ 1%Cr2O3 were formulated and prepared. Thermal Gradient Analysis (TGA) results were used as a guide in selection of three temperatures (7000C, 7500C and 8000C) used for the study, three particle sizes -106+75, -75+53, -53µm and 2 hr sintering time were also used, the sinter crystallization route of glass ceramic production was adopted. The samples were characterized by X-ray diffraction (XRD) and Scanning Electron Microscope (SEM), the density, porosity, hardness and flexural strength of the resulting glass ceramics were also measured. The resulting glass ceramic materials composed mainly of wollastonite, diopside and anorthite phases depending on composition as indicated by XRD and SEM, the density of the samples increased with increasing sintering temperature and decreasing particle size. The porosity is minimal and it decreases with increasing sintering temperature and decreasing particle size. The obtained glass ceramic materials possess appreciable hardness and flexural strength with GC-3 and GC-4 having the best combination of both properties.

scholarly journals Stable and Metastable Phase Equilibria Involving the Cu6Sn5 Intermetallic

2021 ◽  
Author(s):  
A. Leineweber ◽  
M. Löffler ◽  
S. Martin
Keyword(s):  
Phase Equilibria ◽  
Electron Backscatter Diffraction ◽  
Metastable Phase ◽  
Stable Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Ordered Phases ◽  
Backscatter Diffraction ◽  
Kinetics Of

Abstract Cu6Sn5 intermetallic occurs in the form of differently ordered phases η, η′ and η′′. In solder joints, this intermetallic can undergo changes in composition and the state of order without or while interacting with excess Cu and excess Sn in the system, potentially giving rise to detrimental changes in the mechanical properties of the solder. In order to study such processes in fundamental detail and to get more detailed information about the metastable and stable phase equilibria, model alloys consisting of Cu3Sn + Cu6Sn5 as well as Cu6Sn5 + Sn-rich melt were heat treated. Powder x-ray diffraction and scanning electron microscopy supplemented by electron backscatter diffraction were used to investigate the structural and microstructural changes. It was shown that Sn-poor η can increase its Sn content by Cu3Sn precipitation at grain boundaries or by uptake of Sn from the Sn-rich melt. From the kinetics of the former process at 513 K and the grain size of the η phase, we obtained an interdiffusion coefficient in η of (3 ± 1) × 10−16 m2 s−1. Comparison of this value with literature data implies that this value reflects pure volume (inter)diffusion, while Cu6Sn5 growth at low temperature is typically strongly influenced by grain-boundary diffusion. These investigations also confirm that η′′ forming below a composition-dependent transus temperature gradually enriches in Sn content, confirming that Sn-poor η′′ is metastable against decomposition into Cu3Sn and more Sn-rich η or (at lower temperatures) η′. Graphic Abstract

Study on Adsorption of Crosslinked Starch Microspheres towards Heavy Metal Ions

2013 ◽  
Vol 834-836 ◽  
pp. 531-535
Author(s):  
Li Yan Yang ◽  
Yi Hui Guo ◽  
Li Li Yu ◽  
Jing You
Keyword(s):  
Metal Ions ◽  
Reversed Phase ◽  
Adsorption Rate ◽  
X Ray Diffraction ◽  
Adsorption Selectivity ◽  
X Ray ◽  
Starch Microsphere ◽  
Other Substances ◽  
Effects Of Media ◽  
Kinetics Of

A type of cross-linking starch microsphere (CSMs) has been synthesized via reversed phase suspension method. Crosslinked starch microsphere has good adsorption performance to metal ions in water. The adsorption kinetics of Co (II) on the CSMs, selectivity of adsorption CSMs towards Co (II),Cu (II),Pb (II),Cd (II) and adsorption effects of media towards Co (II) were investigated. The CSMs and its adsorption product were comparatively characterized by X-ray diffraction (XRD). The results showed that The adsorption rate is mainly controlled by liquid film diffusion, and the constant of adsorption rate is 0.0686min-1 at 308K. The crystal structure of the CSMs decreased greatly after the incorporation of Co (II). Co (II) has better adsorption selectivity on CSMs. Ions coexist and other substances in the solution have certain impact on adsorption. Those data are helpful for treatment of the wastewater containing heavy ions.

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