空气重介流化床干法选煤加重质的研究

Research on Heavy Medium of Dry Coal Cleaning with Air Dense Medium Fluidized Bed

针对空气重介流化床干法选煤的加重质种类少、粒度范围窄、粒度要求严格等问题 ,找到了一种新的加重质——钒钛磁铁矿 .在空气重介流化床模型机和半工业性试验系统上进行了大量流化试验和分选试验 ,提出了用密度分布标准差和粒度分布标准差作为评定流化床均匀稳定性的指标 ,研究了流化床稳定性与加重质细粒级含量之间的关系 .试验结果表明 ,钒钛磁铁矿具有良好的流化特性和分选特性 ,可以采用较宽的粒度范围 .应用这种介质可以有效地的分选 5 0～ 6 mm级煤 ,分选精度高 ,Ep 值可达 0 .

A new type of heavy medium, vanadium-titanium magnetite, was investigated to solve the existing problems of dry coal preparation with air dense-medium fluidized bed, such as fewer kinds of heavy medium, narrower size range and stricter demand for medium size. Some fluidizing and separating tests have been conducted on the new material in the laboratory model and the pilot test system of air dense-medium fluidized bed. The judging indexes of the uniformity of the fluidized bed were put forward, including the sample standard deviations of density and size distributions. The relationship between the uniformity of the fluidized bed and the contents of fine heavy medium with a size less than 0.15 mm was studied. Test results show that vanadium-titanium magnetite has good fluidizing and separating characteristics, and can be used in a wider size range. Using this heavy medium, coal ranging from 50 to 6 mm can be efficiently separated. A good performance was obtained with the ecart probable moyen value of 0.05.