淮北朔里煤矿岩床附近煤的光学性质和稀土元素分布特征

运用电感耦合等离子质谱(ICP-MS)、X射线荧光光谱(XRF)、离子选择电极(ISE)、显微镜光度计和煤化学等方法,研究安徽淮北朔里煤矿5号煤层与侵入岩浆岩(岩床)接触面附近煤的光学性质和稀土元素分布特征。结果显示,与岩床直接接触的热变质煤在光学上显示天然焦的典型特征,除惰质组以外的显微组分大都变成了较粗大颗粒状镶嵌结构体,各向异性显著,小球体发育,微气孔很发育;与岩床间接接触(岩床之下)的热变质煤镶嵌结构体变细,各向异性变弱,微气孔不发育,未见小球体。研究还发现,从岩床下边缘至煤层底板泥岩表面的8个煤分层都显示铈(Ce)严重亏损的特征;在稀土元素标准化曲线上,Ce负异常"V"型谷非常显目,表明岩浆的高温将煤中原来的Ce3+氧化成Ce4+而与其它三价稀土元素(RE3+)发生了分离。数据显示,在朔里煤矿岩床接触变质煤中,稀土元素丰度与煤的灰分产率没有显著的相关性,表明岩浆熔体中的微量元素迁移到周围煤中并未造成灰分产率大量提高。

Optical Properties and REE Distribution Features of Coal near Sill in Shuoli Huaibei Coalmine

Using methods of inductively coupled plasma mass spectrometry （ICP-MS）, X-ray fluorescence spectrometry （XRF）, ion selective electrode （ISE）, microscope photometer and coal chemistry, studied optical properties and rare earth elements distribution features of coal near contact plane of No.5 coal seam and intrusive rock （sill）.-The result has demonstrated that the thermal metamorphic coal directly contact the sill have typical optical characters of natural coke, coal macerals except inertinite are mostly changed into coarser granular mosaic telinite, notable anisotropy, well developed spherules and very well developed microvesieles; thermal metamorphosed coal indirect contact （below） the sill have finer mosaic telinite, anisotropy weakening, microvesieles not well developed, spherule unseen. The study also has found the 8 coal slices between lower margin of the sill and coal floor mudstone presented character of heavy looses of cerium （Ce）; on standardized curves of REE, present very striking V typed valiey of Ce negative anomalies, thus have demonstrated that the high temperature of magma has oxidized Ce3＋ into Ce4＋, and separated from other trivalent REE （RE3 ＋）. The data shown, in the Shouli coalmine sill contact metamorphosed coal, no obvious dependency between REE abundance and coal ash yield, thus the migration of trace element in magma into surrounding coal has not made the distinct increase of ash yield.