Hasil untuk "Mineral industries. Metal trade"

D. Kossoff, W. Dubbin, M. Alfredsson et al.

On a global scale demand for the products of the extractive industries is ever increasing. Extraction of the targeted resource results in the concurrent production of a significant volume of waste material, including tailings, which are mixtures of crushed rock and processing fluids from mills, washeries or concentrators that remain after the extraction of economic metals, minerals, mineral fuels or coal. The volume of tailings is normally far in excess of the liberated resource, and the tailings often contain potentially hazardous contaminants. A priority for a reasonable and responsible mining organization must be to proactively isolate the tailings so as to forestall them from entering groundwaters, rivers, lakes and the wind. There is ample evidence that, should such tailings enter these environments they may contaminate food chains and drinking water. Furthermore, the tailings undergo physical and chemical change after they have been deposited. The chemical changes are most often a function of exposure to atmospheric oxidation and tends to make previously, perhaps safely held contaminants mobile and available. If the tailings are stored under water, contact with the atmosphere is substantially reduced, thereby forestalling oxygen-mediated chemical change. It is therefore accepted practice for tailings to be stored in isolated impoundments under water and behind dams. However, these dams frequently fail, releasing enormous quantities of tailings into river catchments. These accidents pose a serious threat to animal and human health and are of concern for extractive industries and the wider community. It is therefore of importance to understand the nature of the material held within these dams, what best safety practice is for these structures and, should the worst happen, what adverse effects such accidents might have on the wider environment and how these might be mitigated. This paper reviews these factors, covering the characteristics, types and magnitudes, environmental impacts, and remediation of mine tailings dam failures.

Sizhong Sun

This paper studies firms' optimal response to a trade liberalization shock in terms of export and product innovation both theoretically and empirically. We find that trade liberalization, namely China's WTO accession, reduces trade cost and promotes export, which in turn incentivizes firms to innovate as the marginal benefit of innovation for exporting firms is higher than that for non-exporting firms. In addition, as a firm starts to innovate, it predicts to have a higher probability of moving to a better productivity state and can save the entry cost of innovation in the future, resulting in additional dynamic benefits. Such an innovation-promotion effect is an unintended consequence of trade liberalization.

Xin Yu, Mingdong Jiang, Jia-nan Li et al.

L. Fojtíková, Kateřina Pekarčíková, R. Sousedíková et al.

Hanqin Chen, Ye Lu, Huaqin Huang

Trade policy uncertainty has become a significant feature of today's global economy. While its impact on free trade is evident, its microeconomic effects remain open to debate. This study explores the influence of trade policy uncertainty on corporate ESG performance and its underlying mechanisms, using data from A-share listed companies in China from 2010 to 2020. The findings reveal that increased trade policy uncertainty significantly and robustly enhances corporate ESG performance. Heterogeneity analysis indicates that high-tech enterprises are better equipped to improve their ESG performance in response to trade policy uncertainty. Furthermore, strengthening internal controls and appointing CEOs with environmental backgrounds also help firms seize the opportunities arising from trade policy uncertainty. In terms of mechanisms, trade policy uncertainty intensifies industry competition, compelling firms to enhance their ESG performance to gain market share. Additionally, it stimulates green technological innovation, further optimizing ESG outcomes. Therefore, efforts should focus on improving the ESG standards system, establishing ESG incentive policies, increasing the transparency and predictability of trade policies, and promoting corporate green development to advance national sustainable development goals.

John S. McAlister, Jesse L. Brunner, Danielle J. Galvin et al.

Global trade of material goods involves the potential to create pathways for the spread of infectious pathogens. One trade sector in which this synergy is clearly critical is that of wildlife trade networks. This highly complex system involves important and understudied bidirectional coupling between the economic decision making of the stakeholders and the contagion dynamics on the emergent trade network. While each of these components are independently well studied, there is a meaningful gap in understanding the feedback dynamics that can arise between them. In the present study, we describe a general game theoretic model for trade networks of goods susceptible to contagion. The primary result relies on the acyclic nature of the trade network and shows that, through the course of trading with stochastic infections, the probability of infection converges to a directly computable fixed point. This allows us to compute best responses and thus identify equilibria in the game. We present ways to use this model to describe and evaluate trade networks in terms of global and individual risk of infection under a wide variety of structural or individual modifications to the trade network. In capturing the bidirectional coupling of the system, we provide critical insight into the global and individual drivers and consequences for risks of infection inherent in and arising from the global wildlife trade, and any economic trade network with associated contagion risks.

Alviarez Vanessa, Fioretti Michele, Kikkawa Ken et al.

This paper derives a closed-form expression linking aggregate markups on imported inputs to concentration in a model of firm-to-firm trade with two-sided market power. Our theory extends standard oligopoly insights in two dimensions. First, it reveals that markups increase with exporter concentration and decrease with importer concentration, reflecting the balance of oligopoly and oligopsony forces. Second, it adapts conventional market definitions to reflect rigid trading relationships, yielding new concentration measures that capture competition in firm-to-firm trade. Analysis of Colombian transaction-level import data shows these differences are key to understanding markup dynamics in international trade.

N. S. Gonchar, O. P. Dovzhyk, A. S. Zhokhin et al.

The paper analyses trade between the most developed economies of the world. The analysis is based on the previously proposed model of international trade. This model of international trade is based on the theory of general economic equilibrium. The demand for goods in this model is built on the import of goods by each of the countries participating in the trade. The structure of supply of goods in this model is determined by the structure of exports of each country. It is proved that in such a model, given a certain structure of supply and demand, there exists a so-called ideal equilibrium state in which the trade balance of each country is zero. Under certain conditions on the structure of supply and demand, there is an equilibrium state in which each country have a strictly positive trade balance. Among the equilibrium states under a certain structure of supply and demand, there are some that differ from the ones described above. Such states are characterized by the fact that there is an inequitable distribution of income between the participants in the trade. Such states are called degenerate. In this paper, based on the previously proposed model of international trade, an analysis of the dynamics of international trade of 8 of the world's most developed economies is made. It is shown that trade between these countries was not in a state of economic equilibrium. The found relative equilibrium price vector turned out to be very degenerate, which indicates the unequal exchange of goods on the market of the 8 studied countries. An analysis of the dynamics of supply to the market of the world's most developed economies showed an increase in China's share. The same applies to the share of demand.

Alexandre Antezak, Takemi Kato, Pedro Rezende Gonçalves et al.

Covellite (CuS) is the first known natural mineral superconductor. Despite its simple chemical formula, covellite exhibits a rich crystal structure at the origin of several remarkable properties. The ionic arrangement in CuS crystals leads to a mixed valence of Cu and a second-order structural transition at 55 K. Despite the abundance of structural studies and theoretical reports on its electronic structure, there are scarce references on its experimental band structure. By means of Angle Resolved PhotoEmission Spectroscopy (ARPES), we have probed the experimental electronic structure of covellite. We compare our results with the predictions of density-functional theory (DFT) calculations. Our experimental data are in remarkable agreement with the calculations, revealing subtle fingerprints of the structural phase transition, and confirming the quasi-2D nature of the electronic structure of CuS.

P. Narang

Recent developments in clean energy supply chain amidst the geopolitical crisis have resulted in the friend shoring and nearshoring measures in the clean energy supply chain. Clean energy supply chain is susceptible to Environment, Social and Governance (ESG) risks, particularly resistance from the local communities against the critical minerals mining/exploration projects, due to policy gaps in the legislative framework regarding the community engagement standard and procedures. In context of friend shoring and nearshoring measures, this gap may get widened in the States with critical mineral resources. The article will track the development of the ESG standards pertaining to community engagement at the multilateral forums and the multilateral stakeholder initiative forums. Moreover, the article will analyse the gaps in ESG performance of the mining sector, particularly parameters of the community engagement. Further, the article will identify issues with the current initiatives under trade and economic cooperation agreements and bilateral investment treaties toward ensuring the community consent standards by extractive industry, specifically the mining of critical minerals for clean energy development. The article will conclude that fragmentation of the community consent standard has resulted in widening of ESG risks for investors and host states in the critical mineral sector. Accordingly, the article recommends that host states frame legislative framework for this sector by balancing interest of local communities with sound business environment for the investors. Friendshoring, Nearshoring, Electric Vehicle, Environment, Social and Governance, Trade Agreements, Free Prior and Informed Consent, Community Consent Standard, Investor State Dispute Settlement.

Max Schulze, Yorck Zisgen, Moritz Kirschte et al.

Protecting personal data about individuals, such as event traces in process mining, is an inherently difficult task since an event trace leaks information about the path in a process model that an individual has triggered. Yet, prior anonymization methods of event traces like k-anonymity or event log sanitization struggled to protect against such leakage, in particular against adversaries with sufficient background knowledge. In this work, we provide a method that tackles the challenge of summarizing sensitive event traces by learning the underlying process tree in a privacy-preserving manner. We prove via the so-called Differential Privacy (DP) property that from the resulting summaries no useful inference can be drawn about any personal data in an event trace. On the technical side, we introduce a differentially private approximation (DPIM) of the Inductive Miner. Experimentally, we compare our DPIM with the Inductive Miner on 14 real-world event traces by evaluating well-known metrics: fitness, precision, simplicity, and generalization. The experiments show that our DPIM not only protects personal data but also generates faithful process trees that exhibit little utility loss above the Inductive Miner.

Zauresh Atakhanova, Seribolat Azhibay

Kazakhstan is a leading producer of uranium and chromium and has significant reserves of critical raw materials. We assess economic sustainability of Kazakhstan’s mining, focusing on its labor productivity, a key factor in counteracting the effects of resource depletion and increasing costs. We find that during 2000–2021, labor productivity continued improving in mining of non-ferrous metals and industrial minerals. Our firm-level analysis demonstrates that domestic non-ferrous mining firms were able to achieve productivity level comparable to that of modern mining industries. They reduced energy intensity, increased efficiency of processing plants, and accessed higher-quality reserves. In addition, managerial innovations, engaging with the workforce, and introduction of advanced technologies were prominent in analyzed firms. However, following a period of rapid growth during the early 2000s, productivity stagnated in Kazakhstan’s coal mining while it decreased in iron ore mining. We relate such performance to iron ore depletion from underinvestment in exploration. In coal mining, stagnating productivity reflects this sector’s protected status and substantial fossil fuel subsidies.

Hikaru Hyuga, Yuichiro Cho, Yayoi N. Miura et al.

Dating rocks with a precision of $\pm$200 Myr (2$σ$) has been required to understand the Martian habitability and volcanic history around 4000 Myr ago. In situ potassium-argon (K-Ar) dating techniques employing spot-by-spot laser ablation have been developed for isochron dating on Mars. The precision of isochron ages is predominantly determined by the relationship between the laser spot diameter and the mineral grain size. However, the achievable age precisions for the realistic mineralogy of Martian rocks were not investigated yet. This study simulates isochrons under various conditions, including laser spot size, measurement errors for K and Ar, the number of isochron points, and the mineral compositions of representative Martian meteorites (NWA 817, Zagami, and NWA 1068) analyzed with an electron microprobe. We find that attaining the 200 Myr precision necessitates an isochron data range wider than 6, a laser spot diameter of 250 $μ$m, and measurement errors of 10% for both K and Ar. Furthermore, minimizing the variance in measurement errors between K and Ar is essential for increasing age accuracy. This investigation demonstrates that the required precision for Mars missions is achievable with realistic instrument settings, thus supporting the viability of in situ K-Ar geochronology on Mars.

Ke Wu, Elaine Shi, Hao Chung

Transaction fee mechanism design is a new decentralized mechanism design problem where users bid for space on the blockchain. Several recent works showed that the transaction fee mechanism design fundamentally departs from classical mechanism design. They then systematically explored the mathematical landscape of this new decentralized mechanism design problem in two settings: in the plain setting where no cryptography is employed, and in a cryptography-assisted setting where the rules of the mechanism are enforced by a multi-party computation protocol. Unfortunately, in both settings, prior works showed that if we want the mechanism to incentivize honest behavior for both users as well as miners (possibly colluding with users), then the miner revenue has to be zero. Although adopting a relaxed, approximate notion of incentive compatibility gets around this zero miner-revenue limitation, the scaling of the miner revenue is nonetheless poor. In this paper, we show that if we make a mildly stronger reasonable-world assumption than prior works, we can circumvent the known limitations on miner revenue, and design auctions that generate optimal miner revenue. We also systematically explore the mathematical landscape of transaction fee mechanism design under the new reasonable-world and demonstrate how such assumptions can alter the feasibility and infeasibility landscape.

Fei Wang, D. Dreisinger

Action is currently being taken globally to mitigate global warming.The objective of reducing CO2 emissions is not a burden for society but is a significant opportunity for evolution in various industries for the sustainable production of energy and the essential minerals, metals, and materials required for modern society. CO2 mineralization is one of the most promising methods to effectively reduce CO2 emissions via the formation of stable mineral carbonates. Accelerated mineral carbonation requires high capital costs for implementation. Accordingly, it has thus far not been economically feasible to carry out accelerated CO2 mineralization alone. Accelerated CO2 mineralization must be combined with other associated technologies to produce high-value products. The technical developments in enhanced metal recovery, nanomaterials, enhanced flotation, H2 production and applications in the cement industry may be suitable options. The utilization and generation of valuable byproducts may determine the economic feasibility of CO2 mineralization processes. The need for CO2 reduction and utilization can contribute to driving the development of many innovative and sustainable technologies for the future benefit of society. The implementation of carbon taxation may also significantly motivate the development of these technologies and their potential application.

D. Franks

Abstract The global discourse on mining and development suffers from a fundamental distortion. Mining, is almost ubiquitously framed as the international trade of metals, energy minerals and precious gemstones, neglecting the industrial minerals and construction materials that are most important for local and domestic development and that dominate global mineral production. In this paper I argue for a rethink in the role of minerals in global development and ask whether the development community has been overlooking key commodities, issues, actors and development pathways. The paper also serves as an introduction to a special issue on Development Minerals, i.e. minerals and materials that are mined, processed, manufactured and used domestically in industries such as construction, manufacturing, infrastructure and agriculture. The special issue interrogates the relationship between minerals, development, livelihoods and poverty reduction with papers covering issues of industrialization, urbanization and agriculture and the role of minerals in the structural transformation of developing countries. The paper ends with a call to action for greater prioritization of Development Minerals and the circumstances of their production as a topic of policy making and development programming.

Omar Nuruzade, Elshan Abdullayev, Valentina Erastova

Interactions between organic species and natural minerals are fundamental to the processes around us. With the aid of molecular dynamics simulations, we identify key adsorption mechanisms of apigenin on smectite clay minerals. The mechanism is highly sensitive to the pH -- changing from co-crystallisation in acidic-to-neutral solutions to the ion-bridging in mild-alkaline. The ionic species play a significant role in alkaline environments: the deprotonated apigenin species chelate metals, which, in turn, leads to the formation of a stable organic-metal-mineral complex and stronger adsorption in the presence of divalent cations.Smectite clays buffer the solution to mildly alkaline; hence, the type of exchangeable cations in the clay will be critical in determining the adsorption mechanism and organic retention capacity. Overall, our study showcases a computational strategy that can be transferred to a wide variety of organic-mineral systems in the natural environment.

Wonguk Cho, Daekyung Lee, Beom Jun Kim

The international trade network is a complex system where multiple trade blocs with varying sizes coexist and overlap with each other. However, the resulting structures of community detection in trade networks are often inconsistent and fails to capture the complex landscape of international trade. To address these problems, we propose a multiresolution framework that aggregates all the configuration information from a range of resolutions. This allows us to consider trade communities of different sizes and illuminate the underlying hierarchical structure of trade networks and its constituting blocks. Furthermore, by measuring membership inconsistency (MeI) of each country and conducting multiple regression analysis with various economic and political indicators, we demonstrate that there exists a positive correlation between the external instability of countries and their structural inconsistency in terms of network topology.

M. Faramarzi, Mehdi Mogharabi-Manzari, H. Brandl

Abstract Microbial leaching via biocyanidation process enables efficient extraction of precious metals from low-grade ores and increases attention in mineral industries for applying green and environmentally friendly leaching methods. Microbial cyanidation can be applied in cyanidation process mobilizing precious metals from ores and scraps. Biological solubilization processes also recover metals from secondary raw materials such as e-wastes, car catalysts, coins, etc. In comparison with conventional technologies, biomobilization is associated with advantages including simple operation, reduced cost, and less environmental risks. This review was performed to describe a perspective on metal biocyanidation by applying cyanogenic microorganisms. Factors influencing yield of biocyanidation and electrochemical approaches of metal recovery were discussed. This study also addresses future advances of industrial applications of microbial mobilization of some metals as soluble cyanide complex from secondary resources.

Dennis Brons, Roeland Scheepens, Dirk Fahland

Numerous process discovery techniques exist for generating process models that describe recorded executions of business processes. The models are meant to generalize executions into human-understandable modeling patterns, notably parallelism, and enable rigorous analysis of process deviations. However, well-defined models with parallelism returned by existing techniques are often too complex or generalize the recorded behavior too strongly to be trusted in a practical business context. We bridge this gap by introducing the Probabilistic Inductive Miner (PIM) based on the Inductive Miner framework. PIM compares in each step the most probable operators and structures based on frequency information in the data, which results in block-structured models with significantly higher accuracy. All design choices in PIM are based on business context requirements obtained through a user study with industrial process mining experts. PIM is evaluated quantitatively and in an novel kind of empirical study comparing users' trust in discovered model structures. The evaluations show that PIM strikes a unique trade-off between model accuracy and model complexity, that is conclusively preferred by users over all state-of-the-art process discovery methods.