Extraction of cobalt and iron from refractory co-bearing sulfur concentrate

Abstract

In this study, oxidizing roasting, segregation roasting, and magnetic separation are used to extract cobalt and iron from refractory Co-bearing sulfur concentrate. The Co-bearing sulfur concentrate containing 0.68% Co, 33.26% Fe, and 36.58% S was obtained from V-Ti magnetite in the Panxi area of China by flotation. Cobalt pyrite and linneite were the Co-bearing minerals, and the gangue minerals were mica, chlorite, feldspar, and calcite in Co-bearing sulfur concentrate. The results show that cobalt is transformed from Co-pyrite and linneite to a Co2FeO4-dominated new cobalt mineral phase, and iron is transformed from pyrite to Fe2O3 and an Fe3O4-dominated new iron mineral phase after oxidizing roasting. Cobalt changed from CoFe2O4 to a new cobalt mineral phase dominated by [Co] Fe solid solution, and iron changed from Fe2O3 to a new iron mineral phase dominated by metal Fe and Fe3O4 after segregation roasting. Cobalt concentrate with a cobalt grade of 15.15%, iron content of 71.22%, and cobalt recovery of 90.81% as well as iron concentrate with iron grade of 60.06%, cobalt content of 0.11%, and iron recovery of 76.23% are obtained. The main minerals in the cobalt concentrate are Fe, [Co]Fe, Fe3O4, and SiO2, and the main minerals in the iron concentrate are Fe3O4, FeO, Ca2Si2O4, and Ca2Al2O4.