Limonite Ore Research Articles

Micropores formation and effects in the magnetization roasting of limonite ore

As an abundant iron ore resource, limonite (mainly composed of goethite, hematite, lepidocrocite and other iron minerals) ore is seldom utilized due to its complex compositions, which has led to it lack mature processing methods. Magnetization roasting and magnetic separation is a promising method to process limonite ore. In this paper, the influence of microscopic pores on the reduction roasting of limonite ore was studied. X-ray diffraction, vibrating sample magnetometry, optical microscope, scanning electron microscopy, and the Brunauer-Emmett-Teller method of surface area analysis were used to study the dehydroxylation mechanism. The results indicated that goethite transformed into hematite, and the crystal structure of partly hematite probably changed when the dehydroxylation temperature increased from 600 °C to 1000 °C, making the sample more magnetic, the saturation magnetization increases significantly from 0.29 to 3.20 A·m2·kg−1. Simultaneously, SEM and BET showed the surface property has a big difference after roasting, more and more pores were generated with the temperature increased, then the specific surface area of the sample decreased from 75.94 to 0.59 m2·g−1. The reduction experiment results showed the dehydroxylation temperature has a significant effect on the reduction efficiency, the reduction time increased from 4 to 12.5 min with the temperature increased. This study has implications for the utilization of limonite ore using magnetization roasting technology.

Atmospheric Leaching Behavior and Kinetics of Nickel and Cobalt from Halmahera Limonite Ore

Atmospheric Leaching Behavior and Kinetics of Nickel and Cobalt from Halmahera Limonite Ore

Desulfurization Mechanism of Lead–Zinc-Bearing Hematite–Limonite Ore Through Oxidation Roasting Process

Desulfurization Mechanism of Lead–Zinc-Bearing Hematite–Limonite Ore Through Oxidation Roasting Process

Leaching behaviour of limonite ores from Lapaopao, Southeast Sulawesi, Indonesia: Effect of mineralogy and acid types

An atmospheric leaching study of limonite ores from Lapaopao, Southeast Sulawesi, using hydrochloric acid (HCl), nitric acid (HNO<sub>3</sub>), and sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) has been performed. The objectives of this study were to analyze the effect of ore mineralogy and acid types on the dissolution behavior of minerals and the leaching rate of Ni and Co at atmospheric pressure conditions. Mineralogical analysis was carried out using optical microscopy, scanning electron microscopy (SEM), and X-ray diffractometry (XRD), while the ore's chemical composition was determined by using X-ray fluorescence spectrometry (XRF) and atomic absorption spectrophotometry (AAS). Mineralogically, the limonite ores are dominated by goethite, followed by gibbsite, talc, and lizardite, with less amounts of hematite and quartz. Analysis results of solid residues revealed that mineral dissolution order was determined as follows: goethite > lizardite > gibbsite> hematite > talc> quartz. The results of the leaching experiment exhibited that the order of leaching rates of Ni in the three ores samples using three different acids were found as follows: Ore-1 > Ore-2 > Ore-3. Comparison of HCl, HNO<sub>3</sub>, and H<sub>2</sub>SO<sub>4</sub> as the lixiviants for the leaching of limonite ores demonstrated that HCl was the most reactive acid, followed by HNO<sub>3</sub> and then H<sub>2</sub>SO<sub>4</sub>. This might be due to the differences in mineralogical nature and reactivities of acids during the leaching process.

Atmospheric hydrochloric and nitric acid leaching of a limonite ore from the Wolo mine area, Southeast Sulawesi, Indonesia

The atmospheric acid leaching studies of a limonite ore sample from the Wolo mine area, Southeast Sulawesi, Indonesia, have been performed using hydrochloric acid (HCl) and nitric acid (HNO3). The objectives of these studies were to compare the leaching degree of metals (Ni, Co, Fe, and Al) and to analyze the dissolution behavior of minerals under different acid concentrations. Mineralogical characterization of the ore sample was conducted using optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction, whereas chemical composition was determined by X-ray fluorescence (XRF) spectrometry and atomic absorption spectroscopy (AAS), respectively. An atmospheric leaching test was done with the variables of acid concentration, leaching duration of 90 min, and leaching temperature of 100℃. Limonite ore samples contain goethite, gibbsite, talc, quartz, and lizardite. It was revealed that as much as 92.22% of Ni and 90.14% of Fe could be leached using 3 M HCl, whereas only 63.14% of Ni and 38.74% of Fe could be extracted from limonite ore using 3 M HNO3. The higher leaching degree of Fe in HCl indicates low selectivity with Ni, which might contaminate pregnant leach solution (PLS), leading to further complications in the purification process. Results of the leaching experiment show that goethite was more easily dissolved in HCl than in HNO3.

Transformation mechanism and selective leaching of nickel and cobalt from limonitic laterite ore using sulfation-roasting-leaching process

The sulfation-roasting-leaching process holds promise as an environmentally friendly method of production but has low recovery efficiency and poor selectivity for Ni and Co in ores containing impurity metals, including Fe, Al, and Cr. In this study, the transformation mechanism and leaching behavior of metals in a limonitic laterite ore during the sulfation-roasting-leaching process were investigated. Results suggest that the transformation of ferrous ion can reduce leaching efficiency for impurity metals in air atmosphere. The leaching efficiencies for Ni, Co, and Al were 91.1%, 91.5%, and 3.3%, respectively, during roasting at 725 °C for 1.5 h. The leaching solution equilibrium pH value was 3, the concentration of the added H2O2 was 0.5 wt%, and Fe and Cr were not detected in the leaching solution. Simulation and characterization results indicated that the conversion of Fe(II) into Fe(III) reduced the amount of FeSO4 in the roasting product and inhibited iron dissolution, demonstrating that the sulfation-roasting-leaching process is a feasible and environmentally friendly method that selectively leaches Ni and Co in ores containing trivalent metals.

A Study on the Influence of Drying and Preheating Parameters on the Roasting Properties of Limonite Pellets

In this experiment, a pellet preparation method was investigated to study the drying, preheating, and roasting properties of limonitic iron ore from a plant in Yunnan. The aim was to improve the subsequent iron-making process of limonitic iron ore and make it a substitute for sintered ore. This substitution would reduce the amount of blast furnace slag in the iron-making process. Bentonite is commonly used as a primary binder in many pelletizing plant operations. However, its excessive usage leads to a higher risk of slagging and coking in the furnace. In this paper, we aim to decrease the quantity of bentonite added, enhance the iron content in the pellets, and reduce impurities to improve the grade of limonite pellets. The results show that the optimal drying, preheating, and roasting temperatures of limonite pellets are 200 °C, 700 °C, and 1250 °C, respectively, and the optimal roasting time is 20 min, when the diameter of the pellets is 8–13 mm. The compressive strength of limonite pellets with the addition of 1.5% bentonite was the highest, meeting the demands of a general blast furnace, based on which the iron grade of limonite pellet ore was increased by 10.63%.

Kinetic of Dissolution of Nickel Limonite Calcine by Sulfuric Acid Solution

Currently, more than 60% of nickel processing is carried out using nickel sulfide as a raw material. Nonetheless, due to the depletion reserves of nickel sulphide, nickel laterite has drawn a lot of interest to be processed as raw material. Nickel laterite in Indonesia is generally found in low grades, with nickel concentration of <1.15%. One method of treating nickel limonite is leaching in a sulfuric acid solution. This study aims to determine the reaction rate in the leaching process of calcine nickel limonite and the effect of sulfuric acid concentration and leaching temperature on the percent nickel extraction. In this research, the limonite ore from Pomalaa, Southeast Sulawesi, Indonesia, which has undergone a reduction process, was used as raw material. This research was conducted by leaching method on nickel limonite calcine using sulfuric acid reagent with 0.2, 0.5, and 1 M concentration variation, temperature variations of 60, 70, and 90°C, stirring speed 500 rpm, and %S/L (w/w) 10%. In this leaching research, the activation energy obtained at a sulfuric acid concentration of 0.2, 0.5, and 1 M are 13,7379 kJ/mol, 19,7582 kJ/mol, 20,3161 kJ/mol, respectively. The leaching process of nickel limonite calcine was controlled by diffusion. The optimum nickel extraction percentage in this study was 97.45%, obtained at a concentration of 1 M sulfuric acid, temperature of 70 °C, and leaching time of 240 minutes.

Mineralization Behavior and Strengthening Mechanism of Limonitic Laterite Ore Sintering Process Enhanced by Calcined Lime Coating

Mineralization Behavior and Strengthening Mechanism of Limonitic Laterite Ore Sintering Process Enhanced by Calcined Lime Coating

Efek Pre-Roasting Terhadap Parameter Kinetika Leaching Cr dari Limonit

Hydrometallurgical processes such as leaching of limonite ore to extract valuable metals including Ni and Co are often non-selective, including other metals in the leachate product. The leaching behavior of Cr from the chromite mineral contained in limonite ore is of concern due to the high Cr content of the leachate effluent. The pre-roasted process is frequently used to pre-treat limonite to increase the precious metal content. This study aims to determine the leaching behavior of Cr and the effect of pre-roasting on its kinetic parameters. The pre-roasting process was carried out at 280 and 610 oC for 4 hours. Observation of Cr leaching behavior was carried out in the leaching temperature range of 30-90 oC for 0-120 minutes using sulfuric acid solvent. The highest Cr recovery was achieved in pre-roasted ore leaching at 610 oC with leaching operating conditions of 2 M sulfuric acid, solid-liquid ratio of 5 g/50 mL, 200 rpm, for 120 minutes, at a leaching temperature of 90 oC, under these conditions Cr recovery reached 53.16%. The higher the roasting temperature, the lower the activation energy required for the leaching process. Cr leaching from raw and pre-roasted ore is controlled by the diffusion process through the ash layer with activation energies (EA) of 21.41, 18.64, and 14.71 kJ/mol for raw ore, pre-roasted ore 280 oC, and pre-roasted ore 610 oC, respectively. The comparison of kinetics data from several roasting products for atmospheric leaching feeds will provide industry with information to integrated pyro-hydrometallurgical process to increase Cr production from laterite.

Dehydroxylation of Limonite Ore for Magnetization Roasting: Phase Transformation and Kinetics Analysis

Dehydroxylation of Limonite Ore for Magnetization Roasting: Phase Transformation and Kinetics Analysis

Comparative Analysis of Mixing High Grade Limonite and Low Grade Saprolite Nickel Ore to Meet Market Demand at PT Mandiri Mineral Perkasa

PT Mandiri Mineral Perkasa is a contractor company operating in the field of nickel mining and has fulfilled the market/smelter demand requirements for Ni 1.5% - 2.0%, by setting a Cut Of Grade (COG) collection limit of Ni 1.4%. The aim of this research is to determine the Ni content of high grade limonite and low grade saprolite at the research location, and to determine the Ni content of high grade limonite and low grade saprolite, and to determine the additional tonnage and levels to meet market demand. In this study, the blending method was used, a mixing process between different low grade and high grade nickel ores to obtain appropriate mixture results, so that from the results of blending/mixing high grade limonite nickel ore, Ni 1.43 and Fe 26.71% were obtained, and for low grade saprolite you get 1.59% Ni and 26.73% Fe, for the results of blending/mixing high grade limonite and low grade saprolite you get 1.51% Ni and 26.72% Fe, efforts can be made to meet demand Ni 1.8% market with 5,000 tons needs to increase the grade and tonnage, namely, Ni grade 2.32% and 2,111.45 tons.

Enhanced iron extraction from high-phosphorus waste limonite ore via suspension magnetization roasting: A pilot-scale study

High-phosphorus limonite was unable to be efficiently utilized owing to the difficulty in Fe extraction and dephosphorization. The requirement for iron ore is increasing with the rapid development of industry. Therefore, it is necessary to develop a method for the high utilization of high-phosphorus limonite. Traditional processes can't treat low-grade iron ore and are unable to transform the phase of iron minerals, thus they are very inefficient. To solve these problems, a novel method was proposed in this work for enhancing iron extraction and dephosphorization from high phosphorus limonite by suspension magnetization roasting-two stages of grinding and magnetic separation-flotation. After being treated by the above joint processes, a flotation concentrate with an iron grade of 59.50% and a phosphorus of 0.317% was obtained. The iron recovery and flotation concentrate yield of the total process were 75.39% and 57.52%, respectively. Compared with traditional multi-stage griding-magnetic separation with a Fe grade of 50% concentrate, there were significant improvements in Fe grade and Fe recovery. During SMR, the limonite transformed into magnetite with strong magnetism, and structures of iron ore became loose and porous. These changes enhanced the effect of magnetic separation and separation of apatite from magnetite. In general, this work provides a fresh approach to the efficient utilization of high-phosphorus waste limonite.

The effect of sulfur, temperature, the duration of the process and reductant on the selective reduction of limonite ore

The effect of sulfur, temperature, the duration of the process and reductant on the selective reduction of limonite ore

Recovery of nickel oxide nanorods from a laterite-originated intermediate product by ammonia leach-deammoniation method

Extraction of nickel from laterites, especially low-grade limonitic ores has been facing challenges related to the lack of an effective beneficiation method. A chemo-physical laterite ore processing comprising oxalic acid leaching followed by size separation of the leach residue was recently introduced by the authors as a novel method to collect small amounts of nickel values dispersed in the ore matrix into distinct oxalate particles to form an intermediate product. In the present work, the ammonia leaching of such intermediate product containing about 12 wt% NiC2O4·2H2O was accomplished. Factors such as initial ammonia concentration (NH3: 2.5–25 wt%), temperature (T: 20–50 °C), pulp density (S/L: 50–200 g/L), and sonication were examined in a series of agitated leaching tests. It was found that under the conditions of 25% NH3, T = 50 °C, S/L = 200 g/L, and 15 min of sonication, about 93% of nickel is dissolved resulting in a pregnant leach solution (PLS) with a nickel content of 7.4 g/L. Besides, the activation energy for dissolution of nickel oxalate in ammonia solution was found to be about 71 kJ mol–1 from a kinetic analysis of leaching data. The PLS was subsequently deammoniated by either boiling or vacuum-assisted gentle heating to reclaim the nickel as an oxalate salt. Electron microscopic analysis of nickel oxalate precipitates formed from ammonia solutions exhibited rod-like morphology with high aspect ratio. Deammoniation under boiling led to well-shaped and distinct particles (∼150 nm width), while the precipitates obtained under partial vacuum were splintered and finer (∼40 nm width). The pyrolysis at 400 °C in an air atmosphere of the nickel oxalate particles from the boiling and the vacuum-assisted deammoniation methods generated mesoporous NiO nanorods with average widths of about 100 and 30 nm, and specific surface areas of about 45 and 70 m2 g−1, respectively.

High-grade iron ores in the laterite weathering crust after the banded iron formation in the Simandou mountain range, Republic of Guinea

In West Africa, in the southeastern Guinea, in the Simandou Range region underlain by the Archean gneiss-granite basement, a north–south synclinorium structure is extended, that is composed of the Lower Proterozoic series of metamorphic rocks. A thick sequence of the banded iron formation (itabirites) with interlayers of phyllites and mica schists is exposed in cores of the synclines. According to their composition, the itabirites are subdivided into quartz-magnetite and amphibole-quartz-magnetite varieties. High-grade iron ores (60–66% Fe) formed in a pseudomorphic manner after the itabirites in the Cenozoic lateritic weathering crust. At the North Simandou, Zogota, and Pic-de-Fon deposits, the rich ores compose mantle-shaped orebodies up to 150–350 m deep. The orebodies possess the following vertical zonality: primary magnetite itabirites – martitized itabirites – quartz-martite friable ore – martite friable ore and martite–limonite friable ore – goethite-hematite friable to solid ore – deluvial limonite ore (kanga and cuirass). All the types of the high-grade ores are dominated by hematite. The rich iron ores were formed from itabirites as a result of the oxidation of magnetite to martite, the almost complete removal of silica, and the subsequent additional supply of iron and its precipitation in the form of hydroxides. During the formation of the iron ores, kaolin clays and bauxites were formed after the phyllite interlayers.

Contribution of Obi Island Reducing the Carbon Footprint in the Transport Sector

Transportation is one of the main sectors contributing to greenhouse gas (GHG) emissions that cause global climate change. One of the decarbonization strategies from the transportation sector that can be implemented is by switching to a sustainable mode of transportation, especially battery electric vehicles (BEV). Since mid-2021, Obi Island has been producing Mixed Hydroxide Precipitate (MHP). It is an intermediate product of limonite nickel ore processed using hydrometallurgical processing techniques through the first refining plant in Indonesia using High Pressure Acid Leaching (HPAL) technology. The MHP will be processed into Nickel Sulfate (NiSO4.6H2O) and Cobalt Sulfate (CoSO4.7H2O), the primary precursor materials for electric vehicles. The potential GHG emissions reduction in the transportation sector from the processing of limonite nickel ore in Obi Island is 2.04 MtCO2 in 2022 to 21.02 MtCO2 in 2040 with a total accumulation until 2040 of 344.56 MtCO2.

Literature Review: Comparison of Caron Process and RKEF On The Processing of Nickel Laterite Ore For Battery

Indonesia has abundant resources, especially in natural resources (SDA), one of which is nickel. Nickel is a metal that is loved by many people because of the rapid development of technology in creating electric transportation, in particular, the application of nickel is one of the batteries. Nickel resources in the world are available in the form of Nickel Oxide as much as 60% and the remaining 40% is available in the form of sulfide reserves. Currently, there are 2 extraction methods, namely hydrometallurgy (Caron Process) and pyrometallurgy (Rotary Kiln Electric Furnace). Hydrometallurgy is a process used for nickel ore that has a grade of < 1.5%, while pyrometallurgy is still used for nickel ore that has a Ni content of < 3%. At present, the most common hydrometallurgical process is applied to limonite nickel ore. While the extraction process in pyrometallurgy uses saprolite nickel ore. Nickel metal processing, currently the best and the cheapest in terms of production costs is the hydrometallurgical process followed by the pyrometallurgical process. Using low-grade nickel is more suitable for manufacturing battery manufacture. The reason is that the Limonite Nickel reserves are more and can increase the selling value of the nickel ore. Thus, it is necessary to pay attention to the development in the processing process to increase the purity of the nickel-metal itself.

Atmospheric acid leaching of powdery Ni-Co-Fe alloy derived from reductive roasting of limonitic laterite ore and recovery of battery grade iron phosphate

The efficient and inexpensive extraction of Ni and Co from limonitic laterite ore is becoming imperative due to the rapidly growing demand for nickel and cobalt driven by electric vehicles (EVs). In this work, powdery Ni-Co-Fe alloy was prepared from limonitic laterite via reductive roasting followed by magnetic separation, with nickel and cobalt recoveries of 91.9% and 93.3%, respectively. Most of the gangue material was rejected, and the obtained powdery alloy was readily dissolvable in sulfuric acid solution at atmospheric pressure. Under the conditions of 2.5 M H2SO4, 80 °C, 60 min, L/S ratio of 8 mL/g, the extractions of Ni, Co and Fe were 98.5%, 99.9% and 95.6%, respectively, and chemical reaction was the rate-controlling step. The proposed process is promising for the utilization of limonitic laterite ore with high leaching efficiency and less leach residue discharge.

Fluidization magnetization roasting of limonite ore using H2 as a reductant: Phase transformation, structure evolution, and kinetics

As a rich iron ore resource, limonite ore is seldom utilized due to and lack of mature processing methods. In this paper, fluidization magnetization roasting and low-intensity magnetic separation were used to process limonite ore. A concentrate with an iron grade of 59.92% and an iron recovery of 87.26% was obtained under these optimum roasting conditions: a temperature of 525 °C, a roasting time of 10 min, and a H 2 concentration of 20%. X-ray diffraction, vibrating sample magnetometry, and scanning electron microscopy were used to study the reduction mechanism. The results indicated that the reduction product characteristics greatly changed after roasting. The reduction kinetics followed the nucleation model A 2 , and the activation energy was 29.62 kJ/mol. This study will provide some guidance for limonite ore utilization. • An efficient and green method to recovery iron minerals from refractory limonite ore. • H 2 was used as a reducing agent to reduce refractory limonite ore. • The reduction kinetics was calculated during the process.