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"Reaksi thermal dari campuran kaolin dengan magnesium hidroksida dan kaolin dengan magnesium karbonat diamati untuk mendapatkan keramik cordierite tanpa penambahan zat aditif. Komposisi campuran ditentukan berdasarkan rumus molekul 2MgO.2Al2O3.5SiO2. Pembakaran campuran bahan-bahan pada perbandingan mol berdasarkan formula tersebut diharapkan dapat menghasilkan bentuk fasa amorf pada temperatur sekitar 900°C, yang merupakan temperatur dekomposisi. μ-Cordierite kemudian mengkristal pada temperatur sekitar 950°C, dan perlahan-lahan berubah menjadi keramik α-cordierite. Campuran reaktan dipress menjadi benda uji dan dibakar untuk mendapatkan keramik α-cordierite pada temperatur 1300 oC dan 1350°C. Keramik cordierite sebanyak 80,41 - 86,62 % dihasilkan dari campuran kaolin dengan magnesium karbonat dan metakaolin dengan magnesium karbonat pada temperatur pembakaran 1300 oC dan 1350 oC. Uji katalitik dilakukan terhadap cordierite untuk mendekomposisi gas NO, di mana 44,17 % NO terdekomposisi pada temperatur 400°C.

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Thermal reaction of mixed kaolin with magnesium hydroxide and kaolin with magnesium carbonate were studied to produce cordierite ceramic without additives. Its composition was determined based on the molecular formula of 2MgO.2Al2O3.5SiO2. The firing of those mixed materials at mole ratios of this formula was expected to produce μ-cordierite at temperature of 900°C due to its thermal decomposition. The μ-Cordierite was then crystallized at temperature around 950°C, and was gradually transformed into α-cordierite. This study was conducted by prssing the reactants mixtures as specimens which were then fired to obtain α-cordierite ceramic at 1300°C and 1350°C. Cordierite of 80.41-86.62 % were resulted from the mixture of kaolin with magnesium carbonate and metakaolin with magnesium carbonate at the firing temperature of 1300 oC and 1350°C. The catalityc activity of cordierite was tested to decompose NO was tested, in which 44,17% NO could be decomposed at 400°C."

"This research presents the use of the Rietveld method to study the phase composition of cordierite (MG2AL4SI5O18) ceramics prepared from rice husk silica, after the samples were sintered at 1300, 1400 and 1500 °C. The formation of cordierite is temperature-dependent as indicated by the relative phase composition obtained from x-ray diffraction patterns for the cordierite and spinel increased markedly withincreasing temperature, i.e, from 38.98 to 54.15 wt% and from 11.81 to 17.99 wt % following the increase in temperature from 1300-1500 °C, respectively. The above valueswere obtained with the aid of the Rietveld method, carried out until the goodness of fit values (GoF) reached below 2, which is considered a satisfactory value to reveal the real phase composition. Different plots produced by refinement using the Rietveld method also reveal a reasonable fit between the observed and the calculated plot, demonstrating the usefulness of the method for calculating the quantity of phase composition in the sintering process."

"Pengaruh Temperatur Sintering dan Komposisi Bahan Baku Terhadap Sifat Karateristik Material Cordereite (2MgO.2Al2O3.5SiO2) Pasca Sarjana, 2000 Cordierite [2MgO.2A12O3.5SiO21 adalah merupakan material yang tahan temperatur tinggi sampai dengan 1365 ° C, disamping itu material tersebut memiliki termal ekspansi yang rendah yaitu ג= 2 x 10'° s/d ג = 3 x 10-° dan kekuatan mekanik yang tinggi. Penelitian dan pengembangan keramik cordierite telah dilakukan melalui beberapa tahapan penelitian, diawali dengan penelitian tentang pembuatan serbuk cordierite dari berbagai macam bahan baku alam seperti Kaolin (AI2 03 2SiO 2H2O), Kuarsa (Si02), Talk (3MgO4SiO2H2O) Sian Bauxit (AI203) . Setelah dilakukan pencampuran dari bahan baku tersebut, kemudian dilakukan penganalisaan dengan DTA untuk mengetahui suhu sintering. Selanjutnya campuran tersebut dicetak dan dibakar (sintering) pada berbagai suhu. Karakterisasi yang dilakukan adalah analisa fasa dengan XRD, pengukuran sifat-sifat fisis (densitas, porositas dan water absorbsion), termal ekspansi, kekerasan Vickers serta pengukuran kekuatan patah (bending strength). Dari hasil karakterisasi beberapa sampel ternyata sampel 3 dengan komposisi Kaolin 41.99 %,Talk 36.96 %, Alumina 21.05 % dengan suhu sintering 1350 ° C mempunyai sifat fisis yang paling balk yaitu bending strength 423,255 Kg/cm2, porositas 0.5257 %,densitas 3.7049 g/cm water absorbsion 7.4145%, serta kekuatan vickers 788,46 Kgf/mm2. Dad hasil karakterisasi tersebut maka komposisi dari sampel 3 dapat dipergunakan dan memenuhi syarat untuk aplikasi sebagai refraktori, Kiln Furniture, selubung termokopel,dan sebagai bahan untuk komponen alat penyaring gas pada mobil (Exhaust gas filter/catalys gas carrier).

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Cordierite [2MgO.2A1203.5SiO2] are promising refractory materials for high temperature ceramic application up to 1365 ° C. beside that these materials have a low thermal ג= 2 x 10'° s/d ג = 3 x 10-° and high mechanical strength. Research and development of cordierite ceramics have been done in some stages of researches, first is the preparation of cordierite powders with variation of nature raw materials like Kaulin (AI2 03 2SiO 2H2O), Kuarsa (Si 02), Talk (3MgO4 SiO2 H2O) and Bauxit (AIZ 03 ). After mixing of raw materials, the mixed powders were analyzed by using of DTA, then those powders were formed and fired (sintered) at various temperatures. The characterization consist phase analysis with XRD, measurement of physical properties (density, porosity, water absorpsion), thermal expansion, vickers hardness and bending strength. The physical and mechanical characterization indicated that, the sample with the composition of 41,99 % Kaolin, 36,96 % Talk, 21,05 % Alumina and sintering temperature of 1350 °C have the best physical and mechanical properties. The porosity,density,water absorbsion, bending strength, and vickers hardness are 0,5357 %,3.7049 glcm 3, 7.4145 %, 423,255 Kg/cm2, 788.46 Kgf/mm2 respectively. It is concluded that the sample have fulfiled enough to aplicable as refractories, Kiln Furniture, thermocouple tube and otomotif component (exhaust gas filter/catalys gas carrier)."