Zeolites analcime

Later in the simulations, the zeolite analcime (NaAlSi206 H20) begins to form, largely at the expense of micas, which serve as proxies for clay minerals. In the NaOH flood, the overall reaction (expressed per formula unit of analcime) is,... 

Figure 10.21 TEM image of oriented aggregation of nanoplatelets of zeolite analcime. The inset (top) is the corresponding SAED pattern. Another inset (bottom) is TEM image of a single nanoplatelet.

Dehydration of the small-pore zeolite analcime (NaAlSi20e) has also been studied by high-temperature Na NMR measurements up to 500°C (Kim and Kirkpatrick 1998) in which changes in the Na peak positions and widths with temperature were interpreted in terms of exchange between the Na sites and the effect of motional averaging of the intensity of the ( 1/2, 3/2) satellite transitions. 

This system is represented by a closed basin, made of impermeable rocks and filled in the past by a saline alkaline lake. Water in this case could not permeate downwards but only evaporate, so the deposit develops horizontally, instead of vertically as in the previous occurrence. Here pH and salinity in the fluids tend to increase, giving rise to brines, c.g., basic, alkali-rich solutions. Concentric zones of authigenic minerals are so formed, from an outer and upper ring of little altered glass and clay minerals, to zeolites, analcime and a finally alkali-feldspars. A good example for this type of occurrence is Lake Tecopa, California, where the zeolitic ring is constituted by phillipsitc, clinoptilolite and erionite, followed by the central feldspar zone [36]. 

D-HMQC has also been used to investigate the structure of synthetic alumina-sihcate clays (synthetic sodium montmorillonite, S-Na MMT) [69], More precisely, the presence of impurity was highlighted in the synthetic layered material by Al Si D-HMQC performed at 17.6 MHz and 0) =5 kHz with the SR4 i recoupling method performed during 9.6 ms. In natural Na-MMT, zeolite analcime (NaAlSi20g, hH20) has been identified by XRD as the main impurity. 

If zeolites (analcime) are present (>3%), consider replacing HCI with proprietary organic acids. For higher temperatures (>225-250°F), consider replacing HCI with acetic or formic acid. 

For example, the shape and dimension of channels and/or pores of some common zeolites are being depicted in Fig. 2.1 Ih, i, j [8]. It has been established that Si/Al ratios have considerable effect on other properties (viz., CEC, channel dimension, void volume and specific gravity). Figure 2.1 Ih represents the zeolite, Analcime (ANA)-distorted 8-ring, viewed along [110], which has cubic shaped irregular channels of size (A) 4.2 x 1.6 [8]. 

Kim et al. [19] have synthesized Na-Pl zeolite from coal fly ash by using aqueous solution of 2-3 M NaOH at 100 to 150 °C. It has been reported that Faujasite and Hydroxy-sodaUte are formed when NaOH solution concentrations are maintained at 4 and 5 M, respectively. It has been observed that all MulUte, Quartz and Hematite disappeared after hydrothermal treatment at 160 °C. The final synthesis product containing zeolites, Analcime, with Na-Pl, and Cancrinite with Na-Pl, can be found corresponding to alkali concentration of 2 and 4 M, respectively. It has also been reported that Cancrinite increases if the NaOH concentration is 5 M or more. The authors have opined that Na-Pl zeolite having CEC value of 215 meq./lOO g would exhibit strong afftnity towards Pb and Sr. 

I have carried out widespread studies on the application of a sensitive and selective preconcentration method for the determination of trace a mounts of nickel by atomic absorption spectrometry. The method is based on soi ption of Cu(II) ions on natural Analcime Zeolit column modified with a new Schiff base 5-((4-hexaoxyphenylazo)-N-(n-hexyl-aminophenyl)) Salicylaldimine and then eluted with O.IM EDTA and determination by EAAS. Various parameters such as the effect of pH, flow rate, type and minimum amount of stripping and the effects of various cationic interferences on the recovery of ions were studied in the present work. 

SOLID PHASE EXTRACTION AND DETERMINATION OF TRACE AMOUNT OF Co + BY MODIFIED ANALCIME ZEOLITE WITH A NEW SCHIFF-BASE LIGAND... 

For example. Date et al. (1983) recognized the following alteration zones in the Fukazawa Kuroko mine area of Hokuroku district from the centre (near the orebody) to the margin (1) sericite-chlorite zone (zone 111 in Figs. 1.20-1.22) characterized by quartz + sericite Mg-rich chlorite (2) montmorillonite zone (zone 11 in Fig. 1.20) characterized by Mg-Ca-type montmorillonite + quartz kaolinite calcite sericite Fe-rich chlorite and (3) zeolite zone (zone 1 in Fig. 1.20) characterized by clinoptilolite + mordenite + Mg-Na-type montmorillonite cristobalite calcite or analcime + Mg-Na-type montmorillonite + quartz calcite sericite Fe-rich chlorite (Fig. 1.20). 

In part because of the open crystal structure and resulting low density characteristic of zeolite minerals, analcime is the most voluminous reaction product in the simulations. 

In the simulations, a significant fraction (about 50% to 80%) of the alkali present in solution is consumed by reactions near the wellbore with the reservoir minerals (as shown in Reaction 30.6 for the NaOH flood), mostly by the production of analcime, paragonite, and dawsonite [NaAlC03(0H)2]. In the clastic reservoir considered, therefore, alkali floods might be expected to cause formation damage (mostly due to the precipitation of zeolites) and to be less effective at increasing oil mobility than in a reservoir where they do not react extensively with the formation. 

In analcime-wairakite series (an interesting exeimple of order/disorder in zeolites), wairakite, the calcium analogous to the sodic analcime has a remarkable order. 

Feng X. and Savin S.M. (1993) Oxygen isotope studies of zeolites stiblite, analcime, heulandite and clinoptilolite, II kinetics and mechanism of isotopic exchange between zeolites and water vapor. Geochim. Cosmochim. Acta 57, 4219-4238. 

The displacements of the framework atoms in the H structure of analcime from the symmetrized positions are listed in Table III. They are considerably larger than the displacements of 0.02-0.07 A found in synthetic zeolite NaA (3) which are the smallest displacements recorded so far in a pseudosymmetric structure. The displacement vectors in analcime can be related to the apparent temperature parameters of the A structure. Figure 3 shows the experimentally determined vibration ellipsoids of optically isotropic analcime (7). The strongly anisotropic ellipsoids are in reasonably good accord with the displacement vectors obtained independently by DLS. 

Data enabling comparisons of the compositional differences of sedimentary zeolites of different origin are scarce. Such comparisons have been mostly between zeolites from magmatic rocks and those from sedimentary rocks, independent of the genetic type of the latter (1). The studies of Coombs and Whetton (2), which compared the specific features of analcime in metamorphic and unaltered sedimentary rocks, are evidence of the capabilities of this approach. Clinoptilolites belonging to different groups—alkaline basins of the United States (la), true sedimentary rocks... 

Conventional single-crystal studies of aluminosilicates date back to the early 1950 s, and principal components of the quadrupole-coupling tensors together with asymmetry parameters have been determined for a number of minerals (see Table XI). Wide-line-NMR measurements of the dependence of the 27A1 and 23Na quadrupole-coupling constants in analcime and zeolites Na-X and Na-A on the water content were carried out by Gabuda et al. (137). 

These findings are in broad agreement with the wide-line measurements by Genser (158) who from the second moment of the 27A1 line in hydrated zeolite Y calculated vQ = 390 kHz, but was not able to observe a signal in dehydrated zeolite. Gabuda et al. (137) observed increased values of vQ after dehydration of zeolites. For the hydrated and dehydrated analcime the values were 270 and 390 kHz, respectively for Na-X, 165 and 285 kHz and for Na-A, 75 and 165 kHz. 

ANALCIME. A common zeolite mineral, NaAlSi2C>6 H20, a hydrous soda-aluminum silicate. It crystallizes in the isometric system, hairiness, 5-5.5 specific gravity, 2.2. vitreous luster colorless to white but may be grayish, greenish, yellowish, or reddish. Its trapezohedral crystal resembles garnet but is softer it is distinguished from lcucitc only by chemical tests. 

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