In–situ XRD and EDS method study on the oxidation behaviour of Ni–Cu sulphide ore

Abstract

The oxidation mechanism of sulfides is the key issue during the sulphide–metallurgy process. In this study, the phase transformation and element migration were clearly demonstrated by in–situ laboratory–based X–ray diffraction (XRD) and energy–dispersive X–ray spectroscopy (EDS), respectively. The reaction sequence and a four–step oxidation mechanism were proposed and identified. The elemental distribution demonstrated that at a low temperature, the Fe atoms diffused outward and the Ni/Cu atoms migrated toward the inner core, whereas the opposite diffusion processes were observed at a higher temperature. Importantly, the unique visual presentation of the oxidation behaviour provided by the combination of in–situ XRD and EDS might be useful for optimising the process parameters to improve the Ni/Cu extraction efficiency during Ni–Cu sulphide metallurgy.

Sulfation Roasting of Nickel Oxide–Sulfide Mixed Ore Concentrate in the Presence of Ammonium Sulfate: Experimental and DFT Studies

“…In our previous work, DFT calculations were performed successfully to investigate the oxidation mechanisms of chalcopyrite (CuFeS 2 ) and pentlandite (Fe 4.5 Ni 4.5 S 8 ) [45,46]. The computational results were in good agreement with our experimental observations [47]. Because the sulfation roasting of sulfides is a controllable oxidation process, DFT might be a suitable and powerful technique to study the behavior and mechanism of ammonium sulfate additives during the roasting process.…”

“…Additionally, polymetallic sulfides can be decomposed into monometallic sulfides, for instance, Cu 2 S, NiS, and Ni 3 S 4 . This has been systematically studied and proved by previous work [47], and the reaction equations were deduced and shown as follows:…”

“…DFT calculations were performed as described previously [46,47]. The space group of NiS (millerite) is R3m, and its optimized cell parameters of a = b = 9.564 Å and c = 3.126 Å are consistent with the experimental data (a = b = 9.607 Å , c = 3.143 Å ) [48].…”

One-pot cascade conversion of xylose to furfuryl alcohol over a bifunctional Cu/SBA-15-SO3H catalyst

“…The clear lattice fringes were obtained as 0.244 and 0.209 nm, corresponding to the (111) plane spacings of Cu2O and metallic Cu, respectively [33,36]. The distributions of Cu and S are presented in SEM-EDX elemental mapping, which reveal that the -SO3H groups were uniformly dispersed through the carrier [37], profiting from the co-condensation method with the S-containing organosilanes, while Cu displayed a small bulk aggregation, owing to the in-situ chemical reduction of the metal.…”

Efficient Synchronous Extraction of Nickel, Copper, and Cobalt from Low–Nickel Matte by Sulfation Roasting‒Water Leaching Process

“…Its worth noting that no diffraction peaks of ferric sulfate have been detected at any temperature, which may be related to its inferior thermal stability. Resulting the decomposition of ferric sulfate and generating SO 2 gases in the early roasting stage that is beneficial for the sulfation of nickel and copper 30 .…”