scholarly journals Effect of the Operational Conditions in the Characteristics of Ceramic Foams Obtained from Quartz and Sodium Silicate

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1806
Author(s):  
Lina Uribe ◽  
Juan D. Giraldo ◽  
Alejandro Vargas
Keyword(s):  
Pressing Pressure ◽  
Melting Points ◽  
Statistical Software ◽  
Powder Mixtures ◽  
Foaming Agent ◽  
Ceramic Foams ◽  
Cellular Solid ◽  
Operational Conditions ◽  
Volumetric Expansion ◽  
Foaming Temperature

Ceramic foams were fabricated without using melting pots through the direct foaming of compacted powder mixtures of commercial quartz (SiO2) with fluxing agents (Na2CO3 and CaO) and a foaming agent (Na2SiO3·5H2O) at a relatively low temperature range (850−870 °C). The effects of the pressing pressure of the powders, the foaming time, foaming temperature, and mixture content were evaluated. The obtained cellular solid materials presented an acceptable volumetric expansion at a pressing pressure of 4 t. The materials only presented porosity at a minimum temperature of 850 °C and at a minimum time of 30 min. All the foamed samples showed an acceptable symmetric expansion and non-appreciable fissures. The study of the mixture content through the statistical software MODDE® shows that the porosity of the samples was principally affected by the Na2SiO3 content and the foaming temperature. The samples obtained at the optimum controlling factors proposed by this statistical software presented an apparent density, porosity, and mechanical strength of 1.09 ± 0.03 g/cm3, 56.01% ± 1.12%, and 3.90 ± 0.16 MPa, respectively. Glass and ceramics foams such as those obtained in this work become attractive as insulation materials in applications where high temperatures occur due to their higher melting points.

scholarly journals Alternative foaming agents for fabrication of glass foam

2021 ◽  
Vol 11 (5) ◽  
pp. 39-48
Author(s):  
Ildikó Fóris ◽  
Gábor Mucsi
Keyword(s):  
Raw Materials ◽  
Powder Mixtures ◽  
Foaming Agent ◽  
Foaming Agents ◽  
Heat Treated ◽  
Specimen Density ◽  
Before And After ◽  
Different Temperatures ◽  
Glass Foam ◽  
Eggshell Waste

Glass foam tablets were produced from container glass bottles (CGB) using eggshell waste (ESW) and perlite (P) as foaming agent in different portions. The ground raw materials (CGB, ESW, P) were homogenized and pressed with hydraulic piston press machine at different pressures (in the case of P containing tablets 30 MPa and ESW containing tablets 15 MPa, 30 MPa and 40 MPa were used).The obtained glass tablets were heat treated at different temperatures (in the case of P containing tablets 800 °C, 900°C, 1000°C and 1100°C, and ESW containing tablets 600 °C, 700 °C, 800 °C and 900 °C were used). The study shows the specimen density of tablets before and after heat treatment, as well as the true density of the powder mixtures before tableting and the abrasion resistance of the glass foam products.

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.

Porous Material Production and Material Properties

2019 ◽  
Vol 946 ◽  
pp. 84-90
Author(s):  
Liudmila Shtirc ◽  
Svetlana G. Vlasova ◽  
Dmitry Meshcherskikh
Keyword(s):  
Porous Material ◽  
Caustic Soda ◽  
Material Properties ◽  
Foaming Agent ◽  
Experimental Glass ◽  
Material Production ◽  
Foaming Process ◽  
Foaming Temperature ◽  
Glass Compositions

In our work we defined two directions for synthesizing porous material: pulping selected experimental glass compositions and using caustic soda as a foaming agent. We studied the foaming temperature settings, investigated the porous material properties. The intensity of the foaming process was estimated from the value of the foaming coefficient.

scholarly journals An Alternative Method for the Obtention of Ceramic Foams from Gold and Silver Tailings with High Pyrite Content

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1897
Author(s):  
Cristian Salazar ◽  
Lina Uribe
Keyword(s):  
Mechanical Strength ◽  
Apparent Density ◽  
Mine Drainage ◽  
Flotation Process ◽  
Foaming Agent ◽  
Ceramic Foams ◽  
Foaming Process ◽  
Mineral Phases ◽  
Pyrite Content ◽  
High Sulfide

Mining extraction operations generate a large number of tailings that contain different mineral phases such as quartz (principally), complex silicates, metallic elements, etc. Tailings impose a serious concern as it is possible to have acid mine drainage potential, leaching, and percolation events of heavy metals into the environment under certain conditions. The objective of this work was to evaluate the technical feasibility of producing ceramic foams from gold and silver tailings with high sulfide gangue through a previous flotation process to eliminate impurities associated to this gangue, as it can produce SO2 in the foaming process, and to analyze the effect of the sintering time and the temperature on the characteristics of foams obtained with this type of waste. The results showed that the inverse flotation reduced the presence of impurities associated to sulfides. In addition, it was possible to observe that in the absence of a foaming agent, it was possible to obtain ceramic foams with an apparent density and a mechanical strength near to 1.0 g/cm3 and 0.5 MPa, respectively, when a higher sintering temperature and time were used. On the other hand, the presence of the foaming agent reduced the apparent density to 0.5 g/cm3 without decreasing to a great extent the mechanical strength of ceramic foams at lower sintering temperatures.

scholarly journals The correction of foam glass composition based on its principal parameters

2021 ◽  
Vol 350 ◽  
pp. 00009
Author(s):  
Dmitry Safonchik ◽  
Svetlana Maksimovich
Keyword(s):  
Mechanical Characteristics ◽  
Glass Composition ◽  
Foam Glass ◽  
Cost Price ◽  
Foaming Agent ◽  
Insulating Material ◽  
Leading Position ◽  
The Cost ◽  
Foaming Temperature ◽  
Better Than

Thermal insulation materials are the main link in solving the problem of enclosing constructions energy efficiency. The number of heat insulators is relatively low, that`s why it is important to develop new insulators that would be better than the existing ones in their characteristics. Such heat-insulating material as foam glass is known, but it is practically not applied, despite the fact that it possesses high heatinsulating and mechanical characteristics, it is non-combustible, durable and environmentally friendly. All the advantages of foam glass are inferior to one drawback. It is the high cost price of this material. If the cost price of foam glass was reduced and its main characteristics were at the same level, foam glass would take a leading position among other heatinsulating materials. The article presents some information about the development of foam glass, in which dolomite flour is used as a foaming agent. The material proposed by the authors has a density of about 200 kg / m3, water absorption of 25%. The material is manufactured at maximum foaming temperature of 750 °C.

Correlation of Decompression Time and Foaming Temperature on the Cell Density of Foamed Polystyrene

2005 ◽  
Vol 24 (1) ◽  
pp. 15-27 ◽  
Author(s):  
Keiichi Muratani ◽  
Minoru Shimbo ◽  
Yasushi Miyano
Keyword(s):  
Cell Growth ◽  
Temperature Dependence ◽  
Cell Density ◽  
Saturation State ◽  
Foaming Agent ◽  
Decompression Rate ◽  
Cell Nucleation ◽  
Cell Densities ◽  
Foaming Temperature ◽  
Decompression Time

In this paper, the correlation between the foaming temperature and the decompression rate (decompression time) of the cell density that is the number of cells per unit volume remaining in the foamed plastic will be discussed. Foaming was carried out by the following method: the blowing agent was soaked into the resin as a solid state at high pressure under temperatures higher than the glass transition temperature of the resin. After the foaming agent reached its saturation state, cell nucleation and cell growth were accelerated by decompression. Finally, cell growth was halted by cooling. A device that can accurately control temperature and the decompression rate was designed, produced and verified for accuracy prior to this investigation. The polystyrene (PS) specimens were foamed under various foaming temperatures and the decompression rates using the above-mentioned method. The following results were obtained: 1. Cell density of foamed polystyrene shows time and temperature dependence as follows. The cell density increases when the decompression rate is quick, i.e. the decompression time is shortened under the condition of low foaming temperature, and cell density decreases when the decompression rate is slow, i.e. decompression time is lengthened under the condition of high foaming temperature, 2. Correlation is maintained between the temperature dependence and time dependence of the cell density of foamed PS, and it can be expressed by one master curve, 3. Based on this correlation, it is possible to predict the required foaming conditions of plastics having arbitrary cell densities.

Study on Fabrication, Defects and Compression Properties of Al Foams at Different Foaming Temperatures

2011 ◽  
Vol 214 ◽  
pp. 70-74 ◽  
Author(s):  
Wei Min Zhao ◽  
Hui Zhang ◽  
Hai Peng Li ◽  
Zhi Feng Wang ◽  
Yang Zhao ◽  
...  
Keyword(s):  
Pore Structure ◽  
Aluminum Foams ◽  
Foaming Agent ◽  
Compression Properties ◽  
Al Powder ◽  
Fabrication Defects ◽  
Lower Temperature ◽  
Foaming Temperature ◽  
Better Than ◽  
Al Foams

Using Al powder as thickening agent and CaCO3 powder as foaming agent, Al foams with above 85% porosity, pore sizes between 1mm and 4mm and relatively uniform pore structure have been fabricated by melt foaming method at different foaming temperatures. Meanwhile, the paper researched the effect of foaming temperature on foaming effect and analyzed the defects in Al foams. At last, compression test were taken in order to investigate the mechanical properties of aluminum foams. The results showed that pore structure, pore distribution and compression properties of Al foams fabricated at 720°C were much better than that fabricated at lower temperature.

Preparation of ceramic foams suitable for aircraft arresting by the airport runway based on a protein foaming agent

2014 ◽  
Vol 29 (5) ◽  
pp. 980-989 ◽  
Author(s):  
Liyuan Zhang ◽  
Dali Zhou ◽  
Weizhong Yang ◽  
Ying Chen ◽  
Bin Liang ◽  
...  
Keyword(s):  
Foaming Agent ◽  
Ceramic Foams ◽  
Airport Runway

scholarly journals An experimental study on one-step and two-step foaming of natural rubber/silica nanocomposites

2020 ◽  
Vol 9 (1) ◽  
pp. 427-435 ◽  
Author(s):  
Hossein Bayat ◽  
Mohammad Fasihi ◽  
Yasser Zare ◽  
Kyong Yop Rhee
Keyword(s):  
Natural Rubber ◽  
Cell Size ◽  
Decomposition Temperature ◽  
Nano Silica ◽  
Foaming Agent ◽  
Silica Nanocomposites ◽  
Composite Foams ◽  
Lower Cell Density ◽  
One Step ◽  
Foaming Temperature

AbstractThe curing and cellular structure of natural rubber (NR)/silica composite foams were investigated. The presence of an activator in the rubber formulation significantly lowered the decomposition temperature of the azodicarbonamide foaming agent, which allowed foaming before NR curing. Therefore, two foam methods were designed: foaming initially at 90°C and then curing at 140°C, and foaming and curing simultaneously at 140°C. Two-step foaming generated a lower cell density and higher cell size. Incorporation of nano silica into NR increased the foam density, but decreased the cell size. The higher foaming temperature restricted the bubble growth because of a higher curing rate and inhibited cell coalescence.

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