Abstract The rapid growth in nuclear industries such as uranium ores mining, nuclear energy generation, spent-fuel treatment and nuclear weapon manufacture has caused a legacy of uranium contamination in the aquatic environment, which poses a potential threat to the ecological environment and human health. The safe and effective disposal of uranium-contaminated water has thus been an urgent requirement. For decades, various materials have been shown to be capable for removing uranium from aqueous solution by adsorption technique, namely inorganic materials (e.g., clay minerals, metal oxides, mesoporous silica), organic polymers (e.g., resins, cellulose, chitosan), carbon family materials (e.g., mesoporous carbon, carbon nanotubes, graphene oxides), and porous framework materials (e.g., covalent organic frameworks, metal-organic frameworks). In this review, we provide a systematic and comprehensive overview of the researches conducted from 2005 to 2018 for uranium removal from aqueous solution by these emerging materials. The different approaches in the determination of the adsorption mechanisms between uranium and adsorbents are also briefly summarized, involving macroscopic experimental approaches, microscopic spectroscopic and computational approaches. Finally, we discuss the current limitations and propose future research perspectives in hopes of inspiring more dramatic advancements in the material and environment remediation fields.
The presence of heavy metals in food is a threat to human health. Exposure to heavy metals as a result of consumption of contaminated vegetables, as well as their toxicity, is a serious problem. Different branches of industry and the road traffic have a significant impact on environmental pollution with heavy metals. Municipal and industrial sewage also is an important source of those substances. Furthermore, the mineral content of vegetables depends on factors such as the natural content of trace elements in the environment, their levels in mineral fertilizers, and fertilizer doses. In the soil, a natural source of these metals is bedrock. In soils used for agricultural purposes, some quantities of metals are introduced together with fertilizers, both organic and mineral. Additionally, another sources of the metals are plant protection products. Heavy metal dynamics in the soil and their uptake by plants are influenced by soil properties, which play a key role in the bioavailability of these metals. Metal mobility and assimilation are also influenced by the addition of organic and inorganic matter. A significant body of evidence also suggest that the age of the soil plays an important role in modulation of metal bioavailability to plants. Apart from being influenced by the soil-related factors, absorption of metals differs in different types of plants. A significant variation in metal concentrations was also found depending on their location in plant tissues, on plant species, or even on varieties of the same species.
Kemalcan Aydogdu, Sebnem Duzgun, E. Yaylaci
et al.
Due to climate change risks, the public, regulators, and investors require solid actions to minimize the greenhouse gas (GHG) emissions of mineral extraction and metals production. The mining sector considers alternatives to reduce its carbon footprint by transforming the business and adopting new technologies into operations. Given the capital intensity, technical characteristics, and business structure involved, a shift in the mining industry necessitates impartial insights into the trade-offs and risks. Considering the low-carbon transition trade-offs and risks in mining, this study presents the application of system dynamics modeling (SDM) in mining projects to analyze the impact of decarbonization alternatives with respect to carbon footprint and costs. A system dynamics model of an open-pit copper mine is developed to quantify greenhouse gas (GHG) emissions, as well as capital and operational costs, during the project life cycle. The change in GHG emissions in the business-as-usual scenario with diesel equipment haulage versus the alternative scenario with electric overland conveyor haulage is compared concerning GHG emissions and associated costs. The results unequivocally demonstrated that electrifying material mobility offers significant decarbonization in open-pit mining if the on-site electricity has a low emission factor. The findings also indicate that the substantial cost difference between electrification and diesel alternatives is another major obstacle to implementing electrification in an open-pit copper mine. This research proves that implementing SDM in the mining industry can offer impartial insights into decision-making and enable a thorough evaluation of options using quantitative criteria. It effectively assesses and communicates the trade-offs and risks of transitioning to low-carbon alternatives because it analyzes project variables quantitatively and holistically and is easy to run.
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.
Japan has responded to the supply stability of mineral resources since the early 1970s. Since mineral resources are an important input factor for maintaining and strengthening the international competitiveness of the manufacturing industry in Japan, to secure a stable supply of mineral resources has become a major national task in Japan. With Japan declaring the realization of carbon neutrality in 2020, the importance of securing the base metals and rare metals has grown. The Japanese government is preparing for the competition to secure mineral resources, which will intensify in the future, by expanding and moving the international strategic focus areas in resource supply toward rare metals. Similar to the other developed countries, Korea has declared to move toward carbon neutrality by 2050. This means that, like the other major countries, rare metals are needed. In the area of rare metals, while looking at the market movements, the behaviors of major countries, and the decision of Japan, it is necessary for one to respond in a form that is suitable for Korea.
Vern Putz Anderson, P. Schulte, J. Novakovich
et al.
BACKGROUND We analyzed the Bureau of Labor Statistics (BLS) fatal and nonfatal injuries and illness data on U.S. workers in the wholesale and retail trade (WRT) sector from 2006 to 2016. The purpose was to identify elevated fatal and nonfatal injury and illness rates in WRT subsectors. METHODS To assess the WRT health and economic burden, we retrieved multiple BLS data sets for fatal and nonfatal injury and illness data, affecting more than 20 million employees. We examined yearly changes in incidence rates for lost work-time across event and exposure categories. RESULTS In 2016, 553 100 injuries and illnesses and 461 fatalities occurred among WRT workers. WRT has a disproportionately 5% larger burden of nonfatal injuries for its size. From 2006 through 2016, wholesale sector fatality rates (4.9/100 000 FTE) exceeded private industry rates (3.8/100 000 FTE). The largest causal fatal factors were transportation in wholesale and violence in retail. Private industry and WRT experienced a decline in nonfatal injuries and illnesses. Wholesale subsectors with elevated nonfatal rates included durable and nondurable goods, recycling, motor parts, lumber, metal and mineral, grocery, and alcohol merchants. Retail subsectors with elevated rates included motor parts dealers, gasoline stations, nonstores, tire dealers, home and garden centers, supermarkets, meat markets, warehouse clubs, pet stores, and fuel dealers. DISCUSSION Through the identification of safety and health risks, researchers and safety practitioners will be able to develop interventions and focus future efforts in advancing the safety and health of WRT employees.
This purely descriptive note discusses various aspects of world trade in minerals. It is not aimed at specialist mineral economists who may extract any detailed trade figures they require from the United Nations’ Comtrade database. Rather it is directed to all those who might use readily available aggregate data on minerals trade for broad analyses of the minerals industry. It starts from the most commonly quoted estimates of minerals trade before looking at some of the issues surrounding those measures and highlighting some of the pitfalls involved. It then examines both the product composition and geographical origins of minerals trade and how it has developed over the past half century. The concluding sections turn to a discussion of the merits and demerits of various measures of mineral dependence.
High manganese austenitic steel, popularly called “Hadfield steel” has dominated and played significant role in wear applications, especially in the mines and minerals industries since its invention over a century ago. A review on the researches on this steel revealed that its prominence in these fields is mainly due to its good combination of impact and abrasion wear resistance arising from its high toughness and high hardness respectively. Its strain hardening ability under impact loading is evidenced by increase in hardness as the material work hardens; this lowers the amount of wear in service. The work hardening property of the steel has been linked to governing mechanisms such as dislocation, deformation twinning, and dynamic strain ageing; also, it is enhanced by increase in carbon, ageing temperature and reduction in manganese content. Carbide precipitation along the grain boundaries and within the grains is the major cause of embrittlement of the steel. These carbides together with voids and porosities during casting solidification, improper heat treatment, overheating during welding, use of unsorted scrap metal and wrong wear application have been identified as the causes of premature failure in service. Hardfacing method has been proposed as a means of substituting the steel in wear applications, as alternative wear materials such as white cast iron and austempered ductile iron lack the combination of impact and abrasion resistance being offered by the Hadfield steel.