姚宗序, 杜晨衔, 周郑琪, 杨建国. 焦煤的石墨化及煤系矿物的变迁研究[J]. 选煤技术, 2021, 49(6): 7-13. DOI: 10.16447/j.cnki.cpt.2021.06.002
    引用本文: 姚宗序, 杜晨衔, 周郑琪, 杨建国. 焦煤的石墨化及煤系矿物的变迁研究[J]. 选煤技术, 2021, 49(6): 7-13. DOI: 10.16447/j.cnki.cpt.2021.06.002
    YAO Zongxu, DU Chenxian, ZHOU Zhengqi, YANG Jianguo. Study of graphitization of coking coal and changes and migration of coal-series minerals[J]. Coal Preparation Technology, 2021, 49(6): 7-13. DOI: 10.16447/j.cnki.cpt.2021.06.002
    Citation: YAO Zongxu, DU Chenxian, ZHOU Zhengqi, YANG Jianguo. Study of graphitization of coking coal and changes and migration of coal-series minerals[J]. Coal Preparation Technology, 2021, 49(6): 7-13. DOI: 10.16447/j.cnki.cpt.2021.06.002

    焦煤的石墨化及煤系矿物的变迁研究

    Study of graphitization of coking coal and changes and migration of coal-series minerals

    • 摘要: 为研究煤系矿物在煤制石墨过程中的变化规律和迁移过程,采用浮沉试验、煤岩分析以及X射线衍射等表征手段,分析了煤系矿物的形态及其分布。研究结果表明:低密度组分中煤系矿物主要是带状分布的黏土类矿物,有机组分则以镜质组为主;中密度组分中矿物质主要是团状黏土矿物和浸染自生的石英;高密度组分中矿物质主要是单体石英颗粒、团块状碳酸盐矿物、草莓状的黄铁矿。对原料煤的三个密度组分进行同步高温石墨化试验,结果表明:随着原料煤灰分的增加,产品石墨化度显著提高,在一定程度上表明了煤炭镜质组分和惰质组分在石墨化方面的差异;高密度组分制得的石墨样品石墨化度高达94.68%,属于高度有序的石墨微晶片层石墨。研究还表明:煤系矿物在升温过程中逐渐在原位脱水分解为氧化物,并在1 500~2 200 ℃时氧化物以多氧化物混合液态和气态形式从裂隙中逸出,其中铁、硅元素参与煤的石墨化过程,起到催化作用;经过2 400 ℃以上高温处理,石墨产品中仅存在少量碳化硅,剩余成灰矿物以气态形式溢出,或随着石墨化炉排气管中温度的降低以玻璃态熔融混合物形式析出。

       

      Abstract: In order to bring to light the law governing the variation and migration of coal-series minerals in the coal to graphite process, an analysis is made of the occurrence patterns and distribution of coal-series minerals through float-and-sink, petrographic and XRD analysis. Study results indicate that the low-density components in coal are predominantly clay minerals which are distributed in banded form, and the organic constituents are mostly vitrinite; the medium-density components are chiefly clumpy clay minerals and authigenic quarts of disseminated structure; and the high-density components consist principally of monomer quartz particles, lump carbonate minerals and strawberry-lime pyrite. The components in three densities as described above are graphitized at high temperature. As indicated by test results, the degree of graphitization of the test samples is noticeably increased with the increase of the ash content of the samples; indicating more or less that vitrinite and inert components exhibit different graphitization characteristic; and the high-density components with a graphitization degree as high as 94.68% belongs to a highly-ordered graphite with microcrystalline layered texture, It is also observed that the coal-measure minerals tend to gradually dehydrate and escape out of the cracks as polyoxide mixture in either liquid or gas form at a temperature of 1 500~2 200 ℃; the iron and silicon elements play a catalytic role in the graphitization process; when the temperature reaches above 2 400 ℃ there exists only tiny amount of silicon carbide in graphitized product, and the rest ash-forming minerals either escape in gaseous form or get separated out as glassy molten mixture with the drop of the temperature in the exhaust pipe of graphitization furnace.

       

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