... of montmorillonites, chlorites, mica, and vermiculite. Exchange capacities for the clay fractions range from 24 to 36 milliequivalents per 100 grams, and for the whole samples from 6 to 20 milliequivalents. GeoRef, Copyright 2008, American Geological Institute. Reference includes data from Bibliography and Index...

... (clinoptilolite) in the southern part of the study area. Heulandite and K-feldspar are mainly authigenic minerals in the upper tuff unit. The ammonium-exchange capacities of the 16 samples were investigated to understand the effects of the mineralogical composition on their ion-exchange capacities, which vary...

... to the mineral surface. Titration of H-clays with bases shows that montmorillonites and “illites” behave like a mixture of two or three different acids, whereas kaolinite, with an indefinite number of exchange sites, behaves like an indefinite number of acids. Ion-exchange capacity is measured in chemical...

...; however, the latter caused partial loss of ion-exchange capacity with Mg 2+ . The pathways of the birnessite formation in this study might be: (1) Mn(OH) 2 (amorphous) → feitknechtite → buserite → birnessite, and (2) Mn(OH) 2 (amorphous) → prephase I → feitknechtite → buserite → birnessite Mn(OH) 2...

... REEs into soil solutions during weathering. The released REEs are adsorbed on clay minerals or precipitate as supergene rhabdophane and an Fe-Mn-REE oxyhydroxide phase. Nepheline syenite-derived regolith-hosted REE deposits are enriched in illite and halloysite, which have a higher ion exchange...

... because they are made of rigid, small, and anisometric particles. Kaolinite and mica are made of hard prismatic particles which are lightly abrasive over the skin, teeth, or hair. Electric charges in smectites result in ion-exchange capacities useful in the loading of active cosmetics but also adsorbing...

...María D. Alba; Miguel A. Castro; Pablo Chain; M. Mar Orta; M. Carolina Pazos; Esperanza Pavón Abstract Many environmental applications in the inorganic remediation field are based on the swelling and ion-exchange capacities of smectites, even though these can be affected by hydrothermal treatment...

... capacity. However, practical barriers exist to the continued expansion of their use, including handling issues related to the fine particle size, and continued ion exchange following waste adsorption. This study examines the synthesis and characterization of zeolites adhered to a muscovite mica wafer...

... leaching. The effects of leaching are important for chlorine, sodium, and potassium. Calcium, zinc, iron, magnesium, manganese, lithium, and rubidium are not significantly affected by surface weathering conditions. Subsurface samples would be more suitable for ion-exchange studies. The exchange capacity...

...+ and the silicates. The amounts of Pb 2+ adsorbed were as much as 1.23 mmol Pb/g magadiite and 2.32 mmol Pb/g octosilicate, which are larger than the reported values for various ion exchangers. They were larger than the theoretical cation exchange capacities (2.2 and 3.7 meq/g for magadiite and octosilicate...

... in iso-octane. The maximum amount of the total specific adsorption capacity for binary solute systems was ~0.8 and ~2.0 mmol g –1 for the raw and ion-exchanged Cpt, respectively. For the ternary solute systems, unexpectedly, this capacity increased to ~2.0 and ~3.0 mmol g –1 , respectively. For binary...

... of exchangeable magnesium in the montmorillonitic clays is more common than is generally recognized. Ross and Hendricks, assigning all magnesium to the Al layer in calculating the formulas of montmorillonites, found that the number of ions in octahedral coordination ranged from 2.02 to 2.24. However...

...Osman Uygun; Ayşenur Murat; Gaye Ö. Çakal Abstract Clay minerals are effective adsorbents used for the remediation of toxic heavy metals from wastewater due to their large surface areas and great cation-exchange capacities. In this study, the removal of lead ions from aqueous solutions via...

...-exchange ability not only for Mg 2+ but also towards heavy metal ions. In order to improve the ion exchange capacity the zeolitic tuff was pretreated with NaCl solution. The treatment increased the content of Na (only in the clinoptilolite phase) leading simultaneously to a decrease in the amounts...

..., are detectable down to the base of 4-foot cores. Cation-exchange capacities of these clayey silts are in the order of 30 to 40 milliequivalents per 100/gms. Three quarters of the exchange capacity is accounted for by the organic fraction of the sediments. H (super +) ions (rather than Ca (super ++) , Na (super...