Processing of steel melt-shop flue ashes in the pellet production process

摘要

The present work deals with the processing of steelmelt-shop flue ashes trapped by dry and wet cleaning in steelproduction process in oxygen converters in VSZ a.s. Kosice.Considering the granulometric and qualitative composition, it isimpossible to add this waste directly to furnaces. For compactionand removal of heavy metals (with emphasis on Zn and Pb), theprocess of high-temperature production of pellets in a rotary tubefurnace was utilised. The strength of the produced pellets died notfall behind pellets produced in a common way. It was found outthat heavy metals can be removed in the given process with noadditional reducing agent (the carbon content in steel melt-shopflue ashes is ca 2 percent, its origin is from decarburizationprocess). The efficiency of the zinc and lead removal was over 90percent and it decreased with the time due to accumulation of zinc-lead vapours in the rotary furnace space. Certain measures weresuggested to ensure the required level of steel melt-shop flue ashes refining.