scholarly journals Influence of Waste Materials Containing Tungsten on Melting and Crystallization of Glass-ceramics

2012 ◽  
Vol 02 (04) ◽  
pp. 74-77
Author(s):  
Shaomin Lin ◽  
Bo Wang ◽  
Guishen Liu ◽  
Liqing Li ◽  
Xiaodong Hou
Keyword(s):  
Glass Ceramics ◽  
Waste Materials ◽  
Crystallization Of Glass ◽  
Melting And Crystallization

scholarly journals Ferrosilicate glass ceramics based on wastes from ore concentration

2021 ◽  
pp. 95-103
Keyword(s):  
Surface Layer ◽  
Iron Ore ◽  
Glass Ceramics ◽  
Redox Conditions ◽  
Glass Technology ◽  
Crystalline Phases ◽  
Reducing Conditions ◽  
Deep Layers ◽  
Hematite Fe2o3 ◽  
Crystallization Of Glass

We showed in this work that there is a possibility of recycling the wastes derived from iron ore concentration by using glass technology. The compositions of new glass ceramics with high technological and decorative properties were developed. The influence of Al2O3, MgO and Na2O additives to the waste from ore benefication on the parameters of the synthesized glass and its crystallization products was studied. The optimal temperatures of synthesis, annealing and crystallization of glass samples in the systems (Fe2O3–FeO)–SiO2–Al2O3–Na2O and (Fe2O3–FeO)–SiO2–Al2O3–MgO were shown to be 1450100С, 500–6000С and 700–8000C, respectively. It was established that the redox conditions of crystallization of glasses in the system (FeO–Fe2O3)–SiO2–Al2O3–Na2O strongly affect the nature of the iron-containing phases that are formed: oxidative conditions favors the formation of hematite (Fe2O3) and aegirinite (Na2OFe2O34SiO2), whereas reducing conditions contributes to the formation of wustite (FeO) and fayalite (2FeOSiO2). In the system (FeO–Fe2O3)–SiO2–Al2O3–MgO under both oxidative and reducing conditions of crystallization, the same crystalline phases appear: olivine (2(Mg,Fe)OSiO2), hercin (FeOAl2O3) and iron metasilicate (FeOSiO2). It was shown that the crystallization of samples under reducing conditions allows producing materials with higher microhardness. The surface layer of glasses and glass ceramics exhibited less microhardness than their deep layers.

scholarly journals Mutual Influence of Special Components in Baotou Steel Blast Furnace Slag on the Crystallization Behavior of Glass

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Yici Wang ◽  
Qi Jiang ◽  
Guoping Luo ◽  
Wenwu Yu ◽  
Yan Ban
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Crystallization Behavior ◽  
Mutual Influence ◽  
Raw Materials ◽  
Glass Ceramics ◽  
Nucleating Agent ◽  
Crystal Phase ◽  
Furnace Slag ◽  
Crystallization Of Glass

In the process of glass-ceramics prepared with Baotou steel blast furnace slag, quartz sand, and other raw materials by melting method, the mutual influence of the special components such as CaF2, REXOY, TiO2, K2O, and Na2O in the blast furnace slag on the crystallization behavior of parent glass was investigated using differential thermal analysis (DTA) and X-ray diffraction (XRD). The results show that the special components in slag can reduce the crystallization temperature and promote crystallization of glass phase, which belongs to surface crystallization of glass, and they cannot play the role of the nucleating agent; the major crystal phase composed of diopside, diopside containing aluminum and anorthite, is slightly different from the expected main crystal phase of diopside. Therefore, the nucleating agents of proper species and quantity must be added into the raw materials in order to obtain glass-ceramics. The results have important theoretical guidance meaning for realizing industrial production of Baotou steel blast furnace slag glass-ceramics preparation.

Diopside–Ca-Tschermak clinopyroxene based glass–ceramics processed via sintering and crystallization of glass powder compacts

2007 ◽  
Vol 27 (5) ◽  
pp. 2325-2331 ◽  
Author(s):  
A. Goel ◽  
D.U. Tulyaganov ◽  
S. Agathopoulos ◽  
M.J. Ribeiro ◽  
R.N. Basu ◽  
...  
Keyword(s):  
Glass Powder ◽  
Glass Ceramics ◽  
Powder Compacts ◽  
Crystallization Of Glass

Crystallization of Cordierite Glass Ceramics for Joining SiC: Must Phase Separation Via Spinodal Decomposition Precede Nucleation?

1997 ◽  
Vol 3 (S2) ◽  
pp. 631-632
Author(s):  
Warren J. MoberlyChan ◽  
T. J. Perham ◽  
L. C. DeJonghe
Keyword(s):  
Phase Separation ◽  
Coefficient Of Thermal Expansion ◽  
Glass Ceramics ◽  
Superplastic Forming ◽  
Secondary Phases ◽  
Flexible Control ◽  
Fine Grained ◽  
Cordierite Glass ◽  
Lower Temperature ◽  
Crystallization Of Glass

The crystallization of glass ceramics provides processing advantages for difficult shapes. Machining and sintering are limited to produce complex parts; similarly (superplastic) forming is limited to special ceramics. In theory, however, a liquid (or glass) may be simply poured into any shape, and then crystallized (or partially crystallized) to provide a strong, tough ceramic. In this work, a thin layer of glass ceramic, cordierite (2MgO.2Al2O3.5SiO2), joins SiC [1]. Tailoring secondary phases and percent crystallization provide flexible control of the coefficient of thermal expansion to minimize strain mismatches between the joint components.Three processing steps are involved in crystallization of glass ceramics: first a fast quench produces the initial glass; the second step is a lower temperature “nucleation” anneal, where phase separation and/or precursors and/or the final structure is nucleated and ideally as a fine dispersion; the third step is the higher temperature “crystallization” anneal, where renucleation and/or growth develops a homogeneous (ideally fine grained) final crystalline product [2, 3].

Fabrication and Characterization of Modified Fluorescent Glass-Ceramics Composite from Waste Materials

2018 ◽  
Vol 7 (4) ◽  
pp. 529-534
Author(s):  
R. N. Nnaji ◽  
J. O. Agunsoye ◽  
M. A. Bodude ◽  
O. S. I. Fayomi ◽  
I. O. Talabi
Keyword(s):  
Glass Ceramics ◽  
Waste Materials ◽  
Fabrication And Characterization

Low temperature synthesis of anorthite based glass-ceramics via sintering and crystallization of glass-powder compacts

2006 ◽  
Vol 26 (13) ◽  
pp. 2503-2510 ◽  
Author(s):  
V.M.F. Marques ◽  
D.U. Tulyaganov ◽  
S. Agathopoulos ◽  
V.Kh. Gataullin ◽  
G.P. Kothiyal ◽  
...  
Keyword(s):  
Low Temperature ◽  
Glass Powder ◽  
Glass Ceramics ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Powder Compacts ◽  
Crystallization Of Glass

Effects of Phosphorus and Fluorine on the Crystallization and Structure of CaO-A12O3-SiO2 System Glass-Ceramic

2008 ◽  
Vol 368-372 ◽  
pp. 1412-1414 ◽  
Author(s):  
Jin Shu Cheng ◽  
Hui Guang Qiu ◽  
Hong Li ◽  
Jun Xie
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Yellow Phosphorus ◽  
Crystallization Of Glass ◽  
Scanning Electron

CaO-A12O3-SiO2 (CAS) system glass-ceramics were prepared by sintering with certain amount of yellow phosphorus slag. The effects of phosphorus and fluorine on the nucleation, crystallization and structure of CAS system glass-ceramics were investigated by differential thermal analysis, X-ray diffraction, scanning electron microscopy and other measuring methods. Glass-ceramics of CAS system with 42.32wt% yellow phosphorus slag were obtained by nucleating at 615°C for 1 hour and crystallizing at 926°C for 2 hours. The results showed that the introduction of phosphorus and fluorine promoted the nucleation and crystallization of glass-ceramics, lowering the crystallizing temperature. The main crystal phase of glass-ceramics was β-wollastonite. The density of the glass-ceramic was 2.695g/cm3.

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