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Pyrite and calcium sulfite were used to remove iron and manganese from an acidic aqueous solution. The concentration of Fe was decreased to be smaller than 0.05 g/L in 60 min when pyrite and air were added into the acidic aqueous solution, but the concentration of Mn in the solution remained unchanged. After the process of iron removal, calcium sulfite and air were used to remove manganese ions from the solution, and the efficiency of manganese ion removal was larger than 75% in 240 min (with less than 0.05 g/L Fe and 0.5 g/L Mn in the solution). Meanwhile, experiments were conducted to simultaneously remove iron and manganese from artificially simulated acidic leaching solution of laterite nickel ore. When the proposed method was used to purify the leaching solution of laterite nickel ore, Fe3+ and Mn2+ ions were effectively removed from the acidic solution, and the recovery efficiency of nickel and cobalt was greater than 98%. [ABSTRACT FROM AUTHOR]

The research explores the impact of basicity on the softening and melting behaviors of limonite laterite nickel ore sinter. With the global decline of sulfide nickel ore resources, the extraction of nickel metal from laterite nickel ores has become a primary method. This study conducts a comprehensive experimental analysis and simulation of the behavioral characteristics of laterite nickel ore sinters and the properties of the soft melting zone to understand its key influencing factors and mechanisms in the blast furnace smelting process. Due to the unique composition of laterite nickel ore sinter, its softening zone position in the blast furnace is generally higher. Increasing the basicity can significantly improve the position and range of the softening zone, and when the basicity reaches 1.3, the permeability of the furnace material is optimal. Simultaneously, increasing the basicity can mitigate the adverse effects of the difficult‐to‐reduce and difficult‐to‐melt substance, chrompicotite, and its reduction products. [ABSTRACT FROM AUTHOR]

Prompt gamma neutron activation analysis of nickel ore samples was carried out using a DT portable pulsed neutron generator and a Ø 7.6 × 7.6 cm LaBr3 detector. Rock powders of nickel ore were analyzed and elements Fe, Si, S, Ni were determined by using calibration curves from standard samples. The minimum detection concentrations of Fe, Si, Ni and S determined from ore samples were 0.87, 1.50, 0.04 and 1.05 wt% respectively. [ABSTRACT FROM AUTHOR]

The Jinchang deposit, Ailaoshan Belt, is a hydrothermal gold-nickel deposit in which nickel mineralization formed during Triassic accretionary orogeny and gold mineralization during Miocene collisional orogeny. Although the nickel and gold orebodies largely overlap in an ophiolite melange at the contacts between ultramafic and metasedimentary sequences, nickel and gold concentrations have only a weak correlation in orebodies intersected in drill cores. The hydrothermal nickel sulfide ores are mainly concentrated at ultramafic-metasedimentary rock contacts. Broad alteration zones surround the contacts, with proximal quartz + clinochlore + magnesite in both rocks through quartz + fuchsite to distal muscovite + quartz assemblages in metasedimentary rocks. An apatite U–Pb age of 235.8 ± 1.8 Ma and a pyrite Re-Os age of 254 ± 21 Ma from the nickel mineralization indicate that it formed before the closure of the Ailaoshan Ocean. The As- and S-rich fluids during oceanic subduction leached Ni from the ultramafic rocks in the ophiolite melange forming the hydrothermal nickel sulfide ores. Orogenic gold mineralization comprises auriferous veins that host gold, Au- and Ag-rich sulfosalt. The veins cut the sulfides associated with nickel mineralization. The auriferous fluids reacted with nickel ore-stage pyrite forming porous or sieve-textures and patchy zoning in BSE images with native gold in pores. Geological and paleomagnetic evidence indicates that Miocene gold mineralization occurred in highly deformed Devonian metasedimentary rocks after the Oligocene–Miocene Ailaoshan sinistral shearing (~ 30 to 20 Ma). The auriferous fluids are most likely sourced from the metasomatized mantle lithosphere if Jinchang has a similar source to other orogenic gold deposits in the Ailaoshan Belt. [ABSTRACT FROM AUTHOR]

Nickel is an important key resource and plays an increasingly important role in new energy technologies. The stability of its worldwide supply chain is crucial for addressing country risks and unforeseen events. To explore the impact of country risks on the stability of the global nickel supply chain, this study conducts a complex network analysis and panel regression analysis on nickel ore, ferro-nickel, and the stainless-steel trade data from 2000 to 2022. The study reveals the mechanisms by which economic and political risks affect the trade structure of nickel commodities and identifies the drivers of global nickel supply chain patterns. The study finds that an increase in economic risk promotes diversification of supply sources, while political risk hurts export scale and resource control ability. Industrial structure adjustments and R&D investments have a significant impact on trade structure, especially on the stainless-steel trade. China is a major consumer and importer, and occupies a central position in the global nickel trade network, while Indonesia and the Philippines' policy changes have a significant impact on the market. This study provides an empirical basis for the risk management of the global nickel supply chain and a scientific basis for policy formulation and strategic planning. [ABSTRACT FROM AUTHOR]

In this work, the biomass charcoal from rubber wood, coconut shell, corn cob, palm kernel shell, as a reductant in the smelting process of saprolitic nickel laterite has been observed in a laboratory submerged arc furnace. A total of 5 kg of saprolite, some reductant and limestone were smelted together in this furnace, which was adjusted to 0.8 of carbon stoichiometric and 0.8 of slag basicity. The smelting process was carried out for 1 h, and the pouring temperature was 1400 °C–1500 °C. From the result, the smelting process using corn cob charcoal and palm kernel shell charcoal showed almost similar nickel grade and recovery compared with using coke as a reductant, which is above 12% and 90%, respectively. It also has the same slag phase, that is, diopside, with a low melting point. These two types of biomass waste reductants could be replaced using coke in the future. [ABSTRACT FROM AUTHOR]

Greece has mineral resources in which strategic elements such as nickel (Ni) and cobalt (Co) are present. In this study, characterizations of the metal concentrations of three laterite deposits, as well as minerals from a kiln originating from a mineral processing plant, were carried out. The aim of this research was to integrate technological characterization data on the quantities of cobalt (Co) and nickel (Ni) present in the lateritic profiles of three mineral deposits from Greece and in kiln dust. The study was conducted at the Mineral Processing Laboratory of UPC/Bases Manresa. Aliquots were constituted for particle-size distribution tests by wet sieving followed by laser granulometry. Scanning electron microscopy (SEM) was used to determine the mineralogical compositions. Sink–float tests were conducted to estimate the particle liberation. Mineral liberation analysis (MLA) was performed to understand the liberation and the association of minerals in the samples. [ABSTRACT FROM AUTHOR]

The nickel laterite ore-fluidized reduction roasting technology is a clean and efficient metallurgical. To achieve the nickel enrichment effect, accomplish the controlled reduction of nickel and iron, and reduce nickel to the metallic state while controlling the metallization rate of iron, it is necessary to carry out experimental studies on the directional selective reduction of it. This study investigated the effects of temperature, additive amount, and reductant type on the selective reduction effect of nickel-iron oxides in nickel laterite ore with an iron grade of 24.30 pct and nickel grade of 1.45 pct. The physical phase, micro-morphology, and valence changes of nickel–iron elements of the reduced samples were also analyzed in depth by combining XRD, SEM-EDS, XPS, et al. The results showed that the best reduction effect of H2 was achieved at the reduction temperature of 800 °C and the reduction time of 60 minutes, and the metallization rates of nickel and iron were 95.96 and 14.85 pct, respectively, under this condition. The selective reduction of nickel laterite by Na2SO4 was apparent. The appropriate amount of Na2SO4 has a more significant increase in the metallization rate of nickel in the mixed gas atmosphere, roasting at 800 °C for 60 minutes. When the addition of Na2SO4 is 6 pct, the metallization rate of nickel reaches a maximum of 92.05 pct; when the Na2SO4 increases from 0 to 8 pct, the nickel grade reaches a maximum of 3.65 pct, and the recovery of nickel reaches a maximum of 87.78 pct. The XRD results show that the addition of Na2SO4 destroys the olivine phase in nickel laterite ore, which allows the nickel stored therein to be released to participate in the reaction, thus increasing the rate of nickel metallization. This study provides theoretical support for the further application of fluidized roasting technology on nickel laterite ore smelting. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Extractive Metallurgy) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The rotary kiln-electric furnace process represents one of the most efficient industrial pathways for the extraction of nickel from laterite nickel ores. However, the product of this process, a ferronickel alloy, which contains approximately 55–85% iron and 15–45% nickel, necessitates the selective removal of iron before it can be utilized as a nickel source for power battery production. In this paper, an iodination volatilization roasting method was developed and used to separate iron from the ferronickel alloy, and nickel powder was obtained. Thermodynamic analysis and density functional theory (DFT) calculations were applied to elucidate the underlying mechanism. Our findings indicate that, by controlling the reaction temperature, the iodination volatilization roasting process can efficiently volatilize iron and copper, leaving nickel in its metallic state. Specifically, iron and copper volatilization efficiencies reached 96.5% and 97.1%, respectively, while only 8.4% of the nickel was volatilized after 2 hours of roasting at 1000 °C. This mechanistic insight was further supported by experimental roasting data and subsequent characterization of the roasted slags. Moreover, the potential for iodine regeneration within the process was demonstrated through oxidation roasting experiments of FeI2, confirming the recyclability of iodine in the system. This process provides a route for the high-efficiency separation of Fe from the ferronickel alloy, and Ni in the alloy is obtained in the form of nickel powder. [ABSTRACT FROM AUTHOR]

Australia has large reserves of limonite and clay-based laterites that are currently underutilized. This review summarizes the latest nickel laterite upgrading studies reported in the literature which use physical beneficiation – only studies reported after the most recent review in 2015 included – as well as high-temperature methods involving oxidation/reduction roasting (with and without additives), sulphidation, and other high-temperature methods. The focus of this review is on upgrading limonite ores, but studies using other types of laterites are also discussed for comparative purposes. Oxidative roasting has proven to be ineffective but producing a magnetic phase by reduction roasting then magnetically separating it from gangue minerals has produced nickel grades and recoveries of up to 14% and 99% respectively with limonite ores. The choice of reductant has negligible effect although hydrogen reduction is predicted to occur at slightly lower temperatures and recoveries are slightly lower compared with carbon-based reductants. The addition of sulfurous compounds improves agglomeration of ferronickel particles, increases the nickel grade and recovery. The highest recovery of 97.91% (grade 13.62%) was reported when sulfur was used as an additive during the roasting of a limonite ore with coal and limestone at 1400°C for 6 h. The results show reduction roasting followed by magnetic separation is effective for upgrading nickel ores, but challenges with this technology are the potentially high reagent usage and temperatures required. The economic feasibility for processing limonite ores via this route is not clear and should be investigated further. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Extractive Metallurgy) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nickel is an important raw metal material in industry, which has been identified as a strategic mineral resource by the Chinese Ministry of Land and Resources. Nickel sulfide ore accounts for 40% of all nickel ores worldwide. However, magnesium silicate gangue minerals in sulfide nickel ores, particularly serpentine, pose significant challenges to the flotation of nickel sulfide ores. The presence of magnesium silicate gangue leads to a series of issues, including increased energy consumption in subsequent smelting processes, accelerated equipment wastage, and increased SO2 emissions, which severely impact the comprehensive utilization of nickel resources in sulfide nickel ores. In this regard, flotation depressants are the most direct and effective method to reduce adverse influences caused by magnesium silicate gangue in the flotation of nickel sulfide ore concentrate. Based on the characteristics of the typical magnesium-containing nickel sulfide ore, this review illustrates the difficulties of the depression of magnesium silicate gangue during the flotation of nickel sulfide ore and gives an overview of the common depressants from six aspects (chelation depressants, dispersion depressants, flocculation depressants, depressants for grinding, depressants for slurry adjustment and combination depressants). Each section summarizes the relevant depression mechanisms and analyzes the advantages and disadvantages of various reagents, providing a reference for designing depressants specifically targeting serpentine. [ABSTRACT FROM AUTHOR]

We study the material composition of a ferromagnesian oxidized nickel ore of the Serov deposit. According to the results of chemical analysis, it was found that the studied ore is poor in the nickel content. Note that magnesium and iron are present in the ore as macroimpurities. The main nickel-containing minerals are lizardite and clinochlore; smaller amounts of nickel are contained in talc. To determine the optimal technological parameters of heap leaching and reveal their correlation dependences, we use the mathematical method of data processing, namely, the Box–Wilson steep ascent method. Based on the results of leaching, we compute the values of the efficiency criterion and the variance of the efficiency criterion and deduce a regression equation for the description of the process of leaching. The adequacy of the regression equation is established by using the Fisher criterion. The results of mathematical processing of the experimental data show that the concentration of sulfuric acid in the solution, the pause between irrigations, and the specific consumption of the leaching solution exert a significant effect on the efficiency of leaching in the stage of nickel extraction from 0–30%. On the basis of computed values of the efficiency criterion, we determine the values of variable parameters for the second stage of determination of the optimal conditions of leaching guaranteeing the efficient ore opening in the stage of nickel extraction up to 30%. [ABSTRACT FROM AUTHOR]

Copyright of China Mining Magazine is the property of China Mining Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abundant low-grade nickel sulfide ore reserves hold potential as nickel resources but are hindered by high magnesium silicate content, limiting efficient utilization. The authors investigated the possibility of extracting nickel from a low-grade ultramafic nickel sulfide concentrate into ferronickel alloy. The nickel extraction study involved thermal upgrading and physical separation. Thermal upgrading efficiently concentrated nickel values from ultramafic concentrate into ferronickel alloy, achieving over 90 pct extraction with more than 40 pct nickel grade and a characteristic particle size of d80=100 µm. The presence of magnesium silicate gangues in the concentrate adversely impacted the thermal extraction of nickel. Multiple thermal treatment variables have been studied to improve nickel extraction efficiency, including metallic iron addition rate, heating duration, temperature, additives, and atmosphere. The proposed solid-state thermal upgrading method avoided smelting of materials and generation of sulfur dioxide. Magnetic separation recovered approximately 85 pct of nickel in the thermal treatment products into a ferronickel concentrate at 20 pct nickel grade. [ABSTRACT FROM AUTHOR]

The nickel laterite ore from a mine in Philippines was analyzed for systematic process mineralogy. The results show that the ore sample contains 44.83% iron, 1.96% silicon, 1.18% magnesium, 1.02% nickel and 0.12% cobalt. It is a typical limonitic lateritic nickel ore. The main minerals in the samples are goethite, chrome spinel, quartz and other clay minerals, nickel and cobalt are mainly in iron minerals, and also in other minerals, and no nickel and cobalt minerals exist independently. Based on the characteristics of the minerals, the high- pressure sulfuric acid leaching process was chosen to treat the minerals. The leaching rate of nickel and cobalt is both 95% above, and the leaching rate of iron is less than 1% under the conditions including acid dosage of 29 g for 100 g mineral, temperature of 250 °C, liquid-solid ratio of 3 mL/g, and reaction time of 30 min, which realizes the selective leaching of nickel and cobalt The process mineralogical analysis of the leaching residue was carried out to analyze the causes of incomplete leaching of nickel and cobalt, During the leaching process, the acicular ferrite mineral phase in the raw ore is destroyed, and the nickel and cobalt endowed in it are leached into the solution, while the nickel and cobalt that are not leached are deposited in the chrome spinel, which is the main reason for the incomplete leaching of nickel and cobalt. The main sulfur-containing phase in the leaching residue is alunite produced by aluminum hydrolysis. In addition, the leaching slag may also contain part of the sulfate such as magnesium sulfate, both of which are closely combined with iron minerals. The sulfur-containing minerals in the leaching residue are tightly bound to iron minerals, so chemical desulfurization is required to remove the sulfur and realize its comprehensive utilization. [ABSTRACT FROM AUTHOR]

Two-stage pressure leaching process is proposed to extract Ni from limonite-type and saprolite- type nickel laterite ore. The recommended conditions for the first stage high pressure acid leaching include acid ore ratio of 330 kg/t, temperature of 250 °C, slurry solid content of 30% and reaction time of one hour. The recommended conditions for the second stage pressure leaching include temperature of 230 °C, reaction time of one hour and slurry solid content of 35%. The nickel extraction rate of first stage high pressure acid leaching and second stage pressure leaching is 97.58% and 83.96% respectively, and the total nickel leaching rate is 93.81%, which greatly improves the utilization rate of nickel laterite ore resources. The Fe and Al concentration in solution can be reduced to below 1 g/L, which can reduce the amount of alkali used in subsequent neutralization processes. [ABSTRACT FROM AUTHOR]

Pressure hydrometallurgy is one of the special metallurgical technologies, which is widely used in the separation, extraction, metal reduction and mineral synthesis of alumina, laterite nickel ore, sphalerite and gold ore. The development history of pressurized hydrometallurgy technology in China for more than 60 years shows that the production process, technical equipment and scale have reached the world advanced level. In the face of the increasingly fierce competition in the domestic and foreign non-ferrous metal market, energy conservation, emission reduction and environmental protection awareness, as well as the more stringent technical requirements of the production process, the pressure hydrometallurgy technology has increasingly shown its inherent technical advantages in the efficient and clean utilization of complex and low-grade refractory minerals, the pressurized hydrosynthesis and preparation, pressurized hydrohydrogen reduction and low-carbon metallurgy. In this paper, the development and characteristics of pressure hydrometallurgy technology are described, with emphasis on the research progress of clean production of alumina pressure hydrometallurgy, oxygen pressure leaching of sulfide ore and pressure hydrometallurgy of vanadium slag. Finally, the development prospect and direction of pressure hydrometallurgy technology in the future are prospected. [ABSTRACT FROM AUTHOR]

In this paper, the process of solid-state metalized reduction and magnetic separation was investigated for preparation of nickel–iron concentrate from a low-grade laterite nickel ore. The effects of reduction temperature, reduction time, amount of dosages, and magnetic field strength on grades and recoveries of nickel and iron were studied. The results showed that nickel–iron concentrate with a nickel grade of 7.32%, nickel recovery of 81.84%, iron grade of 78.74%, and iron recovery of 69.78% were obtained under the conditions of a reduction temperature of 1200 °C, reduction time of 120 min, calcium fluoride addition of 12%, ferric oxide addition of 10%, coal addition of 12%, and magnetic field strength of 170 kA/m. [ABSTRACT FROM AUTHOR]

The Corruption Eradication Commission (KPK) sniffed out potential tax evasion through a transfer pricing scheme on alleged illegal nickel ore export practices to China. KPK Deputy for Prevention and Monitoring Pahala Nainggolan said that his agency is currently reviewing if there are weaknesses in the nickel governance system. The system in question is the Coal Mineral System or Simbara, which was launched in March 2022. The population of this study is mining sector manufacturing companies listed on the Indonesia Stock Exchange (IDX) from the period 2020 -- 2023. Determination of samples in this study using the purposive sampling method. The number of samples used was 18 companies with 72 research units. The source of data in this study is taken from the company's published annual report. Testing in this study using E-Views 12 software. The results of the study based on the panel data regression analysis test showed that debt convenant and intangible assets had an effect on transfer pricing, while the size of the company and the bonus mechanism did not affect transfer pricing. Tax minimization is able to moderate the relationship between company size, debt convenant, intangible assets, and bonus mechanisms for transfer pricing. [ABSTRACT FROM AUTHOR]

Slag nikel is a by-product of nickel ore smelting through the pyrometallurgical process, which contains silica (> 50 %). This suggests that nickel slag, possessing pozzolanic properties, which potentially to be used as a binding material in construction projects dealing with low soil bearing capacity, such as soil improvement for road foundation. Pozzolanic reactions are greatly influenced by the chemical bonds formed between the binding material and the soil, causing mechanical characteristic changes in the soil. This study aims to examine the effect of adding nickel slag to soft soil based on changes in its physical, mechanical and chemical properties. Physical and mechanical property tests were conducted according to ASTM standards, while the changes in chemical structure in the soil were analyzed based on X-Ray Diffraction (XRD) test results. In this study, nickel slag percentages of 3, 6, 9 and 12 % were used based on the weight ratio of clay soil, at optimum water content (wopt). Furthermore, the test specimens were cured for 14, 28 and 56 days to observe the effect of time on the increase of crystal phases in each variation. The results showed that the presence of nickel slag in the soil can affect its physical and mechanical properties. The nickel slag content in the soil of 3, 6, 9 and 12 % reduces the plasticity index by 16.69, 12.02, 8.86 and 6.38 %, respectively. Meanwhile, the density values increased by 10.97, 11.27, 11.68 and 12.01 kN/m³, respectively. The changes in physical and mechanical properties can be explained by the XRD analysis results, showing changes in the spectrum curve and peak intensity of X-Ray Diffraction in the soil with the addition of nickel slag. This explanation clarifies the transformation of the soil's atomic structure from an amorphous state to a crystalline form, which is stabilized by nickel slag. [ABSTRACT FROM AUTHOR]

Nickel has excellent physicochemical properties and a wide range of applications, nickel resources are mainly found in nickel sulfide ores and nickel laterite ores, and nickel laterite ores are gradually becoming the main raw materials for nickel extraction. Due to the high water-content of nickel laterite ores, high temperature pre-treatment of the ores is usually required in the smelting process to remove hydroxylated water in the lattice of the ores and to prereduction of part of the metal, but this part of the hydroxylated water removal needs to consume a lot of energy and produce physical phase changes, which will affect the prereduction and leaching. However, the removal of this part of hydroxyl water needs to consume a large amount of energy, and produces physical phase changes, which will have an impact on the prereduction and leaching, so it is important to investigate the physical phase changes and kinetic conditions of the dehydroxylation process of nickel laterite ores for the subsequent processing operations. In this paper, the possible chemical reactions during the heating process of nickel laterite ore were simulated and calculated using thermodynamic analysis software, and the physical phase changes during the heating process of nickel laterite ore of silica-magnesium type were investigated using thermogravimetric-differential thermal analysis and XRD analysis, and nonisothermal kinetic experiments were carried out at five heating rates from room temperature to 1 400 °C. Three characteristic peaks were observed at 256.8, 582.8 and 823.0 °C, corresponding to the fuselage dehydroxylation process. The three characteristic peaks corresponding to the dehydroxylation of limonite, dehydroxylation of serpentine, and phase transformation of silicate minerals respectively. A nonisothermal kinetic model solution was used to determine the apparent activation energy and the finger front factor of the reaction. The activation energy of the serpentine dehydroxylation process was calculated by using the Flynn-Wall-Ozawa method and the Kissinger Akahira-Sunose method, and 30 commonly used mechanistic functions were fitted by using the Satava-Sestak method, and the eligible mechanistic functions were retained. The A1/3 function of the Avrami-Erofeev equation was determined to be consistent with the dehydroxylation process, and is integral form was G(α) = + - ln (1-α)] ³, which yielded the activation energy of the serpentine dehydroxylation reaction to be 258.71 kj/mol, lnA being 28.94, and the average linear correlation coefficient of 0.995 1. The serpentine dehydroxylation process is consistent with stochastic nucleation and subsequent growth of serpentines. The process is consistent with the stochastic nucleation and subsequent growth model. [ABSTRACT FROM AUTHOR]

In recent years, with the increasing demand for stainless steel and new energy nickel, the wet nickel extraction process from laterite nickel ore has been widely used, and the corresponding acid leaching residue piles of laterite nickel ore has also rapidly increased. It is urgent to scientifically consume and comprehensively utilize such solid waste. The comprehensive utilization of new technologies and equipment for the high content of sulfur and iron elements in acid leaching slag of laterite nickel ore has important theoretical and practical significance for the sustainable development of the laterite nickel ore wet metallurgical industry. The hydrometallurgical formation process, composition, and physical and chemical properties of laterite nickel ore acid leaching residue has been introduced. A systematic review was conducted on the direct treatment methods of laterite nickel ore acid leaching residue in tailings dam accumulation, underground pressure filtration backfilling, and deep-sea landfill. Valuable metal resources such as iron, chromium, aluminum, and rare earths were extracted and utilized, and the research progress in the comprehensive utilization technology for building materials such as diatomaceous earth, ceramic particles, and mineral fibers as well as the consumption in preparation of high value-added materials such as lithium battery electrodes and zeolites. It also looks forward to the development prospects of fluidized reduction roasting technology and equipment in reducing sulfur and improving iron content of laterite nickel ore acid leaching residue. [ABSTRACT FROM AUTHOR]

The article presents the results of obtaining a composite material by sintering nickel-containing raw materials mixed with carbon-containing materials, namely using coke and semi-coke. The sintering process was performed at a charge layer height of 240 mm and the temperature of the lower layer was T = 1200 °C. The results of the sieve analysis showed (a fraction of 10 mm) that the yield of a suitable composite material using coke was 68.3% and with semi-coke 67.0%. The average nickel and chromium content in the composite materials was 1.42% and 3.07%, accordingly. As a result of determining the strength characteristics of the obtained composite materials with various reducing agents by dropping from a height of 2 m onto a steel pallet, it was found that the obtained composite materials have high mechanical properties in terms of strength of 81% and 89.2%. The results of the elemental composition at the studied points and the thermal analysis of the studied composite material are presented. The mineralogical composition of the composite material is presented in the form of serpentine and nontronite, and the empty rock is made of quartz and talc. The activation energy of thermal analysis by the method of non-isothermal kinetics were calculated. The results of experiments on the production of composite materials from nickel-containing raw materials will be recommended for obtaining the optimal composition of composite materials at the stage of pilot tests and industrial development of the developed technology for processing nickel ores of the Republic of Kazakhstan. For the processing of nickel-poor nickel ores, it is of great importance to obtain optimal technological and technical and economic indicators that ensure low cost of nickel in the resulting product. [ABSTRACT FROM AUTHOR]

In anticipation of future demands, a comprehensive understanding of the chemical and mineralogical characteristics of nickel-bearing minerals is a prerequisite to devising effective nickel beneficiation methods. Of particular importance are markers in the mineralogy of the flotation concentrate that inform beneficiation strategies to improve concentrate grades, increasing both the marketability and cost of refining. In this work, a detailed characterization of a complex nickel sulfide flotation concentrate from a Western Australian deposit was carried out to determine the mode of occurrence and distribution of nickel and the associated gangue minerals, with the view of identifying prudent beneficiation strategies to improve concentrate grades. The concentrate was characterized via particle, chemical, and mineralogical techniques. Particle size analysis of the concentrate showed that it consisted predominantly of fine and ultra-fine particles (<20 μm), with the nickel value concentrated in the finer size fractions. Nickel mineralization in the ore (by quantitative X-ray diffraction) was found to be within pentlandite, violarite, millerite, and gersdorffite. The sulfide gangue was predominantly pyrrhotite, pyrite, chalcopyrite, sphalerite, arsenopyrite, and galena. Quantitative evaluation of minerals by scanning microscopy (QEMSCAN) analysis revealed that nickel minerals are at least 91% liberated, and the remaining portion (around 7%) is locked within binary iron (Fe) sulfides and 2% within complex minerals. Based on these findings, potential processing options, such as magnetic separation, gravity separation, and froth flotation, for recovering and upgrading nickel from this concentrate are discussed. Notably, with the significant presence of ultrafine/fine pyrrhotite content, averaging around 52% in the minus 38 µm fraction, novel flotation cells, including the Jameson cell, column flotation cells, and Reflux flotation cell (RFC), have been identified as potential candidates for fine/ultrafine pentlandite recovery. Overall, the characterization study conducted suggests that acquiring knowledge about the mineralogical characteristics of existing mineral concentrates can serve as a pathway to improving future concentrate grades. [ABSTRACT FROM AUTHOR]

This study was intended to investigate the effects of basicity and oxygen partial pressure on the distribution behavior of Ni in the nickel smelting process using nickel oxide ore, the raw material of nickel, among natural ores. Experiments were conducted in a vertical tube furnace using Fe-Ni metal and FeO-MgO-SiO2 ternary slag, which simulated the composition of natural ore. An equilibrium experiment was conducted to observe the distribution ratio of Ni, and thermodynamic data required for this experiment was calculated through Factsage. As a result, it was found that as the oxygen partial pressure increased, the Ni content in the slag increased linearly. The Ni content in the slag increased as the basicity moved away from 0.60. [ABSTRACT FROM AUTHOR]

The article presents the results of physicochemical studies of nickel ore and charges based on it for smelting nickel-containing ferroalloys. Using a derivatogram, the main phase transformations of nickel ore and mixtures with various carbon-containing reducing agents, such as coal and coke, are established. The activation energy of the processes occurring during the heat treatment of nickel ore and a mixture of nickel ore with various reducing agents by non-isothermal kinetics were determined. [ABSTRACT FROM AUTHOR]

In this study, we investigated a nickel laterite ore with Ni content of 1.56 wt% and a red mud with Fe content of 20.98 wt%, the main Ni-bearing mineral in the nickel laterite ore was nickel-lizardite, and the main Fe-bearing mineral in the red mud was hematite. A novel process of roasting and magnetic separation was purposed to extract nickel and iron from the nickel laterite ore and red mud. The nickel laterite ore, red mud, calcium chloride, and coke were mixed and put in a roaster for roasting, and the ferronickel concentrate was obtained from the roasted ore by magnetic separation. The results showed that a ferronickel concentrate with Ni content of 7.97 wt%, Fe content of 73.09 wt%, iron recovery of 76.87%, and nickel recovery of 90.28% was obtained under the optimal conditions: a mass ratio of m (nickel laterite ore): m (red mud) : m (coke) : m (calcium chloride) : of 0.6:0.4:0.2:0.1, a roasting temperature of 1373 K, a roasting time of 90 min, a grinding fineness of − 0.045 mm occupying 90%, and a magnetic field strength of 0.20 T. The main minerals in the ferronickel product were metallic Fe and FeNi. [ABSTRACT FROM AUTHOR]

In this study, the settling performance of lateritic nickel ores in the Counter Current Decantation (CCD) thickeners following the High-Pressure Acid Leaching (HPAL) process was investigated in detail. The samples used within the scope of the study were obtained from the overflow of the 2nd CCD thickener under the condition that Manisa-Gördes and Eskişehir-Karaçam lateritic nickel ores were fed to the plant at different times. A series of settling tests were performed for both ores using anionic, cationic, and nonionic flocculants of various ionicity and molecular weight. Sedimentation performance was evaluated based on parameters such as settling time, clarity, and compression. To determine the optimum conditions for the tests, a preliminary test was performed, and the pulp solids content was determined as 7% and the flocculant dosage as 850 g/t. According to the test results, nonionic and very low anionic flocculants gave better results. It was found that flocculation was negatively affected with increasing anionicity, and results could be obtained only with very low anionicity flocculants. It was determined that the settling rate was very fast with cationic flocculants, but the amount of compression was not favorable, especially for Gördes ore. However, it is envisaged that the amount of consumption can be reduced if cationic flocculants are used especially for Karaçam ore. When a comparison was made between the ores, similar results were obtained in general and only for Karaçam ore, thickener underflow density gave a successful result for all flocculant performances. On the other hand, it was concluded that variable ore structures and unstable process parameters influence the flocculant adsorption mechanisms and thus on the settling behavior. [ABSTRACT FROM AUTHOR]

We present a carbonation-assisted flotation method for nickel (Ni) separation from low-grade ultramafic ores. The high process economics of conventional flotation of low-grade ultramafic ores makes Ni unrecoverable on an industrial scale. Based on the fundamentals of CO2 sequestration in minerals, we carbonated a low-grade serpentine (lizardite) ore specimen under extreme conditions (185 °C, 15 MPa, and 24 h) and attained a conversion efficiency of serpentine to magnesite of 22% and 16% in the presence and absence of inorganic salts, respectively. Rhombohedral structures on carbonated particles detected using scanning electron microscopy suggested the formation of magnesite. We also found that Ni–Fe existed as sulfides, as confirmed by elemental mapping micrographs, and did not leach out as Ni2+ and Fe2+, as confirmed through carbonation supernatant analysis. Here, we introduced Denver cell froth flotation experiments after carbonation, which showed that the carbonated ore in the presence of inorganic salts had 29% higher Ni recovery and 0.15 wt% higher nickel grade than the uncarbonated ore. This study is the first to successfully show that the carbonation of serpentine containing nickel-bearing pentlandite leads to magnesite formation, does not lead to the dissolution of nickel sulphide, and enhances the nickel separation efficiency during froth flotation. This study paves the path forward for the integration of mineral carbonation in the processing of low-grade ultramafic nickel ores. [ABSTRACT FROM AUTHOR]

The change of iron grade in the leaching residue and the leaching kinetics under normal pressure and pressure were examined. The pressure leaching of nickel and cobalt from a high iron and low grade laterite nickel ore in Indonesia with sulfuric acid was studied. The results show that under the conditions of acid/ore ratio of 260 kg/t, leaching temperature of 250 °C (corresponding to water vapor pressure of 4. 0 MPa), liquid volume/solid mass ratio of 3/1, stirring speed of 300 r/min, particle size of 100 mesh and reaction time of 1 h, the leaching rates of nickel, cobalt and iron are 98. 1 %, 98. 3% and 4. 7%, respectively, and the iron grade can reach 51. 3%. The leaching processes of nickel and cobalt under pressure and atmospheric pressure are in line with the shrinkage kernel model of interfacial chemical reaction control, and the activation energies of the reactions are 116 kj/mol and 91 kj/mol under pressure, respectively, and the activation energies of the reaction under atmospheric pressure are 41 kj/mol and 53 kj/mol, respectively. The leaching is mainly goethite under normal pressure, and chromite, magnetite and other mineral phases under high pressure. [ABSTRACT FROM AUTHOR]

Rotary kiln-electric furnace (RKEF) technology accounts for 95 pct of the lateritic nickel ore processing. Coal is commonly used as fuel and reducing agent in the rotary kiln to produce solid reduction product which is then melted in the electric furnace. The use of coal in the process leads to the emission of approximately 70 tons of CO2 for every 1 ton of nickel in ferronickel or nickel pig iron product. One of the possible solutions for minimizing CO2 emission in the RKEF process is through the substitution of carbon-based fuel and reducing agent with hydrogen gas. This research focuses on experimental investigation on the reduction of saprolite nickel ore under hydrogen-argon atmosphere. The research was initiated by performing a thermodynamic simulation using FactSage 8.0 to preliminary evaluate the effects of different parameters on the reduction process. Reduction experiments of saprolite nickel ore were then carried out in a horizontal tube furnace with varying temperature (500 °C, 600 °C, 700 °C, 800 °C, and 900 °C), hydrogen gas composition (25 and 75 pct H2 in H2–Ar gas mixture), and reaction time (0.25 to 3 hours) to simulate the process in the rotary kiln. The solid reduction products were analyzed using ICP-MS, SEM-EDS, and XRD. The overall reduction extents in all conditions were also monitored by weight measurements of the samples before and after the reduction processes. Based on the weight changes, the reduction process was found to be significantly rapid so that it reached completion in 15 minutes. Each solid reduction product was then melted in a vertical tube furnace at 1550 °C for 2 hours under inert, argon atmosphere to simulate the process in the electric furnace. The metal product after melting had an average composition of 80.6 pct Fe and 8.3 pct Ni which is similar to commercially produced nickel pig iron. [ABSTRACT FROM AUTHOR]

The magnesium slag (magnesium nitrate hydrate Mg(NO3)2·6H2O) produced in the nitric acid leaching process of laterite nickel ore can be effectively recycled by thermal decomposition. To this end, this study placed great emphasis on disclosing the thermal decomposition mechanism of Mg(NO3)2·6H2O. Firstly, thermal decomposition paths of Mg(NO3)2·6H2O were revealed through Thermogravimetry-Mass Spectrometry, Differential Scanning Calorimetry and powder X-ray diffraction. It was found that the thermal decomposition of Mg(NO3)2·6H2O was a multistep endothermic reaction involving two dehydration stages and one denitration stage. The two dehydration stages were characterized by the evolution of H2O, with the formation of magnesium nitrate dihydrate and anhydrous magnesium nitrate. The denitration stage was characterized by the simultaneous evolution of O2 and NO2, with the formation of MgO. The conventional kinetic analysis was not suitable for describing such complex multistep reaction behaviour. Thus, the kinetic rate data (dα/dt-T) for the overall reaction were separated into those for three contributing stages by mathematical peak deconvolution. Then, the complete kinetic interpretations of the separated reaction stages for Mg(NO3)2·6H2O pyrolysis were achieved by the Friedman method and the master plots method. Finally, the original experimental α-T curves were successfully simulated using the resulting kinetic triplets. [ABSTRACT FROM AUTHOR]

This paper delves into the intricate dynamics of international law and dispute resolution within the context of renewable energy development, focusing on Indonesia's downstreaming of nickel ores. As renewable energy initiatives gain prominence globally, the demand for essential minerals like nickel increases, prompting nations like Indonesia to explore downstreaming processes. However, this transition presents complex legal challenges, including international trade agreements, environmental regulations, and indigenous rights. Through a comprehensive review of relevant literature and case studies, this study analyzes Indonesia's approach to nickel ore downstreaming and its implications for international law and dispute resolution mechanisms. Additionally, it examines the role of international organizations, such as the World Trade Organization (WTO) and the United Nations Commission on International Trade Law (UNCITRAL), in resolving disputes arising from renewable energy projects. By synthesizing legal frameworks, environmental concerns, and socio-economic factors, this paper offers insights into navigating the legal complexities of renewable energy development, with a focus on Indonesia's nickel industry. Ultimately, the findings contribute to the discourse on sustainable resource management and the role of international law in facilitating equitable and environmentally responsible energy transitions.

Under the background of carbon peaking and carbon neutrality, compared with a traditional carbon thermal reduction to produce nickel, gas-based reduction has outstanding advantages in efficiency and carbon reduction. However, there are few studies on gas-based reduction at present. This article explores the reduction behavior of methane on laterite nickel ore. The effects of different reaction temperatures, reaction times and gas concentrations on the reduction reaction were studied. The phase and morphology of laterite nickel ore and its calcined products were analyzed by XRD, SEM-EDS and gas chromatography. The results show that when the reduction temperature is 900 °C, the reduction time is 60 min, and the concentration of CH4 is 50%, a concentrate with a nickel grade of 3.06% and a recovery of 52.09% can be obtained. After analysis, the reason for the low nickel grade and recovery rate in the concentrate is, on the one hand, due to the incomplete reduction of NiO, and a large amount of nickel still exists in the silicate in the tailings; on the other hand, it is due to the fine grain size of the partially reduced nickel iron alloy, which is lost in the tailings and filtrate. [ABSTRACT FROM AUTHOR]

Growing demand for ‘critical minerals’ – such as lithium, cobalt, and nickel – and strategic rivalries between large economies have prompted a scramble to secure control of such minerals and the supply chains that organise their processing and distribution. Public policies have sustained these processes, producing new types of international instruments – from standalone agreements, such as the Japan-US Critical Minerals Agreement; to tailored provisions in trade treaties, such as the ‘energy and raw materials’ chapter of the Chile–EU trade agreement; all the way to soft instruments that provide a shared framework and roadmap for cooperation, such as the strategic partnerships the EU has negotiated with several mineral-rich states. Through the prism of critical minerals supply chains, these instruments cut across different areas of law and policy: trade, investment, aid, labour rights, the environment and collaboration in research and innovation. Critical minerals have also featured in international dispute settlement processes, including a dispute at the World Trade Organization over Indonesia’s restrictions on unprocessed nickel ore exports. An initial appraisal of these developments highlights the role of law in sustaining and regulating commodity production and trading, while the widespread use of soft instruments points to the limits of legal processes in the context of rapidly evolving economic and geopolitical realities. The developments reflect both continuities and ruptures in international economic law, particularly in relation to the roles of states and markets. They also illustrate the interrelatedness of climate imperatives, territorial governance, international investment and trade, and the need to more effectively integrate ecological sustainability and ‘just transition’ principles into the fabric of the global economic order. [ABSTRACT FROM AUTHOR]

The contradiction between the supply and demand of nickel resources is intensifying, and it is urgent to develop new processing and smelting processes for laterite nickel ore. Gas based smelting with H2 and CH4 as reductants is of great significance to solve the "double carbon" problem faced by the traditional metallurgical industry. Taking low-grade laterite nickel ore as the research object, CH4 as the reductant and elemental sulfur as the additive, under the conditions of different reduction temperature, reduction time, gas concentration and additive dosage, this paper discusses the reduction behavior of CH4 and iron nickel oxide in laterite nickel ore. Combined with XRD, SEM-EDS, gas analysis and other characterization methods, the phase and morphology of laterite nickel ore and its reduction products were deeply analyzed. Results surface: under the conditions of reduction temperature 800°C, reduction time 60 min, CH4 concentration 20%, elemental sulfur dosage 4%, the metallization rate of nickel and iron in the reduction product can reach 98.01% and 8.44%, respectively. Nickel oxide is almost completely reduced to nickel, and most of iron is reduced to low-price iron oxide. In the reduction process, the amorphous silicate recrystallizes into magnesium olivine phase in the reduction process. It hinders further reduction of nickel. According to SEM-EDS analysis, some metal iron and elemental sulfur generate FeS around the iron oxide region, which hinders the contact between reducing gas and FeO. Therefore, the reduction of iron is inhibited and the iron oxide content increases. It promoted the selective reduction of nickel. [ABSTRACT FROM AUTHOR]

There is a variation in nickel content produced by PT. Aneka Tambang Tbk Site Pakal with the needs of the processing industry so that the blending method needs to be applied. Blending is the process of mixing two or more materials that have different qualities to get the right mixture. In the blending process, it must meet the specific ore according to the needs of the processing plant. The results of the XRF analysis on the stockpile Sosolat, Bicoli, Maba, Mafia, Sangaji, Roomstock Harmony, Resampling Sangaji were respectively 2.26%, 1.61%, 1.48%, 1.35%, 1.32%, 1.53%, and 1.60%. The results of theoretical simulations and actual blending in the field obtained factory quality of 1.75%, Buana Jaya barge with simulated Ni content of 1.87% and realized Ni content of 1.76%, Bukit Emas barge with simulated Ni content of 1.83% and realized Ni content of 1.90, TGH barge with simulated Ni content of 1.85% and realized Ni content of 1.76%, Ilir Jaya barge with simulated Ni content of 1.87% and real Ni content sai is 1.85%, the DBS 3029 barge with a simulated Ni content of 1.88% and a realized Ni content of 1.78%. [ABSTRACT FROM AUTHOR]