The reuse of slag for the extraction of iron oxides, besides allowing the use of potentially polluting material, allows its strategic use in biotechnological applications. For this it is necessary a characterization of the slag as the proportion of iron oxides to study the feasibility of extraction and reuse. For this work siderurgy slag was collected in the steel mill slag yards, as a remnant of the transformation of pig iron into steel and study for identify the presence of magnetite in the samples. Results were discussed in the context of reuse possibility in biotechnological application, for example, in implants of the magnetic materials. The siderurgy slag studied presents iron oxides in a proportion that encourages future work of extraction for use in the composition of magnetic materials for biotechnological applications.

Present day steelmaking slags are being successfully used as a high quality mineral aggregate for the building industry. With this, it is of vital importance to be familiar with the technical significance of the secondary application of steel slag, because some steel slag might contain increased concentration of substances harmful to human health. In terms of steel slag impact on the environment, radionuclides are the least researched of all pollutants emitted from the metallurgical processes. This work presents the preliminary study about the presence of the uranium in siderurgy slag aggregates for the purpose of its use in the production of construction material. The results showed that this slag is free of uranium which brings greater security in its use as building material.

Steel slag is considered a by-product of the steel industry and its reuse is a strategy for environmental protection, since it consists of potential polluting materials. Its main applications involve the use of large quantities of the raw material, but the extraction of ores in smaller proportions can be attractive. For example, magnetite (Fe3O4) may be of great interest for its magnetic properties in the production of composites with different applications. On the other hand, rare earth elements (REE) production is vital for new technologies and since traces of the different REE are found in most iron ores, their extraction can be conducted together. However, previous characterization of the slag is necessary; since they vary in mineralogical composition conform to steelmaking operations. Classical characterization techniques of ores such as X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) may be limited to characterize small fractions of materials. Therefore, in this study, neutron activation analysis was used as the characterization technique to confirm the presence of iron and REE in the slag. The steel slag composite sample of the Linz-Donawitz (LD) process was collected in a steelwork localized in the Iron Quadrangle, Minas Gerais, Brazil. The steel slag sample was characterized by instrumental neutron activation analysis (INAA), using the nuclear research reactor TRIGA MARK I IPR-R1. The results are compared with the characterizations made with XRD and SEM-EDS. Although XRD and EDS results indicated the presence of magnetite in a small proportion, INAA was decisive confirming the presence of REE in the mineralogical composition of the composite sample collected.