TREATMENT OF BLAST FURNACE SECONDARY DRY DUST

摘要

PURPOSE:To classify efficiently blast furnace secondary dry dust by classifying said dust to high Zn-contg. dust and high Fe-contg. dust by a micron separator, measuring a dezincification rate and controlling the micron separator. CONSTITUTION:The blast furnace secondary dry dust captured by a dry process dust collector 1 for blast furnace gas is supplied into a raw material hopper 2 from which the dust is fed via a constant quantity feeder 3 to a micron separator 4. Centrifugal force and centripetal force are acted by the rotation of a rotor 6 to the dust to classify the dust to coarse particle dust (high Fe-contg. dust) and fine particle dust (high Zn-contg. dust) which are respectively fed to a coarse particle hopper 10 and a fine particle hopper 9. The respective Zn contents in the blast furnace secondary dry dust prior to classification and the high Fe- contg. dust after classification are measured at every specified cycle and the classifying capacity of the micron separator 4 is controlled in accordance with the measured values, by which the dezincification rate and the recovery rate of the high Fe-contg. dust are increased.