Processing and characterization of chalcopyrite (CuFeS2) sample from Botswana

Abstract

Beneficiation of chalcopyrite and most minerals in general requires specific conditions and raw materials based on characteristics of the mineral to optimize processing hence income. Therefore characterization of minerals is an important aspect in mineral processing. In this investigation X-ray diffraction (XRD) and Scanning Electronic Microscope (SEM) techniques where applied on a sample of chalcopyrite. XRD was mainly applied to obtain phase compositions, lattice parameters hence the crystal structure and its amorphous nature. The XRD intensity peaks obtained were analyzed using Match3 software which showed the sample to contain phases of CuFeS2 as a dominant compound, also phases of clinochlore which is Fe-rich (in the form of Fe and FeO) where observed. The mineralogical analysis showed other relatively small peaks which reflect less dominant compounds such as calcite, TiC, Yoshiokaite etc. From this CuFeS2 data, the lattice parameters obtained where α= 5. 2 29 Å and c = 10.422 (Tetragonal lattice). These represent the compound in its natural state. Chemical analysis determined by Energy dispersive XRD analysis (SEM) revealed elemental compositions of Cu, Fe and S as 31.02, 33.07 and 34.08 wt.% respectively while majority other occurring elements averaged at <0.2 wt%. XRD information is valuable in mineral processing or extraction of concentrations. Gangue materials affect the recovery/beneficiation of chalcopyrite during hydrometallurgical or pyrometallurgical processes. In SEM analysis the surface properties such as presence of surface films are closely linked to stability of a material during hydrometallurgical processing hence determination of leaching agents is dictated by such information. Based on XRD and SEM analysis on characteristics of chalcopyrite a possible processes route can thus be identified mainly to recover iron that can be used as an alternative feed material for steelmaking plants particularly to replace scrap steel.