Study on the Production of Ultraclean Coal

对超精煤的生产进行了研究。研究结果总结如下：1)共使用了6个国内外煤样。2)将煤中的杂质矿物分为石英矿物、黄铁矿矿物、高岭石矿物和氧化铁矿物。3)基于高温灰分的电感耦合等离子体自动发射光谱分析结果，发现灰分的最小下限取决于难脱除矿物的种类和数量。4)研究了粉磨参数对煤的可磨性的影响。内胎部分…的磨损介质搅拌磨的RTS较多是由煤中存在的硬矿物引起的。通过使用较小直径的磨矿介质和/或提高搅拌速度，缩短了将煤粉碎到指定粒度所需的磨矿时间。5)利用本研究建立的解离度模型对解离度进行了估计。6)建立并改进了一种新型浮选柱。对新型浮选柱与其他常规选煤方法进行了对比试验。结果表明，新型浮选柱对常规浮选方法难以回收的细小颗粒也是有效的。7)水中团聚法脱灰效果优于释放法。对于每种煤都需要选择合适的桥接液。建立了精煤中矿物质含量和灰分的预测方法。预测结果与水中团聚法的实测值吻合较好。较少

Studies on the production of ultraclean coal were carried out. The results are summarized as follows;1) A total of six domestic and foreign coal samples were used. The basic properties were initially measured and the floatability, density of pure coal, calorific value and minimum limit of ash content were determined.2) Impurity minerals in coal were grouped into quartz, pyrite, kaolinite and iron oxide minerals. The changes of the size distribution of each mineral before and after crushing and gravity separation were utilized to determine their liberation characteristics.3) Based on the results of Inductively Coupled Plasma Automatic Emission Spectroscopy of high temperature ash, it was shown that the minimum limit of ash content depends on the type and amount of minerals which are difficult to remove. A new method for predicting the minimum limit of ash content was demonstrated.4) The effects of grinding parameters on grindability of coal were investigated. The wear of the internal pa … More rts of media agitated mill was caused by the hard minerals present in the coal. The grinding time needed to reduce the coal to a specified size was shortened by using a grinding media with smaller diameter and/or by increasing the speed of agitation.5) The estimation of liberation degree by using the liberation model developed from this research was demonstrated.6) A new type of flotation column was built and modified. Comparative experiments using the new flotation column and other conventional coal cleaning methods were carried out. The results showed that the new flotation column was effective even with fine particles which are difficult to recover in conventional methods.7) The deashing of ultrafine coal using the method of agglomeration in water was superior than that using the release analysis method. Proper selection of bridging liquid was needed for each coal. The method for predicting the amount of minerals and the ash content in clean coal was established. The predicted results were in good agreement with the measured values from the method of agglomeration in water. Less