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BACKGROUND AND OBJECTIVES: The nickel processing industry has always been related with the issue of carbón dioxide emission. The production of carbon dioxide occurs at different phases of nickel processing, from pretreatment to smelting and refining. In addition to offgas, the nickel processing sector also produces solid waste known as slag, which is a byproduct of both smelting and refining processes. One of the slags in the nickel industry is known to contain iron, which is dominant compared to other elements. The primary objective of this study is to investigate the process of carbon dioxide capture by utilizing iron-rich slag derived from the nickel processing industry. The aim is to assess the feasibility of applying iron-rich slag from nickel smelters in the solid carbonation gas process for carbon dioxide capture, focusing on chemical reactions and overall kinetics. METHODS: The iron-rich slag analyzed in this study contains a significant amount of iron oxide. It is theoretically anticipated that the iron oxide content in iron-rich slag could potentially sequester carbon dioxide. The study commenced by preparing the materials, undergoing the carbonation process, and then conducting various characterizations including X-ray diffractometer analysis and thermal gravimetric analysis. Additionally, calculations were performed to determine the percentage of carbon dioxide in the sample and the efficiency of carbonation. The kinetics analysis was also carried out using several models, such as mass transport, chemical reaction, and diffusion-controlled model to estimate the carbón dioxide capture mechanism that occurs. FINDINGS: The carbon dioxide capture capacity of the iron-rich slag from the ferronickel industry is somewhat limited, albeit still relatively modest. Iron-rich slag was effectively utilized to capture carbon dioxide after thorough analysis. After undergoing a carbonation process for a duration of 4 hours, the percentage of carbon dioxide in the slag witnessed a significant increase, rising from an initial value of 0.28 percent to 1.12 percent. The capture of carbón dioxide gas is due to the reaction between silicate with carbón dioxide gas and water vapor to form siderite. The iron-rich slag operates under the diffusion-controlled model when it comes to capturing carbon dioxide. CONCLUSION: Iron-rich slag is reported to capture carbón dioxide at 175 degrees celsius with carbón dioxide and water vapor condition, which is proven both from thermodynamic calculations and experiments. Iron(II) carbonate is a carbonate compound generated by the carbón dioxide capture reaction by iron-rich slag. However, the stability of iron(II) carbonate in carbón dioxide and water vapor atmosphere is something that needs to be considered in future research. Further investigation can be conducted in the future to explore the potential of utilizing iron-rich slag for capturing carbon dioxide gas, building upon the findings of this preliminary study. [ABSTRACT FROM AUTHOR]

Facing the situation of nickel resource shortage and increasing nickel demand, it is an important task for the development of nickel industry to realize efficient utilization of low-grade nickel sulfide ore. In this work, the process of NaCl roasting-water leaching was proposed to simultaneously extract valuable metals from low-grade nickel concentrate. Based on the thermodynamic analysis of roasting process, the effect of several key factors on metal extraction was investigated. The results show that the extraction of Ni, Cu and Co can reach approximately 94.08, 92.81 and 91.85 pct, respectively, under the following optimum conditions: temperature 400 °C, time 90 minutes, NaCl dosage 100 pct and concentrate particle size 70–88 µm. The evolution behavior and mechanism of metallic minerals are determined through thermodynamic analysis, differential thermogravimetric analysis, and phase composition analysis of roasted product. The kinetics of the roasting process based on the differential thermal and thermogravimetric experiment was analyzed by Kissinger method and Doyle-Ozawa method. The average apparent activation energy of metallic minerals being chlorinated is determined as 400.12 kJ/mol and the kinetic equation was expressed as d α dt = 2.41 × 10 12 e - 400.12 RT (1 - α) 1.27 . [ABSTRACT FROM AUTHOR]

The purpose of this research was to increase the energy efficiency in the transport of fluids in the nickel industry through modeling and solving an optimization problem, where the factors analyzed are: solids content, granulometry, chemical composition and temperature, due to the little knowledge of how these variables influence the energy efficiency of said equipment. Based on experimental studies and using statistical procedures and estimators, the behavior of the rheological parameters is modeled as a function of temperature, solids content and chemical composition. It is observed that the lateritic hydromixtures present plastic properties adjusting to a Herschel Bulkley model for real plastics. From an appropriate discretization of the raw pulp pumping system model and the application of the combinatorial optimization procedure, the exploitation parameters of this system were obtained. [ABSTRACT FROM AUTHOR]

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This article examines the nickel export restriction and downstream policy in Indonesia. It evaluates the government's policies and their implications for global nickel requirements and future energy estimates. The study finds that the current policy overlooks important factors such as environmental effects, disparities in benefits, and social implications. It emphasizes the need to consider the impacts on social, environmental, and national resilience. The article also discusses the negative consequences of the ban on nickel ore exports and the potential for illegal exports. It aims to provide a better understanding of Indonesia's role in meeting global energy and food needs, particularly in the nickel sector, and to inform the formulation of appropriate policies. The article also discusses the stakeholders involved in the policy, including President Joko Widodo, economists, members of the Indonesian Ombudsman, and INDEF researchers, who have differing opinions on the matter. The article highlights the negative social and environmental impacts of the nickel downstream industry, including the loss of livelihoods for farmers, fishermen, and women. It suggests that the policy should be reconsidered and adjusted to address these concerns. The article concludes by recommending policy adjustments that strike a balance between economic growth, environmental sustainability, and social welfare. It emphasizes the importance of involving stakeholders and conducting regular evaluations of the policy's impact. [Extracted from the article]

Preliminary studies showed that almost 50% of the people around the Morosi nickel mining industry had very high creatinine levels (26 mmol/l). High creatinine levels indicate impaired kidney function. This study aims to analyze the determinants of high creatinine levels in the urine of people around the Morosi nickel mines. There were 61 participants who were interviewed and urine samples were taken to test their creatinine levels. High levels of creatinine indicate kidney disorders. Measurement of creatinine levels used urine reagent strips 13G. Then it was connected between the condition of water sources, houses, solid and liquid waste management with the participants' creatinine levels with the multinomial regression statistical test. The house condition and liquid waste management had significant association with creatinine levels (P=0.005 and P=0.026, respectively). More than 80% of people lived in houses with good condition and had very low creatinine levels (≤0.9 mmol/l). Most of them had done appropriate liquid waste management (63.9%). However, water sources and solid waste management had no association with creatinine levels (P=0.195 and P=0.130, respectively). The majority of them had used good water sources such as piped and gallon water (80.3%). There were only 19.7% of them who used dug wells and 60.7% who throw their solid waste into the river or burn it. This study concludes that house condition and liquid waste management determine of the high urine-creatinine levels of people leaving around the Morosi Nickel Mining Industries. [ABSTRACT FROM AUTHOR]

The purpose of the study was to obtain new data on the causes, development, prevalence and nature of occupational multimorbidity in the nickel industry workers. We extracted data from the register of occupational disease and intoxication cases in the population of the Murmansk region and the Krasnoyarsk Territory in 2007–2021. In 2007–2021, 24.6% of nickel industry workers with newly diagnosed occupational diseases developed a multimorbid pathology. Its prevalence rose from 0% in 2007 to 83.3% in 2021, and the number of occupational diseases increased by 3.17 times. Two diagnoses were found in 66 (14.9%), three in 22 (5.0%), four in fifteen (3.4%), five in eleven (2.5%), and six in three (0.7%) employees. Respiratory and musculoskeletal diseases were the most prevalent disorders, accounting for 31.5% and 23.0% of cases, respectively. Occupational multimorbidity resulted from the increased combined exposure to occupational hazards, outdated technological processes, and the working conditions in the finished product cleaners and crane operators. Multimorbid diseases can be better prevented with improvement in working conditions and better quality of periodic medical examinations. [ABSTRACT FROM AUTHOR]

ABSTRACTThe purpose of the study was to obtain new data on the causes, development, prevalence and nature of occupational multimorbidity in the nickel industry workers. We extracted data from the register of occupational disease and intoxication cases in the population of the Murmansk region and the Krasnoyarsk Territory in 2007–2021. In 2007–2021, 24.6% of nickel industry workers with newly diagnosed occupational diseases developed a multimorbid pathology. Its prevalence rose from 0% in 2007 to 83.3% in 2021, and the number of occupational diseases increased by 3.17 times. Two diagnoses were found in 66 (14.9%), three in 22 (5.0%), four in fifteen (3.4%), five in eleven (2.5%), and six in three (0.7%) employees. Respiratory and musculoskeletal diseases were the most prevalent disorders, accounting for 31.5% and 23.0% of cases, respectively. Occupational multimorbidity resulted from the increased combined exposure to occupational hazards, outdated technological processes, and the working conditions in the finished product cleaners and crane operators. Multimorbid diseases can be better prevented with improvement in working conditions and better quality of periodic medical examinations.

The present work constitutes a proposal for an automation system for the process control of the carbonated sludge utilization circuit in the Moa Nickel S.A. Mixed Company, located in the municipality of Moa, Holguín province, belonging to the Nickel Business Group (CUBANIQUEL). The nickel industry plays an important role within the national economy, which is why the efficiency of the operation of the main parameters of the different equipment and facilities that comprise it has a considerable impact on the production of nickel and cobalt. This work is carried out with the objective of designing an automation system for the rejection utilization circuit that allows it to be operated efficiently; In it, the necessary field instrumentation for the main regulation loops involved in the process is proposed and the control architecture design proposal is made based on Programmable Logic Controllers (PLC) and using the Siemens TIA Selection Tool. A complete list of necessary materials and accessories is additionally generated. [ABSTRACT FROM AUTHOR]

The high density sludge (HDS) process was used for acid wastewater treatment ol a pyrite mine, the optimization ol parameters and economic analysis were conducted. The optimal process conditions were obtained as lollows: hydraulic ret ention time ol 30 min, gas-water ratio ol 5 : 1, pH value of 9.0 9. 2, the lime dosage of 0. 83 kg/m$, the PAM dosage ol 15 g/m$, sulfuric acid dosage(98 % concentration) ol 0, 016 7 L/m$. The results showed that under the optimal process conditions, the ellluent quality could stably meet the pollutant limit requirements specilied in table 2 ol emission standard ol pollutants for copper, nickel and cobalt industry (GB 25467 2010), table 2 ol emission standard ol pollutants for mining and mineral processing industry (GB 28661 2012), and the first level ol integrated waste water discharge standard (GB 8978 1996). The operating cost ol HDS process was about 1.57 Yuan/m$, with good economic elliciency. The experimental results could be used as the design basis for the upgrading and reconstruction project ol the wastewater treatment plant. [ABSTRACT FROM AUTHOR]

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