FT-i.r. study of coal oxidation at low temperature

Calemma, Vincenzo; Rausa, R.; Margarit, R.; Girardi, E.

doi:10.1016/0016-2361(88)90147-0

Cited by 101 publications

(45 citation statements)

References 7 publications

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“…The experimental approach developed in this study was first applied to the understanding of the long-term evolution of coal submitted to weathering [15,24,33]. Low temperatures were used to accelerate oxidation reactions and then compensate the long time of oxidation (several years) that could not be reproduced in laboratory experiments.…”

Section: Does Low Temperature Oxidation Simulate the Long Term Evolutmentioning

confidence: 99%

Low temperature oxidation of a coking plant soil organic matter and its major constituents: An experimental approach to simulate a long term evolution

Biache

Ghislain

Faure

et al. 2011

Journal of Hazardous Materials

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Section: Does Low Temperature Oxidation Simulate the Long Term Evolutmentioning

confidence: 99%

Low temperature oxidation of a coking plant soil organic matter and its major constituents: An experimental approach to simulate a long term evolution

Biache

Ghislain

Faure

et al. 2011

Journal of Hazardous Materials

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“…Adsorption of oxygen is exothermic and, besides the moieties formed on the coal surface, such reaction products as CO, CO 2 and H 2 O may be released from the structure (Itay et al, 1989). The most susceptible linkages to oxidation were found to be the a-CH 2 groups to polyaromatics using a variety of techniques such as FTIR, UV Fluorescence and DRIFT spectroscopy (Calemma et al, 1988;Kochi, 1973;Kister et al, 1988;Xiao et al, 1990). An interesting point on oxidation was revealed by Mitchell et al (1996) who showed that blue-light irradiation was also a strong agent in oxidizing the vitrinite surfaces.…”

Section: Effect Of the Oxidation Of Coal Particles In Flotationmentioning

confidence: 99%

Physical and chemical interactions in coal flotation

Polat

Chander

2003

International Journal of Mineral Processing

189

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Coal flotation is a complex process involving several phases (particles, oil droplets and air bubbles). These phases simultaneously interact with each other and with other species such as the molecules of a promoting reagent and dissolved ions in water. The physical and chemical interactions determine the outcome of the flotation process. Physical and chemical interactions between fine coal particles could lead to aggregation, especially for high rank coals. Non-selective particle aggregation could be said to be the main reason for the selectivity problems in coal flotation. It should be addressed by physical (conditioning) or chemical (promoters) pretreatment before or during flotation. Although the interactions between the oil droplets and coal particles are actually favored, stabilization of the oil droplets by small amounts of fine hydrophobic particles may lead to a decrease in selectivity and an increase in oil consumption. These problems could be remedied by use of promoters that modify the coal surface for suitable particle -particle, droplet -particle and particle -bubble contact while emulsifying the oil droplets. The role of promoters may be different for different types of coals, however. They could be employed as modifiers to increase the hydrophobicity of low rank coals whereas their main role might be emulsification and aggregation control for high rank coals. In this paper, a detailed description of the various phases in coal flotation, their physical and chemical interactions with each other in the flotation pulp, the major parameters that affect these interactions and how these interactions, in turn, influence the flotation process are discussed. D

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“…Obvious differences of chemical composition are observed for three coal samples. These differences are mainly reflected in the regions of 3000-2800 cm −1 and 1850-1500 cm − 1 , which are assigned to the absorptions of aliphatic C\H stretching region and carbonyl stretching region, respectively (Calemma et al, 1988;Chen et al, 2012). It can be seen that the absorption of the aliphatic hydrogen in the regions of 3000-2800 cm −1 decreases with the increase of coal metamorphic degree; while an obvious increase trend in the regions of 1850-1500 cm −1 (carbonyl adsorption region) is observed.…”

Section: Testing Of Functional Groups In Original Coal Samplesmentioning

confidence: 99%