The effect of microwave radiation on coal grindability

Marland, S.; Han, Bangwoo; Merchant, A.J.; Rowson, Neil A.

doi:10.1016/s0016-2361(99)00285-9

Cited by 110 publications

(58 citation statements)

References 3 publications

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“…And the response of sulphide minerals to microwaves is much stronger than that of coal matrix and quartz. Pyrites tightly embedded in the coal will tend to have fissures under microwave irradiation to allow the monomers to be dissociated, which will improve the reaction between pyrite and desulfurization agent (Marland et al 2000).…”

Section: Organic Sulfuràcoalmentioning

confidence: 99%

Progress of the technique of coal microwave desulfurization

Tao

Xie

et al. 2014

Int J Coal Sci Technol

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With the advantages of its fast speed, effective and moderate controllable conditions, desulfurization of coal by microwave has become research focus in the field of clean coal technology. Coal is a homogeneous mixture which consists of various components with different dielectric properties, so their abilities to absorb microwaves are different, and the sulfur-containing components are better absorbers of microwave, which makes them can be selectively heated and reacted under microwave irradiation. There still remain controversies on the principle of microwave desulfurization at present, thermal effects or non-thermal effects. The point of thermal effects of microwave is mainly base on its characters of rapidly and selectly heating. While, in view of non-thermal effect, direct interactions between the microwave electromagnetic field and sulfur containing components are proposed. It is a fundamental problem to determine the dielectric properties of coal and the sulfur-containing components to reveal the interaction of microwave and sulfur-containing compounds. However, the test of dielectric property of coal is affected by many factors, which makes it difficult to measure dielectric properties accurately. In order to achieve better desulfurization effect, the researchers employ methods of adding chemical additives such as acid, alkali, oxidant, reductant, or changing the reaction atmosphere, or combining with other methods such as magnetic separation, ultrasonic and microorganism. Researchers in this field have also put forward several processes, and have obtained a number of patents. Obscurity of microwave desulfurization mechanism, uncertainties in qualitative and quantitative analysis of sulfur-containing functional groups in coal, and the lack of special microwave equipment have limited further development of microwave desulfurization technology.

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Section: Organic Sulfuràcoalmentioning

confidence: 99%

Progress of the technique of coal microwave desulfurization

Tao

Xie

et al. 2014

Int J Coal Sci Technol

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“…Estos resultados son comparables a los obtenidos para otros materiales (Marland et al, 2000;Kingman et al, 2004;Lester y Kingman, 2004). Esto vendría a suponer, que una vez conseguido el efecto inicial de fisuración de la partícula por shock térmico, cada vez resulta más difícil incrementar el deterioro de la partícula usando este procedimiento.…”

Section: Mejora En El Tiempo De Moliendaunclassified

“…Este contenido en agua es el principal absorbente de radiación en los carbones además de otros minerales como la pirita. La liberación de la primera y la expansión de los segundos provocará la fractura de la piezas de carbón que posteriormente facilitarán su molienda (Marland et al, 2000;Lester y Kingman, 2004). Recientemente, ya se ha informado sobre experimentos con la molienda de carbones en parámetros de operación similares a los que se usarían industrialmente (Lester et al, 2005).…”

Section: Introductionunclassified

Molienda asistida con microondas de un coque metalúrgico

Ruisánchez¹,

Juárez-Pérez²,

Arenillas³

et al. 2014

REVMETAL

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RESUMEN:Los coques metalúrgicos están compuestos mayoritariamente de carbono grafítico (s2p2) y diferentes compuestos inorgánicos con distintas capacidades de absorber la radiación de microondas. Cuando se irradian con microondas fragmentos de estos coques, algunas partes de las partículas experimentan un rápido calentamiento, mientras otras no. Además, debido a que el coque presenta una cierta conductividad eléctrica, al ser irradiados con microondas se producen de forma puntual arcos eléctricos o microplasmas, dando lugar a puntos muy calientes. Como consecuencia de las diferentes dilataciones y tensiones producidas por el choque térmico, se producen en las partículas pequeñas grietas y microfisuras. Esto produce una mayor fragilidad en las partículas de coque y un incremento en la molturabilidad de las mismas. En el presente artículo se estudia la molienda de coque asistida con microondas y se evalúan las mejoras en la molturabilidad y el ahorro de energía producido. ABSTRACT:Microwave-assisted grinding of metallurgical coke. Metallurgical cokes are composed of graphitic carbon (s2p2) and different inorganic compounds with very different capacities to absorb microwave radiation. Moreover, due to the electric conductivity shown by the metallurgical cokes, microwave radiation produces electric arcs or microplasmas, which gives rise to hot spots. Therefore, when these cokes are irradiated with microwaves some parts of the particle experiment a rapid heating, while some others do not heat at all. As a result of the different expansion and stress caused by thermal the shock, small cracks and micro-fissures are produced in the particle. The weakening of the coke particles, and therefore an improvement of its grindability, is produced. This paper studies the microwave-assisted grinding of metallurgical coke and evaluates the grinding improvement and energy saving.

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“…Work on the grind ability of coal by Marland et al, 2000 30 , indicated that reductions in work index of up to 50% occur after microwave pretreatment. The greatest strength reductions were obtained from lower ranked coals, and it was suggested that this was most likely due to the higher inherent moisture content of such coals, with gaseous evolutions of water and volatile matter the main causes of damage to the coal particles.…”

Section: Microwave Assisted Ore Grindingmentioning

confidence: 99%