Investigation Tnto the Reduction Behavior of Iron Ore Fines in Multi-Stages Fluidized Bed Reactor

摘要

Gradually increasing costs of raw materials have driven steelmakers to make more efforts on the development of new ironmaking technologies. Although huge amount of financial investment has been input to find alternatives to be able to replace the traditional blast furnace, only a few processes were survived in the commercial stage. One of the important features for the commercialization is the flexibility of raw materials. Fine ores and lower grade coal should be able to be used. FINEX~R? process has the flexibility of raw materials. The process consists of multi-stages fluidized bed reactors, coal briquetters, hot DPI compactors and a melter-gasifier. Owing to the fluidized bed reactors and coal briquetters, it can use iron ore fines and low grade coal, respectively. FINEX~R process has successfully been commercialized, and recently 1.5MTPA and 2.0MTPA plants are running in Pohang Works. They are showing satisfactory operational results. In order to make this process quantum-leap to more advanced state, it is critical to understand the whole reaction occurring in the whole process. Especially, it is a key to understand the reduction behavior of the iron ores in each stage of the reactors. Several authors have studies the reduction behavior of the ore fines in the fluidized bed reactor1"3. However they did not show clearly the reduction behavior of the ores in the multi-stage reactors. Therefore, in the present study, we would like to investigate into the reduction behavior of ore fines in the multi-stage fluidized bed reactors using a 'brand-new' lab-scale fluidized bed reactor.