Urbano EEMC, Costa JFCL, Graça LM, Scholz RAC. Ore-waste and ore type classification using portable XRF: a case study of an iron mine from the Quadrilátero Ferrífero, Brazil. Geol. USP. Sér. Cient. 2020;20(2):3-15. doi:10.11606/issn.2316-9095.v20-162436