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As a clean and efficient renewable energy source, solar energy has been rapidly applied worldwide. The growth rate of China's installed capacity ranks first in the world. However, the life span of photovoltaic (PV) modules is 25 to 30 years, and the rapid development of installed capacity indicates that a large number of PV modules will be decommissioned in the future. Therefore, the ongoing treatment of the scrapped PV waste cells in the near future requires urgent plans and countermeasures. Proper recycling and disposal of decommissioned PV modules is a practical requirement for the sustainable development of the country and industry. Crystalline silicon (c-Si) solar cells currently occupy 85%–90% of the market share, and some scholars have begun to seek the utilization pathways of the waste Si in and outside the PV industry. In this paper, the research status of the separation and recycling process of crystalline Si PV modules is reviewed, and the recycling ways of crystalline silicon are particularly focused on. In addition, the current bottlenecks in the PV recycling industry in China are analyzed and some suggestions on the sustainable development of the PV industry are proposed. [ABSTRACT FROM AUTHOR]

In recent years, photocatalytic technology(PEC) has attracted much attention due to its integration of the ad-vantages of electrochemistry and photocatalytic technology. This technology not only shows excellent catalytic performance, but also solves the problem that the traditional powder photocatalyst is difficult to separate and recycle. The substrate material of photoelectrode is the core of PEC technology, which significantly affects the efficiency of electron transfer, the recombination rate of photogenerated carrier and the stability of photoelectrode. Although PEC technology has made many achievements, the research progress of photoelectrode substrate materials has not been fully reported. In view of this, this paper aims to systematically classify the substrate materials of photoelectrode, including metals, conductive glass, carbon-based materials and other emerging materials, and review the recent research progress on these materials. The preparation method, performance and mechanism of photoelectrode are discussed in detail in order to provide readers with a comprehensive and in-depth understanding. At the same time, we also put forward some suggestions on the future research direction of optical electrode substrate materials, hoping to provide useful reference for the further development of this field. [ABSTRACT FROM AUTHOR]

The exceptional photoelectromagnetic characteristics of rare-earth elements contribute significantly to their indispensable position in the high-tech industry. The exponential expansion of the demand for high-purity rare earth and related compounds can be attributed to the swift advancement of contemporary technology. Nevertheless, rare-earth elements are finite and limited resources, and their excessive mining unavoidably results in resource depletion and environmental degradation. Hence, it is crucial to establish a highly effective approach for the extraction and reclamation of rare-earth elements. Adsorption is regarded as a promising technique for the recovery of rare-earth elements owing to its simplicity, environmentally friendly nature, and cost-effectiveness. The efficacy of adsorption is contingent upon the performance characteristics of the adsorbent material. Presently, there is a prevalent utilization of porous adsorbent materials with substantial specific surface areas and plentiful surface functional groups in the realm of selectively separating and recovering rare-earth elements. This paper presents a thorough examination of porous inorganic carbon materials, porous inorganic silicon materials, porous organic polymers, and metal–organic framework materials. The adsorption performance and processes for rare-earth elements are the focal points of discussion about these materials. Furthermore, this work investigates the potential applications of porous materials in the domain of the adsorption of rare-earth elements. [ABSTRACT FROM AUTHOR]

The separation and recovery of valuable metals from the Huayangchuan uranium polymetallic ore was investigated based on mineralogical research and mineral processing experiments. The most promising valuable elements in the ore, according to mineralogical studies, are U, Nb, and Pb. 95.75% of U and 93.00% of Nb are found in betafite, 46.85% of Pb is present in galena, 52.01% of Pb occurs in cerussite, and associated Ag exists primarily in galena. The beneficiation process involving gravity concentration, magnetic separation, and flotation was determined based on the mineralogical characteristics of the ore. The U-Nb concentrate with U grade of 3578 ppm and recovery of 83.18 %, Nb2O5 grade of 4391 ppm and recovery of 74.55 % can be obtained, and five elements including U, Nb, Pb, Ag, and Fe are recovered. Compared with the previous beneficiation experimental process, the flowsheet is greatly simplified and the beneficiation recovery efficiency has been improved. The results of this investigation can help to address the gaps in the processing of low-grade uranium deposits with similar mineralogical properties. [ABSTRACT FROM AUTHOR]

The exceptional photoelectromagnetic characteristics of rare-earth elements contribute significantly to their indispensable position in the high-tech industry. The exponential expansion of the demand for high-purity rare earth and related compounds can be attributed to the swift advancement of contemporary technology. Nevertheless, rare-earth elements are finite and limited resources, and their excessive mining unavoidably results in resource depletion and environmental degradation. Hence, it is crucial to establish a highly effective approach for the extraction and reclamation of rare-earth elements. Adsorption is regarded as a promising technique for the recovery of rare-earth elements owing to its simplicity, environmentally friendly nature, and cost-effectiveness. The efficacy of adsorption is contingent upon the performance characteristics of the adsorbent material. Presently, there is a prevalent utilization of porous adsorbent materials with substantial specific surface areas and plentiful surface functional groups in the realm of selectively separating and recovering rare-earth elements. This paper presents a thorough examination of porous inorganic carbon materials, porous inorganic silicon materials, porous organic polymers, and metal–organic framework materials. The adsorption performance and processes for rare-earth elements are the focal points of discussion about these materials. Furthermore, this work investigates the potential applications of porous materials in the domain of the adsorption of rare-earth elements.

Extraction of Sc from Sc-rich limonitic laterite without interfering with the main nickel-cobalt production circuit will significantly enhance the economic value of laterite. A process for separation and recovery of Sc from high pressure acid leach (HPAL) liquor of limonitic laterite was proposed in this paper. Based on the chemical composition of the leach liquor, precipitation thermodynamic analysis and experiments were conducted. The results indicated that after a first step to precipitate Fe3+ at pH = 2.5 and 90 °C, Sc could be enriched through a second step precipitate at pH = 4.8 and 60 °C to 267 g/t in Sc-containing precipitate. Then, Sc was re-leached from the Sc-containing precipitate via 1 mol/L sulfuric acid at L:S ratio of 5 mL/g, 80 °C, and 40 min. Meanwhile, gypsum in the Sc-containing precipitate transformed into calcium sulfate hemihydrate during leaching. After that, Sc was synergistically extracted from the leach solution via 5% P204 and 2.5% TBP. Moreover, impurities extracted into the organic phase during the extraction of Sc were scrubbed by HCl. Finally, Sc was stripped by NaOH. By using this process, Sc could be efficiently recovered from limonitic laterite in a facile way. [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.)

• A clean and efficient method for recovering Ag from Ag-Sn alloy is proposed, and the feasibility of this method is studied through theory and experiment. • The migration modes of Ag and Sn metal vapours were discussed. • The purity of crude Ag is more than 95 wt%, which can be directly electrolysed to produce electro-silver, with short process flow and high efficiency. The recycling of waste lead-free solder and the tin refining process generates large quantities of silver-tin alloys, which have a very high potential for recovery but for which there is no clean and efficient means of recovery. This study examined the saturation vapour pressure, separation coefficients, prediction of the T - x (y) phase diagram of the silver-tin alloys, and condensation rate to explore the feasibility of using vacuum evaporation-multistage condensation as a method for separating silver-tin alloys. The results suggest that in the process of vacuum evaporation, both silver and tin will evaporate, and the evaporability of silver is slightly greater than that of tin. In the process of multistage condensation, tin condenses before silver. Furthermore, the vacuum evaporation-multistage condensation method was experimentally validated. The results suggest that the TF consists of crude silver, with a silver content of 98.17 wt% and a silver distribution rate of 43.60%. The MP consists of a silver-tin alloy with 7.87 wt% silver content and exhibits a silver distribution rate of 53.06%. The RE is crude tin containing 0.27 wt% of silver content and a silver distribution rate of 5.14%. The separation rate of Ag is 96.64%. This study provides a clean and efficient method that is instructive for the recovery of Ag-Sn alloys. [ABSTRACT FROM AUTHOR]

Copyright of Mining & Metallurgy (10057854) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group 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.)

In this paper, the parameters affecting the adsorption of CuII and NiII by PAN‐NHx fiber and PAN‐COONa fiber were discussed firstly, such as initial ion concentration, pH, and temperature. Secondly, influence factors toward the separation of CuII and NiII by PAN‐NHx fiber were systematically evaluated by single‐column experiments. The results showed that the PAN‐NHx fiber had good separation of CuII and NiII; NiII accounts for more than 99.00 % of total metal ion content in the initial 1000 mL effluent, while CuII is less than 1 %. With the changed from CCuII: CNiII=90 %:10 % to 95 %:5 %, the ratio of CCuII: CNiII in the treated effluent changed from 6 %: 94 % to 2 %: 98 % (fed flow rate: 0.42 BV min−1). The adsorption capacity of PAN‐NHx adsorption column was well maintained after six cycles. Finally, based on the above laboratory results, a multi‐column process was designed to separate and recover CuII and NiII from wastewater. [ABSTRACT FROM AUTHOR]

Since the discovery of microemulsions, they have attracted great attention due to its unique properties, such as ultra-low interfacial tension and nanoscale droplets. During the past several decades, microemulsions have shown unparalleled advantages in critical metal separation and recovery, e.g., high separation rate, high recovery efficiency, and good selectivity. Therefore, fundamental understandings of such metal recovery behavior are of great significance for the continuous development of microemulsion-based separation technology in this field. Herein, we first systematically reviewed the application of regular microemulsion in the separation and recovery process of critical metals focusing on their separation mechanisms. Then, we summarized the recent progress of CO 2 -responsive microemulsions and highlighted their potential application in critical metal separation and recovery, aiming to provide some insights into alleviating the difficulties in demulsification during the stripping stage using regular microemulsions. In this section, the latest development of CO 2 -responsive microemulsions is introduced, and the relationship between their composition, microstructure and macroscopic properties is discussed. Discussion and future perspectives are provided highlighting the design of new microemulsions and potential application of CO 2 -responsive microemulsions for metal separation and recovery in the future. [Display omitted] • Microemulsions for critical metal recovery were summarized focusing on mechanisms. • The latest development of CO 2 -responsive microemulsions was introduced. • Future perspectives of microemulsions for metal recovery were discussed. • Potential use of CO 2 -responsive microemulsions for metal recovery was explored. [ABSTRACT FROM AUTHOR]

Traditional methods of vanadium recovery from vanadium slag suffer from serious environmental pollution due to the residue and wastewater containing highly toxic V(V) and Cr(VI). To avoid this, a complexation method based on sodium diethyldithiocarbamate (DDTC) complexing agent was proposed to separate and recover V(IV), Fe(II), Cr(III) in the leaching solution directly prepared from vanadium slag. Firstly, the recovery effect of DDTC on metal ions was studied in the imitated solution containing V (IV), Fe (II) and Cr (III), 97.67% vanadium, 99.51% iron and 98.99% chromium were recovered, respectively. In addition, DDTC was recycled in the complexation process. After four cycles, the regeneration rate of DDTC remained above 86%. Then, this method was applied to the leaching solution of vanadium slag, and 97.38% Cr, 97.69% V, 99.66% Fe and 97.64% Mn were recovered, respectively. Chromium was recovered as Cr 2 O 3 with purity of 97.1%. Most iron was recovered as (NH 4) 2 Fe(SO 4) 2 ·6H 2 O with purity of 99.23%. Manganese and a small amount of iron were enriched in the slag, which could be used to produce manganese alloy. Vanadium was recovered as calcium salt, which could be used to produce VOSO 4 electrolyte with purity greater than 99.8%. Without waste water and residue containing highly toxic V(V) and Cr(VI) produced in this new method, which provides a new strategy for cleaner comprehensive utilization of vanadium slag. A novel method for deep separation and recovery of V(IV), Fe(II) and Cr(III) in solution. [Display omitted] [ABSTRACT FROM AUTHOR]

In recent years, the rapid development of copper indium gallium selenide (GIGS) solar cells makes it necessary to recycle spent CIGS in order to realize circular economy. In this work, a novel and efficient method for comprehensive recovery valuable metals in spent CIGS materials was investigated, mainly including three steps: (1) leaching of spent CIGS with nitric acid to separate indium; (2) precipitating to obtain copper gallium selenite mixture with magnesium oxide as precipitant; (3) calcination of the residue and the precipitation to recover selenium. X-ray photoelectron spectroscopy (XPS) analysis indicates that the valence state of selenium was converted from negative divalent to positive tetravalent after oxidative leaching. In addition, the results of X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR) and scanning electron microscope/energy dispersive spectrometer (SEM/EDS) shows that the dissolution of metals in CIGS during leaching were significantly different. Copper and gallium were almost completely leached, while indium entered the slag phase as indium selenite, which achieved the separation of indium. Moreover, the reaction mechanism of leaching was analyzed from the perspective of thermodynamics. After leaching, copper, gallium and selenium can be completely recovered from the leach liquor using magnesium oxide as precipitant. Subsequently, the separation of Se in the residue and precipitates can be achieved at 800 °C for 90 min. Finally, the recovery yields of Cu, In, Ga and Se were 99.23%, 96.82, 98.08% and 96.38% respectively. This research represents an important innovation from the perspective of circular economy and provides a new idea for comprehensive utilization of secondary solar cells. [Display omitted] • An innovative technology for treating spent CIGS via HNO 3 leaching was proposed. • Leaching agent (HNO 3) and precipitation agent (MgO) were regenerated and recycled. • Indium was efficiently separated by one-step leaching. • The recovery of selenium was completed quickly at much lower temperatures. [ABSTRACT FROM AUTHOR]