Preparation of Sintered Glass-Ceramics: A Comparison of Different Binders

2014 ◽  
Vol 563 ◽  
pp. 123-126
Author(s):  
Na Li ◽  
Hong Hai Shen ◽  
Wei Juan Zhang ◽  
Shi Quan Liu
Keyword(s):  
Waste Water ◽  
Polyvinyl Alcohol ◽  
Water Glass ◽  
Glass Powder ◽  
Glass Ceramics ◽  
Solid Wastes ◽  
Fine Grained ◽  
Sintered Glass ◽  
Negative Effect ◽  
Sintering Shrinkage

With the rapid increase of solid wastes and the decrease in natural resources, the reutilization of the wastes has become an urgent need. Sintered glass-ceramics with gehlenite and anorthite as main crystalline phases have been prepared with glass powder made from a waste water flocculate. In this work, different binders, including diluted water glass, polyvinyl alcohol (PVA) solution and kaolin were added to form green bodies for making sintered glasses ceramics. Effects of the binders on the sintering shrinkage of the green bodies, the crystallization of the glass powder upon sintering and the microstructure of the sintered glass-ceramics have been investigated. The results indicate that the kaolin benefits the reduction of the shrinkage and may have negative effect on the formation of glass-ceramics with fine grained crystallites. In contrast, PVA and water glass solutions as binders lead to larger shrinkage values and glass-ceramics with well distributed smaller crystallites.

Optimal Conditions for Preparing Sintered Glass-Ceramics with Glass Frit from a Waste Water Flocculate

2014 ◽  
Vol 563 ◽  
pp. 36-40
Author(s):  
Na Li ◽  
Hong Hai Shen ◽  
Shi Quan Liu
Keyword(s):  
Waste Water ◽  
Glass Ceramics ◽  
High Hardness ◽  
Glass Frit ◽  
Sem Analysis ◽  
Preparation Conditions ◽  
Sintered Glass ◽  
Treatment Conditions ◽  
Short Period ◽  
Size And Morphology

Sintered glass-ceramics have been successfully prepared using glass particles derived from a waste water flocculate. Influence of heat treatment conditions (sintering temperature and soaking time, heating rate) and size of the glass particles on the microstructure and density, hardness of the obtained glass-ceramics has been studied. The results show that the prepared glass-ceramics have gehlenite and anorthite as main crystalline phases. SEM analysis indicates that the size and morphology of the crystallites vary with the preparation conditions. A dense glass-ceramic with a high hardness can be obtained by sintering glass powder sized smaller than 0.075mm with a relatively slow ramping rate (3°C/min) to a temperature higher than the crystallization peak temperature of the parent glass for a short period of 30min to 1h.

scholarly journals Regulating Effect of Cement Accelerator on High Content Solid-Wastes Autoclaved Aerated Concrete (HCS-AAC) Slurry Performance and Subsequent Influence

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 799
Author(s):  
Dingkun Xie ◽  
Lixiong Cai ◽  
Jie Wang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Solid Wastes ◽  
Hydration Products ◽  
Promoting Effect ◽  
Adverse Side Effects ◽  
Foaming Process ◽  
Carbide Slag ◽  
Negative Effect ◽  
Aerated Concrete

Adverse side-effects occurred in slurry foaming and thickening process when carbide slag was substituted for quicklime in HCS-AAC. Cement accelerators were introduced to modify the slurry foaming and coagulating process during pre-curing. Meanwhile, the affiliated effects on the physical-mechanical properties and hydration products were discussed to evaluate the applicability and influence of the cement accelerator. The hydration products were characterized by mineralogical (XRD) and thermal analysis (DSC-TG). The results indicated that substituting carbide slag for quicklime retarded slurry foaming and curing progress; meanwhile, the induced mechanical property declination had a negative effect on the generation of C–S–H (I) and tobermorite. Na2SO4 and Na2O·2.0SiO2 can effectively accelerate the slurry foaming rate, but the promoting effect on slurry thickening was inconspicuous. The compressive strength of HCS-AAC obviously declined with increasing cement coagulant content, which was mainly ascribed to the decrease in bulk density caused by the accelerating effect on the slurry foaming process. Dosing Na2SO4 under 0.4% has little effect on the generation of strength contributing to hydration products while the addition of Na2O·2.0SiO2 can accelerate the generation and crystallization of C–S–H, which contributed to the high activity gelatinous SiO2 generated from the reaction between Na2O·2.0SiO2 and Ca(OH)2.

Li+ conductivity in the system Li2O-Nb2O5-P2O5-LiCl as solid electrolyte based on synthesized glasses and sintered glass ceramics

2021 ◽  
Vol 372 ◽  
pp. 115769
Author(s):  
K. Waetzig ◽  
J. Schilm ◽  
C. Heubner ◽  
K. Nikolowski ◽  
M. Partsch
Keyword(s):  
Solid Electrolyte ◽  
Glass Ceramics ◽  
Sintered Glass

Indirect Cytotoxicity Evaluation of Silver Doped Bioglass Ag-S70C30 on Human Primary Keratinocytes

2005 ◽  
Vol 284-286 ◽  
pp. 431-434 ◽  
Author(s):  
U. Lohbauer ◽  
G. Jell ◽  
Priya Saravanapavan ◽  
Julian R. Jones ◽  
Larry L. Hench
Keyword(s):  
Cell Viability ◽  
Glass Powder ◽  
Culture Medium ◽  
Neutral Red ◽  
Epidermal Keratinocytes ◽  
Mitochondrial Activity ◽  
Human Epidermal Keratinocytes ◽  
Negative Effect ◽  
Healing Agent ◽  
Gel Glasses

Bioactive gel-glasses, such as the silver-doped Ag-S70C30 glass, can be used to modify the inflammatory response in a local body compartment such as in acne lesions and in nonhealing dermal wounds. In this study, the cytotoxicity of soluble silver, calcium and silica ions on human epidermal keratinocytes was investigated by measurements of mitochondrial activity (MTT assay) and neutral red dye uptake (NR assay). Ag-S70C30 extracts were prepared by soaking glass powder in complete culture medium at concentrations of 1 mg/ml and 2 mg/ml (mg of glass powder per ml of culture medium). Silver concentrations for both concentrations of approximately 1 ppm were detected by inductive coupled plasma analysis (ICP). No negative effect on the cell viability was measured for an initial gel-glass concentration of 1 mg/ml and for the two shortest extraction times at a concentration of 2 mg/ml. Based on the results from MTT/ NR assays, a pH rise of approximately one unit had no negative effect on the NHEK-A cell viability. This preliminary study on keratinocyte viability merits future investigations on silver bioglass as a novel antimicrobial wound healing agent.

scholarly journals High strength glass-ceramics sintered with coal gangue аs а raw material

2019 ◽  
Vol 51 (3) ◽  
pp. 285-294
Author(s):  
Dang Wei ◽  
H.-Y. He
Keyword(s):  
Building Materials ◽  
Raw Materials ◽  
Glass Ceramics ◽  
High Strength ◽  
Coal Gangue ◽  
Raw Material ◽  
Sintering Process ◽  
Forming Process ◽  
Sintered Glass ◽  
Utilization Ratio

High strength lightweight glass-ceramics were fabricated with coal gangue and clay as main raw materials. The utilization ratio of coal gangue, the ratio of the coal gangue with clay, mineralization agents, forming process and sintering process on the properties of the fabricated glass-ceramics were optimized. The utilization ratio of coal gangue reached 75, and the ratio of coal gangue to clay was 3/1, as an optimal property was observed. The optimal sintering temperature was found to be 1370?C. At this optimal temperature, the sintered glass-ceramics showed the main phase of mullite and spindle and so showed high strength, low density, and low water absorbance. The appropriate amounts of codoping of the TiO2, ZnO, and MnO2/dolomite as mineralization agents obviously enhanced the properties of the glass-ceramics. Process optimizations further determined reasonable and optimal process parameters. The high strength lightweight glass-ceramics fabricated in this work may be very suitable for various applications including building materials, cooking ceramics, and proppant materials, et al.

Reindeer herding and petroleum development on Poluostrov Yamal: sustainable or mutually incompatible uses?

Polar Record ◽  
1999 ◽  
Vol 35 (195) ◽  
pp. 317-322 ◽  
Author(s):  
Bruce C. Forbes
Keyword(s):  
Industrial Development ◽  
Organic Layer ◽  
Fine Grained ◽  
Nomadic Pastoralists ◽  
Natural Gas Development ◽  
Large Populations ◽  
Negative Effect ◽  
Petroleum Development ◽  
Wild Reindeer

AbstractThe Yamal Nenets have exploited reindeer via hunting and/or husbandry in northwest Siberia for several hundred years, although wild reindeer have been virtually absent on Poluostrov Yamal since the early 1900s. Nonetheless, the region retains large populations of wild animals, indicating that nomadic pastoralists, semi-domestic animals, and wildlife were not competing vigorously for resources or space prior to industrialization. Natural-gas development is a relative newcomer to the region, but has already had a significant impact on the bio-physical and socioeconomic environments. The withdrawal of lands for industrial infrastructure, in addition to direct and cumulative impacts from three decades of exploration, has led to a serious decline in the quantity and quality of the remaining tundrasuitable for reindeer pasture.Available records indicate that some preferred fur-bearing game species have been significantly reduced in recent years, primarily by non-natives. At the same time, it appears that extensive grazing by the reindeer themselves is having an overall negative effect on the area's pastures. Specifically, reindeer grazing is resulting in the thinning of the organic layer on well-drained ground and the exposure of fine-grained sands. The surfaces of these patches are highly erodable and unstable, therefore spreading easily as long as they remain unvegetated. The significant expansion of such areas is a genuine threat as long as, first, industrial development continues to degrade the land, and, second, the numbers of reindeer remain at current levels or increase.

scholarly journals Effect of the bur grit size on the flexural strength of a glass-ceramic

Cerâmica ◽  
2016 ◽  
Vol 62 (362) ◽  
pp. 121-127 ◽  
Author(s):  
P. P. Kist ◽  
I. L. Aurélio ◽  
M. Amaral ◽  
L. G. May
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Internal Surface ◽  
Grit Size ◽  
Diamond Grit ◽  
Cad Cam ◽  
Negative Effect ◽  
Ceramic Blocks

Abstract The purpose of the present study was to determine the biaxial flexural strength (BFS) of a CAD/CAM leucite reinforced glass-ceramic ground by diamond burs of different grit sizes and the influence of surface roughness on the BFS. For this, 104 plates were obtained from CAD/CAM ceramic blocks and divided into 4 groups (n = 26), according to bur grit size: extra-fine, fine, medium and coarse. Roughness parameters (Ra, RyMax) were measured, and plates were kept dry for 7 days. The flexural test was carried out and BFS was calculated. Ra, RyMax and BFS data were subjected to analysis of variance and post-hoc test. Weibull analysis was used to compare characteristic strength and Weibull modulus. Regression analysis was performed for BFS vs. Ra and RyMax. When burs with coarse grit were used, higher surface roughness values were found, causing a negative effect on the ceramic BFS (117 MPa for extra-fine, and 83 MPa for coarse). Correlation (r) between surface roughness and BFS was 0.78 for RyMax and 0.73 for Ra. Increases in diamond grit size have a significant negative effect on the BFS of leucite-reinforced glass-ceramics, suggesting that grinding of sintered glass-ceramic should be performed using burs with the finest grit possible in order to minimize internal surface flaws and maximize flexural strength.

Preparation of Foam Glass Ceramics from Phosphorus Slag

2010 ◽  
Vol 105-106 ◽  
pp. 600-603 ◽  
Author(s):  
Ben Xu ◽  
Kai Ming Liang ◽  
J.W. Cao ◽  
Y.H. Li
Keyword(s):  
Glass Powder ◽  
Foam Glass ◽  
Glass Ceramics ◽  
Processing Parameters ◽  
Treatment Temperature ◽  
Homogeneous Distribution ◽  
Sintering Process ◽  
Foaming Agent ◽  
Foaming Temperature ◽  
Foam Glass Ceramics

Phosphorus slag could be used to prepare wollastonite glass ceramics. With the aid of incorporated foaming agent, foam glass ceramics can be obtained via the sintering of the slag-based glass. After the glass powder reacted with graphite, macro-size pores with homogeneous distribution were formed. The level of porosity of the fabricated foams was controlled by varying heat treatment temperature and amount of foaming agent. It was found that the preferential processing parameters for producing foam glass ceramics were foaming temperature of 1000°C with holding time of 10 min and 1 wt. % of graphite. In this case, the porosity reached about 80%. The results show that dominant crystalline phase is wollastonite, and the high compression strength results from the crystallization of glass during sintering process.

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