Reduction roasting/ammonia leaching of nickeliferous laterites

Chander, S.; Sharma, Vivekanand

doi:10.1016/0304-386x(81)90029-3

Cited by 35 publications

(12 citation statements)

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“…1-3 (Rhamdhani et al, 2009a,b). Depending on the starting laterite ore, the calcine (~43 µm) is coarser than the feed (~21 µm); (particle sizes quoted are average P 80 values and are relevant to the Yabulu refinery) (Rhamdhani et al, 2009a,b); it consists of a mixture of α-Fe, Ni x Fe (1-x) , FeO, NiO, Fe 3 O 4 , NiFe 2 O 4 or (Fe,Ni) 3 O 4 with Fe-Ni alloy nanoparticles (taenite, 15-20 nm) interspersed in porous magnetite (Canterford, 1978;De Graaf, 1979, 1980Richardson et al, 1981;Chander and Sharma, 1981). The majority of iron forms Fe 3 O 4 during roasting with about 20% of iron reduced to the alloy (Fittock, 2007).…”

Section: Accepted Manuscript 1 Introductionmentioning

confidence: 99%

Effect of iron(II) and manganese(II) on oxidation and co-precipitation of cobalt(II) in ammonia/ammonium carbonate solutions during aeration - An update and insight to cobalt losses in the Caron process for laterite ores

Thompson

Senanayake

2018

Hydrometallurgy

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The Caron process involves the roasting of nickel laterite ore at 750 o C with fuel oil to produce a calcine containing Fe-Ni-Co alloy and other reacted or unreacted host minerals. The leaching of the calcine in the form of a quenched slurry in ammonia/ammonium carbonate solutions at pH ~10 and 45 o C under anaerobic and aerobic conditions sequentially dissolves alloy to iron(II), nickel(II) and cobalt(II), oxidizes iron(II), precipitates iron(III) and allows the discard of iron rich tailings after counter current decantation and steam stripping of ammonia and carbon dioxide for recycling. Oxidation of aqueous cobalt(II) during aeration in the Caron Process is one of the critical steps to reduce the incorporation of cobalt into the tailings. Cobalt(II) species which are co-precipitated with the iron phase are not able to be leached back into solution and lost to the tailings, but cobalt(III) remains in solution. Fast oxidation of cobalt(II) to cobalt(III) is expected to minimise the co-precipitation of cobalt(II) during iron precipitation, resulting in smaller losses of cobalt to tailings. Results from this study show that the oxidation of cobalt(II) species (1 g L -1 ) in a synthetic ammonium carbonate (SAC) solution containing 5.3 M NH 3 /NH 4 + (total) and 1.5 M HCO 3 is relatively slow at room temperature and follows first order kinetics with respect to cobalt(II) concentration. The rate of reaction is temperature dependent with an activation energy of 65.8 kJ mol -1 . The presence of manganese(II) and iron(II) increases the rate of oxidation of cobalt(II) when compared to that of cobalt(II) alone. The oxidation of cobalt(II) occurs only after most of iron(II) is oxidised to iron(III) solids which facilitates the co-precipitation of cobalt(II). The variation of the concentration of manganese(II) (0.025-1.25 g L -1 ) in SAC solution demonstrates minimal effect on cobalt oxidation. Analysis of the solids, using XRD, show that the final solid formed in the laboratory test by the aeration of iron(II) in SAC solution consisted of goethite and ferrihydrite and that formed by the aeration of manganese(II) in SAC solution was rhodochrosite (MnCO 3 ). While the iron oxide precipitated during the oxidation of Fe(II)+Co(II) for 1 h in the laboratory test contains 0.38% Co, the solids formed in aerated tanks in the Caron processing plant increases from 0.15% in Tank 1 to 0.17% in Tank 4, but in all cases too low to be detected in XRD scans.

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Section: Accepted Manuscript 1 Introductionmentioning

confidence: 99%

Effect of iron(II) and manganese(II) on oxidation and co-precipitation of cobalt(II) in ammonia/ammonium carbonate solutions during aeration - An update and insight to cobalt losses in the Caron process for laterite ores

Thompson

Senanayake

2018

Hydrometallurgy

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“…Hydrometallurgical processes, as the effective technologies, are preferred to extract the nickel from limonitic laterite which is a principal nickel-bearing ore [6][7][8]. Therein, reduction roasting-ammonia leaching (RRAL) is one of mature technologies to process the limonitic laterite and has been extensively used in industrial applications for decades [9][10][11][12]. Until now, this process is commercially used in several countries, including Cuba, Australia and Philippines [9].…”

Section: Introductionmentioning

confidence: 99%

Mineralogical Characteristics and Preliminary Beneficiation of Nickel Slag from Reduction Roasting-Ammonia Leaching

et al. 2017

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Abstract:The reduction roasting ammonia leaching process (RRAL) originally defined by Caron (1950) has been extensively applied to treat low grade nickel laterite and a large amount of slag-containing some valuable metals, has been generated and accumulated over the years since then. However, there are no reports on how to utilize it based on its essential properties. In this investigation, the textural and mineralogical characterization of the typical nickel slag from RRAL in Western Australia was performed by X-ray diffraction (XRD), and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). The results show that the nickel slag is dominated by magnetite, maghemite, gangue minerals and minor Cr-spinel. The magnetite and maghemite possess simple distribution relationship with other minerals and their particles are highly variable with most over 50 µm, which are easily able to be recovered. In term of the complex association and distribution feature of chromium and nickel minerals, it is very difficult to recovery them. Meanwhile, an economically viable extraction process was proposed to preliminarily utilize the nickel slag based on textural and mineralogical characteristics of the slag, and the magnetic concentrate, assaying about 62% iron grade at over 75% recovery rate, was obtained through the recommended method.

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“…Reoxidation of the reduced wustite phase to magnetite impeded the effectiveness of magnetic separation to remove the gangue. Chander and Sharma [18] found that cooling in an inert atmosphere prevented reoxidation to magnetite. The reoxidation was limited to the surface layers of the sample.…”

Section: Reduction Roast and Upgradementioning

confidence: 99%

Factors Affecting the Upgrading of a Nickeliferous Limonitic Laterite Ore by Reduction Roasting, Thermal Growth and Magnetic Separation

et al. 2017

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Abstract:There is considerable interest in the development of new processes to extract the nickel from the oxidic nickeliferous laterite deposits, as the global nickel sulphide resources are rapidly becoming more difficult to access. In comparison to sulphide ores, where the nickel-containing mineral can be readily concentrated by flotation, nickel laterites are not amenable to significant upgrading, due to their complex mineralogy. In this paper, firstly, a brief overview of the conventional techniques used to process the nickeliferous limonitic laterites is given, as well as a review of current research in the area. Secondly, a thermodynamic model is developed to simulate the roasting process and to aid in the selection of process parameters to maximize the nickel recovery and grade and also to minimize the magnetite content of the concentrate. Thirdly, a two-stage process involving reduction roasting and thermal growth in either a tube furnace or a rotary kiln furnace, followed by magnetic separation, was investigated. Thermogravimetric, differential thermal and mineral liberation analyses techniques were utilized to further understand the process. Finally, the nickel grades and recovery results were compared to those available in the literature.

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Reduction roasting/ammonia leaching of nickeliferous laterites

Cited by 35 publications

References 1 publication

Effect of iron(II) and manganese(II) on oxidation and co-precipitation of cobalt(II) in ammonia/ammonium carbonate solutions during aeration - An update and insight to cobalt losses in the Caron process for laterite ores

Effect of iron(II) and manganese(II) on oxidation and co-precipitation of cobalt(II) in ammonia/ammonium carbonate solutions during aeration - An update and insight to cobalt losses in the Caron process for laterite ores

Mineralogical Characteristics and Preliminary Beneficiation of Nickel Slag from Reduction Roasting-Ammonia Leaching

Factors Affecting the Upgrading of a Nickeliferous Limonitic Laterite Ore by Reduction Roasting, Thermal Growth and Magnetic Separation

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