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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]

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 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]

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]

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]

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]

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]

Nickel is widely used in industrial processes and plays a crucial role in many applications. However, most of the nickel resource mainly exists as nickel oxide in laterite nickel ore with complex composition, resulting in difficulty in upgrading the nickel content using physical separation methods. In this study, high-grade ferronickel concentrates were obtained through a carbothermal reduction and magnetic separation using laterite nickel ore and anthracite as raw materials. The effects of different types of additives (CaF2, Na2SO4, and H3BO3), carbon ratio (the molar ratio of oxygen atoms in the laterite nickel ore to carbon atoms in anthracite), and grinding time on the recoveries and grades of ferronickel concentrates were experimentally investigated, along with the microstructure and chemical composition of the products. CaF2 was proved to be the primary active additive in the aggregation and growth of the ferronickel particles and the improvement of the grade of the product. Under the optimal conditions of CaF2 addition of 9.85 wt%, carbon ratio of 1.4, and grinding time of 240 s, high-grade magnetically separable ferronickel concentrate with nickel grade 8.93 wt% and iron grade 63.96 wt% was successfully prepared. This work presents a practical method for the highly efficient recovery and utilization of iron and nickel from low-grade laterite nickel ore, contributing to the development of strategies for the sustainable extraction and utilization of nickel resources. [ABSTRACT FROM AUTHOR]

This paper investigates the synergistic extraction performance of Scandium using a mixture of Cyanex572 and Cyanex923 in sulfuric acid medium. The results show that the best synergistic effect is achieved when the pH value of the aqueous phase is 2 and the mole fraction of Cyanex572 is 0.5, with a synergy coefficient value R of 4.78. In addition, the extraction mechanism of this synergistic system is discussed, and the extracted complex is determined to be [Sc(SO4)0.5(HL2)2B2] by slope analysis. The loaded Scandium can be stripped within two times by 2 mol/L sulfuric acid to obtain a stripping efficiency of 99.4 %. Finally, this synergistic system was applied to extract Scandium, demonstrating the potential application in separation of Scandium from the leachate of laterite nickel ore. [ABSTRACT FROM AUTHOR]

Attempts have been made to extract nickel from ores and nickel-containing wastes using the chlorination method. However, the use of gaseous chlorinating agents is limited due to their toxicity. High-temperature chlorination of nickel oxide using calcium chloride is analyzed in this study. The volatilization percentage is positively correlated to temperature and CaCl2 dosage and negatively correlated to oxygen partial pressure. The apparent activation energy is calculated to be 142.91 kJ/mol, between 1173 K and 1323 K, which suggests that the high-temperature chlorination of nickel oxide using calcium chloride is controlled by a chemical reaction. [ABSTRACT FROM AUTHOR]

Dewatering unit operations are essential steps in mineral processing routes to obtain materials with high levels of solid content (60-70 wt.%). Polymers have been used for coagulation and flocculation in wastewater treatment for many years, and its application is mostly based on the ad-sorption mechanisms. In the case of fine nickel ore tailings, wastewaters typically contain large amounts of particles within microscale (d50 = 9.5 µm). The use of flocculant polymers, mostly poly-acrylamides, acts to remove colloids from these effluents. Environmentally friendly natural polymers, such as chitosan and humic acid, when used combined can be a highly effective reagent for the treatment of these tailings. Therefore, the purpose of this study is to evaluate the use of these natural polymers in the treatment of wastewater containing colloidal material to adequate the fine particles content to less than 50 NTU, satisfying environmental standards. Particle removal efficiency was calculated based on turbidity on wastewater as well as on thickener overflow. For fine 24 nickel tailings containing 2.15% (wt./vl.), a mixture of chitosan/humic acid of 24.9/6.3 g/t at pH=6.7 25 achieved a sedimentation of 95 wt.%. The turbidity was reduced to 40 NTU, motivating the use of 26 this technique to adequate wastewater to water reuse. [ABSTRACT FROM AUTHOR]

At present, scholars mainly study the relationship between nanobubbles and useful minerals, often ignoring the influence of bubbles on fine gangue minerals. When selecting nickel sulfide ore, scholars often faced with mudded and irrepressible serpentine, which seriously affects the quality of the concentrate. This mudded serpentine mineral often enters foam products with bubbles. In this study, the role of nanobubbles in the flotation behavior of hydrophilic serpentine was examined. Nanobubbles were successfully prepared via ultrasonic cavitation, with sizes ranging from 50 to 250 nm. The size and number of bubbles produced at 1 min and 2 min of sonication were significantly better than those of the prolonged test group, and it was found that longer sonication time did not produce better results. The stability of the nanobubbles produced via ultrasound was studied, and it was found that the nanobubbles were stable, with no change in size and only a slight decrease in number as the resting time increased. Nanobubbles were introduced into serpentine flotation, we found that the presence of nanobubbles significantly reduced the flotation recovery of serpentine. The presence of nanobubbles reduced the froth entrainment rate of microfine-grained serpentine, which in turn reduced its flotation rate. In the depressant group trials, it was found that the nanobubbles also reduced the amount of depressant. In short, the presence of nanobubbles can prevent the floating of fine hydrophilic gangues during flotation. [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.

Most nickel laterite smelting to produce ferronickel is carried out using an AC-arc furnace. Although the DC-arc furnace is advantageous in the smelting of fine ore, it is rarely used for nickel laterite. In this work, the effects of slag basicity and stoichiometry of reductant addition during smelting of low-grade saprolitic nickel ore on nickel content and nickel recovery, yield, and phases of the slag were studied in detail. The smelting process was conducted in a laboratory DC-arc furnace with a a single electrode of 30 cm diameter. A 5 kg of low-grade saprolitic nickel ore (1.92 Ni-12.97 Fe), some coke as reductant, and some limestone as flux were smelted in a DC-arc furnace for about one hour. The pouring temperature of hot metal and slag was 1400-1500 °C. The basicity of the quaternary slag of 0.8 and the stoichiometric carbon of 0.8 of the reductant resulted in an optimum smelting process of nickel ore in a DC-arc furnace, producing ferronickel with a Ni content of 14.59% with 92.26% recovery. [ABSTRACT FROM AUTHOR]

Strict environmental regulations have made on many industrial sectors to try and reduce CO2 gas production, including the nickel and ferronickel manufacturing industries. One of the promising technologies in reducing CO2 emissions is carbothermic reduction using a lower operating temperature than smelting process. This study aims to study the effects of adding and laying reductant (coal) on composite briquette. By using the same C/O molar ratio, this research tries to study the effects of inner and outer coal on the carbothermic reduction of laterite nickel ore. The carbothermal reduction process was carried out at 700 °C for 2 h and then followed by heating at 1400 °C for 6 h. Then, the ferronickel was separated from the impurities by magnetic separation. Several tests and calculations were carried out to assess process performance, such as energy dispersive X-ray, scanning electron microscope, X-ray diffractometer, calculation of nickel recovery, calculation of selectivity factor, and calculation of separation efficiency. The result showed that inner and outer coal in the carbothermic reduction process of laterite nickel ore can affect the selectivity performance of nickel. The best nickel recovery (93%) was obtained when using 70% inner coal and 30% outer coal. On the other hand, the best nickel content (13.99%) was achieved when using 90% inner coal and 10% outer coal. The ferronickel product obtained from this process can be applied as a raw material in stainless steel making or further processed into nickel sulfate powder. [ABSTRACT FROM AUTHOR]

This study aimed to increase the recovery efficiency of nickel metal and reduce smelting energy consumption by analyzing the effect of adding B2O3 on the melting characteristics of nickel flash melting slag and the separation of slag and matte. In particular, thermodynamic analysis and high-temperature experimental investigations showed that adding B2O3 decreased the melting temperature of the slag system and enhanced the slag flow characteristics. Furthermore, the primary process parameters required for slag and nickel matte separation were predicted and optimized using single-factor experiments and the response surface method. The degree of the effect on the slag-matte separation was as follows: temperature > MgO content > FeO/SiO2 > B2O3 content. The optimal separation conditions were settling temperature 1300°C, MgO content 8 wt.%, FeO/SiO2 1.55, and B2O3 content 2.4 wt.%. The mechanism demonstrated that adding B2O3 could significantly reduce the impact of low-quality nickel ore on smelting. Moreover, the separation and recovery of the matte and slag were both successful. Findings indicate that an efficient way to optimize the smelting process is adding B2O3, which is expected to improve the development of metal recovery technologies. [ABSTRACT FROM AUTHOR]

The development of the electric vehicle industry has increased the need for batteries. The NMC (Nickel Manganese Cobalt) battery is one type with superior properties. The nickel used to manufacture NMC batteries is nickel (II) sulfate hexahydrate (NiSO4·6H2O) compounds. A mixed sulfate precipitate should be synthesized to obtain it. Thus, nickel ore has been first smelted in the Mini Blast Furnace, after which the smelted and cooled Nickel Pig Iron (NPI) has been leached into a solution. This study has aimed to analyze the influence of agitation speed and particle size of NPI in the leaching process of mixed sulfate precipitate. The leaching process has used a 2M H2SO4. The leaching temperature is set at 90 °C for 6 hours with agitation speeds of 100, 200, and 300 rpm and particle sizes of -50 µm, +50 -80 µm, and +80 -112 µm. Next, the precipitation process has been carried out by using NaOH solution. Next, the crystallization process has been conducted to eliminate water in the solution and produce powder. The best nickel extraction has been obtained at a particle size of -50 µm at 98.19%. [ABSTRACT FROM AUTHOR]

Large amounts of solid waste-spent cathode carbon (SCC) was produced in aluminum electrolysis process. At present, landfill and storage methods are widely used, which will not only cause great harm to the environment, but also cause a lot of waste of resources. Nickel and iron were recovered from laterite nickel ore by reduction roasting-magnetic separation using SCC as reducing agent. The fluorine in SCC was fixed in roasted ore by adding CaO. The feasibility of the method was verified by thermodynamic analysis and experiments, and the optimum conditions for CaO addition were determined. The recovery of nickel and iron reached 91.23% and 89.63% respectively when the addition of SCC was 14 wt.% and CaO was 8 wt.%. Adding 8 wt.% CaO under the condition of SCC as reducing agent can change the viscosity of roasted ore and promote the aggregation of ferronickel particles. The concentration of soluble F? in roasted ore was reduced and fixed in roasted ore in the form of insoluble calcium fluoride. Under the condition of adding 8 wt.% CaO, the fluorine fixation rate was 95.99%, and the concentration of F? in roasted ore was only 31 mg·L-1. [ABSTRACT FROM AUTHOR]

The North Konawe region in Indonesia, known for its lateritic nickel (Ni) deposits, holds significant potential for obtaining Ni resources. However, the complex topographic conditions of this area pose challenges. Exploring the application of remote sensing technology to reveal the spectral response mechanism of Ni grade from high-precision multispectral data and inversion of Ni grade represents a novel direction in future Ni resource exploration. Traditional remote sensing inversion methods solely consider the spectral characteristics of sample data and ignore vital geospatial location information. As a result, efficiently obtaining regional details of target substance content over large areas has become challenging. The introduction of the geographically weighted regression (GWR) method offers an opportunity for fine-grained Ni grade inversion based on remote sensing. This study focused on the E and K blocks within the lateritic Ni mining area in North Konawe. Through utilizing the WordView-3 multispectral data which exhibits immense potential in quantitative remote sensing inversion studies, GWR was employed to integrate spectral features and spatial information. The goal was to reveal the correlation between multispectral remote sensing data and Ni grade. The obtained results were then compared and analyzed with multiple linear regression (MLR) and back propagation neural network (BPNN) models. The findings revealed that GWR achieved the highest coefficient of determination R2 of 0.96, surpassing MLR and BPNN values of 0.05 and 0.17, respectively. Additionally, GWR exhibited the lowest root mean square error of 0.04, which was lower than those of MLR and BPNN with the values of 0.25 and 0.23, respectively. These results confirmed the enhanced stability and accuracy of the GWR method compared to MLR and BPNN. Furthermore, GWR effectively mapped the spatial distribution trends of Ni grades in the study area, providing evidence of the method's effectiveness in Ni grade inversion. The study also delved into the inversion effect of the GWR method in areas with varying weathering crust thickness and vegetation cover. The research revealed that higher values of weathering crust thickness negatively impacted the inversion effect. However, the influence mechanism of vegetation cover on Ni grade inversion necessitated further investigation. These results served as a significant demonstration of the remote sensing inversion of mineral resource grades in similar areas. They provided valuable insights for future exploration and decision-making processes. [ABSTRACT FROM AUTHOR]

Conductive concrete with nanographite–cupric nickel sulfate ore was prepared in this paper. As a new type of multifunctional multiphase conductive building material with conductive, electrothermal, electromagnetic shielding, piezoresistive properties, etc., nanographite–cupric nickel sulfate ore conductive concrete will have a wide range of applications in snow melting, electromagnetic shielding, cathodic protection and structural health monitoring, and other fields. In this paper, different dosage of nanographite and cupric nickel sulfate ore admixture that the mixture was excited by alkali excitation, ultrasonic vibration and combined alkali excitation and ultrasonic vibration, respectively were used to study the electrical conductivity and mechanical properties of conductive concrete, 36 groups of nanographite–cupric nickel sulfate ore conductive concrete specimens and seven groups of comparative specimens were cured for 28 days, and the unconfined compression test, three-point bending test, and electrical conductivity test were carried out. The results show that the electrical conductivity and mechanical properties of the specimens with 6% nanographite and 60% cupric nickel sulfate ore were the best, with the compressive strength, flexural strength and resistance reaching 40.83 MPa, 6.81 MPa, and 5,850 Ω·cm, respectively. Compared with the comparative specimens, the compressive strength and the flexural strength of the specimens are increased by 38.5% and 20.4%, respectively, and the resistivity is decreased by 55.7%. This shows that the alkali excitation-ultrasonic vibration activation method can not only improve the electrical conductivity of nanographite–cupric nickel sulfate ore conductive concrete pavement but also ensure the stability of its mechanical properties. [ABSTRACT FROM AUTHOR]

Development of downstream on the mining industry has been encouraged by the government of Indonesia these past years. With the increasing demand for nickel ore, the government focused on implementing downstream in this sector. Establishing an export ban and domestic processing requirement on nickel ore caused the EU to challenge Indonesia before the DSB WTO. In its report to the Panel, it was concluded that Indonesia had violated the provisions of GATT 1994. While it is understandable that Indonesia has absolute sovereignty over its natural resources, it is also bounded to international organisations and regulations, for it has expressed its consent. This paper aims to examine the analysis by the Panel on what caused Indonesia to decide as the losing party and how Indonesia would implement the development downstream in the middle of its sovereignty and obligations on an international level. Through a juridical normative method, it is concluded that Indonesia had failed to comply with the provisions of GATT 1994 that obliged it. It does not mean it has no sovereignty towards its natural resources, for it has agreed to be bound by the provisions. In order to exercise downstream development, it is recommended that Indonesia create national policies or regulations related to adhering to the provisions of the WTO. A cautious approach to governing the downstream may prevent potentially damaging disputes. [ABSTRACT FROM AUTHOR]

Copyright of Mining & Metallurgy (10057854) 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.)

Copyright of Mining & Metallurgy (10057854) 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 utilization of low-grade laterite ores has become necessary due to the intensive mining of high-grade nickel sulphide ores for a long time. In this study, metallic reduction roasting followed by magnetic separation to produce ferronickel alloy and abandon gangue minerals provides an effectively treatment for laterite ores. The experimental results indicate that ferronickel alloy containing more than 7.5% Ni with its recovery of 95% and more than 70% Fe with its recovery of 90% was produced successfully from the low-grade laterite ore. In the metallic reduction roasting process, the thermodynamic analysis displayed that the higher temperature promotes the conversion percentage of the oxidic nickel and iron to metallic nickel and iron. The ferronickel particle morphology with a liquid-solid growth and aggregation mechanism in the reduced laterite ore were investigated by SEM/EDS. XRD analysis revealed that the nickel laterite ore was transformed from hortonolite (MgOx · FeO2-x · SiO2) to forsterite (MgOx · CaOy · SiO2) during the metallic reduction process. [ABSTRACT FROM AUTHOR]

Odisha is blessed with an abundance of natural resources, including minerals, forests, marine life, and water. Odisha is one of India's top producers of valuable minerals such as chromites, nickel ore, coal, bauxite, iron ore, and manganese. In addition to providing habitat and a means of subsistence for the state's expanding tribal population, around 30 percent of its land is covered with forests, which also serve as the catchment areas of key rivers, home to rich mineral deposits and biodiversity hotspots. This article aims to analyse the current status of several extractive industries as well as their potential for the future. A significant portion of the study is based on secondary data. Simple percentage shares and yearly average growth rate have been used to analyse data and strengthen the argument. The results from the paper demonstrate that mining production and value have grown over time. However, the average yearly growth rate has been declining. The Gross State Value Added (GSVA) of the mining sector in Odisha has hardly increased and still lags behind the manufacturing sub-sector. Furthermore, the state's exchequer has profited significantly from the mining sector's performance (in terms of output, value, and income) and from its broad use of mining activities. However, employment statistics indicate that the locals in the mining region have not seen a significant increase in wealth. [ABSTRACT FROM AUTHOR]

Copyright of Mining & Metallurgy (10057854) 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.)