EXPERIMENTAL STUDY ON TREATMENT OF COREX DUST BY COLD BOND PELLETIZING

摘要

COREX shaft furnace dust contains large amounts of valuable elements, such as iron and carbon. Compared with blast furnace dust, it contains more metallic iron. Therefore, taking the appropriate processes to recycle COREX dust can further achieve efficient utilization of resources. The chemical composition, particle size distribution, microstructure and mineral composition of the dust were characterized by chemical analysis, particle size distribution analyzer, and electron microscopy (SEM) and X-ray diffraction (XRD) scanning. Carbon-bearing cold-bonded pellets were prepared by COREX dust and further reduced to study the effect of C/O molar ratio, reduction temperature as well as reduction time on the reduction. Results showed that with the increase of C/O, reaction fraction increased first and then decreased; the metallization rate also showed a gradual increasing trend with the increase of reduction temperature and reduction time. The optimum process parameters were obtained and as follows: reduction temperature, 1300°C; reduction time, 15 minutes and C/O molar ratio, 1.2. Under such conditions, the metallization rate reached to nearly 80%, which showed the feasibility of recycle COREX dust recycling by cold bond pelletizing.