Effective beneficiation of low content nickel ferrous laterite using fluxing agent through Na2SO4 selective reduction

Abstract

AbstractTo address the issue of high energy employment and un‐green processing in limonitic laterites extraction, selective reduction using Na2SO4 additive with the introduction of different fluxes including quicklime, dolomite, and limestone followed by magnetic separation was studied. The objective of the research was to find out the influence of fluxes in optimizing ferronickel product of reduction. The reduction process was carried out at 1400 °C for 6 hours and the obtained product was characterized by scanning electron microscopy (SEM), emission dispersive x‐ray (EDX), and x‐ray diffraction (XRD) to image the morphology, determine the composition, and examine the mineralogical structure. Result showed that the employment of fluxes exhibited positive effect in improving the product. The highest nickel grade was 21.68 % using limestone flux, while the most promising recovery was 93.73 % utilizing dolomite flux. Meanwhile, mineralogical assessment also proved that the ascending of nickel content is due to the formation of troilite (FeS) as the result of synergy between Na2SO4 additives and carbonate minerals from fluxes. This result exhibits a notable performance of fluxes for improving the product of selective reduction.