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This ion-exchange process is the basis of the " negative europium anomaly ", the low europium content in many lanthanide minerals such as monazite, relative to the chondritic abundance.
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ion-exchange and process
In this process, rare-earth ions are adsorbed onto suitable ion-exchange resin by exchange with hydrogen, ammonium or cupric ions present in the resin.
A South African company claims to have developed a patented ion-exchange process that treats mine effluents ( and AMD ) economically, but such claims remain unsubstantiated at present.
The trapping of ions takes place only with simultaneous releasing of other ions ; thus the process is called ion-exchange.
The purification process is usually performed in several steps with " mixed bed ion-exchange columns " at the end of the technological chain.
The ion-exchange process is also used to separate other sets of very similar chemical elements, such as zirconium and hafnium, which incidentally is also very important for the nuclear industry.
Deionization is a chemical process which uses specially manufactured ion-exchange resins which exchange hydrogen ion and hydroxide ion for dissolved minerals, which then recombine to form water.
The ion-exchange process is also used to separate other sets of very similar chemical elements, such as zirconium and hafnium, which is also very important for the nuclear industry.
In brief, the PUREX process is a liquid-liquid extraction ion-exchange method used to reprocess spent nuclear fuel, in order to extract primarily uranium and plutonium, independent of each other, from the other constituents.
ion-exchange and is
It is commercially extracted via ion-exchange from monazite sand ( 0. 05 % holmium ) but is still difficult to separate from other rare earths.
Thulium is principally extracted from monazite (~ 0. 007 % thulium ) ores found in river sands, through ion-exchange.
Ytterbium is normally difficult to separate from other rare earths, but ion-exchange and solvent extraction techniques developed in the mid-to late 20th century have simplified separation.
Dishwasher salt, which is coarse-grained sodium chloride ( table salt ), is used to recharge the resin in the built-in ion-exchange system.
In ion-exchange chromatography ( IC ), retention is based on the attraction between solute ions and charged sites bound to the stationary phase.
This form of chromatography is widely used in the following applications: water purification, preconcentration of trace components, ligand-exchange chromatography, ion-exchange chromatography of proteins, high-pH anion-exchange chromatography of carbohydrates and oligosaccharides, and others.
* Collectors accumulate scale in hard water areas, unless an ion-exchange softener is used.
Final removal of leftover electrolytes is done by passing the water through a tank with ion-exchange resins, which remove any leftover anions or cations and replace them with hydroxyl and hydrogen molecules, respectively, leaving ultrapure water.
An example is the potassium selective electrode, based on valinomycin as an ion-exchange agent.
Nicotine Polacrilex is nicotine bound to an ion-exchange resin ( polymethacrilic acid, such as Amberlite IRP64 or Purolite C115HMR ...).
Ion exchange resin beadsAn ion-exchange resin or ion-exchange polymer is an insoluble matrix ( or support structure ) normally in the form of small ( 1 – 2 mm diameter ) beads, usually white or yellowish, fabricated from an organic polymer substrate.
The salt is used to recharge an ion-exchange resin which itself is used to soften the water.
Few ion-exchange resins remove chlorine or organic contaminants from water-this is usually done by using an activated charcoal filter mixed in with the resin.
Such water is produced using ion-exchange processes or combinations of membrane and ion-exchange methods.
Sodium polystyrene sulfonate is a strongly acidic ion-exchange resin and is used to treat hyperkalemia.
ion-exchange and many
In many cases ion-exchange resins were introduced in such processes as a more flexible alternative to the use of natural or artificial zeolites.
ion-exchange and minerals
Minerals called zeolites also exhibit ion-exchange properties ; these minerals are widely used in laundry detergents.
ion-exchange and such
The hydrogen form of zeolites ( prepared by ion-exchange ) are powerful solid-state acids, and can facilitate a host of acid-catalyzed reactions, such as isomerisation, alkylation, and cracking.
In this application, ion-exchange resins are used to remove poisonous ( e. g. copper ) and heavy metal ( e. g. lead or cadmium ) ions from solution, replacing them with more innocuous ions, such as sodium and potassium.
There are some ion-exchange resins that do remove organic ions, such as MIEX ( magnetic ion-exchange ) resins.
ion-exchange and .
In 1955, W. Thomas Grubb, a chemist working for the General Electric Company ( GE ), further modified the original fuel cell design by using a sulphonated polystyrene ion-exchange membrane as the electrolyte.
The first 17 atoms of this element were created and analyzed using the ion-exchange adsorption-elution method.
Lindsay Chemical Division was the first to commercialize large-scale ion-exchange purification of neodymium.
High-purity thulium oxide was first offered commercially in the late 1950s, as a result of the adoption of ion-exchange separation technology.
Newer ion-exchange and solvent-extraction techniques have led to easier separation of the rare earths, which has yielded much lower costs for thulium production.
The chemical and physical properties of ytterbium could not be determined with any precision until 1953, when the first nearly pure ytterbium metal was produced by using ion-exchange processes.
The concept of the solvation interaction can also be applied to an insoluble material, for example, solvation of functional groups on a surface of ion-exchange resin.
Table salt may contain added iodine in the form of sodium iodide or potassium iodide, but these compounds will not affect the ion-exchange system, but adding table salt to the dishwasher's water softening unit can damage it.
Adding salt along with the detergent does not soften the water as does a dishwasher with an ion-exchange water softener, but the water will gain some additional ability to dissolve hard water ions.
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification, softening, and other applications.
However, a further saturation of solution with silica impedes hydrolysis and causes the glass to return to an ion-exchange, e. g. diffusion-controlled regime of corrosion.
process and is
A concept of responsibility is in process of articulation and establishment.
An approach that has appealed to some choreographers is reminiscent of Charles Olson's statement of the process of projective verse: `` one perception must immediately and directly lead to a further perception ''.
According to Katherine Litz, `` the becoming, the process of realization, is the dance ''.
The process stipulates that the choreographer sense the quality of the initial movement he has discovered and that he feel the rightness of the quality that is to follow it.
She, too, is concerned with `` the becoming, the process of realization '', but she does not think in terms of subtle variations of spatial or temporal patterns.
In its place is a passionate consciousness grasped and molded to feelings of positive or negative values even as the actions of one's life are determined by constellations of process in which one is caught.
But it is a clumsy and wasteful process: it can produce negative results but not much that is positive.
In the case of social decay, form is displaced simply by the process of dissolution with no form at the terminus of the process.
Within institutions there is a marked decline of the process of persuasion and the substitution of a force-fear process which masquerades as the earlier one of persuasion.
The continuing modernization of these forces is a costly but necessary process.
Social process is always anchored in past predisposition ; ;
Britain in the nineteenth century is a textbook designed `` to give the sense of continuous growth, to show how economic led to social, and social to political change, how the political events reacted on the economic and social, and how new thoughts and new ideals accompanied or directed the whole complicated process ''.
Each year another grade is added to the process, until finally all 12 grades are integrated.
But it is in the process of so doing because it apparently gives priority to trying to downgrade John F. Kennedy.
In still others which are barely on the threshold of the transition into modernity, the decade can bring significant progress in launching the slow process of developing their human resources and their basic services to the point where an expanded range of developmental activities is possible.
Aid is a long-term process
It is an answer in its way, individual and highly dramatic, to the charge that the democratic process is necessarily vicious in its campaign characteristics.
But this we know: Here is a great life that in every area of American politics gives the American people occasion for pride and that has invested the democratic process with the most decent qualities of honor, decency, and self-respect.
It is but part of the whole process within the Department that goes into the making of the final recommendation to the appeal board.
It was recognized years ago that the transition from daytime to nighttime propagation conditions, and vice versa, is not an instantaneous process, but takes place over periods of time from roughly 2 hours before sunset until about 2 hours after sunset, and again from roughly 2 hours before sunrise until some 2 hours after sunrise.
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