PREPARATION OF IRON ORE STOCK MATERIAL TO BE SINTERED

摘要

PURPOSE:To attain to enhance the JIS reduction ratio and the reduction powdering index of a sintered ore, by obtaining a stock material to be sintered by mixing a granulated stock material to be sintered not contributing to the formation of calcium ferrite during sintering, limestone with a proper particle size and a powdery ore. CONSTITUTION:An iron ore powder forming calcium ferrite during sintering, limestone having particle size distribution wherein 70% or more is 1-3mm., pref., 10% or less is 3-5mm. and a fine particle with a particle size of -1.0mm. is 20% or less and a return ore are compounded in a first mixer. On the other hand, stock materials to be sintered each not contributed to the formation of calcium ferrite during sintering such as an iron ore powder, a silica sand powder or serpentinite are compounded with water, a binder or the like in a disc pelletizer to be granulated. Subsequently, the above mentioned granulated material and the stock material of the first mixer and mixed and granulated in a second mixer to obtain an iron ore stock material to be sintered wherein the above mentioned granulated material 1 and coarse particulate limestone 2 are dispersed in the powdery ore 3 so as to be coated with said powdery ore 3.