Oxidative dissolution of nickel matte in dilute sulfuric acid solutions


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Morcalı M. H. , Tafaghodi Khajavi L., Aktaş S. , Dreisinger D. B.

Hydrometallurgy, cilt.185, ss.257-265, 2019 (SCI İndekslerine Giren Dergi)

Özet

Nickel matte (Ni3S2) is the most common feedstock for producing nickel oxide and nickel metal in associated

refineries. Nickel matte is produced from sulfide or laterite ores, and contains around 73 wt% nickel. This study

investigated the dissolution parameters of nickel matte in dilute sulfuric acid media in the presence of air as

oxidant with the goal of presenting a cost-effective process for leaching nickel matte. The dissolution experiments

were carried out to examine the following effects: air flow rate, stirring speed, S/L ratio, acid concentration,

reaction temperature, reaction time and the amount of ferrous sulfate added. Nickel extraction of

90% and cobalt extraction of 80% were achieved using dilute H2SO4 and sparging of air as a source of oxygen. To

increase the dissolution percentage of the matte, ferrous sulfate addition was studied and the oxidation and

reduction potential (ORP) was measured to investigate the effect of ferrous ions on nickel and cobalt recovery.

The highest nickel dissolution percentage (95%) was observed with the initial addition of 1200 mg/L Fe (II).

Characterization of samples has been carried out with quantitative X-ray diffraction (XRD) and scanning electron

microscopy, along with an energy dispersive system (SEM-EDS).