Designate the pisoraito iron ore as the raw materials the sintering ore and its production manner null for the iron manufacture

摘要

An iron-making sintered ore having a cross section wherein at least 80 % of a solid part except for non fused residues of the sintering materials other than pisolitic iron ore is composed of a densified pisolitic iron ore enclosed by fine calcium ferrite with a width of 10 νm or less, or of hematite particles and calcium ferrite which bonds the hematite particles together while holding traces of the pisolitic iron ore, or of a mixture thereof. The production process comprises sintering iron-containing starting material such as iron ore, carbonaceous material, water, and the like in a sintering machine by using 40-70 mass % of pisolitic iron ore and a high-grade iron or containing 1.5 mass % or less of SiO2 as the iron-containing starting material other than returns.