Oxidation roasting of pentlandite samples at elevated temperatures

Abstract

It is known that virtually all of the nickel in nickel sulfide ores occurs in the mineral pentlandite [(Ni,Fe)9S8]. Therefore, pentlandite is the most common and abundant ore for extraction of nickel, accounting for over 60% of nickel world production [1, 2]. The pyrometallurgical extraction of nickel from its sulfide ores is very similar to the copper extraction process from copper sulfide concentrates. In essence, iron and sulfur are eliminated by selective oxidation and fluxing. In fact, the oxidation of pentlandite is the most important chemical process in the pyrometallurgical route [3]. Because of all mentioned, the characterization of the structural properties of six pentlandite samples was carried out in this paper. The samples of pentlandite were roasted in air atmosphere for 30min, in five different temperatures: 400, 500, 600, 700 and 800 °C. Investigation of structural properties and obtained oxidation products was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS).