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Copyright of Precious Metals / Guijinshu is the property of Precious Metals Editorial Office 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 increasing demand for platinum group metals (PGMs) across various industries indicates the importance of recovering these noble metals from secondary resources. Typically, after pretreatment, PGMs are dissolved using hydrochloric acid solutions containing strong oxidant by virtue of the chemical stability of their anionic chloro-complexes. Several separation techniques, including cementation, precipitation, ion exchange, and solvent extraction, are employed to separate PGMs from leaching solutions. Each method has distinct advantages and limitations concerning efficiency and product purity. Cementation proves effective for concentrating PGMs in solutions containing base metal ions. However, ion exchange and solvent extraction are more commonly used for the separation of PGMs present in hydrochloric acid leaching solutions. Especially, solvent extraction processes employing commercial extractants, ionic liquids, and deep eutectic solvents have been extensively investigated. While deep eutectic solvents show promising as ‘green’ extractants, further research is required to overcome their limitations for industrial applications. A combined process integrating leaching, solvent extraction, and precipitation could offer an efficient solution for recovering high-purity PGMs from the solution containing diverse metal ions. [ABSTRACT FROM AUTHOR]

Vanadium is a critical metal that has been widely used in a broad variety of applications with almost no metal substitutes. However, the limited availability of its (vanadium) primary resources has raised concerns of supply security. In view of the criticality, recycling vanadium from secondary resources has been identified as a vital supply alternative. This article thus presents a comprehensive overview of metallurgical processes used in the recycling of vanadium from a variety of secondary resources, including spent HDS catalyst, spent SCR catalyst, fly ash, red mud, Bayer's sludge, alloy scrap, tailings, etc. First, the physicochemical characteristics of these secondary resources are emphasized. Understanding the characteristics of vanadium-bearing secondary resources is important as it determines the recycling route. The metallurgical recycling processes of vanadium, which include aqueous- and thermal processes are discussed in depth, along with the theoretical backgrounds and fundamentals of each process. Also discussed are the industrial-scale processes and trend in research and development (R&D) for the respective secondary resources. Besides highlighting the status of recycling processes, the article also provides prospective directions for such resources. [ABSTRACT FROM AUTHOR]

In the conditions of natural resources depletion, and Climate changes caused by the greenhouse effect, world community is focused on exploring new raw materials, secondary raw materials, including waste that can be usefully used. Fat-containing waste generated in the food, pulp and paper, leather and other industries, catering facilities have significant potential in this field. Analysis of official statistics on the fat-containing waste management in the Russian Federation shows that about 22% of such waste is disposed in landfills and is irretrievably lost as raw materials. And those fat-containing wastes that are utilized are used in the production of low-profit products. At the same time, fatcontaining waste can be used to receive products that fully replace analogs produced from petrochemical and chemical raw materials. In the total mass of fat-containing waste, a significant part is made up of products with a high content of free fatty acids, which serve as raw materials for receiving a wide range of useful products. Therefore, research in this way is relevant and promising. In this study, ethyl and butyl ethers were received from waste from the food and pulp and paper industries and studied. Then ethyl and butyl ethers received from waste were tested as plasticizers for compatibility with polyvinyl chloride. A toxicity assessment was carried out for the initial waste, ethyl and butyl ethers thereof, and plasticizers with polyvinyl chloride. Based on the analysis of results, recommendations were formulated for the practical application of the method for the utilization of such waste. The novelty of the research is demonstrating the possibility of using esters received from fatcontaining waste to replace petrochemical synthesis products such as plasticizers for polymers. [ABSTRACT FROM AUTHOR]

Copyright of Precious Metals / Guijinshu is the property of Precious Metals Editorial Office 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 Precious Metals / Guijinshu is the property of Precious Metals Editorial Office 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.)

Solid particles as heat absorptances and storage mediums promise enhanced energy storage densities in concentrated solar power/thermal (CSP/T) plants. Employment of metallurgical slags as a secondary precursor material for solid particle preparation is ecologically and economically beneficial. Although these processed wastes, comprised of several oxides, exhibit generally promising high-temperature properties, chemical scattering from batch to batch may result in distinct material and functional properties, which may be an obstacle for their utilization. In this study, a steelmaking slag, LiDonit (LD), produced using a unique controlled slag treatment with high reproducibility is investigated as a candidate material. The aforementioned subsequent unique slag treatment makes LD a very promising and distinguishable secondary raw material for high-temperature applications. The as-received microstructure, phase components, and chemical composition of the LD material were analyzed to understand its material properties and to assess its reproducibility. The as-received LD chunks were transferred into pellets by subsequent milling, gel-casting, and sintering stages to reveal the potential processing routes. The CSP/T-related properties of sintered pellets, such as high temperature stability, heat capacity, and solar absorptance, were also examined to reveal their potential use in CSP/T applications and expand application areas with high added value. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office 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 number of metal-containing waste streams resulting from electronic end-of life products, metallurgical by-products, and mine tailings to name but a few, is increasing worldwide. In recent decades, the potential to exploit these waste streams as valuable secondary resources to meet the high demand of critical and economically important raw materials has become more prominent. In this review, fundamental principles of bio-based metal recovery technologies are discussed focusing on microbial metabolism-dependent and metabolism-independent mechanisms as sustainable alternatives to conventional chemical metal recovery methods. In contrast to previous reviews which have partially addressed this topic, a special focus will be given on how fundamental principles of bio-based recovery technologies can influence the selectivity and specificity of metal recovery. While conventional methods for metal recovery show benefits in terms of economic affordability, bio-based recovery technologies offer advantages in terms of efficiency and environmentally friendliness. Modifications and adaptations in the processes of biosorption, bioaccumulation and bioelectrochemical systems are highlighted, further emphasizing the application of metal-binding peptides and siderophores to increase selectivity in the recovery of metals. Single metal solutions or mixtures with a low complexity have been the focus of previous studies and reviews, but this does not reflect the nature of complex industrial effluents. Therefore, key challenges that arise when dealing with complex polymetallic solutions are addressed and the focus is set on optimizing bio-based technologies to recover metals efficiently and selectively from bio-leachates or liquid waste streams.

Anthropogenic geology (AG) is the study of geological materials and morphologies created, reshaped, or otherwise modified by humans and human activity. Geologists and geological surveys need to include anthropogenically created geology into their science discipline to sustainably resource classify human-made deposits driven by socioeconomic models rather than natural forces. Concepts coupled to anthropogenic geology like circular economy, geosystem services, secondary resources, etc., are important features for the implementation of AG into sustainable economics and resource handling. Thus, it is important for geological surveys and other public agents to gain deep knowledge into these concepts and how the public agents can support sustainable use of anthropogenic geological features.

With the development and utilization of phosphorus resources, phosphorus tailings continue to pile up, which has become a serious problem that cannot be ignored, so the resource utilization of phosphorus tailings has extremely significant research significance. This study takes "phosphorus tailings" and "phosphate tailings" as keywords, 989 related research articles were selected from the Web of Science (WOS) database, and the research results were summarized. The research progress and research hotspots of phosphorus tailings resource utilization in the past 23 years were investigated. Citespace and VOSviewer were used to analyze the published literature in this research field. The results show that the research trend exhibits slow growth-fluctuating growth-rapid growth. The research organizations in this field present the form of independent research groups, among which there are more Chinese research teams. This paper systematically introduces the research hotspot of phosphorus tailings resource utilization, including the collaborative extraction of valuable elements from various solid wastes, and the collaborative preparation of functional materials from various solid wastes under the green closed cycle without by-product system. The future research focus is also put forward. [ABSTRACT FROM AUTHOR]

Statistical data on the level of use of ash and slag from thermal power plants is provided. The results of an analysis of regulatory and technical documentation in the field of ash and slag management in the energy sector are presented. Laws, regulations, and other documents regulating the management of by-products of coal combustion are considered. It was noted that it is necessary to refine the existing documentation, introduce legally defined terms and definitions for a number of ash and slag processing products, and also legally consider ash and slag as mineral raw materials and not waste. Definitions of ash and slag are given in accordance with the current industry regulatory document, in which ash and slag are тще called waste but mineral residues of solid fuel. It is shown that various government agencies are preparing regulatory documents related to the involvement of ash and slag into economic circulation. However, the existing regulatory framework does not meet the goals of achieving the level of low-waste and waste-free production. It was noted that regional programs have currently been approved to increase the level of ash and slag utilization from thermal power plants in the constituent entities of the Russian Federation. Activities are presented that will make it possible to achieve the indicators for the level of utilization of ash and slag from thermal power plants in accordance with the Energy Development Strategy of the Russian Federation until 2035. It is explained how legally correct regulatory and technical documentation will make it possible to increase the level of ash and slag utilization in Russia and will help eliminate accumulated harm to the environment. It has been shown that the most large-scale, high-tech, environmentally friendly and economical use of fly ash is its replacement of up to 40% of cement in the construction of buildings and structures. Definitions of fly ash used in cements and concretes are given in the standards of different countries (EU countries, United States, Australia, India, China, Japan, Russia) depending on the type of ash formed. A comparative analysis of Russian and foreign national standards for the use of ash in cements and concretes was carried out in terms of physical and chemical characteristics, which are significant limiting factors when choosing directions and projects for the use of ash. [ABSTRACT FROM AUTHOR]

The demand of Rare Earth Elements (REEs) has increased for the development of clean and green technologies. Conventional geological sources of REE are insufficient to overcome the high demand of REE; hence, the secondary resources are being actively explored. Coal ashes (CAs), a potentially hazardous material, is one of the best secondary sources containing high concentration of REE. The present study aims to explore the abundance of REE in coal and coal ash from different Thermal Power Stations (TPS). The mineralogy and surface morphology of all samples have been determined. The coals mostly consist of quartz and kaolinite, whereas CAs predominantly contain quartz and mullite. Both coal and CAs are dominated by LREE elements, followed by MREE and HREE. The outlook coefficient (Cout) is close to "1" and the critical percentage (Cp) is more than 30%. Coal ash from some of the TPS is identified as secondary source for REE. Fractionation study of REE from coal to CA is carried out to understand the feasibility of CA. A Pearson correlation has been plotted for individual REE elements with other parameters to understand the affinity of REE to different phases of CA. [ABSTRACT FROM AUTHOR]

Gallium and indium are crucial metals in various industries, such as the medical and telecommunication industries. They can find applications as pure metals, alloys and alloy admixtures, oxides, organometallic compounds, and compounds with elements such as nitrogen or arsenic. Recovery of these two metals from waste is an important issue for two main reasons. First, gallium and indium are scattered in the Earth's crust and their minerals are too rare to serve as a primary source. Second, e-waste contributes to the rapidly growing problem of Earth littering, as its amount increased significantly in recent years. Therefore, it is essential to develop and implement procedures that will enable the recovery of valuable elements from waste and limit the emission of harmful substances into the environment. This paper discusses technological operations and methods that are currently used or may be used to produce pure gallium and indium or their oxides from waste. The first step was described—waste pretreatment, including disassembly and sorting in several stages. Then, mechanical treatment as well as physical, chemical, and physicochemical separations were discussed. The greatest emphasis was placed on the hydrometallurgical methods of gallium and indium recovery, to be more precise on the extraction and various sorption methods following the leaching stage. Methods of obtaining pure metals or metal oxides and their refining processes were also mentioned. [ABSTRACT FROM AUTHOR]

Smelting used to be less efficient; therefore, wastes obtained from historical processing at smelter plants usually contain certain quantities of valuable metals. Upon the extraction of useful metal elements, metallurgical slag can be repurposed as an alternative mineral raw material in the building sector. A case study was conducted, which included an investigation of the physico-chemical, mineralogical, and microstructural properties of Pb–Zn slag found at the historic landfill near the Topilnica Veles smelter in North Macedonia. The slag was sampled using drill holes. The mineralogical and microstructural analysis revealed that Pb–Zn slag is a very complex and inhomogeneous alternative raw material with utilizable levels of metals, specifically Pb (2.3 wt.%), Zn (7.1 wt.%), and Ag (27.5 ppm). Crystalline mineral phases of wurtzite, sphalerite, galena, cerussite, akermanite, wüstite, monticellite, franklinite, and zincite were identified in the analyzed samples. The slag's matrix consisted of alumino-silicates, amorphous silicates, and mixtures of spinel and silicates. Due to the economic potential of Pb, Zn, and Ag extraction, the first stage of reutilization will be to transform metal concentrates into their collective concentrate, from which the maximum amount of these crucial components can be extracted. This procedure will include combination of gravity concentration and separation techniques. The next step is to assess the Pb–Zn slag's potential applications in civil engineering, based on its mineralogical and physico-mechanical properties. Alumino-silicates present in Pb–Zn slag, which contain high concentrations of SiO2, Al2O3, CaO, and Fe2O3, are suitable for use in cementitious building composites. The goal of this research is to suggest a solution by which to close the circle of slag's reutilization in terms of zero waste principles. It is therefore critical to thoroughly investigate the material, the established methods and preparation processes, and the ways of concentrating useful components into commercial products. [ABSTRACT FROM AUTHOR]

Biological treatment of domestic wastewater is not limited to wastewater treatment. The main problem in this activity is the processing and disposal of waste generated at treatment facilities, where the main task is to reduce the volume of sludge with its subsequent transformation into a useful product that does not cause environmental pollution. Currently, representatives of landfills refuse to accept this type of waste, arguing that this type of waste does not belong to the category of municipal solid waste. The issue of waste disposal of this production remains open, but, in our opinion, this type of waste can be recycled. The practical value lies in carrying out industrial tests of the converter of municipal solid waste into liquid effluents, including waste generated during the operation of treatment facilities, with subsequent post-treatment of the converted waste at treatment facilities. These tests will reduce the volume of waste by up to 90%, which will minimize the intensive accumulation of waste and sewage sludge and improve the environment. [ABSTRACT FROM AUTHOR]

The article reveals key aspects of managing secondary resources in closed cycle economy, whose ideology implies zero-waste manufacturing and careful attitude to the environment in accordance with the concept of sustainable development being implemented in conditions of permanent institutional restructuring. Today when the model of manufacturing arrangement is linear, the impact on nature is not taken into account adequately: ecologically unstable resources are used, waste is utilized and damage is not evaluated in a proper way. Joining the closed cycle economy presupposes thorough selection of raw materials, whose waste can be recycled and repeatedly used in production process (as a renewable energy). In altered conditions of implementing business-processes a new approach to managing secondary resources will be needed. Special attention will be paid to information-analytical and engineering – technological support. Economic expediency of using secondary resources was shown on practical examples, it is necessary to extend financial opportunities for business entities through well-balanced managerial solutions. The experience of best practices demonstrates that advanced innovation developments rely on max proved consumption of resources, which envisages repeated use of waste that could raise profitability of business and prevent unfavorable ecological impact on the environment.

Carotenoids are widely used and demanded as natural dyes in food technologies due to their biologically active properties. Due to antioxidant properties, carotenoids are widely used for the prevention and treatment of various human diseases, including oncological, cardiovascular, diabetes, etc. In addition, carotenoids are the main sources of vitamin A, which is not produced by the human body, but has a great influence on eye-sight, growth, development and reproductive function of the body. The purpose of the research is to analyze scientific and technical literature to determine the physiological function of carotenoids and the possibilities of their use in food technologies. Carotenoids enter the human body with food and their presence in sufficient quantities in the human diet ensures the normal functioning of the body. The issues of using lycopine and beta-carotene as food dyes and food additives in food technologies have been considered, as well as biologically active components when creating food products, including specialized, functional and personalized ones.The analysis of scientific information has shown that, due to their biological properties, carotenoids perform an important physiological function in a person’s life. The expansion of the area of their use determines the increase in the production of carotenoids and food using them. In accordance with this, studies in the field of improving existing technologies for obtaining carotenoids and expanding the raw material base are relevant, including the use of secondary resources of processing carotene -containing raw materials.

Smelting of copper, a crucially important resource, releases small amounts of mercury into the atmosphere, thereby endangering people and the global environment. This study estimated the expected changes in mercury emissions from copper smelting in response to future changes in copper demand in major copper-producing countries (China, DR Congo, Germany, Iran, Japan, Russia, South Korea, and the USA). Then it evaluated the expected effects of copper recycling promotion and mercury removal technology introduction on emissions. Results indicate that (1) the total expected copper demand of the major countries in 2050 is 15.9 Mton. (2) Under a business-as-usual scenario, the total atmospheric mercury emissions from major countries will be 36% greater than the 2022 estimate. However, promoting copper recycling and introducing mercury removal technologies can reduce that by 99.3%. (3) China, Russia, and Iran account for about 98% of 2022 total mercury emissions from copper smelting in the major countries. The introduction of mercury removal technologies in these countries is expected to have considerable reduction effects. (4) Changes in copper ore grades can cause atmospheric mercury emissions to fluctuate. Overall, these findings highlight the potential risks of increased atmospheric mercury emissions and underscore the importance of implementing effective countermeasures to mitigate these risks. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office 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.)

Use aqua regia to treat the iridium in the iridium containing resin. Experiments have shown that the dissolution rate of metal iridium can reach 90%, and the metal will not be lost. The effects of aqua regia concentration, heating temperature, holding time, and material liquid ratio on the dissolution rate of iridium were investigated; Under the optimal conditions of 80% aqua regia concentration, heating temperature at 85 °C, holding time of 1.5 hours, and a material liquid ratio of 1:3, the dissolution rate of metallic iridium can reach 90%. [ABSTRACT FROM AUTHOR]

The relevance of the research is caused by the importance of the problem of rational use of natural resources in the production of composite building materials. The ability to replace natural raw materials: limestone, clay, sand in the production of cement binders, concretes and mortars with production waste will significantly reduce the load on the raw material base. A serious environmental problem for mining enterprises is the disposal of stone crushing waste. The use of inorganic wastes of various chemical composition makes it possible to control the processes of structure formation and hardening of filled cement systems and to obtain composite materials with high physical and mechanical properties. The main aim is to scientifically substantiate and explore the possibility of using waste from mining enterprises as a component for the production of modifying additives in cement systems. Objects: modified cement stone; modified cement-sand mortars. Methods: determination of the mobility of mixtures, flexural and compressive strength according to SS; thermal analysis; electron microscopiy. Results. The paper introduces the results of studies on the effect of adding microcalcite from different deposits on the properties of cement systems. It is shown that the addition of microcalcite (MCa) additive from the Dalnegorsk mining quarry increases the compressive strength of cement stone on the first day by 16 %, but on days 3 and 7, the strength of the modified samples decreases relative to the control samples. The introduction of the MCa additive of the Novo-Ivanovsky quarry, near the town of Polevskoy, Everest LLC in the amount of 5 % by weight of cement significantly increases the compressive strength of the cement stone, promotes the formation of an additional amount of low-basic calcium hydrosilicates, stable high-basic calcium hydroaluminates with an overgrown needle-like structure, tightening pores.

China is a big consumer of iridium. In the situation of shortage of iridium resources and strict control abroad, efficient utilization and recovery of iridium resources is imminent. Iridium's chemical stability makes it difficult to separate from other precious metals. This paper reviews the iridium resources, applications and secondary resource recovery technologies. From classical chemical precipitation to solvent/solid phase extraction, it can be seen that the iridium recovery technology has the characteristics of short process, low energy consumption, environmental friendliness, high efficiency and so on. And the prospect of iridium recovery technologies is proposed. [ABSTRACT FROM AUTHOR]

In recent two decades, ultrasound has been broadly applied to the hydrometallurgical leaching process to recover valuable metals within raw materials, aiming to solve the shortcomings of the conventional leaching process, including relatively low leaching recovery, long leaching duration, high reagent usage, high energy consumption and so on. The present work focuses on a comprehensive overview of the ultrasound-enhanced leaching of various metals, such as common nonferrous and ferrous metals, rare metals, rare earth elements, and precious metals, from raw metal ores and secondary resources. Moreover, the enhanced leaching mechanisms by ultrasound are discussed in detail and summarized based on the improvement of leaching kinetics, enhancement of the mass transfer and diffusion of lixiviants, and promotion of the oxidative conversion of metals from insoluble to soluble states. Lastly, the challenges and outlooks of future research on the leaching recovery for valuable metals with the assistance of ultrasound irradiation are proposed.

Gallium and indium are crucial metals in various industries, such as the medical and telecommunication industries. They can find applications as pure metals, alloys and alloy admixtures, oxides, organometallic compounds, and compounds with elements such as nitrogen or arsenic. Recovery of these two metals from waste is an important issue for two main reasons. First, gallium and indium are scattered in the Earth’s crust and their minerals are too rare to serve as a primary source. Second, e-waste contributes to the rapidly growing problem of Earth littering, as its amount increased significantly in recent years. Therefore, it is essential to develop and implement procedures that will enable the recovery of valuable elements from waste and limit the emission of harmful substances into the environment. This paper discusses technological operations and methods that are currently used or may be used to produce pure gallium and indium or their oxides from waste. The first step was described—waste pretreatment, including disassembly and sorting in several stages. Then, mechanical treatment as well as physical, chemical, and physicochemical separations were discussed. The greatest emphasis was placed on the hydrometallurgical methods of gallium and indium recovery, to be more precise on the extraction and various sorption methods following the leaching stage. Methods of obtaining pure metals or metal oxides and their refining processes were also mentioned.

The aim of the present work was to explore insights into the possibility of cultivating the mycelium of the edible basidiomycetes, i.e., Agaricus bisporus (J.E. Lange) Imbach, Lentinula edodes (Berk.) Pegler, and Pleurotus ostreatus (Jacq.) P. Kumm. on wastes produced from lavender, sage, mint, and rose. To achieve this goal, we assessed the growth and development of strains on various substrates, a component analysis of the biomass of strains, initial essential oil raw materials after processing, and raw materials after exposure to the mycelium of basidial fungi strains. The wastes of essential oil production can be transformed with the help of edible basidiomycetes (A. bisporus, L. edodes, P. ostreatus) into a valuable fodder product enriched with proteins and vitamins and with good organoleptic properties. The best of the tested substrates was the green mass of mint after successive distillation and extraction. The conversion of solid waste from lavender, rose, sage, and mint processing depends on the types of strains. The high accumulation of octen-3-ol (up to 1.38 g/kg of the substrate) by P. ostreatus was confirmed by its organoleptic evaluation. The results suggested the cultivation of edible mushroom mycelium on the solid waste of mint, lavender, and sage processing could produce high-grade (enriched in proteins and vitamins) biomass for the purpose of fodder. These by-products could serve as a basis for the creation of cultivation technology for champignon, shiitake, and oyster mushrooms as food products using secondary resources of essential oil production. [ABSTRACT FROM AUTHOR]

Copyright of Acta Geoscientica Sinica is the property of Acta Geoscientica Sinica Editorial Office 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 Acta Geoscientica Sinica is the property of Acta Geoscientica Sinica Editorial Office 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 Acta Geoscientica Sinica is the property of Acta Geoscientica Sinica Editorial Office 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 Precious Metals / Guijinshu is the property of Precious Metals Editorial Office 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.)

Carotenoids, in particular, beta-carotene and lycopene, have high antioxidant properties and are used to prevent and treat various diseases associated with human aging. The search for new or intensification of the existing methods of their preparation from plant raw materials and the secondary resources of its processing is relevant due to the high demand for carotenoids in the food, cosmetic and pharmacological industries. The purpose of the research is to analyze the patent information for determining the most optimal and promising directions in the technology of obtaining carotenoids from vegetable raw materials. The main method of obtaining carotenoids from vegetable raw materials and secondary resources of its processing is their extraction using organic solvents. Domestic and foreign scientists have been conducting scientific research in the field of intensification of the process of extraction of carotenoids from vegetable raw materials and secondary resources of its processing in order to increase the environmental safety of the technological process and the quality of the product obtained. Various technical solutions have been proposed on pre-processing of the feedstock using ultrasound (US) effects and microwave radiation, as well as enzymes and enzyme preparations for carotenoids. Analysis of foreign and domestic patent information has shown that studies in the field of integrated use of physical (ultrasound and microwave radiation) and biotechnological (enzymes and enzyme preparations) of pretreatment of the initial raw materials are most promising to increase the efficiency of the extraction of carotenoids from vegetable raw materials and secondary resources of its recycling.

• PLE contributes to reducing GHG emissions to achieve the European Green Deal targets by 2050. • The marginal effect of PLE on the GWP decreases with an increasing lifetime. • Policy scenarios in tandem with PLE can diminish the positive impact of PLE on the GWP. • In the short term, PLE increases the demand for primary resources. • In the long term, PLE reduces the need for primary resources and thus decreases GHG emissions. This paper models, quantifies, and analyzes the environmental impacts of Product Lifetime Extension (PLE) on circular materials in the short and long term. The European Aluminum Rolled Products Automotive Supply Chain (ARPASC) is used as a case study. We present a system dynamics model for the European ARPASC to fit short-term and long-term goals. The computational results show that PLE reduces the demand for products and primary and secondary resources in the short and long term. A 25 % PLE starting in 2025 is found to reduce the global warming potential of the European ARPASC by 16.7 % in 2050. The results of different scenarios show that the degree of PLE and the timing of its implementation should be chosen carefully to ensure that the long-term objectives of the Paris Agreement are achieved without compromising short-term goals. PLE proves to be a sustainable product development strategy for realizing the European Green Deal. [Display omitted] [ABSTRACT FROM AUTHOR]

Primary resources are typically used in lithium extraction. However, it impacts the dependency on the availability of primary resources to fulfill the lithium demand. Therefore, the use of secondary resources can be an alternative to using lithium resources. Gold bullion slag is an example of a potential secondary resource used as a lithium source because it contains 0.009 % lithium. This research aims at increasing lithium recovery from the gold bullion slag by studying the effects of various variables to enhance lithium recovery. Lithium extraction was carried out via HCl leaching process with concentrations of 0.5, 1.0, 1.5, and 2.0 M at 25, 40, 55, and 70 °C for 15, 30, 60, and 120 minutes. Inductively coupled plasma-optical emission spectrometry (ICP-OES) was used to examine lithium level, whereas scanning electron microscope equipped with energy dispersive X-ray spectroscopy (SEM-EDX) was used to look over the morphology. The significance of the recovery value was analyzed statistically using analysis of variance (ANOVA). The optimum variables to reach 98 % as the highest lithium recovery percentage are 1 M HCl at 55 °C for 60 minutes. ANOVA results on the acid concentration significance of the recovery value show that the p-value (0.001) is smaller than the alpha value (0.005). While, ANOVA results on the temperature and time significance of the recovery value show that the p-value (0.894) is greater than the alpha value (0.005) and p-value (0.9986) is greater than the alpha value (0.005), respectively. Analysis showed that variation in HCl concentration affected the lithium recovery value; however, temperature and time of leaching had an insignificant effect on lithium recovery. These data show that slag can be used as alternative resources to produce the lithium. [ABSTRACT FROM AUTHOR]

Due to the advancement of industrialization and the development of the metal smelting industry, cadmium (Cd), as a highly toxic heavy metal element, is discharged into the natural environment in the form of dust, slag, and waste solutions during the Cu-Pb-Zn smelting process, causing great harm to the soil, water environment, and human health. Meanwhile, Cd is a key component of Ni-Cd batteries and CdTe semiconductor materials. The removal and recovery of Cd from the Cu-Pb-Zn smelting process faces a dual concern with respect to resource recycling and environmental protection. This paper briefly introduces the Cd-containing secondary resources produced in the Cu-Pb-Zn smelting process, systematically reviews the recovery methods of Cd from dust, slag and waste solutions, and compares the technical principles, process parameters, separation efficiency, advantages and disadvantages, and application requirements. In addition, a new route to treat Cd-containing solutions via the foam extraction method was proposed, which has the advantages of a short reaction time, large handling capacity, high removal efficiency, and simple operation equipment, showing superior application prospects, especially for industrial bulk waste solutions with ultralow concentrations. [ABSTRACT FROM AUTHOR]

The sustainability and economic competitiveness of alkali activation technology greatly depends on expanding the raw materials database with locally available resources. Therefore, a notable trend has been witnessed toward the exploitation of common clays as alternatives to well-established solid aluminosilicate precursors due to their availability and wide geographical distribution. However, common clays are complex and dedicated research is needed to tailor synthesis procedures and mix designs for different clay resources. This paper describes the outcomes of a study conducted to investigate the influence of several synthesis parameters (solid-to-liquid ratio, NaOH molarity, Si availability, and curing conditions) on the properties of alkali activated binders produced from different thermally modified clays. Optimal synthesis conditions for benchmark metakaolin systems have been identified and binders were produced with progressive dosages of metakaolin replacement by common local clays. Fundamental physical and mechanical properties such as apparent density, open porosity, water absorption, and compressive strength were examined at different curing ages, and X-ray diffraction (XRD) was used to provide complementary mineralogical insights. By combining the effects of the parameters studied, mortar specimens were produced with the developed binders, reaching compressive strength values exceeding 28.2 ± 0.1 MPa, a bulk density as low as 1.78 ± 0.0 g/cm3, and open porosity and water absorption values lower than 15% and 8%, respectively. These properties are comparable to those of conventional hydraulic products, which presents them as interesting candidates for construction. Ultimately, this work aims to contribute with valuable insights toward the valorization of a large group of unexploited clay precursors by demonstrating the feasibility of producing technologically competitive alkali activated materials with little or no use of the prime precursors, thus adding to the extant knowledge and contributing to future scientific and industrial developments in this field. [ABSTRACT FROM AUTHOR]

Cobalt demand has witnessed tremendous growth in recent years due to its wide utilization in many critical industries. However, more than half the world's demand for cobalt is supplied only by one country, raising concerns about the potential future supply. Considering the status of cobalt as a critical raw material, recycling is viewed as an option to provide an alternative stream of supply by recovering cobalt from secondary resources. In this paper the importance of cobalt recovery from secondary resources is highlighted. The current state of research on Co recovery from secondary resources such as catalysts, magnets, superalloys, cemented carbides, rechargeable batteries, and metallurgical wastes are discussed. The industrial-scale cobalt recycling has also been reviewed to give a better overview of the overall progress. This review provides insights into the future outlook and challenges associated with cobalt recovery from secondary resources. Despite the challenges, cobalt recovery technologies from secondary resources should be further developed. [ABSTRACT FROM AUTHOR]

In accordance with the Energy Strategy until 2035, the possibility of increasing the efficiency of energy use of secondary energy resources in the form of associated oil and waste gases has been substantiated by increasing the energy efficiency of the primary energy carrier to 90-95 % by means of cogeneration plants with a binary cycle of electricity generation and trigeneration systems with using the energy of the waste gas to cool the air flow at the inlet of gas turbine plants. The conditions for maintaining the rated power of the main generator with variations in the ambient temperature are shown. An effective topology of electrical complexes in a multi-connected power supply system of oil and gas enterprises according to the reliability condition is presented, which allows increasing the availability factor by 0.6 %, mean time between failures by 33 %, the probability of failure-free operation by 15 % and reducing the mean time of system recovery by 40 %. The article considers the use of parallel active filters to improve the quality of electricity and reduce voltage drops to 0.1 s when used in autonomous electrical complexes of oil and gas enterprises. The possibility of providing uninterrupted power supply when using thyristor systems for automatic reserve input has been proven. A comparative analysis was carried out to assess the effect of parallel active filters and thyristor systems of automatic transfer of reserve on the main indicators of the reliability of power supply systems of oil and gas enterprises.

• An efficient process for extracting valuable metals from EAFD was developed. • Reactions and phase transitions in the migration of valuable metals were revealed. • The kinetic model of the zinc extraction process was established. • Zinc and lead extraction ratios were 93.38 % and 98.14 %, respectively. • Closed-loop production, a green process of waste control by waste. Electric arc furnace dust (EAFD) is a hazardous waste by-product generated during the process of electric furnace steelmaking, which is rich in valuable metal elements. In order to solve the problem of environmental pollution and resource utilization of EAFD, we propose a new process for medium-temperature suspension roasting EAFD and coke dry quenching dust to extract valuable metals. The thermodynamic properties and migration behavior of valuable elements involved in the reaction were analyzed using thermodynamic simulation software FactSage8.1 and thermogravimetric mass spectrometry. The mechanism and kinetic equation of the dezincification process were investigated using the Kissinger method and Coats-Redfern model. The impact of various parameters on the process efficacy and ash fusion characteristics of the material were investigated through boiling furnace experiments. The results demonstrate that elevating the reaction temperature and decreasing the zinc partial pressure is more favorable for reducing and separating zinc. The corresponding kinetic equations for the decomposition of ZnFe 2 O 4 and reduction of ZnO are denoted as d α/ d T = 1.69 × 1012exp (−3.37 × 104/ T) and d α/ d T = 6.76 × 106 exp (−2.08 × 104/ T) × (1 − α) [−ln(1 − α)]3/4, respectively. The optimum reaction temperature was 1050 °C, the C/O ratio was 0.8, the reaction time was 40 min, and the ventilation rate was 3500 mL/min. Under these conditions, the material had no liquid phase agglomeration, and the removal rates of zinc and lead were 93.38 % and 98.14 %, respectively. The crude zinc dust with a zinc grade of 87.57 % and the alloy slag with an iron grade of 52.38 % was obtained. The new process utilizes the excellent heat transfer characteristics and fluidization conditions of the boiling furnace to efficiently realize the high-grade recovery of valuable metals in the EAFD, which provides new insights for the clean treatment of zinc-containing waste. [ABSTRACT FROM AUTHOR]