Potassium-ion exchange

In a similar process, platinum supported on the potassium-ion-exchanged zeolite L (Pt/K-L) has been found to be an excellent catalyst for the aromati-sation of hexane and heptane. This is thought to be due to its ability to support small clusters of platinum metal that act as a molecular die . The lack of acidity in this catalyst is important because it prevents side reactions, including cracking. ... 

A chloride-sensitive microelectrode is made in an identical manner, except that Corning 477315 chloride ion exchanger is used in place of the potassium ion exchanger. 

The ability of living organisms to differentiate between the chemically similar sodium and potassium ions must depend upon some difference between these two ions in aqueous solution. Essentially, this difference is one of size of the hydrated ions, which in turn means a difference in the force of electrostatic (coulombic) attraction between the hydrated cation and a negatively-charged site in the cell membrane thus a site may be able to accept the smaller ion Na (aq) and reject the larger K (aq). This same mechanism of selectivity operates in other ion-selection processes, notably in ion-exchange resins. 

Fluorozirconate Crystallization. Repeated dissolution and fractional crystallization of potassium hexafluorozirconate was the method first used to separate hafnium and zirconium (15), potassium fluorohafnate solubility being higher. This process is used in the Prinieprovsky Chemical Plant in Dnieprodzerzhinsk, Ukraine, to produce hafnium-free zirconium. Hafnium-enriched (about 6%) zirconium hydrous oxide is precipitated from the first-stage mother Hquors, and redissolved in acid to feed ion-exchange columns to obtain pure hafnium (10). 

In Canada, ion-exchange (qv) technology has been used to produce potassium sulfate (4). Ion-exchange resins remove sulfate ions from lake water containing sodium sulfate. This is followed by a wash with aqueous solutions prepared from lower grade muriate of potash. High purity potassium sulfate is collected from the crystallizers into which the wash mns. 

CP has been used as an ion-exchange material to remove radioisotopes, such as Sr, Cs (43) and U (VI) (44) from solution. CP ion-exchange resins have been used to remove calcium ions from blood (45) and calcium, magnesium, and potassium ions from wine (46). A commercial product made using CP, Calci-Bind, has been used for the treatment of kidney stones (47). 

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