EFFECT OF REDUCTION CONDITIONS ON PRE-REDUCTION BEHAVIORS OF SELF-FLUXED PELLETS IN COREX PROCESS

摘要

In order to produce high quality metalized products and prevent from burden cohesion during pre-reduction, self-fluxed pellets were made for COREX process in the paper. The effects of reduction temperature and reducing gas composition on pre-reduction behaviors of self-fluxed pellets are studied. The results show that the prereduced pellets have poor quality and deposited carbon appears when the reduction temperature is between 600°C and 700*C. The metallization rate, reduction degree and compressive strength of prereduced pellets are promoted by the elevating reduction temperature and mole fraction of H_2. Pellets reduced by pure H_2 at 800°C have high metallization rate (96.2%), reduction degree (99.4%) and compressive strength (960N/pellet). In all tests, self-fluxed pellets display normal swelling (RSI＜15%) behavior which reveals that self-fluxed pellets are suitable for COREX process. Increasing reduction temperature and mole fraction of H_2 in reducing gas is benefit for pre-reduction of pellets.