Fabrication and Properties of Porous Anorthite⁄Mullite Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 590-595 ◽  
Author(s):  
Ya Mei Lin ◽  
Cui Wei Li ◽  
Feng Kun Yang ◽  
Chang An Wang
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Open Porosity ◽  
Raw Material ◽  
Composite Ceramics ◽  
Porous Composite ◽  
Mullite Phase ◽  
Powder Content ◽  
Mullite Powder ◽  
Mullite Ceramics

Porous anorthite/mullite composite ceramics with different mullite content were fabricated by foam-gelcasting, using CaCO3, SiO2, α-Al2O3as raw material for anorthite phase and mullite powder for mullite phase. Effects of mullite powder content on bulk density, porosity, compressive strength and thermal conductivity of the porous composite ceramics were researched. It has been shown that mullite powder content has great effect on microstructure and properties of the porous anorthite⁄mullite composite ceramics. The open porosity of the prepared porous anorthite⁄mullite composite ceramics is in the range of 58.7 %~77.5 %, the compressive strength is between 4.2 and 30.9 MPa, and the thermal conductivity is in the range of 0.18 ~1.47 W⁄(m·K).

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.

Effects of Activating Solution and Liquid/Solid Ratio on Engineering Properties of Metakaolin-Based Geopolymer

2012 ◽  
Vol 204-208 ◽  
pp. 4101-4104 ◽  
Author(s):  
Tzong Ruey Yang ◽  
Ta Peng Chang ◽  
Chun Tao Chen ◽  
Yuan Kai Lee ◽  
Bo Tsun Chen
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Weight Ratio ◽  
Degree Of Polymerization ◽  
Controlling Factors ◽  
Experimental Results ◽  
Raw Material ◽  
Engineering Properties ◽  
Solid Ratio ◽  
Activating Solution

In this paper, the metakaolin is used as the raw material with aluminosilicate compounds to produce the geopolymer. The effects of three levels of two major controlling factors, the degree of polymerization of the activating solution (weight ratio of SiO2 to Na2O) of 0.4, 0.7 and 1.0 and the weight ratio of liquid to solid (L/S) of 0.7, 0.85 and 1.00 on the engineering properties of geopolymer are investigated. The experimental results show that, at age of 28 days, the compressive strength increases from the lowest 37.33 MPa (SiO2/Na2O = 0.4 and L/S = 0.7) to the highest 71.21 MPa (SiO2/Na2O = 0.7 and L/S = 0.7). While, the thermal conductivity increases from the lowest 0.39 w/mk (SiO2/Na2O = 0.4 and L/S = 1.0) to the highest 0.761 w/mk (SiO2/Na2O = 1.0 and L/S = 0.7).

Influence of Metal Oxides Additives on the Porous Mullite Ceramics

2014 ◽  
Vol 604 ◽  
pp. 293-296 ◽  
Author(s):  
Ludmila Mahnicka-Goremikina ◽  
Ruta Svinka ◽  
Visvaldis Svinka
Keyword(s):  
Thermal Conductivity ◽  
Metal Oxides ◽  
Slip Casting ◽  
Casting Method ◽  
Mullite Phase ◽  
Porous Mullite ◽  
Positive Effect ◽  
Dominant Phase ◽  
Mullite Ceramics

The porous mullite ceramics doped with such metal oxides as ZrO2, WO3 and MgO in quantity of 5 wt% were prepared by slip casting method. The mullite phase was the main and dominant phase of ZrO2-, WO3- and MgO-doped samples, which were sintered at the temperatures of 1650°C, 1500°C, respectively. The ZrO2, WO3 and MgO had the positive effect on the increase of porosity and decrease of thermal conductivity of porous mullite ceramics and the degree of this effect was in the order of ZrO2<MgO<WO3.

Effect of Borax on Lightweight Material from Cullet and Fly Ash

2016 ◽  
Vol 690 ◽  
pp. 109-113 ◽  
Author(s):  
Sutthima Sriprasertsuk ◽  
Phatthiya Suwannason ◽  
Wanna T. Saengchantara
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Silicate ◽  
Raw Materials ◽  
Raw Material ◽  
Test Results ◽  
Heat Process ◽  
Lightweight Material

This work investigated the recycling of fly ash waste and cullet as the raw materials for lightweight bodies produced by heat treatment and using sodium silicate as the binder. Borax was mixed with fly ash and cullet, and put into the block in dimension 10x10x2 cm3. The lightweight materials thus produced were then sintered at temperature of 800 °C. Density, compressive strength and thermal conductivity were determined. Borax showed a positive sintering effect on the porosity of lightweight material during the heat process. The compressive strength of lightweight material diminished with the reduction of density and thermal conductivity. Lightweight material manufactured with borax showed the lower density and thermal conductivity accompanied by the higher compressive strength. The test results indicated that using fly ash and cullet as the raw material with borax could obtain the lightweight material, thus enhancing the possibility of its reuse in a sustainable way.

scholarly journals Improvement in mechanical properties in AlN-h-BN composites with high thermal conductivity

2021 ◽  
Author(s):  
Zetan Liu ◽  
Shiqiang Zhao ◽  
Tian Yang ◽  
Ji Zhou
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Hexagonal Boron Nitride ◽  
Relative Dielectric Constant ◽  
High Strength ◽  
Secondary Phase ◽  
High Thermal Conductivity ◽  
Raw Material ◽  
Composite Ceramics ◽  
Powder Particles

AbstractIt is possible to improve the machinability of aluminum nitride-hexagonal boron nitride (AlN-h-BN) ceramics while maintaining high strength and high thermal conductivity. The composite ceramics with 0–30 wt% BN as secondary phase were prepared by hot pressed sintering, using yttrium oxide (Y2O3) as sintering aid. The phase composition, density, microstructure, mechanical properties, thermal conductivity, and dielectric properties were investigated. The sintering additives were favorable to purify the grain boundaries and improve densification, reacting with oxide impurities on the surface of raw material powder particles. The optimum BN content improved the flexural strength and fracture toughness of composite ceramics with 475 MPa and 4.86 MPa·m1/2, respectively. With increasing the amount of BN, the thermal conductivity and hardness of composites gradually decreased, but the minimum value of thermal conductivity was still 85.6 W·m−1·K−1. The relative dielectric constant and dielectric loss tangent of the samples ranged from 6.8 to 8.3 and from 2.4 × 10−3 to 6.4 × 10−3, respectively, in 22–26 GHz.

Effect of Calcium Hydroxide and Water to Solid Ratio on Compressive Strength of Mordenite-Based Geopolymer and the Evaluation of its Thermal Transmission Property

2018 ◽  
Author(s):  
Mauricio H. Cornejo ◽  
Jan Elsen ◽  
Bolivar Togra ◽  
Haci Baykara ◽  
Guillermo Soriano ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Experimental Design ◽  
Calcium Hydroxide ◽  
Building Material ◽  
Building Materials ◽  
Raw Material ◽  
Scanning Calorimetry ◽  
Solid Ratio ◽  
Central Composite Experimental Design

Mordenite-rich tuff is one of most available zeolitic rocks all over the world. Because of this, the research of natural mordenite as a raw material of geopolymeric materials can provide an almost unlimited source of solid precursor for manufacturing such building materials. Despite efforts to shed light on the behaviour of mordenite-rich tuff during geopolymeric reaction, the performance of these novel materials is barely understood. The aim of this study is to explore the effect of the content of calcium hydroxide, CH, and water-to-solid ratio, W/S, as mixing parameters on compressive strength of mordenite-based geopolymers, MBG, and its thermal conductivity. As solid precursor was used mordenite-rich tuff and mixed with sodium hydroxide (NaOH) at 10M that kept constant during the experiment. Two experimental parameters were selected as independent variables i.e, the content of CH and water-to-solid ratio, and their levels, according to a central composite experimental design. All these designed mixes were characterized by using quantitative X-ray diffraction (QXRD), Fourier Transform Infrared spectroscopy (FTIR), Thermogravimetry and differential scanning calorimetry (TGA-DSC), scanning electron microscopy coupled with energy dispersed spectroscopy (SEM-EDS), in addition thermal conductivity tests were also run according to standard method ASTM C177 at 9, 24, 39°C. The overall results suggested that MBG can be used as building material, however its thermal conductivity was higher than that of commercial isolate building material. The experimental design analysis indicated that the optimum water-to-solid ratio was 0.35, but in the case of the content of CH, the optimum value was not observed on this experimental range because the compressive strength increased as the content of CH increased as well. The compressive strength of MBG was observed in the range between 8.7 and 11.3 MPa. On the other hand, QXRD and FTIR showed that mordenite reacted during the geopolymeric reaction, but instead quartz, also found in zeolitic tuff, acted as inert filler.

Fabrication of Porous Mullite Ceramics with High Porosity Using Foam-Gelcasting

2012 ◽  
Vol 512-515 ◽  
pp. 580-585 ◽  
Author(s):  
Feng Kun Yang ◽  
Cui Wei Li ◽  
Ya Mei Lin ◽  
Chan Gan Wang
Keyword(s):  
Apparent Porosity ◽  
Raw Material ◽  
Solid Loading ◽  
High Porosity ◽  
Obvious Effect ◽  
Porous Mullite ◽  
Porous Microstructure ◽  
Mullite Powder ◽  
Large Spherical ◽  
Mullite Ceramics

In this paper, porous mullite ceramics with an apparent porosity up to 81 % were fabricated by foam-gelcasting using mullite powder as raw material with solid loading of 40 vol.%. The monomers content and sitering temperature have obvious effect on the properties of porous mullite ceramics. The apparent porosity of the prepared samples was in the range of 75~82%, compressive strength, was in the range of 3.0~16.02 MPa, and thermal conductivity was between 0.14 and 0.47 W/(m•K). A complex porous microstructure was formed, where large spherical pores contained small cellular pores on their internal walls.

scholarly journals Effects of Kaolin Additives in Fly Ash on Sintering and Properties of Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 887
Author(s):  
Marta Valášková ◽  
Veronika Blahůšková ◽  
Jozef Vlček
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Bulk Density ◽  
Porous Ceramics ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Effective Utilization ◽  
Sintering Properties ◽  
Mullite Ceramics

The effective utilization of fly ash (FA) as a raw material for ceramics production is performed on the FA-kaolin mixtures containing kaolins 10% by mass. The mixtures in comparison with FA and three raw kaolins were annealed to mullite ceramics at temperatures of 1000, 1100, 1200 and 1300 °C. The main aims were to contribute to the discussion on the effect of impurity of Na,K-feldspars in kaolins and Fe2O3 in FA on sintering procedure, porous ceramics properties and mullite structural properties. The phases were characterized using X-ray diffraction and thermogravimetry DTA/TGA methods. Mercury intrusion porosimetry was used for characterization of porosity of ceramic samples. Results evidenced the influence of feldspars in kaolins and Fe2O3 in FA on the sintering temperatures and properties of mullite ceramics. The fully FA-based ceramic sintered at 1100 °C exhibited post-sintering properties of bulk density 2.1 g/cm3; compressive strength 77.5 MPa; and porosity, 2% in comparison with the FA/kaolin-based ceramics properties of bulk density 2.2 g/cm3; compressive strength, 60–65 MPa; and porosity from 9.3 to 16.4% influenced by Na,K-feldspars. The best structural and mechanical characteristics were found for the FAK3 sample, supported by the high content of kaolinite and orthoclase in the kaolin K3 additive. The FAK3 annealed at 1100 °C exhibited good compressive strength of 87.6 MPa at a porosity of 10.6% and density of 2.24 g/cm3 and annealed at 1300 °C the compressive strength of 41.3 MPa at a porosity of 19.2% and density of 1.93 g/cm3.

Effect of Fly Ash Pre-Sintering Temperature on Adiabatic Foam Fabricated by Sodium Silicate

2019 ◽  
Vol 295 ◽  
pp. 105-109
Author(s):  
Ye Li ◽  
Heng Ze Zhao ◽  
Xu Dong Cheng
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Fly Ash ◽  
Pore Structure ◽  
Pore Size ◽  
Sodium Silicate ◽  
Sintering Temperature ◽  
Raw Material ◽  
Sintering Process ◽  
Spherical Pore

Adiabatic foam was fabricated successfully using sodium silicate as the raw material with pre-sintered fly ash as additive. Fly ash was pre-sintered at 500 to 900 oC and the effect of the pre-sintering temperature on the performance, including the thermal conductivity, density, compressive strength and microstructure, was researched. The results show that the pre-sintering process effectively reduces the density of the samples while the thermal conductivity and compressive strength are higher than those of the samples fabricated by the fly ash without being pre-sintered. Moreover, the samples exhibit tri-modal spherical pore structure with macropores and mesopores. The pore size remains unchanged until the pre-sintering temperature exceeds 700 oC, and then starts to increase.

Application of slag from thermal power plant for the production of porous filler

2021 ◽  
Vol 6 (2) ◽  
pp. 110-116
Author(s):  
Ihor Mitin ◽  
◽  
Diana Kindzera ◽  
Volodymyr Atamanyuk ◽  
◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Power Plant ◽  
Thermal Power Plant ◽  
Raw Materials ◽  
Thermal Power ◽  
Raw Material ◽  
Drying Process ◽  
Filtration Method ◽  
Porous Filler

The article is devoted to obtaining a porous filler from the slag of the Thermal Power Plant and investigation of the filtration method for the drying of slag and clay as main raw materials for preparing the charge for porous filler production. The possibility of using TPP slag as the raw material for the production of porous filler has been proved. The main benefits of using such wastes in the production process are environmental protection, conservation of raw resources for the production of finished products. According to the results of the research, insignificant values of the pressure drop confirm the application feasibility of the filtration drying as an energy-saving method of the drying of slag and clay for preparing the charge for porous filler production. The influence of the temperature of the drying agent in the range from 313 to 373K on kinetic during filtration drying of slag and clay has been established. Obtained results are useful for the organization and intensification of the filtration drying process of slag and clay as the preliminary stage at the porous fillers production line. The qualitative new porous filler with the bulk density of 230 kg/m3, the specific heat of 0,82 kJ/kg∙K, the thermal conductivity of 0,067 W/m∙K and compressive strength of 27,7 MPa has been obtained which can be used for the production of lightweight concretes.

Sign in / Sign up

Export Citation Format

Share Document