Background: There are great resources of natural zeolite in Iran. Zeolite, an inorganic ion-exchanger, may be used as a suitable technical-economical solution for water treatment in many regions of Iran. In this study, the characterization of natural zeolite natrolite and the feasibility of removing hardness, cations, and anions were investigated. Methods: First, zeolite composition and type we...

Hypogene alteration of ussingite from the southern part of the Ilimaussaq intrusion in South Greenland has resulted in the formation of three associations: gmelinite--apophyllite, gmeliniteherschelite-earthy-natrolite, and earthy natrolite alone. Ossingite reacted with late magmatic fluids, producing the secondary minerals either by in situ replacement of the ussingite or in cavities, which may...

Temperature dependency of radiation damage in albite and natrolite was studied quantitatively by measuring the diffraction intensity with imaging plates. Radiation damage was reduced at low temperature in albite but was enhanced in natrolite. A damage process model, in which creation and annihilation of localized defects were considered, was proposed. According to this model, Boltzmann factor i...

The 1H nuclear magnetic resonance (NMR) spectra and the dipolar spin-lattice relaxation time T1D for 1H in the natural natrolite (Na2Al2Si3O10·2H2O) have been measured in the temperature range of 190-390 K. From the temperature transformations of 1H NMR spectra, it follows that at T > 300 K, the diffusion of water molecules along the nano-channels is observed. From experimental T1D data, it fol...

We report on high-pressure and high-temperature chemical transformations of Pb(2+)-exchanged natrolite (Pb-NAT, Pb8Al16Si24O80·16H2O) using a combination of in situ synchrotron X-ray powder diffraction and ex situ HAADF-STEM real space imaging. Three high-pressure polymorphs of natrolites (Pb-NAT-I, II, III) are observed via step-wise pressure-induced hydrations (PIH) up to 4.5 GPa, during whic...

Here we present the one-dimensional (29)Si and (27)Al MAS NMR and two-dimensional (27)Al MQMAS and DQF-STMAS NMR spectra of the monovalent (Na(+), K(+), Rb(+), Cs(+) and NH4(+)) and divalent (Ca(2+), Sr(2+) and Ba(2+)) cation forms of the natural zeolite natrolite (framework type NAT) with complete Si-Al ordering over the crystallographically distinct tetrahedral sites and with the same hydrati...

Background: There are great resources of natural zeolite in Iran. Zeolite, an inorganic ion-exchanger, may be used as a suitable technical-economical solution for water treatment in many regions of Iran. In this study, the characterization of natural zeolite natrolite and the feasibility of removing hardness, cations, and anions were investigated. Methods: First, zeolite composition and type...

The temperature dependence of the heat of hydration of natrolite was studied by isothermal adsorption calorimetry from 412 to 472 K. The heat capacity of hydration implied by these results is about 5 times greater than the calorimetric heat capacity of reaction, suggesting atypical behavior across this solid solution.