Process of Re-Resourcing of Converter Slag

The process of “re-resourcing of converter slag” was put forward based on the analysis of the existing steel slag treatment process. The converter slag obtained from Jinan steel plant was studied. After grinding, the slag contained 33% of iron particles, 5484% of magnetic part (wTFe=20%), and 4184% of non-magnetic part, which could be used for making cement directly. At a temperature below 1000 ℃, the non-magnetic Fe2O3 in the slag could be efficiently reduced to magnetic iron by pure H2 and CO. The slag after precise reduction had high degree of dispersion and did not get sintered, which provided an optimum condition for the separation of iron and impurities. To separate the slag and enrich the iron after reduction, the laboratory-scale device of magnetic separation was designed and made. The process of slag re-resourcing, which included magnetic sorting, precise reduction, magnetic separation, and removal of free calcium oxide (f-CaO), was proposed to obtain iron-rich magnetic materials and cement adulterant materials. Through this process, 33 kg iron particles, 150 kg iron-rich material and 700 kg cement could be obtained in each ton slag. Besides, this process to recycle converter slag had a lower energy and material consumption and no pollutant emission.