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Coal Ash Characteristic from Bukit Asam as Raw Material for Ceramics Production

Jurnal ILMU DASAR Vol 9, No 2 (2008)
Publisher : Fakultas MIPA Universitas Jember

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Abstract

This study was carried out to characterize coal ash obtained from Bukit Asam, Tarahan Lampung, after the samples were sintered at various temperatures ranging from 900C - 1300C. The characteristics of the investigated samples included density, porosity, hardness, structure and microstructure. The results indicated that porosity decreased with increasing sintering temperature, while density and hardness increased with increasing temperature. The x-ray diffraction (XRD) study revealed that the main crystalline phase was silicon dioxide (SiO2), with the minor constituents of CaSiO2, MgSiO3, FeSiO4 and Ca12Al14O33. SEM investigations clearly demonstrated the presence of a fine crystallised phase dispersed in the microstructure.Keywords: Coal ash, sintering, microstructure, XRD

Pengaruh Suhu Tinggi terhadap Karakteristik Keramik Cordierite Berbasis Silika Sekam Padi

Jurnal Fisika dan Aplikasinya Vol 5, No 1 (2009)
Publisher : Jurnal Fisika dan Aplikasinya

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Abstract

This study was carried out to investigate the effect of high temperature on the functional groups, microstructure and physical characteristics of cordierite ceramics obtained from an aqueous solution of magnesium nitrate hydrate ((Mg(NO3)2.6.12H2O)), aluminium nitrate hydrate (Al(NO3)2.9.15H2O) and silica sols extracted from rice husk. The samples were sintered at temperature of 1000◦C, 1200◦C and 1400◦C. Functional groups and microstructural characteristics of cordierite ceramics were examined by FTIR and SEM, respectivelly. FTIR study shows that the absence of the vibration bands of Na-OH, Si-OH, C-O, Si-O-Si on the samples. However, the formation of cordierite structure was dominated on this high temperature. Microstructure results confirmed the presence of irregular morphology of the solid and compact phases. In addition, the densities, shrinkage andhardness of cordierite increase significantly with increasing temperature, but porosity decreases with increasingtemperature.

Coal Ash Characteristic from Bukit Asam as Raw Material for Ceramics Production

Jurnal ILMU DASAR Vol 9 No 2 (2008)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

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Abstract

This study was carried out to characterize coal ash obtained from Bukit Asam, Tarahan Lampung, after the samples were sintered at various temperatures ranging from 900C - 1300C. The characteristics of the investigated samples included density, porosity, hardness, structure and microstructure. The results indicated that porosity decreased with increasing sintering temperature, while density and hardness increased with increasing temperature. The x-ray diffraction (XRD) study revealed that the main crystalline phase was silicon dioxide (SiO2), with the minor constituents of CaSiO2, MgSiO3, FeSiO4 and Ca12Al14O33. SEM investigations clearly demonstrated the presence of a fine crystallised phase dispersed in the microstructure.

Characteristics of Nanosize Spinel NixFe3-xO4 Prepared by Sol-Gel Method Using Egg White as Emulsifying Agent

Indonesian Journal of Chemistry Vol 15, No 2 (2015)
Publisher : Universitas Gadjah Mada

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Abstract

In this study, sol-gel method using egg white as emulsifying agent was applied to prepare nano size spinel NixFe3-xO4 (with x = 0.2–1). Sample preparation was carried out by mixing the solution of Fe(NO3)3.9 H2O and Ni(NO3)3.6 H2O with egg white, and then the sample was stirred thoroughly using magnetic stirrer. After freeze–drying process, the sample was subjected to calcination treatment and subsequently characterized. The phase composition was evaluated using the X-ray diffraction (XRD) technique, followed by quantitative analysis using Rietveld and Debye-Scherrer Methods. The functionality of the sample was identified using Fourier Transform Infrared (FTIR) spectroscopy, and surface morphology and elemental composition were analyzed using scanning electron microscopycoupled with electron dispersive spectroscopy (SEM/EDS). The results of XRD characterization indicated that materials consist of various crystalline phases, with NiFe2O4 as a major phase. FTIR Analysis revealed the existence of both Lewis and Brønsted–Lowry acid sites, with Lewis acid as the prominent site. The sample was found to display relatively homogeneous surface morphology, having the crystallite size in the range of 33 to 61 nm according to the Debye-Scherrer equation. The EDS data indicated that the ratio of Fe/Ni is in agreement with the composition of the raw materials used.

EFFECT OF PYROLYSIS TEMPERATURES ON COMPOSITION AND ELECTRICAL CONDUCTIVITY OF CARBOSIL PREPARED FROM RICE HUSK

Indonesian Journal of Chemistry Vol 12, No 2 (2012)
Publisher : Universitas Gadjah Mada

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Abstract

The objective of this study was to evaluate the effect of pyrolysis temperatures on composition and electrical conductivity of carbosil produced from rice husk, by conducting pyrolysis experiments at three different temperatures of 200; 400; and 700 °C. The structure of the samples was characterized using Fourier Transform Infrared (FTIR) Spectroscopy and X-Ray Diffraction (XRD). The microstructure and elemental composition were characterized using Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS), and the electrical conductivity was measured using four probe method. The FTIR analyses revealed the existence of Si-O-Si and Si-OH functional groups, but no functional groups associated with carbon, confirming the formation of carbosil. This formation of carbosil is also supported by the results of EDS analyses which show the presence of only three elements of C, O, and Si, respectively. The XRD results indicate that the carbosils are amorphous, suggesting that no transformation of carbon and silica into crystalline phase to the limit of the temperatures applied. The carbosil formation decreased with increasing of pyrolysis temperature. The microstructure of the carbosils indicates that the higher the temperature, the smaller the grain size of the samples. The values of electrical conductivity of the samples are in the range of 1.13 x 10-3 to 6.81 x 10-3/(Ω.m) with the application of 10 tones compression pressure, but the conductivities of the sample prepared at 200 °C were found to increase with increased compression pressure to six fold from 6.81 x 10-3 to 41.94 x 10-3/(Ω.m) by increasing compression pressure to 80 tones. Based on these conductivity values, the samples are considered as semiconductor, suggesting the potential use of the carbosil in semiconductor devices.

SYNTHESIS AND CHARATERISATION OF RICE HUSK SILICA BASED BOROSILICATE (B2SiO5) CERAMIC BY SOL-GEL ROUTES

Indonesian Journal of Chemistry Vol 11, No 1 (2011)
Publisher : Universitas Gadjah Mada

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Abstract

In this research, borosilicate ceramics were produced from rice husk silica. Preparation of borosilicate ceramics was conducted by mixing boron oxide sol from borax with silica sol extracted from rice husk. The boron oxide was produced by hydrolysis of borax using H2SO4 5%. The samples were synthesized with different compositions, with the ratios of silica to boron oxide are 8:1, 8:2, 8:3 and 8:4. The samples were sintered at 900 °C. Functional groups were examined using FTIR spectroscopic technique. Structural and microstructural characteristics were examined by XRD and SEM, respectively. The chemical resistance of borosilicate is evaluated by gravimetric method using H2SO4, HCl, NaOH and KOH. The FTIR study revealed that the main functional groups are Si-O-Si, B-O-B, and B-O-Si. The x-ray diffraction (XRD) study revealed that the main crystalline phases are borosilicate (B2SiO5) and boron oxide (B2O3). SEM investigations clearly demonstrated that the smaller particle size was found with increasing in boron oxide concentration. From the chemical resistance test carried out, it was obtained that the produced borosilicate possessed high resistance to acids and alkalis.

Analisis Kuantitatif Data Diffraksi Sinar X Fasa Keramik Crystoballite Berbasis Silika Sekam Padi dengan Metode Rietveld

JIEMS (Journal of Industrial Engineering and Management Systems) Vol 3, No 2 (2010): Journal of Industrial Engineering and Management Systems (JIEMS)
Publisher : Universitas Bunda Mulia

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Abstract

Rietveld analysis is a means of revealing the detailed structure and composition of crystalline sample using x-ray powder diffraction data. This research presents the use of the Rietveld method using Rietica program to obtain the phase abundance of crystoballite crystal from rice husk sintered at 850oC, 950oC and 1100oC that has previously been demonstrated.The model parameters are refined by the methodof least squares until a good fit (2) to the observed data is obtained. The refined parameters in this study are background, scale factor, space groups, atom co-ordinates (U,V,W), preferred orientation, and the lattice parameters. The results showed that quantitative crystoballite crystal were 87.8, 89.8 and 98.4% weight, respectively. An acceptable result for estimation of lattice parameters and weightpercentage of crystoballite with reliability (2) was found to be < 4. The results also show that analysis by Rietveld method is efficient to control the quantity of crystoballite in the sintering process.Keywords: Rietveld, Rice Husk, X-Ray Diffraction

Sintesis dan Karakterisasi Fasa Crystoballite Berbasis Silika Sekam Padi dengan Metode Sintering (Solid State)

JIEMS (Journal of Industrial Engineering and Management Systems) Vol 2, No 2 (2009): Journal of Industrial Engineering and Management Systems (JIEMS)
Publisher : Universitas Bunda Mulia

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Abstract

This study was carried out to characterize the formation of crystoballite crystall of silica extracted from rice husk by sintering. Extraction of silica using 5% KOH and 10% HCl solution was sintered at 750, 900, 1000,and 1100 C. The products were characterised in term of functional groups, microstructure and structure (FTIR, SEM and XRD). Characterisation of the silica using FTIR shows the presence of silanol and siloxane. XRD results confirmed that silica amorph was formed at 750C, through the intermediate formation of crystoballite 900, 1000, and 1100C. The formation of crystoballite structure increases with increasing temperature of sintering, which confirms the presence of regular particle size using SEM analysis.Keywords: Rice Husk, Silica, Crystoballite, FTIR, SEM and XRD

Analisis Transisi Fasa dan Sifat Dielektrik Pada Li2CoSiO4 yang Dipreparasi dari Silika Sekam Padi dan Produk Daur Ulang Katoda Baterai Ion Litium Bekas

ALCHEMY Jurnal Penelitian Kimia Vol 15, No 1 (2019): INPRESS Vol 15, No 1 (2019) Alchemy Jurnal Penelitian Kimia
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

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Abstract

Studi ini mendeskripsikan analisis transisi fasa dan sifat dielektrik pada bahan litium kobalt silikat (Li2CoSiO4) yang dipreparasi dari silika sekam padi dan produk daur ulang katoda baterai ion litium bekas dengan perbandingan massa 1:1. Transisi fasa pada sampel Li2CoSiO4 dipelajari menggunakan teknik termogravimetry/differential thermal analysis (TG/DTA). Sedangkan, nilai konstanta dielektrik pada sampel yang telah disinter pada suhu 600 – 900 oC dikarakterisasi menggunakan inductance, capacitance, dan resistance (LCR) meter. Hasilnya, pada rentang suhu 410 – 850 oC terjadi transisi polimorfik fasa  menjadi fasa . Suhu 850 oC juga merupakan titik transisi dimana fasa  berubah menjadi fasa . Transisi fasa yang terjadi pada sampel  Li2CoSiO4 diikuti dengan peningkatan nilai konstanta dielektrik dalam rentang frekuensi 450 – 100.000 Hz.Analysis of Phase Transition and Dielectric Properties of Li2CoSiO4 Prepared from Rice Husk Silica and The Recycling Product of Used Lithium Ion Batteries Cathode. This study describes the analysis of the phase transition and dielectric properties of lithium cobalt silicate (Li2CoSiO4) prepared from rice husk silica and the recycling product of used lithium ion batteries cathode with mass ratio of 1:1. Phase transition in Li2CoSiO4 sample was studied using thermogravimetry/differential thermal analysis (TG/DTA) techniques. Meanwhile, the dielectric constant value in the samples sintered at temperature of 600 – 900 oC were characterized using inductance, capacitance, and resistance (LCR) meter. As a result, a polymorphic transition from  phase to  phase was occured in the temperature range of 410 ­– 850 oC. Temperature of 850 oC is a transition point from  phase to  phase. The phase transitions occured in the Li2CoSiO4 was followed by the increasing of the dielectric constant in the frequency range of 450 – 100,000 Hz.