气固磁场流态化分选细粒煤

Fine coal particles separation by air-solid magnetic fluidization

利用研制的横流式气固磁稳定流化床,以0.074～0.045 mm粒级磁铁矿粉和磁珠作为高密度和低密度分选介质,对6.0～0.5 mm细粒煤进行连续分选试验。结果表明:当处于稳定流化时,磁场气固流化床比普通气固流化床具有更宽的稳定操作气速范围;外加磁场使磁性颗粒沿磁力线形成平行磁链,增大了床层空隙率,形成了分布均匀的通道,气体通过时不会产生气泡,由此形成了稳定的散式气固磁场流化床;高密度分选和低密度分选的可能偏差分别为0.085,0.075 g/cm3。

Continuous separation tests of fine coal particles of 6. 0-0. 5 mm were done by a crossflow air-solid magneti- cally stabilized fluidized bed （ MSFB ）, which used 0. 074-0. 045 mm magnetite powder and magnetite beads as medi- um of high and low density separation respectively. The results show that the range of steadily operational air velocity in air-solid magnetically fluidized beds is broader than that in standard air-solid fluidized beds when they are at stable fluidization. External magnetic field compels the magnetic grains to form parallel magnetic chains following the magnet- ic induction lines, which enlarge the bed voidage and form the uniform air channels. Air bubbles cannot be produced when the air flows through the channels, thus stable and particulate air-solid magnetically fluidized beds coming into being. The possible deviation of high and low density separation are 0. 085 and 0. 075 g/cm3 respectively.