Thermodynamics of the Reduction Roasting of Nickeliferous Laterite Ores

Elliott, R.; Pickles, C.A.; Forster, J.

doi:10.4236/jmmce.2016.46028

Cited by 25 publications

(20 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…According to a previous report [28], the first endothermic peak at 352 K represents the loss of the adsorption water, the second endothermic peak at 885.4 K represents the dehydroxylation of the lizardite, and the third strong exothermic peak at 1097.8 K represents the decomposition of Mg 3 Si 2 O 7 . The process is expressed in Equations (14) and (15…”

Section: Behavior Of Cafmentioning

confidence: 99%

“…According to the different compositions of every layer, nickel laterite ores are treated using different methods, including pyrometallurgical and hydrometallurgical methods [13]. Hydrometallurgical techniques are more applicable to limonitic ore, which includes ammonia-ammonium carbonate leaching, pressure acid leaching (PAL), and high-pressure acid leaching (HPAL) [14][15][16][17][18][19][20]. Garnierite is more suitable for pyrometallurgical methods due to the high content of magnesium.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mechanism of CaF2 under Vacuum Carbothermal Conditions for Recovering Nickel, Iron, and Magnesium from Garnierite

Wang

et al. 2020

Metals

View full text Add to dashboard Cite

Nickel laterite ore is divided into three layers and the garnierite examined in this study belongs to the third layer. Garnierite is characterized by high magnesium and silicon contents. The main contents of garnierite are silicates, and nickel, iron, and magnesium exist in silicates in the form of lattice exchange. Silicate minerals are difficult to destroy so are suitable for smelting using high-temperature pyrometallurgy. To solve the problem of the large amounts of slag produced and the inability to recycle the magnesium in the traditional pyrometallurgical process, we propose a vacuum carbothermal reduction and magnetic separation process to recover nickel, iron, and magnesium from garnierite, and the behavior of the additive CaF2 in the reduction process was investigated. Experiments were conducted under pressures ranging from 10 to 50 Pa with different proportions of CaF2 at different temperatures. The experimental data were obtained by various methods, such as thermogravimetry, differential scanning calorimetry, scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and inductively coupled plasma atomic emission spectroscopy. The analysis results indicate that CaF2 directly reacted with Mg2SiO4, MgSiO3, Ni2SiO4, and Fe2SiO4, which were isolated from the bearing minerals, to produce low-melting-point compounds (FeF2, MgF2, NiF2, etc.) at 1315 and 1400 K. This promoted the conversion of the raw materials from a solid–solid reaction to a liquid–liquid reaction, accelerating the mass transfer and the heat transfer of Fe–Ni particles, and formed Si–Ni–Fe alloy particles with diameters of approximately of 20 mm. The smelting materials appeared stratified, hindering the reduction of magnesium. The results of the experiments indicate that at 1723 K, the molar ratio of ore/C was 1:1.2, the addition of CaF2 was 3%, the recovery of Fe and Ni reached 82.97% and 98.21% in the vacuum carbothermal reduction–magnetic separation process, respectively, and the enrichment ratios of Fe and Ni were maximized, reaching 3.18 and 9.35, respectively.

show abstract

Section: Behavior Of Cafmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Mechanism of CaF2 under Vacuum Carbothermal Conditions for Recovering Nickel, Iron, and Magnesium from Garnierite

Wang

et al. 2020

Metals

View full text Add to dashboard Cite

show abstract

“…From a thermodynamic perspective, it would be expected that the major factors affecting the grade, the recovery and the amount of magnetite, would be as follows: the ore composition and any additives, the reduction temperature, the type of reducing agent and the amount of reducing agent per unit of ore. Previously, a thermodynamic model has been developed for the limonitic ores [28], and it is utilized here to determine the influence of variables on the grades and recoveries and in particular, the amount of magnetite, for the particular ore composition utilized in this research. A ferronickel phase containing some cobalt was assumed to form, while the other condensed species were considered to be part of the oxide phase.…”

Section: Thermodynamic Considerationsmentioning

confidence: 99%

“…A ferronickel phase containing some cobalt was assumed to form, while the other condensed species were considered to be part of the oxide phase. Activity coefficient data available in the literature for various species were utilized as described previously [28][29][30]. The ore was mainly composed of goethite, but for the purposes of the calculation, the ore was assumed to be dewatered, and therefore the iron content was reported as 91.88% hematite (Fe 2 O 3 ).…”

Section: Thermodynamic Considerationsmentioning

confidence: 99%

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

et al. 2017

View full text Add to dashboard Cite

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.

show abstract

“…After dehydroxylation, nickel is formed in the hematite spinel structure. Nickel will join into the magnetite spinel phase under the condition of reduction through the reaction in equation 3which is then reduced, through the reaction in equation 4to be Ni metal and iron hematite compound [7]. The process of reducing iron oxide to iron metal is shown in the reaction in equation (5)(6)(7).…”

Section: Introductionmentioning

confidence: 99%

The Effect of Additives and Reductors in Selective Reduction Process of Laterite Nickel Ore

Nurjaman¹,

Sa'adah

Shofi³

et al. 2018

jsmi

View full text Add to dashboard Cite

THE EFFECT OF ADDITIVES AND REDUCTORS IN SELECTIVE REDUCTION PROCESS OF LATERITE NICKEL ORE. Selective reduction of laterite nickel ore followed by magnetic separation was carried out to produce ferronickel products. The effect of adding additives and reductor types in the selective reduction process was studied in this study. Reductors used were anthracite coal and palm shell charcoal with variations of 5 to 15% by weight, while the additive used was sodium sulfate (Na2SO4). The reduction process was carried out at temperatures of 950 ºC, 1050 ºC and 1150 ºC for 60 minutes. The addition of 10% sodium sulfate additives by weight in the reduction process of laterite nickel ore produced higher concentrations of nickel as 6.09%, compared to no additives, i.e. 2.45%. The addition of reductors in the selective reduction process of laterite nickel ore shows that the higher the amount of reductors causes a decrease in the concentrate level of nickel. Furhtermore, the type of reductors used shows that the concentrate from the reduction result using anthracite coal reductor produces higher level of nickel and lower level of iron compared to the use of palm shell charcoal reductor.

show abstract

Thermodynamics of the Reduction Roasting of Nickeliferous Laterite Ores

Cited by 25 publications

References 22 publications

Mechanism of CaF2 under Vacuum Carbothermal Conditions for Recovering Nickel, Iron, and Magnesium from Garnierite

Mechanism of CaF2 under Vacuum Carbothermal Conditions for Recovering Nickel, Iron, and Magnesium from Garnierite

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

The Effect of Additives and Reductors in Selective Reduction Process of Laterite Nickel Ore

Contact Info

Product

Resources

About