Hasil untuk "Mineral industries. Metal trade"

S. Muthayya, J. Sugimoto, S. Montgomery et al.

I. Ilankoon, Y. Ghorbani, M. Chong et al.

E-waste, or waste generated from electrical and electronic equipment, is considered as one of the fastest-growing waste categories, growing at a rate of 3-5% per year in the world. In 2016, 44.7 million tonnes of e-waste were generated in the world, which is equivalent to 6.1 kg for each person. E-waste is classified as a hazardous waste, but unlike other categories, e-waste also has significant potential for value recovery. As a result it is traded significantly between the developed and developing world, both as waste for disposal and as a resource for metal recovery. Only 20% of global e-waste in 2016 was properly recycled or disposed of, with the fate of the remaining 80% undocumented - likely to be dumped, traded or recycled under inferior conditions. This review paper provides an overview of the global e-waste resource and identifies the major challenges in the sector in terms of generation, global trade and waste management strategies. It lists the specific hazards associated with this type of waste that need to be taken into account in its management and includes a detailed overview of technologies employed or proposed for the recovery of value from e-waste. On the basis of this overview the paper identifies future directions for effective e-waste processing towards sustainable waste/resource management. It becomes clear that there is a strong divide between developed and developing countries with regard to this sector. While value recovery is practiced in centralised facilities employing advanced technologies in a highly regulated industrial environment in the developed world, in the developing world such recovery is practiced in a largely unregulated artisanal industry employing simplistic, labour intensive and environmentally hazardous approaches. Thus value is generated safely in the hi-tech environment of the developed world, whereas environmental burdens associated with exported waste and residual waste from simplistic processing remain largely in developing countries. It is argued that given the breadth of available technologies, a more systematic evaluation of the entire e-waste value chain needs to be conducted with a view to establishing integrated management of this resource (in terms of well-regulated value recovery and final residue disposal) at the appropriately local rather than global scale.

Tuama Alobaidi

Sicily's location in the center of the Mediterranean Sea gave it significant political and economic importance, as it served as a link between the continents of Europe and Africa. Its extensive coasts connected it to North Africa and Andalusia through abundant transportation routes, which facilitated civilizational and commercial exchange between them. Consequently, there were economic relations at various agricultural and industrial levels, as well as thriving trade between them. Sicily was renowned for its abundant agricultural production, cultivating various crops such as wheat, barley, rice, and others. It was also famous for growing grapes, apples, cotton, saffron, palm trees, olives, lemons, and oranges. Additionally, various types of animals were raised in Sicily, and there was a diversity of plant, animal, and mineral industries, such as sugar production, cotton textiles, and linen manufacturing. Shipbuilding also flourished, with several shipyards established for this purpose. Due to the island's richness in minerals, mining and metal extraction industries spread. Sicily was also known for its pottery and ceramic industries. Thanks to Sicily's abundance of natural and agricultural wealth, there were numerous markets in its cities, each specialized according to the type of goods or products. As for its commercial relations with North Africa and Andalusia, Sicily was connected to these regions through a vast network of maritime routes that linked it to both North Africa and Andalusia. It exported various agricultural and industrial products to North Africa and Andalusia and imported the agricultural and industrial products it needed from them.

Huan Li, J. Eksteen, G. Kuang

Abstract Lithium (Li), as a new energy metal, is becoming a “hot” topic in both academia and industry due to the rapid vehicle electrification and grid storage. Although brines have been the major Li sources, Li-bearing minerals, owing to the wider distribution and more rapid pathway to market, have also attracted much attention in recent years, with a number of new industrial projects launched and various novel methods proposed. The present study provides a start-of-the-art review of Li recovery from different mineral resources (i.e. excluding brines), and gives perspectives and outlook towards various recovery methods. In this study, the major mineral deposits of Li are summarised and illustrated, which shows its high abundance and wide distribution around the global. Various methods of Li recovery reported so far are then summarised with flowsheets and discussed by different type of minerals, covering spodumene, lepidolite, zinnwaldite, amblygonite and clays. It is predicted that spodumene will continue being dominantly used as Li source over other minerals with sulfuric acid (H2SO4) roasting as a major method of processing. However, other novel methods including direct processing of natural spodumene and the process that favours the direct production of LiOH will be the trends of future research. Fluoride-based methods can achieve low energy consumption and high extraction efficiency but still need to be further investigated for a sustainable, economical and safe application. To compete with spodumene, the comprehensive utilization of all the valuable elements contained in lepidolite and zinnwaldite is crucial. In most of the recovery processes, more attention should be paid to the treatment of voluminous residue and waste for a safe disposal or further reuse. In addition, this study not only presents the methods for Li recovery, but also includes various downstream separation and purification steps to make the process integrated. It is expected that, as a review specialising in mineral resources of Li, the present study can provide insights for the development of this particular area.

Zauresh Atakhanova, P. Howie, Nasser Madani et al.

Vlado Vivoda, I. Overland, Roman Vakulchuk

Jie Chen, Jie Chen, Sanmang Wu et al.

This study systematically examines the evolution and driving factors of embodied CO2 emission transfers in trade between Chinese provinces and ASEAN countries from 2002 to 2017. Employing a global multi-regional input–output (MRIO) model embedded with Chinese provincial data and structural decomposition analysis (SDA), we quantify the CO2 emissions embodied in exports (EEE) from 30 Chinese provinces to 10 ASEAN member countries. The analysis explores temporal trends, provincial and sectoral distribution, export routes, and driving forces. The key findings are as follows: (1) As China-ASEAN economic ties have strengthened, China’s EEE to ASEAN have shown a sustained upward trend, with Indonesia, Malaysia, Thailand, and Vietnam being the primary recipients. Heavy industries such as electricity, metal smelting, non-metallic mineral products, and chemicals are the dominant sources of these embodied emissions. (2) Coastal provinces such as Guangdong, Jiangsu, and Zhejiang have consistently served as major contributors to EEE. However, the contribution from several inland provinces has increased in later periods, revealing a spatial pattern of “coastal dominance and inland indirect participation” in interprovincial carbon transfer. (3) The export routes have shifted from predominantly international circulation toward a coexistence of domestic and international dual circulation, indicating the growing resilience of China’s domestic market and supply chains under the “dual circulation” strategy. (4) The expansion of final demand in ASEAN countries is identified as the primary driver behind China’s increasing EEE, whereas reductions in carbon intensity and structural upgrading of exports have partially offset the growth in emissions. This study highlights the importance of holistically considering inter-provincial disparities in emission transfers and advocates for improving regional and sectoral coordination in carbon mitigation policies, aiming to facilitate a green transition in China–ASEAN trade relations.

Topalović Dušan B., Smičiklas Ivana D., Radenković Mirjana B. et al.

This study examines the applicability of the XG calibration procedure for the PAQMON 1.0 portable platform in field conditions. Although PAQMON 1.0 is designed to accommodate additional sensor modules, this study utilized a version adapted explicitly for monitoring respirable particulate matter concentrations and meteorological parameters. Measurements were conducted in Bor, Serbia, during both the heating (GP) and non-heating (NGP) periods to account for seasonal climate and air quality variations. The platform demonstrated stable performance without significant signal drift or hardware failures. The correlation between PM2.5 concentrations and the reference Grimm EDM180 monitor was R = 0.65 (p ≤ 0.001) during GP and R = 0.40 (p ≤ 0.001) during NGP. The application of the XGBoost (XG) model significantly improved the accuracy of PM2.5 measurements compared to linear regression models. The adjusted R² values were 0.68 for GP and 0.44 for NGP, while NRMSE values ranged from 0.43 to 0.83. Although the XG model exhibited slightly lower performance during NGP, its calibration enabled the PAQMON 1.0 platform to achieve a Data Quality Objective (DQO) of 50% in both measurement campaigns. These findings confirm the practical applicability of XG calibration for enhancing the accuracy of low-cost sensor systems in air quality monitoring.

Chae-Deug Yi

This study analyzes the integrated effects of the USJTA, USJDTA, and the agreement on minerals for electric vehicle batteries. While most previous studies adopted the perfect competitive Armington model to analyze the economic effect of FTAs, it is unrealistic since monopolistic competition is taking place in export markets. To overcome those gaps, this study introduces the computable general equilibrium framework with monopolistic heterogeneity. The empirical results utilize the GTAP-HET transformed data using seven commodity sectors and seven countries which consist of four developed countries such as US, Japan, Canada and the EU and three developing countries such as China, Mexico, and the ROW. The new finding shows that the changes in industry outputs, domestic industry sales, demand for labor and capital, industry sector price, and terms of trade appeared significantly different according to perfect, monopolistic competition, and firm heterogeneity models.

Miljković Nikola, Živanović Miloš, Jovanović Nikola et al.

After the ecological reconstruction of the "Pljevlja" thermal power plant, ash and slag are produced as combustion by-products in amounts of 420.000 t and 70.000 t, while after desulphurization process, gypsum is obtained in the amount of 154.000 t. This paper deals with the transportation of all three materials by conveyors from the storage silo to the new material loading location within the thermal power plant.

Apostolovski-Trujić Tatjana, Radović Bojan, Kovačević Renata et al.

The air quality in the city of Bor in 2023 is analysed in this paper. In the period from May 1, 2022 until April 1, 2023 the copper smelter in Bor was not working due to reconstruction and capacity increase. The analyses show that in 2023, no exceeding of the daily limit value for SO2 , PM10, and soot concentrations was detected at any measuring point. During the reconstruction of the copper smelter, correlation coefficients (Pearson) at measurement point "Jugopetrol" between PM10 and the chemical elements Cd and As were moderate (0.6>r>0.4), while in the period before and after the reconstruction of the smelter, they were strong (0.8>r>0.6), and very strong (r>0.8). The results presented in the paper indicate that despite the reconstruction of the copper smelter, the problem of emission of high concentrations of carcinogenic elements in PM10 from the copper smelter is still present. It is necessary to urgently implement additional measures to reduce these emissions to the values provided by law.

Hao Zhan, Cheng-Zhi Li, Yi Kang et al.

Mineral elements typically act as transported substrates for metal tolerance proteins (MTPs). The chelation of MTPs with heavy metal ions is a suggestive detoxification pathway in plants; therefore, the trade-off between transporting mineral elements and chelating excess toxic metal ions is inevitable. Gallium (Ga) is an emerging pollutant associated with high-tech industries. This study investigated the impact of Ga stress on MTPs, subsequently altering the transport and distribution of mineral elements. Gallium exposure reduced rice seedling biomass, with roots accumulating more Ga than shoots. Ga stress also changed the rice plants’ subcellular mineral element distribution. PCR assays showed that Ga stress negatively affected all genes belonging to the Mn group, except OsMTP9. While Mn accumulation in the rice cellular compartments did not respond positively to Ga stress, OsMTP8, OsMTP8.1, OsMTP11, and OsMTP11.1 were found to be intimately connected to Mn transport and repressed by increased Ga accumulation in roots. Mg and Cu accumulated in the cytosol and organelles of Ga-treated rice plants, while OsMTP9 expression increased, demonstrating its importance in transporting Mg and Cu. A positive link between Ga stress and Zn accumulation in the cytosol and organelles was found, and OsMTP7 and OsMTP12 expression was positive, suggesting that Ga stress did not impair their Zn transport. Notably, Ga exposure down-regulated Fe-transporting OsMTP1 and OsMTP6, wherein the subcellular concentrations of Fe showed negative responses to Ga accumulation. These findings provide valuable insights into elucidating the roles of OsMTPs in Ga tolerance and the transport of these mineral elements.

Novak Emil, Stevanović Dimitrije, Mandić Milorad et al.

Awareness of environmental conservation has become a critical imperative in today's society, making waste management and pollution control central concerns for every local government. Fires on landfills and open spaces cause severe air contamination, and depending on wind direction and fire size, they can significantly affect air quality even at distances of several tens of kilometers from the source. A particular issue arises from fires on unsanitary landfills, often located near residential areas, where large amounts of improperly disposed waste accumulate without protective and control systems. These fires frequently result from incomplete combustion of waste, due to a lack of compaction and inadequate daily cover, which allows for surface oxygenation and conditions for anaerobic methanogenesis in deeper layers. Methane, a flammable and explosive greenhouse gas, contributes to ozone layer damage 21 times more than carbon dioxide. Installing gas wells (biotubes) on unsanitary landfills is crucial for preventing fires, reducing the risk of methane pocket formation, and enabling landfill monitoring. This paper presents conclusions from the remediation and fire extinguishing project at the unsanitary landfill Mislov do in Nikšić, with a capacity of 450,000 m³, where measures are being implemented to achieve measurable and sustainable results aimed at improving the existing conditions and enhancing environmental protection.

Pavlov-Kagadejev Marijana, Radivojević Milan, Stolić Predrag

This paper describes an example of applying the machine learning to predict the SO2 blower vibrations. The SVR (Support Vector Regression) algorithm was used to form the model. The paper includes an overview of machine learning and mathematical fundamentals of the SVM model. Based on a large amount of data, obtained from the monitoring system, a mathematical model was constructed. After testing, the measures of model accuracy such as the MSE (Mean Squared Error) and R2 were provided.

Vujić Jovan, Ilić Božo, Đenić Nebojša

The aim of this paper is to present the principle of testing electrical insulation mats and the results of the tests as well as observed irregularities in their operation in transformer stations 35/10 kV (TS 35/10) in Serbia. In accordance with the progress of technology, more and more automation and computers are being introduced in the management of the operation of TS, and the basic concepts of protection against contact voltage and step voltage of the staff who work and stay in these facilities are neglected. The fact is that these TS are facilities where people are not constantly present, but they still spend a certain amount of time in them and are exposed to various dangers. Electrical insulation mats were tested in several TS and the results were devastating. In addition to non-compliance with work procedures, these facilities often leak, various rodents are present, and unsanitary conditions are at an enviable level. The main problem is that the electrical insulating mats are not adequate for their purpose, they are not properly installed, the lack of proper inspection supervision, as well as the shortcomings in the legal regulations that define this area

Niobium Columbium

Domestic Production and Use: Significant U.S. niobium mine production has not been reported since 1959. Domestic niobium resources are of low grade, some are mineralogically complex, and most are not commercially recoverable. Forty-three companies in the United States produced niobium-containing materials from imported niobium minerals, oxides, and ferroniobium. Niobium was consumed mostly in the form of ferroniobium by the steel industry and as niobium alloys and metal by the aerospace industry. Major end-use distribution of reported niobium consumption was as follows: steels, 79%; and superalloys, 21%. In 2014, the estimated value of niobium consumption was $500 million, as measured by the value of imports.

N. Timothy, E. T. Williams

Environmental pollution by heavy metals has become a global issue in the recent years as it affects public health. Especially with the continue increase in anthropogenic activities such as industries and urbanization which releases pollutants in to the environment without control and effects remedies. Among the numerous environmental pollutants, heavy metals plays an important role as its concentrations in air, soil and water are continuously increasing due to anthropogenic activities. Heavy metal is any metal that is toxic regardless of their density or atomic mass. Heavy metals occur naturally in the soil environment from the pedogenetic processes of weathering of parent materials and from anthropogenic sources such as traffic emission, industrial and energy production, waste disposal, vehicle exhaust as well as coal and fuel combustion. Excess of metal pollutants deposited on soils may be transformed and transported to vegetation and from plants they pass on to animals and human being through the food chain. Excessive levels of heavy metal can be damaging to the organism and plants by disrupt metabolic functions of vital organs and glands. Also they displace the vital nutritional minerals from their original place, thereby, hindering their biological function. Therefore it is important to continually assess and monitor the levels of heavy metals in an environment due to increase in anthropogenic activities for evaluation of human exposure and for sustainable environment The aim of this paper is to discuss illustratively environmental (air, soil and water) pollution by heavy metals. Sources of heavy metals in an environment as well as their effects on organisms and plants were examined. Different methods of assessing their level of pollution were also considered and remedies were presented.

Miao Wang, Chao Feng

As an energy-intensive industry, the mining, smelting, processing and production of metallic mineral resources consumes a large amount of fossil energy and simultaneously emits high amounts of carbon dioxide. This paper discusses the decoupling relationship between the economy and CO2 emissions of China's metal industry (MI) and then adopts an integrated decomposition approach (which reveals the roles of technology and efficiency) to investigate the drivers of CO2 emissions. The main findings indicate that, during 2000-2016: (1) China's MI experienced four decoupling stages (i.e., weak decoupling, expansive negative decoupling, expansive coupling, and strong decoupling) and was characterized by weak decoupling. Overall, China's MI showed a clear tendency toward strong decoupling. (2) Potential energy intensity change, investment efficiency decline, and production technological progress were three pivotal factors contributing to emission abatement. Industrial structure regulation and energy-saving technology advancement also made a small contribution to emission abatement and the decoupling state. (3) Investment scale expansion was the primary factor promoting emission growth and impeding the progress of decoupling. Meanwhile, the energy structure adjustment during the sampling period failed to inhibit emissions but restricted decoupling. Finally, possible policies for mitigating carbon emissions in China's MI are provided.

Jian-Guo Li, Kai Zhan

Abstract This article analyzes the current research status and development trend of intelligent technologies for underground metal mines in China, where such technologies are under development for use to develop mineral resources in a safe, efficient, and environmentally friendly manner. We analyze and summarize the research status of underground metal mining technology at home and abroad, including some specific examples of equipment, technology, and applications. We introduce the latest equipment and technologies with independent intellectual property rights for unmanned mining, including intelligent and unmanned control technologies for rock-drilling jumbos, down-the-hole (DTH) drills, underground scrapers, underground mining trucks, and underground charging vehicles. Three basic platforms are used for intelligent and unmanned mining: the positioning and navigation platform, information-acquisition and communication platform, and scheduling and control platform. Unmanned equipment was tested in the Fankou Lead-Zinc Mine in China, and industrial tests on the basic platforms of intelligent and unmanned mining were carried out in the mine. The experiment focused on the intelligent scraper, which can achieve autonomous intelligent driving by relying on a wireless communication system, location and navigation system, and data-acquisition system. These industrial experiments indicate that the technology is feasible. The results show that unmanned mining can promote mining technology in China to an intelligent level and can enhance the core competitive ability of China’s mining industry.

M. Bazilian