THERMAL INSULATING MATERIAL WITH HIGH MECHANICAL STRENGTH MADE FROM CLAY BRICK WASTE AND COAL ASH USING THE MICROWAVE ENERGY

2020 ◽  
Vol 26 (2) ◽  
pp. 28-34
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE
Keyword(s):  
Mechanical Strength ◽  
Coal Ash ◽  
Microwave Energy ◽  
Raw Material ◽  
Clay Brick ◽  
High Mechanical Strength ◽  
Foaming Agent ◽  
Insulating Material ◽  
Thermal Insulating ◽  
Foaming Process

The paper presents the results of experimental research for manufacture a high mechanical strength thermal insulating material using the microwave energy. Clay brick waste (75 - 83 mass %) and coal ash (15 - 23 mass %) as raw material and silicon carbide (2%) as a foaming agent have been used as a powder mixture. The porous product obtained by a sintering/ foaming process at 1115 - 1145 ºC had relatively low density and thermal conductivity (0.50 - 0.68 g/cm3 and 0.078 - 0.095 W/mK, respectively) and high compressive strength (up to 7.5 MPa). This remarkable combination of some physical and mechanical characteristics of the insulating material allows its use in applications involving mechanical stress resistance.

USE OF THE MICROWAVE ENERGY FOR ALUMINUM WASTE FOAMING

2019 ◽  
Vol 25 (4) ◽  
pp. 43-49
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE ◽  
ANA CASANDRA SEBE
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Porous Structure ◽  
Powder Mixture ◽  
Aluminum Foam ◽  
Fine Powder ◽  
Microwave Energy ◽  
Raw Material ◽  
Foaming Agent ◽  
Foaming Process

The paper presents an aluminum foam experimental technique using the microwave energy. The raw material was recycling aluminum waste processed by ecological melting and gas atomizing to obtain the fine powder required in the foaming process. The powder mixture was completed with dolomite as a foaming agent. The products had a fine and homogeneous porous structure (pore size between 0.4-0.9 mm). The density (1.17-1.19 g/cm3), the compressive strength (6.83-7.01 MPa) and the thermal conductivity (5.71-5.84 W/m·K) had values almost similar to the foams made by conventional methods.

COMPARATIVE ANALYSIS OF THE OWN EXPERIMENTAL TECHNIQUES OF PRODUCING THE FOAMED GLASS-CERAMIC

2016 ◽  
Vol 22 (2) ◽  
pp. 55-64
Author(s):  
LUCIAN PĂUNESCU ◽  
MARIUS FLORIN DRĂGOESCU ◽  
SORIN MIRCEA AXINTE
Keyword(s):  
Glass Ceramic ◽  
Mechanical Characteristics ◽  
Fossil Fuel ◽  
Coal Ash ◽  
Microwave Energy ◽  
High Porosity ◽  
Foaming Agent ◽  
Insulating Material ◽  
Foamed Glass ◽  
Physical And Mechanical Characteristics

The paper presents experimental results obtained by a team of researchers from the company Daily Sourcing & Research SRL Bucharest in the field of producing the foamed glass-ceramic from waste bottle glass, coal ash and silicon carbide as foaming agent. The originality of the experiments consists in the use of electricity or microwave energy, unlike all techniques known worldwide consumers of fossil fuel. The product, obtained with low energy consumptions and very low pollutants emissions, has physical and mechanical characteristics of an insulating material, i.e. high porosity, low thermal conductivity and an adequate compressive strength.

scholarly journals COMPARATIVE ANALYSIS OF THE OWN EXPERIMENTAL TECHNIQUES OF PRODUCING THE FOAMED GLASS-CERAMIC

2017 ◽  
Vol 22 (2) ◽  
Author(s):  
LUCIAN PĂUNESCU ◽  
MARIUS FLORIN DRĂGOESCU ◽  
SORIN MIRCEA AXINTE
Keyword(s):  
Glass Ceramic ◽  
Mechanical Characteristics ◽  
Fossil Fuel ◽  
Coal Ash ◽  
Microwave Energy ◽  
High Porosity ◽  
Foaming Agent ◽  
Insulating Material ◽  
Foamed Glass ◽  
Physical And Mechanical Characteristics

The paper presents experimental results obtained by a team of researchers from the company Daily Sourcing & Research SRL Bucharest in the field of producing the foamed glass-ceramic from waste bottle glass, coal ash and silicon carbide as foaming agent. The originality of the experiments consists in the use of electricity or microwave energy, unlike all techniques known worldwide consumers of fossil fuel. The product, obtained with low energy consumptions and very low pollutants emissions, has physical and mechanical characteristics of an insulating material, i.e. high porosity, low thermal conductivity and an adequate compressive strength

scholarly journals USE OF THE MICROWAVE ENERGY FOR ALUMINUM WASTE FOAMING

2019 ◽  
Vol 25 (4) ◽  
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE ◽  
ANA CASANDRA SEBE
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Porous Structure ◽  
Powder Mixture ◽  
Aluminum Foam ◽  
Fine Powder ◽  
Microwave Energy ◽  
Raw Material ◽  
Foaming Agent ◽  
Foaming Process

<p>The paper presents an aluminum foam experimental technique using the microwave energy. The raw material was recycling aluminum waste processed by ecological melting and gas atomizing to obtain the fine powder required in the foaming process. The powder mixture was completed with dolomite as a foaming agent. The products had a fine and homogeneous porous structure (pore size between 0.4-0.9 mm). The density (1.17-1.19 g/cm<sup>3</sup>), the compressive strength (6.83-7.01 MPa) and the thermal conductivity (5.71-5.84 W/m·K) had values almost similar to the foams made by conventional methods.</p>

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 Glass Foam Made with Silicon Nitride and Manganese Oxide by Microwave Irradiation

2021 ◽  
Vol 2 (2) ◽  
pp. 1-9
Author(s):  
Marius Florin Dragoescu ◽  
Lucian Paunescu ◽  
Sorin Mircea Axinte
Keyword(s):  
Flat Glass ◽  
Morphological Characteristics ◽  
Raw Material ◽  
Conventional Heating ◽  
Insulation Material ◽  
Glass Waste ◽  
High Mechanical Strength ◽  
Foaming Agent ◽  
Optimal Sample ◽  
Glass Foam

A high mechanical strength (6.1 MPa) glass foam was produced by sintering/foaming at 830 ºC in an experimental 0.8 kW-microwave oven. The basic raw material was a colorless flat glass waste and the foaming agent was Si3N4 powder (2 wt.%). As an oxygen supplying agent, a MnO2 powder (3.1 wt.%) was used. The main physical, mechanical, thermal and morphological characteristics of the optimal sample were: apparent density of 0.47 g/cm3, porosity of 77.6%, thermal conductivity of 0.105 W/m·K, compressive strength of 6.1 MPa and pore size between 0.15-0.40 mm. The optimal glass foam sample has the required characteristics of a thermal insulation material usable under mechanical stress conditions in civil engineering. The originality of the paper is the application of the unconventional microwave heating technique, faster and more economical, unlike the other papers in the same area published in the literature, followers of the traditional conventional heating technique.

USE OF NATURAL DOLOMITE AS A CHEAP FOAMING AGENT FOR PRODUCING GLASS FOAMS FROM GLASS WASTE IN THE MICROWAVE FIELD

2020 ◽  
Vol 26 (1) ◽  
pp. 57-64
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE
Keyword(s):  
Thermal Conductivity ◽  
Microwave Field ◽  
Specific Energy Consumption ◽  
Morphological Characteristics ◽  
Microwave Energy ◽  
Glass Waste ◽  
Foaming Agent ◽  
Insulating Material ◽  
The World ◽  
Glass Foam

The paper presents experimental results obtained in the process of making glass foam from glass waste using a cheap foaming agent (natural dolomite). The originality of the work is the application of the microwave energy, unlike the conventional techniques commonly used in the world. The main advantage highlighted by the experiments is the very low specific energy consumption (below 1.5 kWh/kg), due to the peculiarities of the microwave heating technique. The foamed product has physical, mechanical and morphological characteristics (density between 0.30-0.32 g/cm3, thermal conductivity between 0.064-0.067 W/m·K, compressive strength in the range 2.2-2.6 MPa), which are similar to those of foams made by conventional methods and are suitable for its use as insulating material in construction.

Study on the Influences of Foaming Gypsums Performance

2013 ◽  
Vol 743-744 ◽  
pp. 222-227 ◽  
Author(s):  
Bin Huang ◽  
Yi Zhang ◽  
Dong Xu Li
Keyword(s):  
Mechanical Strength ◽  
Pore Structure ◽  
Chemical Reaction ◽  
Apparent Density ◽  
Weight Ratio ◽  
Insulation Property ◽  
Foaming Agent ◽  
Fgd Gypsum ◽  
Foaming Process ◽  
Thermal Insulation Property

Utilizing the chemical reaction principles H2O2 was catalyzed by MnO2, instead of being catalyzed by warm water. In the gypsum slurry, due to the chemical reaction of hydrogen peroxide a large number of bubbles were produced, and the material was self-foaming. The H2O2 foaming agent and the method of foaming affected the performance of the foaming gypsum, such as mechanical strength, apparent density, thermal conductivity, and the pore structure of foaming gypsum. The result showed that with adding H2O2, the apparent density and mechanical strength decreased; the different water/plaster weight ratio ranged from 0.65 to 0.75, affecting the foaming process. The thermal insulation property of FGD gypsum is related to the content of H2O2, the water/plaster weight ratio, and the pore structure of foaming gypsum.

scholarly journals NONCONVENTIONAL TECHNIQUE FOR PRODUCING HIGH MECHANICAL STRENGTH GLASS FOAM FROM GLASS WASTE

2019 ◽  
Vol 25 (2) ◽  
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE ◽  
ANA CASANDRA SEBE
Keyword(s):  
Thermal Conductivity ◽  
Energy Source ◽  
Mechanical Strength ◽  
Electromagnetic Waves ◽  
Building Materials ◽  
Glass Waste ◽  
High Mechanical Strength ◽  
Foaming Agent ◽  
Heating Efficiency ◽  
Glass Foam

In the work experimental results on the manufacture of glass foam with high mechanical strength from glass waste are presented. By replacing the usual conventional energy source with a nonconventional energy (electromagnetic waves) the heating efficiency allows a fast and economical manufacturing process. Calcium carbonate as a foaming agent and an addition of sodium silicate (aqueous solution) as a binder were used. By their physico-mechanical and morphological features (0.40-0.66 g/ cm<sup>3 </sup>the apparent density, 0.054-0113 W/ m·K the thermal conductivity, 2.2-6.3 MPa the compressive strength, below 1.2 % the water absorption and under 2 mm the pore size), the foams are appropriate for their use as replacer of existing similar building materials on the market.

scholarly journals CARACTERIZAÇÃO ANATÔMICA E DESCRIÇÃO FÍSICO-QUÍMICA E MECÂNICA DA MADEIRA DE Mimosa schomburgkii

FLORESTA ◽  
2017 ◽  
Vol 47 (4) ◽  
pp. 383 ◽  
Author(s):  
Luciano Junqueira Costa ◽  
Camila Batista da Silva Lopes ◽  
Matheus Fernandes de Carvalho Reis ◽  
Welliton Lelis Cândido ◽  
Bruno De Freitas Homem de Faria ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Mechanical Strength ◽  
Basic Density ◽  
Raw Material ◽  
Mechanical Resistance ◽  
Extractive Content ◽  
Anisotropy Coefficient ◽  
High Mechanical Strength ◽  
Physical Chemical ◽  
Vessel Elements

O uso de madeira de espécies alternativas na construção civil é uma alternativa para reduzir a utilização concentrada em poucas espécies e evitar a falta de matéria prima no mercado. Diante do exposto, o objetivo deste estudo foi avaliar propriedades físicas, químicas, anatômicas e mecânicas da madeira de Mimosa schomburgkii visando identificar o seu potencial para o uso na construção civil. Foi utilizada a madeira de Mimosa schomburgkii, com idade de 33 anos. As características anatômicas avaliadas foram as dimensões dos elementos de vasos (diâmetro e frequência), dos raios (altura e largura) e das fibras (comprimento, largura total, espessura de parede e de lume). Foi determinada a constituição química com a quantificação do teor de extrativo, lignina e holocelulose.  Para a caracterização físico-mecânica, foram avaliadas a densidade básica e aparente, contrações, o coeficiente de anisotropia, a resistência à flexão estática, à compressão paralela às fibras, à tração paralela às fibras, ao cisalhamento e a dureza Janka (paralela e perpendicular às fibras). A madeira possui fibras libriformes, com comprimento médio de 1180 μm, sendo classificadas como curtas. A densidade básica da madeira é em média 0,80 g.cm-3 (alta densidade), o coeficiente de anisotropia, em média 1,74. A madeira apresenta elevada resistência mecânica, sendo classificada como pertencente à classe C 60. Pelos resultados obtidos no estudo, a madeira de jurema (Mimosa schomburgkii) apresenta aspectos estéticos atrativos e elevada resistência mecânica, sendo, portanto, indicada para uso na construção civil.Palavras–chave: Propriedades da madeira, construção civil, elevada resistência mecânica, alta densidade básica. AbstractAnatomical characterization and physical-chemical and mechanical description of Mimosa schomburgkii wood. The use of wood of alternative species in civil construction has been an option to reduce the concentrated use of few species and to avoid the lack of raw material in the market. The objective of this study was to evaluate the physical, chemical, anatomical and mechanical properties of Mimosa schomburgkii wood, in order to identify its potential use in civil construction. Mimosa schomburgkii wood, at the age of 33 years, was used. The anatomical characteristics evaluated were the dimensions of vessel elements (diameter and frequency), rays (height and width) and fibers (length, width, wall thickness and lumen thickness). The chemical constitution was determined with the quantification of extractive content, lignin and holocellulose. For the physical-mechanical characterization, it was evaluated the specific gravity and apparent density, contractions, anisotropy coefficient, static bending strength, compression strength parallel to grain, traction strength parallel to grain, shear strength and Janka hardness (parallel and perpendicular to grain). The wood has libriform fibers, average length of 1180 μm, and it is classified as short. The wood basic density is on average of 0.80 g.cm-3 (high density). The anisotropy coefficient is on average of 1.74. The wood presents high mechanical strength, being classified as C 60 class. From the results obtained in this study, the Mimosa schomburgkii wood presents attractive aesthetic aspects and high mechanical resistance. Therefore, this wood is indicated for use in civil construction.Keywords: Wood properties, civil construction, high mechanical strength, high specific gravity.

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