Effects of Magmatic Intrusion on Mineralogy and Geochemistry of Coals from the Fengfeng-Handan Coalfield, Hebei, China

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• 作者：Shifeng Dai ; Deyi Ren
• 刊名：Energy & Fuels
• 出版年：2007
• 出版时间：May 2007
• 年：2007
• 卷：21
• 期：3
• 页码：1663 - 1673
• 全文大小：570K
• 年卷期：v.21,no.3(May 2007)
• ISSN：1520-5029

文摘

This paper describes the effects of magmatic intrusions on petrology, mineralogy, and geochemistry of thelate Palaeozoic coals from the Fengfeng-Handan coalfield, Hebei, China. The narrowly zoned coals of variableranks, from high-volatile A bituminous (hvAb), through medium-volatile bituminous (mvb), low-volatilebituminous (lvb), semianthracite (sa), and anthracite (an), to meta-anthracite (ma) in the coalfield, were foundto be best explained by magmatic inputs. The minerals derived from magmatic thermal alteration consist ofpyrite, calcite, and ankerite, which mainly occur as fracture or vesicle fillings in the thermally altered high-rank coals. The variation in element concentrations with coal ranks (enrichment, depletion, and no variation)and mineralogical affinity were used to classify elements in coals into six groups, groups A-F. Elements ingroup A (B, F, Cl, Br, and Hg), group B (As, Co, Cu, Ni, and Pb), group C (Sr, Mg, Ca, Mn, and Zn), andGroup D (U) were enriched in the altered coals, indicating that the magmatic inputs are the source of theseelements. Group A elements are volatile elements that probably came from the hydrothermal solutions, thendeposited or were driven off from an organic component in coal by magmatic heat, and then redeposited inthe coal. Group B elements mainly distribute in the fracture or vesicle fillings of pyrites. The dominant carriersof group C elements are thermally altered calcite and ankerite. Uranium in group D occurs in organic-bondedand silicate associations. Group E elements, including Sb, Sc, and V, have a depletion trend in the alteredcoals, and the remaining elements in group F do not clearly vary in the unaltered, slightly altered, or alteredcoals. The element concentrations independent of coal ranks in groups E and F may suggest that these elementsare inherent to the coal.