(p400) Straw Fiber Utilization in Rotary Hearth Furnace Process for Direct Reduced Iron Production

摘要

Straw fiber is a waste obtained by jet milling after extracting valuable substances form corn straw through steamexplosion - washing - mechanical carding process. At the same time, it is also a clean and renewable reducingagent. In this study, physical and chemical characteristics of straw fiber were investigated firstly. Then the strawfiber used in rotary hearth furnace process for direct reduced iron(DRI) production was discussed. The resultsshow that the fixed carbon content of straw fiber is low, but the hydrogen content is high, ash and sulfur content islow, so there is little impact on production efficiency and product quality of DRI. Compared with common reducingagent, straw fiber has better reduction effect, and the straw fiber carbon-containing pellets possess highercompressive strength and larger volume shrinkage, which is conducive to increasing layer thickness of carboncontainingpellets and improving production efficiency. In addition, the straw fiber carbon-containing pellets alsohave advantage of low C/O and short reduction time, the appropriate C/O is 0.8, the appropriate reduction time is15min, and the particle size of straw fiber <0.15mm has the better reduction effect. So applying straw fiber asreducing agent into the RHF process would reduce the additional amount of common reducing agent, decreaseproduction cost, and reduce CO2 emissions. This study aims to provide theoretical and technical basis for utilizationof straw fiber in rotary hearth furnace process.