Hollow silicate microspheres from fly ashes of the Chelyabinsk brown coals (South Urals, Russia)

Sokol, Ella V.; Maksimova, N. V.; Волкова, Н. И.; Nigmatulina, E. N.; Frenkel, A.E

doi:10.1016/s0378-3820(00)00084-9

Cited by 87 publications

(80 citation statements)

References 6 publications

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“…The genesis of the term cenosphere lies in two Greek words: kenos (hollow) and sphaira (sphere) (Torey, 1978). These are essentially hollow silicate microspheres (Sokol, et al, 2000) formed during the mineral transformation stage in coal combustion. The outer shell is made up of silica, iron, alumina, and alkali salts.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Cenospheres Collected from Ash-pond of a Super Thermal Power Plant

Sarkar

Rano

Mishra

et al. 2007

Energy Sources, Part A: Recovery, Utilization, and Environmenta

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As received cenospheres obtained from Rihand Super Thermal Power Plant, Uttar Pradesh, India, were processed using sink float method. The solvent system consisted of 1% TEALS (Triethanolamine lauryl sulphate) in acetone. Further flotation of the float with the same solvent system led to another float. Various fractions thus obtained were characterized in respect of their chemical, mineralogical, and morphological properties. The float obtained from second flotation was richer in cenospheres, which are round and within a small size range. The residues obtained were broken spheres. Phase-mineralogical analysis has revealed mullite enrichment in the floats. Chemical composition of the various fractions does not indicate high concentration of harmful elements. SEM analysis leads to the conclusion that the cenospheres are essentially open-pore type. Based on such experimental observations, various potential uses have been suggested.

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Section: Introductionmentioning

confidence: 99%

Characterization of Cenospheres Collected from Ash-pond of a Super Thermal Power Plant

Sarkar

Rano

Mishra

et al. 2007

Energy Sources, Part A: Recovery, Utilization, and Environmenta

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“…According to the chemical composition, the initial ceno spheres represent an alumina-iron-silicate multicom ponent system with the glassy phase content from 80 to 90% in which the crystalline phases of quartz, mullite, ferritic spinels, and calcite are determined. 9, 11 The main distinction of the cenospheres used is defined by the content of iron and the ferrospinel phase, which achieves 10 and 6 wt.%, respectively (see Table 1). …”

Section: Resultsmentioning

confidence: 99%

“…9-13 According to the chemical com position, they are multicomponent systems SiO 2 -Al 2 O 3 -Fe 2 O 3 -CaO-MgO-Na 2 O-K 2 O-TiO 2 with the glassy phase content from 80 to 90% in which the crystalline phases of quartz, mullite, ferritic sphinels, and calcite are distributed. 9, 11 Since the magnetic cenos pheres contain up to 6 wt.% of the ferrospinel phase, the migration rate of the microspherical containers can be varied by the magnetic field. The porous structure of the aluminosilicate shell of the cenospheres can be changed by etching with various chemical reagents, par ticularly, hydrofluoric and hydrochloric acids.…”

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confidence: 99%

Perforated cenosphere-supported pH-sensitive spin probes

et al. 2008

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Porous supports with an accessible internal volume and a shell providing the diffusive migration of pH sensitive spin probes were obtained for the first time from hollow aluminosilicate cenospheres isolated from the coal fly ash. Using the methods of scanning electron microscopy and electron spin resonance, the morphology of different porous cenosphere modifications and its influence on the diffusion of spin probes from the internal volume were studied. When supporting aqueous solutions of a radical, the characteristic diffusion time for the mesoporous structure of the support is longer by a factor of 3-5 than that for the macroporous structure. Ferrospinel in a content of 6 wt.% do not virtually affect the diffusion rate of spin probes. A constant rate of radical migration of 1 μmol min -1 , determined by radical solubility in water, is achieved when a radical in the solid aggregate state is supported on the magnetic cenospheres.

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“…The metal processing industry and involved plants are another major source of environmental pollution. During the high temperature processes, magnetic spherical particles are usually formed (Sokol et al, 2000;McLennan et al, 2000). Nevertheless, the deposition of these particles on the ground contributes significantly to the magnetic component and heavy metal concentrations in the road dusts near power plants.…”

Section: Tracing Of Contamination Sourcesmentioning

confidence: 99%

Magnetic properties of street dust from Chibi City, Hubei Province, China: Its implications for urban environment

et al. 2009

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Magnetic measurements and heavy metal analyses were performed on street dusts from the main urban area of Chibi (赤壁) City, Hubei (湖北) Province, China. Results revealed that a PSD/MD (pseudo-single-domain/multi-domain) magnetite-like phase dominates the magnetic phases of the street dust. Concentration-related magnetic parameters, such as magnetic susceptibility (χ), anhysteretic remanent magnetization (ARM), and saturation isothermal remanent magnetization (SIRM) of samples increased in the main roads but appeared lower in the landscape area of the Lushui (陆水) Lake and closely correlated with the concentration of heavy metal Fe, Cu, and Co, and the correlation coefficients are 0.786 for Fe-χ, 0.548 for Cu-χ, and 0.580 for Co-χ, respectively. However, much strong correlations between SIRM and the concentrations of heavy metal suggest that SIRM is a better indicator for heavy metal pollution in the street dust in the study area. The magnetic particles in the street dust are mainly derived from anthropogenic activities, such as vehicle emissions, abrasion of tires, coal combustion, cement works, and building materials. These results make it possible to use magnetic techniques as simple, rapid, and nondestructive tools for assessing the heavy metal pollutions in urbanization process. KEY WORDS: environmental magnetism, street dust, heavy metal, Chibi City.

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Hollow silicate microspheres from fly ashes of the Chelyabinsk brown coals (South Urals, Russia)

Cited by 87 publications

References 6 publications

Characterization of Cenospheres Collected from Ash-pond of a Super Thermal Power Plant

Characterization of Cenospheres Collected from Ash-pond of a Super Thermal Power Plant

Perforated cenosphere-supported pH-sensitive spin probes

Magnetic properties of street dust from Chibi City, Hubei Province, China: Its implications for urban environment

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