In situ high-temperature phase transformation studies on pyrite

Bhargava, Suresh K.; Garg, A.; Subasinghe, Nalaka Deepal

doi:10.1016/j.fuel.2008.12.005

Cited by 139 publications

(74 citation statements)

References 26 publications

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“…Accordingly, in crystallography, simple cubic crystal system was transformed to monoclinic or hexagonal crystal symmetry. Transformation of pyrite to pyrrhotite is endothermic and can be expressed by the chemical equation as follows (Bhargava et al 2009):…”

Section: Structure and Property Of Pyrite Calcinatedmentioning

confidence: 99%

“…In inert atmosphere (nitrogen, argon and helium) at high temperature, pyrrhotite, a non-stoichiometric iron sulfide, is the most dominant product of pyrite calcination (Bhargava et al 2009). Previous research has revealed that not only pyrite is transformed into pyrrhotite after calcination in N 2 atmosphere, but also the crystal size of the calcinate is becomes nanometer or submicron (Lambert et al 1998).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Phosphorus removal from aqueous solutions containing low concentration of phosphate using pyrite calcinate sorbent

Chen

Wang

Xie

et al. 2014

Int. J. Environ. Sci. Technol.

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Natural pyrite was modified by calcination under nitrogen (N 2 ) atmosphere to produce a novel sorbent for removing phosphorus (P) with low concentration from aqueous solutions. The crystallinity, porous texture, magnetic susceptibility and performance in P removal of pyrite calcinates depended on calcination temperatures. The sorbent obtained at calcination temperature of 500-600°C possessed the most efficient P removal. Solution pH in the range of 3.0-9.0 and anions of chloridion (Cl -), nitrate (NO 3 )-and sulfate (SO 4 2-) had ignorable effect on P removal. The batch adsorption experiment shows that the maximum sorption capacities for P of this novel sorbent (q m ) were up to 1.61-5.36 mg P/g at adsorption temperatures of 15-35°C. Dynamic sorption and regeneration experiments were conducted in an adsorption column filled with pyrite calcined at 600°C. The study found that oxygen was an important control factor responsible for P adsorption because the oxidization of Fe 2? to Fe 3? on the surface of the sorbent followed by P being bound to a ferric hydroxide surface film was the crucial processes. The mechanism was confirmed with surface characterization techniques including field emission scanning electron microscope and X-ray photoelectron spectroscopy. This research potentially provides a cheap, abundant sorbent for P removal from the secondary effluent of municipal wastewater treatment plant.

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Section: Structure and Property Of Pyrite Calcinatedmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Phosphorus removal from aqueous solutions containing low concentration of phosphate using pyrite calcinate sorbent

Chen

Wang

Xie

et al. 2014

Int. J. Environ. Sci. Technol.

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“…The alumi nosilicate peaks are probably too high to allow observations on the transformation of iron and calcium containing phases and carbon ates. Other researchers [19,27] have performed detailed tests on the transformation of iron containing phases and conclude that un der oxyfuel conditions the iron containing phases (pyrite) can lead to the formation of low melting point FeO FeS though pyrrhotite oxidation. This could partly explain the higher deposition propen sity of the fuels under oxyfuel conditions, while the temperatures and the fuels are the same; however this is strongly depending on the fuel composition itself.…”

Section: Ash Crystallographic (Xrd) Analysesmentioning

confidence: 99%

“…The intermediate products, including pyrrhotite with the melting point of 1100°C and FeO FeS with the eutectic tem perature of 940°C, are prone to coalesce with inherent silicates and form glass silicates. Char combustion under O 2 /CO 2 may lead to higher CO concentrations than under O 2 /N 2 combustion, which slows the transformation of pyrite to oxides, thus possibly increas ing the slagging propensity of the ash [20,27].…”

Section: Introduction and Scope Of Workmentioning

confidence: 99%

Study of ash deposition during coal combustion under oxyfuel conditions

Fryda

Sobrino

Glazer

et al. 2012

Fuel

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a b s t r a c tThis paper presents a comparative study on ash deposition of two selected coals, Russian coal and lignite, under oxyfuel (O 2 /CO 2 ) and air combustion conditions. The comparison is based on experimental results and subsequent evaluation of the data and observed trends. Deposited as well as remaining filter ash (fine ash) samples were subjected to XRD and ICP analyses in order to study the chemical composition and mineral transformations undergone in the ash under the combustion conditions. The experimental results show higher deposition propensities under oxyfuel conditions; the possible reasons for this are investigated by analyzing the parameters affecting the ash deposition phenomena. Particle size seems to be larger for the Russian coal oxy fired ash, leading to increased impaction on the deposition surfaces. The chemical and mineralogical compositions do not seem to differ significantly between air and oxyfuel conditions.The differences in the physical properties of the flue gas between air combustion and oxyfuel combus tion, e.g. density, viscosity, molar heat capacity, lead to changes in the flow field (velocities, particle tra jectory and temperature) that together with the ash particle size shift seem to play a role in the observed ash deposition phenomena.

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“…The kaolinite phase disappears and a new phase silimanite is formed at 600°C. The silimanite (Pan et al 2000;Bhargava et al 2009). …”

Section: Phase Transformation Of Mineral Matter At High Temperaturesmentioning

confidence: 99%

Distribution of mineral species in different coal seams of Talcher coalfield and its transformation behavior at varying temperatures

Banerjee

Mishra

Mohanty

et al. 2016

Int J Coal Sci Technol

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Mineral phase characterization and thorough understanding of its transformation behavior during combustion are imperative to know the potential utilization of coal in the thermal industries. The primary objective of this work is to analyze the quality of Indian Coals and obtain their mineral species-specific information at different depths. The samples were obtained from Talcher Coalfield, Odisha, India. Coal from four seam sections in the Talcher coalfield, India are mainly high ash coal ([50 %) and volatile matter deceases along with the seam depth. XRD results show that the major mineral phases present in the coal are quartz and kaolinite. Siderite, illite, and anatase were found in minor quantities. It has been observed that the clay minerals (kaolinite, silimanite, illite) decompose at higher temperature and traces of dolomite, mullite, hematite etc. are formed during the process of combustion. Among the four seams (M2, M12, M24 and M43) studied, ash of M43 has high Al 2 O 3 %, TiO 2 % and K 2 O% content and low SiO 2 %, CaO% and MgO% content. High acidto-base ratios contributed to high ash fusion temperatures (IDT [ 1500°C) and low slagging potential of the coals studied. Relatively low fouling index (\0.3) was estimated for all the coal seams studied. Furthermore, thermodynamic modeling software, FactSage, have been used to envision the mineral phase transformations that take place between 800 and 1500°C during coal combustion.

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In situ high-temperature phase transformation studies on pyrite

Cited by 139 publications

References 26 publications

Phosphorus removal from aqueous solutions containing low concentration of phosphate using pyrite calcinate sorbent

Phosphorus removal from aqueous solutions containing low concentration of phosphate using pyrite calcinate sorbent

Study of ash deposition during coal combustion under oxyfuel conditions

Distribution of mineral species in different coal seams of Talcher coalfield and its transformation behavior at varying temperatures

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