scholarly journals The Removal of Rare-Earth Metals from Water-Salt Systems – An Innovative Aspect of the Modern Industry

2021 ◽  
Author(s):  
Olga Leonidovna Lobacheva
Keyword(s):  
Rare Earth ◽  
Sodium Dodecyl ◽  
Raw Material ◽  
Ion Flotation ◽  
Water Salt ◽  
Living Organisms ◽  
Effective Use ◽  
Salt Systems ◽  
Theoretical Results

Considering the ever-increasing role of rare-earth elements (REE) in the modern hi-tech field, their effective use has a tremendous significance, although the production process is inevitably linked to the large volumes of industrial ammonia effluents and heavy metal wastes. In the process of metallurgical separation of metals, the emission of large volumes of noxious gases and radioactive substances is inevitable. Lean technogenic raw material processing is sensible under the condition of the development of non-waste technology. The lack of competent regulations governing the disposal of waste containing REE has an impact on adjacent territories, accumulating in water bodies and, as a result, in the human body. Such an impact cannot pass without a trace, however, the ambiguity of opinions in the scientific community regarding the toxic effects of REE on living organisms determines the relevance of a more detailed study of this issue. The paper presents experimental and theoretical results of studies of ion flotation in the aqueous solutions containing ytterbium cations and a surfactant as a collector - sodium dodecyl sulphate (NaDS).

scholarly journals Ion Flotation of Ytterbium Water-Salt Systems—An Innovative Aspect of the Modern Industry

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3493
Author(s):  
Olga Leonidovna Lobacheva
Keyword(s):  
Ph Value ◽  
Sodium Dodecyl ◽  
Hydrate Formation ◽  
Distribution Coefficients ◽  
Standard Test ◽  
Raw Material ◽  
Ion Flotation ◽  
Water Salt ◽  
Living Organisms ◽  
Salt Systems

Considering the ever-increasing role of rare-earth elements (REE) in the modern hi-tech field, their effective use has tremendous significance, although the production process is inevitably linked to the large volumes of industrial ammonia effluents and heavy metal wastes. In the process of metallurgical separation of metals, the emission of large volumes of noxious gases and radioactive substances is inevitable. Lean technogenic raw material processing is sensible under the condition of the development of non-waste technology. The lack of competent regulations governing the disposal of waste containing REE has an impact on adjacent territories, accumulating in water bodies and, as a result, in the human body. Such an impact cannot pass without a trace, however, the ambiguity of opinions in the scientific community regarding the toxic effects of REE on living organisms determines the relevance of a more detailed study of this issue. The study of ytterbium ions removal from aqueous standard test solutions by the adsorptive bubble method—ion flotation—was conducted. The experiments showed that by using the ion flotation method, the maximum removal of ytterbium (III) was achieved at pH = 8.30. It was shown that ytterbium (+3) distribution coefficients as a function of aqueous phase pH value in the process of ion flotation with sodium dodecyl sulphate were derived. The comparison of values of removal pH with those of hydrate formation pH allowed to conclude that ytterbium floate as basic dihydroxoytterbium dodecyl sulphate Yb(OH)2(C12H25OSO3).

scholarly journals Physical and chemical parameters of processes producing rare-metal deposits in granitoid systems with fluorine: experimental data

2019 ◽  
Vol 27 (6) ◽  
pp. 617-637
Author(s):  
Yu. B. Shapovalov ◽  
V. Yu. Chevychelov ◽  
V. S. Korzhinskaya ◽  
N. P. Kotova ◽  
A. F. Redkin ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Rare Metal ◽  
Magmatic Fluid ◽  
Ore Minerals ◽  
Water Salt ◽  
Salt Phase ◽  
Melt Composition ◽  
Physical And Chemical ◽  
Salt Systems

The problem of the origin of rare-metal deposits in granites is considered, taking into account the results of experimental studies, which make it possible to introduce restrictions on the interpretation of geological materials and the construction of genetic models. The role of both magmatic and hydrothermal-metasomatic factors in the formation of various types of rare-metal deposits is discussed. The saturation concentrations of Ta and Nb in granite melt significantly depend on the melt composition, varying from ~ 25 to ~ 0.1 wt.%. They depend on temperature and pressure, to a lesser extent. The partitioning of Ta and Nb between the fluorine-containing fluid and the granite melt is sharply biased in favor of the melt. The principal difference in the partitioning of W and Ta, Nb, Sn in melt granite-salt systems is shown. Fluoride water-salt phase is a very effective extractant of tungsten, while Ta, Nb and Sn completely remain in the aluminosilicate melt. The model magmatic fluid, that is in equilibrium with Li-F granite melt, is multiphase and contains significant amounts of SiO2 and fluorides of Na, Al, Li and K. The solubility of ore minerals in this fluid is insignificant, but the concentration of Nb substantially exceeds that of Ta. The concentrations of HF in high-temperature magmatic fluids were estimated that could reach ~ 0.51 M HF. The experimentally determined solidus temperatures of Li-F granites are ~ 570630C at a pressure of 100200 MPa. At T = 300550С and P = 50100 MPa the actual hydrothermal transfer of Ta and Nb is possible only by sufficiently highly concentrated solutions (fluids) of HF and, possibly, KF. At alkaline sodium solutions, hydrothermal transport of Nb is quite probable, and for Ta it is difficult, at that the solubility of pyrochlore is higher than the solubility of columbite.

scholarly journals Solubility of Rare Earth Chlorides in Ternary Water-Salt Systems in the Presence of a Fullerenol—C60(OH)24 Nanoclusters at 25 °C. Models of Nonelectrolyte Solubility in Electrolyte Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 349
Author(s):  
Nikolay A. Charykov ◽  
Viktor A. Keskinov ◽  
Kirill A. Tsvetkov ◽  
Ayat Kanbar ◽  
Konstantin N. Semenov ◽  
...  
Keyword(s):  
Rare Earth ◽  
Pure Water ◽  
Pitzer Model ◽  
Ternary Systems ◽  
Electrolyte Solutions ◽  
Water Soluble ◽  
Salting Out ◽  
Isothermal Saturation ◽  
Water Salt ◽  
Salt Systems

The solubility in triple water-salt systems containing NdCl3, PrCl3, YCl3, TbCl3 chlorides, and water-soluble fullerenol C60(OH)24 at 25 °C was studied by isothermal saturation in ampoules. The analysis for the content of rare earth elements was carried out by atomic absorption spectroscopy, for the content of fullerenol—by electronic spectrophotometry. The solubility diagrams in all four ternary systems are simple eutonic, both consisting of two branches, corresponding to the crystallization of fullerenol crystal-hydrate and rare earth chloride crystal-hydrates, and containing one nonvariant point corresponding to the saturation of both solid phases. On the long branches of C60(OH)24*18H2O crystallization, a C60(OH)24 decreases by more than 2 orders of magnitude compared to the solubility of fullerenol in pure water (salting-out effect). On very short branches of crystallization of NdCl3*6H2O, PrCl3*7H2O, YCl3*6H2O, and TbCl3*6H2O, the salting-in effect is clearly observed, and the solubility of all four chlorides increases markedly. The four diagrams cannot be correctly approximated by the simple one-term Sechenov equation (SE-1), and very accurately approximated by the three-term modified Sechenov equation (SEM-3). Both equations for the calculation of nonelectrolyte solubility in electrolyte solutions (SE-1 and SEM-3 models) are obtained, using Pitzer model of virial decomposition of excess Gibbs energy of electrolyte solution. It is shown that semi-empirical equations of SE-1 and SEM-3 models may be extended to the systems with crystallization of crystal-solvates.

Ion flotation of rare-earth metals with sodium dodecyl sulfate

2011 ◽  
Vol 84 (9) ◽  
pp. 1476-1482 ◽  
Author(s):  
D. E. Chirkst ◽  
O. L. Lobacheva ◽  
N. V. Dzhevaga
Keyword(s):  
Rare Earth ◽  
Sodium Dodecyl Sulfate ◽  
Rare Earth Metals ◽  
Sodium Dodecyl ◽  
Ion Flotation ◽  
Dodecyl Sulfate

Clustering-Triggered Efficient Room Temperature Phosphorescence from Nonconventional Luminophores

2019 ◽  
Author(s):  
Shuyuan Zheng ◽  
Taiping Hu ◽  
Xin Bin ◽  
Yunzhong Wang ◽  
Yuanping Yi ◽  
...  
Keyword(s):  
Room Temperature ◽  
High Efficiency ◽  
Spin Orbit Coupling ◽  
Design Rationale ◽  
Emission Mechanism ◽  
Room Temperature Phosphorescence ◽  
Electronic Interactions ◽  
Energy Gaps ◽  
Theoretical Results

Pure organic room temperature phosphorescence (RTP) and luminescence from nonconventional luminophores have gained increasing attention. However, it remains challenging to achieve efficient RTP from unorthodox luminophores, on account of the unsophisticated understanding of the emission mechanism. Here we propose a strategy to realize efficient RTP in nonconventional luminophores through incorporation of lone pairs together with clustering and effective electronic interactions. The former promotes spin-orbit coupling and boost the consequent intersystem crossing, whereas the latter narrows energy gaps and stabilizes the triplets, thus synergistically affording remarkable RTP. Experimental and theoretical results of urea and its derivatives verify the design rationale. Remarkably, RTP from thiourea solids with unprecedentedly high efficiency of up to 24.5% is obtained. Further control experiments testify the crucial role of through-space delocalization on the emission. These results would spur the future fabrication of nonconventional phosphors, and moreover should advance understanding of the underlying emission mechanism.<br>

THE PROVENANCE OF WINE: THE ROLE OF BEDROCK AND SOIL IN TRANSFERRING TRACE AND RARE EARTH ELEMENTS INTO WINE GRAPES, SONOMA COUNTY, CA

2019 ◽  
Author(s):  
Kylie E. Dupuis ◽  
◽  
Owen A. Anfinson ◽  
Laura Waters ◽  
Holli M. Frey ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Wine Grapes ◽  
Sonoma County

Complementary Tools and Incentives

2018 ◽  
Author(s):  
Mokal et
Keyword(s):  
Modular Approach ◽  
Insolvency Law ◽  
Financial Situation ◽  
Legal Advice ◽  
Effective Use

This chapter discusses the complementary tools and incentives that can be adopted by jurisdictions to ensure the proper and effective use of the Modular Approach and to give due regard to the position and role of the various types of stakeholders involved in a MSME insolvency process. It specifically focuses on the roles and obligations of the MSME entrepreneur, both at times approaching insolvency and during the MSME insolvency process. Entrepreneurs do not always possess the education and skills to monitor the financial situation of their business and to react accordingly. With regard to the MSME framework, they would usually not be capable of designing a proper continuation plan. They might not even be aware that there is a chance to turn their business around by using mechanisms under insolvency law. In all these areas, education is a useful remedy. Jurisdictions should establish a method for providing affordable educational counselling and legal advice.

scholarly journals Investigating the Feasibility of Mefenamic Acid Nanosuspension for Pediatric Delivery: Preparation, Characterization, and Role of Excipients

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 574
Author(s):  
Nikhat Perween ◽  
Sultan Alshehri ◽  
T. S. Easwari ◽  
Vivek Verma ◽  
Md. Faiyazuddin ◽  
...  
Keyword(s):  
Particle Size ◽  
Mefenamic Acid ◽  
Hydroxypropyl Methylcellulose ◽  
Sodium Dodecyl ◽  
Aqueous Solubility ◽  
Oral Route ◽  
Precipitation Method ◽  
Antisolvent Precipitation

Molecules with poor aqueous solubility are difficult to formulate using conventional approaches and are associated with many formulation delivery issues. To overcome these obstacles, nanosuspension technology can be one of the promising approaches. Hence, in this study, the feasibility of mefenamic acid (MA) oral nanosuspension was investigated for pediatric delivery by studying the role of excipients and optimizing the techniques. Nanosuspensions of MA were prepared by adopting an antisolvent precipitation method, followed by ultrasonication with varying concentrations of polymers, surfactants, and microfluidics. The prepared nanosuspensions were evaluated for particle size, morphology, and rheological measures. Hydroxypropyl methylcellulose (HPMC) with varying concentrations and different stabilizers including Tween® 80 and sodium dodecyl sulfate (SLS) were used to restrain the particle size growth of the developed nanosuspension. The optimized nanosuspension formula was stable for more than 3 weeks and showed a reduced particle size of 510 nm with a polydispersity index of 0.329. It was observed that the type and ratio of polymer stabilizers were responsive on the particle contour and dimension and stability. We have developed a biologically compatible oral nanoformulation for a first-in-class drug beautifully designed for pediatric delivery that will be progressed toward further in vivo enabling studies. Finally, the nanosuspension could be considered a promising carrier for pediatric delivery of MA through the oral route with enhanced biological impact.

scholarly journals Rheological Characterization of a Concentrated Phosphate Slurry

Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 178
Author(s):  
Souhail Maazioui ◽  
Abderrahim Maazouz ◽  
Fayssal Benkhaldoun ◽  
Driss Ouazar ◽  
Khalid Lamnawar
Keyword(s):  
Flow Behavior ◽  
Continuous Phase ◽  
Raw Material ◽  
Rheological Characterization ◽  
Phosphate Ore ◽  
Insoluble Particles ◽  
Experimental Protocols ◽  
Solid Liquid

Phosphate ore slurry is a suspension of insoluble particles of phosphate rock, the primary raw material for fertilizer and phosphoric acid, in a continuous phase of water. This suspension has a non-Newtonian flow behavior and exhibits yield stress as the shear rate tends toward zero. The suspended particles in the present study were assumed to be noncolloidal. Various grades and phosphate ore concentrations were chosen for this rheological investigation. We created some experimental protocols to determine the main characteristics of these complex fluids and established relevant rheological models with a view to simulate the numerical flow in a cylindrical pipeline. Rheograms of these slurries were obtained using a rotational rheometer and were accurately modeled with commonly used yield-pseudoplastic models. The results show that the concentration of solids in a solid–liquid mixture could be increased while maintaining a desired apparent viscosity. Finally, the design equations for the laminar pipe flow of yield pseudoplastics were investigated to highlight the role of rheological studies in this context.

scholarly journals Contribution of Cyanotoxins to the Ecotoxicological Role of Lichens

Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 321
Author(s):  
Dobri Ivanov ◽  
Galina Yaneva ◽  
Irina Potoroko ◽  
Diana G. Ivanova
Keyword(s):  
Research Methods ◽  
Raw Material ◽  
Modern Times ◽  
Effective Application ◽  
The World ◽  
The Common

The fascinating world of lichens draws the attention of the researchers because of the numerous properties of lichens used traditionally and, in modern times, as a raw material for medicines and in the perfumery industry, for food and spices, for fodder, as dyes, and for other various purposes all over the world. However, lichens being widespread symbiotic entities between fungi and photosynthetic partners may acquire toxic features due to either the fungi, algae, or cyano-procaryotes producing toxins. By this way, several common lichens acquire toxic features. In this survey, recent data about the ecology, phytogenetics, and biology of some lichens with respect to the associated toxin-producing cyanoprokaryotes in different habitats around the world are discussed. Special attention is paid to the common toxins, called microcystin and nodularin, produced mainly by the Nostoc species. The effective application of a series of modern research methods to approach the issue of lichen toxicity as contributed by the cyanophotobiont partner is emphasized.

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