XPS studies of magnesium silicide obtained from rice husk

Ghosh, Tapas; Nandi, K.C.; Acharya, H. N.; Mukherjee, Dibyendu

doi:10.1016/0167-577x(91)90179-a

Cited by 17 publications

(7 citation statements)

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“…The high reactivity and purity of RHA makes it an ideal starting material/silica source for preparing advanced materials like sialon (Sun & Gong, 2001;Rahnman & Saleh, 1995), silicon carbide (Krishnarao et al, 1998;Rodriguez-Lugo et al, 2002;Sujirote & Leangsuwan, 2003), silicon nitride (Kumar & Godkhindi, 1996;Real et al, 2004), cordierite (Sun & Gong, 2001;S. Kurama & H. Kurama, 2008), forsterite (Sun & Gong, 2001), gehlenite (Sun & Gong, 2001;Han et al, 1999), pure elemental silicon (Sun & Gong, 2001;Hunt et al, 1984), magnesium silicide (Acharya et al, 1980;Ghosh et al, 1991), Si-O-C fibers (Sun & Gong, 2001;Shimokawa et al, 1992), zeolites (Gokhal et al, 1986;Chareonpanich et al, 2004) etc. Recently, RHA has been successfully used as a sorbent of heavy metal ions, dyes and pigments from aqueous solutions (Mohanty et al, 2006;Lakshmi et al, 2009;Sharma et al, 2010) and as a support of Ni, Cu, Cr or V containing catalysts for various organic reactions and it was found to be preferable over silica gel (Tsai & Chang, 2000;Chang et al, 2005Chang et al, , 2006Renu et al, 2008).…”

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Obtaining Some Polymer Composites Filled with Rice Husks Ash-A Review

Turmanova

Genieva²,

Vlaev³

2012

IJC

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Rice husks are an important by-product of rice milling process and are major waste product of the agricultural industry. Rice husk contain nearly 20 mass% silica, which is present in hydrated amorphous form. They have now become a great source as a raw biomass material for manufacturing of value-added silicon composite products, including silicon carbide, silicon nitride, silicon tetrachloride, magnesium silicide, pure silicon, zeolite, fillers of rubber and plastic composites, cement, adsorbent and support of heterogeneous catalysts. The rice husk was subjected to pyrolysis in fluidized-bed pilot plant in air or nitrogen atmosphere. The controlled thermal degradation of the rice husks in air or nitrogen leads to production of white rice husks ash (WRHA) and black rice husks ash (BRHA) respectively. WRHA contains almost pure (95mass %) silica in a hydrated amorphous form, similar to silica gel, with high porosity and reactive surface OH groups. BRHA contains different amounts of carbon and silica in amorphous form with high specific surface area and porosity. The raw rice husks and the obtained pyrolysis products were used as fillers of polypropylene (PP) and tetrafluoroethylene-ethylene copolymer (TFE-E) composites. The kinetics and thermodynamics of water adsorption onto filled polypropylene composites during soaking were studied at different temperatures, quantities and nature of fillers. It was established, that the adsorption kinetics was limited by intra-particle diffusion in plane sheet particles. The sorption process is exothermal in nature and accompanied with decrease of the entropy.The physicomechanical properties of composite materials were determined. The fillers introduced in polypropylene change the mechanical strength and make the composites brittle. This change is more pronounced for the composites with BRHA and RRH, followed by WRHA. The composites studied showed lower elongation at break. The biggest decrease was observed for the composites with BRHA where ε decrease from 500 (for the initial PP) to 7 % at filling degree of 20 mass %. The effects of the amount of adsorbed water, temperature and treatment time on the composites tensile properties were estimated. It was found after immersion in water that the composites improve their tensile strength compared to initial non-treated samples. The thermal stability and kinetics of non-isothermal degradation of PP and TFE-E composites filled with 10 or 20 mass % vigorously grounded and mixed RRH, BRHA, WRHA and Aerosil Degussa (AR) were studied. Using different calculation procedures the most probably kinetic mechanism was found to be described by kinetic equations of n -th order (F n mechanism). The kinetic parameters were obtained, and a linear dependence between ln A and E was observed, known also as kinetic compensation effect.The abundance of a waste from paddy milling industry, as well as its interesting complex of behaviors are prerequisite for success for obtaining of cheap and valuable products and gives a new alternatives for its ...

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Obtaining Some Polymer Composites Filled with Rice Husks Ash-A Review

Turmanova

Genieva²,

Vlaev³

2012

IJC

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“…It was found that RH char contains amorphous silica in addition to amorphous carbon as the main constituents (Yamaguchi et al, 2006). Many authors have concluded that rice husk is an excellent source of high grade amorphous silica (Chen and Chang, 1991;Ghosh et al, 1991;Nandi et al, 1991). This portion of the silica cannot be dissolved in alkali and can withstand very high temperatures (Patel et al, 1991).…”

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of activated carbon & amorphous silica from rice husk

Rhaman¹,

Haque²,

Rouf

et al. 2015

Bangladesh J. Sci. Ind. Res.

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Activated carbon (AC) was prepared by the conventional carbonization and KOH activation and amorphous silica was extracted by alkali extraction followed by acid precipitation from rice husk on a laboratory scale. The performance of the produced activated carbon and amorphous silica were examined using I2 value measurement, methylene blue (MB) adsorption test, pH measurement, FTIR and SEM-EDX analysis. The optimum temperature for production of AC was obtained at 700 0C. The AC by alkali extraction method was show higher activity than KOH activation. The maximum I2 value, MB adsorption value & pH value shows at 700 0C followed by alkali extraction with 15% NaOH, which were 510.82 mg/g, 61.1 mg/g and 7.32 respectively. The FTIR analysis shows presence of Si-O-Si bond with a strong peak at 1078.28 cm-1. The SEM image of silica sample shows that the most of organic component is burnt out during combustion.Bangladesh J. Sci. Ind. Res. 50(4), 263-270, 2015

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“…As reviewed also by Real et al [9], a number of published literatures [14,15] had concluded that RH are an excellent source of high-grade amorphous silica. The silica obtained from RH ash is a good material for synthesis of very pure silicon [16][17][18], silicon nitride [19], silicon carbide [20,21] and magnesium silicide [22]. In addition, the obtained silica has been claimed [17,18 and 23] to be an excellent source of very pure silicon, useful for manufacturing solar cells and for photo-voltaic power generation as well as various types of semiconductors [24,25].…”

Section: Introductionmentioning

confidence: 99%

Utilization of Pure Silica Extracted from Rice Husk and FTIR Structural Analysis of the Prepared Glasses

Saudi¹

2015

AJPA

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Egyptian rice husk was subjected to different chemical and thermal treatment methods, aiming to extract high pure silica. Three samples (S 1 , S 2 and S 3) were prepared applying three different chemical treatment methods. Two sets of the obtained samples were prepared, where the first set was calcinated at 600 o C and the other set was calcinated at 750 o C by slow heating (starting at RT and ending at the desired calcinations temperature for 2 h).XRF was applied to identify the chemical composition and purity of the extracted silica, while XRD was applied to confirm the amorphous nature and the presence of some induced carbon black in the obtained silica. It was found that S 3 slowly heated at 750 o C presents the highest silica content (98.6 %). Such sample was fed directly to the calcinations furnace at 750 o C (sudden heating for comparison) where it presents only 90.6% silica, and 3.74 % residual carbon black. However, the extracted silica from sample S 3 was used to prepare glasses obeying the composition (75-x) mol% RH-silica, x mol% Bi 2 O 3 , 25 mol% Na 2 O, (where 0 ≤ x ≤ 20).FTIR spectroscopic analysis was applied to investigate the internal structure of the prepared glasses, where the glass networks were found to contain mainly SiO 4 , BiO 3 and BiO 6 structural groups, as well as some bridging and non-bridging oxygen anions. Also, some O-H and H-O-H groups were also detected which may be due to the used KBr disk technique.

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XPS studies of magnesium silicide obtained from rice husk

Cited by 17 publications

References 1 publication

Obtaining Some Polymer Composites Filled with Rice Husks Ash-A Review

Obtaining Some Polymer Composites Filled with Rice Husks Ash-A Review

Preparation and characterization of activated carbon & amorphous silica from rice husk

Utilization of Pure Silica Extracted from Rice Husk and FTIR Structural Analysis of the Prepared Glasses

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