Analcime Formation Research Articles

Preparation and characterization of different zeolites from andesite rock: Product evaluation for efficient dye removal

Synthetic Zeolite mixture (ZM) containing Analcime (ANA), Wairakite (W), and Phillipsite (PHI) was produced by alkali activation of andesite rock (AR) under hydrothermal conditions of 1.0&3.0 M NaOH, 100 °C, and duration of 1–5 days. The main affecting parameters for ZM phase crystallization were alkalinity, solution chemistry, parent rock dissolution rate, and reaction duration. The low alkali concentration was advantageous for ANA formation, and the hetero cationic slurry environment containing sodium and calcium resulted in co-crystallization of ANA-W zeolite series in the same pot. High alkalinity unfavored ANA persistence but was more suitable for PHI domination. The FT-IR results confirmed the conversion of the precursor rock into zeolites, whereas the measured surface area indicated the enlargement of the BET of the rock from 2.62 into 91.4 m2/g after zeolitization. The rock and synthetic product were identified using the X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), specific surface area (BET), and the structural groups for AR and ZM were tested using the FT-IR technique. The phase internal structures and microanalysis are monitored by the Scanning Electron Microscopy- Energy Dispersive X-ray Spectroscopy (SEM-EDS). Zeta potential of samples was measured using a particle size analyzer. For economic aspect, ZM formed at low alkali content of 1.0 M NaOH, 100 °C, and 5 days was evaluated for methylene blue dye removal as a model of textile wastewater. The effect of pH, contact time, initial concentration and zeolite dose on adsorption has been investigated. Zeta potential measurements revealed that, the pH pzc was 1.9. The maximum sorption performance was found to be 95.7% at 10 pH within 240 min and 1.5 g/L zeolite dosage. Furthermore, the application of the zeolitic product on a synthetic simulated effluent composed of different dyes and salts implied a removal efficiency of 92.63%. The isothermal investigation of Langmuir and Freundlich models at different temperatures revealed that, MB adsorption using the formed zeolite was adapted to the Freundlich isotherm. The dye removal was matched with the pseudo-first kinetic model. Also, the high efficiencies in the removal of dye molecules through 5 consecutive cycles were demonstrated in the regeneration experiments.

Hydrothermal decomposition process of K‐feldspar in NaOH solution

AbstractThis work investigates the decomposition of K‐feldspar into analcime under alkaline hydrothermal conditions. Two types of raw materials, potassic syenite powder and microcline crystal lumps, were used for hydrothermal treatment. Research techniques of minerals alteration path simulation, powder decomposition experiments, and specific observations were conducted. Results show that K‐feldspar did not alter into analcime directly under hydrothermal conditions, and instead, hydroxycancrinite was an important intermediate. Formation route of analcime from potassic syenite powder was derived as follows: syenite dissolution → hydroxycancrinite precipitation → hydroxycancrinite assembling → reversed recrystallization → analcime, where the assembling of hydroxycancrinite into analcime‐shaped spheres was the key step for analcime formation. Above all, a novel and different to natural reaction process with feldspar decomposition and analcime formation process was proposed.

Hydrothermal synthesis of analcime without template

Abstract Analcime is a highly crystalline material that is found in nature or can be produced artificially. In this work the hydrothermal synthesis of analcime zeolite without organic template was carried out by evaluating the influence of SiO2/Al2O3, NaOH/SiO2 and H2SO4/SiO2 ratios. The samples were characterized with SBET, XRD and SEM. The results show that there is a wide range of synthesis parameters for obtaining analcime zeolite without template. The most important parameter for material formation and characteristics was the H2SO4/SiO2 ratio. The variation of SiO2/Al2O3 ratio influences the crystallinity of the formed material and, mainly, the synthesis yield. The minimum SiO2/Al2O3 ratio for analcime formation was 10.

Synthesis of Analcime Crystals and Simultaneous Potassium Extraction from Natrolite Syenite

Analcime single crystals were successfully synthesized from natrolite syenite powder (K2O 10.89%) and 92.6% of potassium was extracted simultaneously by means of soda roasting followed by alkali-hydrothermal method. Effects of NaOH concentration, reaction temperature, and holding period on the analcime formation and potassium extraction were investigated systemically. The results indicated that NaOH concentration plays an important role in determining the chemical composition of zeolites and size distribution; by turning the NaOH concentrations, three different pure zeolites (i.e., the phillipsite-Na, the analcime, and the sodalite) were prepared. Besides, a higher temperature could accelerate the dissolution of K+ions and enhance the crystallinity degree of zeolite. The reactions involved in the analcime synthesis can be summarized as follows: sodium aluminum silicate dissolution→precipitation and dissolution of metastable zeolite-P→analcime nucleation→analcime growth. The extraction ratio of K+is associated with the types of synthesized zeolites, among which analcime is the most effective to promote potassium leaching out from zeolite lattice position. The optimal condition for analcime crystallization and K+leaching is found to be as follows: 175°C for 4 h in 0.5 mol/L NaOH solution.

Hydrothermal synthesis of hardened diatomite-based adsorbents with analcime formation for methylene blue adsorption

A tough diatomite-based adsorbent with analcime formation was synthesized hydrothermally and used to capture methylene blue efficiently.

Multiple Zeolite Structures from One Ionic Liquid Template

This study reports the use of 1-butyl-3-methyl imidazolium methanesulfonate ionic liquid as a template in the synthesis of zeolites. It is found that the silicon source determines the formation of beta (BEA), mordenite framework inverted (MFI), or analcime (ANA) zeolites. Depending on this source, different preorganized complexes are obtained that drive the formation of the different zeolite structures. In the presence of ethanol, the ionic liquid form preorganized complexes that drive the formation of MFI. In its absence, BEA is obtained. Whereas, the large amount of sodium present when using sodium metasilicate leads to ANA formation. A molecular simulation study of the relative stability of the template-framework system and location of the template provides further insight into the mechanism of synthesis.

Hydrothermal solidification of diatomaceous earth with analcime formation

Diatomaceous earth (DE) solidifies hydrothermally with analcime formation. With analcime formation, strength development was much greater than that with calcium silicate hydrate (CSH) formation. NaOH addition conditioned analcime formation because NaOH solution not only promoted dissolution of quartz and montmorillonite but also provided Na+ to form the analcime. Curing temperature and time affected analcime formation, and, in this study, over 6 h (at 200 °C) and 175 °C (for 12 h), analcime seemed to form readily. After hydrothermal treatment, the skeletons of diatoms can still be seen in the solid after analcime formation but can hardly be found after CSH formation.

Origin of analcime in the Neogene Arikli Tuff, Biga Peninsula, NW Turkey

The Arikli Tuff in the Behram Volcanics, NW Anatolia, is characterized by its dominance of authigenic analcime. It was studied by optical microscopy, XRD, SEM/EDX, and ICP for a better understanding of the analcime formation, which occurs as coarse-grained euhedral to subhedral crystals in pores and pumice fragments as well as in clusters or fi ne-grained single crystals embedded in the matrix. Besides analcime, K-feldspar, dolomite, and smectite are found as further authigenic minerals. Based on the dominance of these authigenic minerals, the tuffs are petrographically separated into phyllosilicate-bearing vitric tuff, dolomiterich vitric tuff, and K-feldspar-dominated vitric tuff. No precursor of zeolites other than analcime was detected. Petrographical and SEM investigations indicate that euhedral to subhedral analcime crystals found as a coarse-grained fi lling cement in voids and pumice fragments are precipitated from pore water, whereas fi ne-grained disseminated crystals are formed by the dissolutionprecipitation of glassy material. Hydrolysis of glassy material that is similar in composition to analcime provides the additional Na, Al, Si, and K elements which are necessary for the formation of analcime.

Thermodynamic evaluation of the major synthesis factors influence on the formation of analcime

Thermodynamic calculations of the reactions of analcime synthesis have been done in order to evaluate the influence of the major factors such as temperature and the excess of Na2O on the formation of analcime.The influence of these factors has been evaluated fhermodynamically according to the following reactions:a) according to the stechiometric quantity of agents necessary for the formation of analcime:I Na2O + γ-Al2O3 + 4 SiO2 + 5 H2O → 2 NaAlSi2O6 · H2O + 3 H2Ob) according to the existing excess of Na2O in the initial mixtures:II 2Na2O + γ-Al2O3 + 4SiO2 + 5H2O → 2NaAlSi2O6 · H2O + 2NaOH + 2H2OIII 3Na2O + γ-Al2O3 + 4SiO2 + 5H2O → 2NaAlSi2O6 · H2O + 4NaOH + H2OIV 4Na2O + γ-Al2O3 + 4SiO2 + 5H2O → 2NaAlSi2O6 · H2O + 6NaOHQuite inconsiderable influence of the increasing synthesis temperature on Gibbs energy has been calculated, however the influence of excess of alkaline component is very significant. The probability that the analcime formation occurs has increased significantly due to the higher excess of Na2O.

Clay mineral assemblages and analcime formation in a Palaeogene fluvial–lacustrine sequence (Maíz Gordo Formation Palaeogen) from northwestern Argentina

The Palaeogene Maíz Gordo Formation is one of the main lacustrine events recorded in northwestern Argentina. It consists of sandstone, mudstone, and limestone beds 200 m thick, deposited in a brackish–alkaline lake and braided alluvial systems. The Maíz Gordo Lake evolved mainly as a closed system, with brief periods as an open one. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to study samples from seven sites, corresponding respectively to proximal, intermediate, and transitional positions of the fluvial environment and marginal and inner-lake environment, focusing on the clay mineralogy and analcime formation. The basinward zonation of diagenetic minerals identified in the Maíz Gordo Lake was: mordenite → analcime → K-feldspar. Although not a typical zonation of saline–alkaline lakes, it does indicate an increase in salinity and alkalinity towards the centre. In proximal fluvial settings, smectite predominates at the base of the sequence, with scarce kaolinite. Towards the top, a striking increase in kaolinite content suggests a change from a relatively arid climate with alternating humid and dry seasons, towards a warm and humid climate. Kaolinite content clearly decreases in a basinward direction. Such a variation is attributable to changes in hydro-geochemistry, denoting the progressive influence of the brackish and alkaline lake water on interstitial pores. SEM images of intermediate fluvial samples reveal authigenesis of illite at the expense of kaolinite booklets. In littoral and inner-lake settings the clay fraction is composed of muscovite, sometimes with subordinate smectite. Analcime occurs in variable amounts in all sedimentary facies, in rock pores or filling veins. It forms subhedral square to hexagonal, or anhedral rounded crystals, denoting that they coarsened at low to moderate degrees of supersaturation. Although the mordenite identified in a fluvial level would have been the precursor of analcime in the Maíz Gordo Basin, no textural evidence of analcime formation through replacement of mordenite or other precursor zeolite was found. Hence it is more probable that analcime formation took place by direct authigenic precipitation or through the reaction between interstitial brines and clay minerals or plagioclase.

Effect of reaction temperature on Fe–Al analcime formation

The effects of reaction period, temperature, and iron species on the zeolite framework type were studied in this work. Gismondine (GIS) is usually synthesized by hydrothermal method at 80°C from sodium metasilicate and aluminum nitrate as starting materials preferentially independent of the presence/absence of iron source. However, the present work revealed that pure analcime (ANA) could be formed at temperatures more than 120°C. A large polyhedral ANA crystal with a diameter of 180 µm was obtained even at a comparatively low temperature such as 150°C at a short reaction period of 1 week. The presence of iron source promoted the formation of pure ANA. Infrared spectroscopy, X-ray diffraction, and ICP-OES analysis suggested that the iron component added as a reactant was incorporated into the ANA framework through the isomorphous substitution for Al.

Controlling of Solution Concentration on Nucleation During Hydrothermal Synthesis of Analcime

AbstractHydrothermal experiments of analcime nucleation and glass dissolution were carried out in autoclaves under the conditions of autogeneous pressures, temperatures of 150 °C ∼ 210 °C, and 0.25 M ∼ 0.75 M NaOH solutions. The curves of the glass dissolution and analcime formation are S‐shaped. Yet, the two curves are essentially parallel to each other. The time required for a complete dissolution of glass or the commencement of analcime formation is shorter when the concentration of NaOH solution or the temperature is higher. The amount of the weight percent of analcime synthesized is obviously less than the glass dissolved at a given time of an experiment. The weight difference between glass dissolved and analcime (dehydrated) formed is calculated to be represented as the solution concentration.During an experiment, the solution concentration increases gradually to a maximum, then decreases slowly to a constant value with time. On the other hand, nucleation is also gradually increased to a maximum, then is decreased finally to zero with time in a bell‐shaped curve. It is clear that nucleation of analcime is mainly controlled by the solution concentration.

Alteration-Phase formation and Associated Cesium Release During Alteration of R7T7 Waste Glass

ABSTRACTStatic corrosion tests were performed with an inactive HLW glass of R7T7 type in order to evaluate alteration-phase formation and associated Cs release during the glass corrosion. The tests were performed in NaOH solutions at elevated temperatures in order to accelerate the corrosion. Crystalline phases formed in the corroded glass were analyzed by use of XRD, in addition to the solution analysis. The results indicated that; 1)Analcime or Na-beidellite or both of them form during the corrosion depending on the conditions, 2)Si rich amorphous phases are contained in the alteration-phases, 3)In addition to solution pH, solution concentrations of Na and K sensitively affect formation of analcime and Na-beidellite, 4)Analcime formation accelerates the glass corrosion, 5)Most of Cs in the glass is retained in the alteration-phases by sorption onto Na-beidellite or incorporation into amorphous phases and pollucite

Nucleation and growth kinetics of analcime from precursor Na-clinoptilolite

The kinetics and mechanism of analcime formation from precursor Na-clinoptilolite (Cpt-Na) and Na-mordenite (Mor-Na) were investigated from 125–225 °C, pressures up to 34.5 MPa, and pH = 9.2–10.7. By using batch and flow-through experimental methodologies, compositions of solids and solutions were monitored to track reaction progress, determine rates of analcime nucleation and growth, and evaluate the rate dependency of these processes on aqueous supersaturation. Analcime formation proceeds via a clinoptilolite (or mordenite) dissolution→analcime nucleation→analcime growth sequence. Synthetic analcime crystals are similar in morphology (trapezohedron to cubic trapezohedron) and composition (Si/Al = 2.1–2.7) to sedimentary analcimes formed during the low-grade alteration of crustal rocks, evidence that the experimental reaction mechanism is similar to that in natural environments. Rates of analcime nucleation were approximated by evaluating the time-dependence of the size and number of particles and range between 109.80 and 1011.88 per h per cm3 at 150° and 225 °C, respectively. The nucleation rate is a function of temperature and degree of supersaturation: ln rate = 56.76 – 15978.9/ T + 2.99 × 10−4·Δ G r, where Δ G r is the free energy change of analcime precipitation and T is temperature in Kelvins. This rate equation is consistent with an apparent activation energy of analcime nucleation ( E a,n) of 132.8 ± 8.3 kJ/mol. Although conditions were thermodynamically favorable for analcime formation at 125 °C, nucleation was not detected after 144 hours. These data suggest that diagenetic timing of the clinoptilolite to analcime transformation is principally controlled by kinetics rather than by thermodynamic equilibrium. Rates of analcime growth were estimated by measuring particle size distributions. Average growth rates ranged from 0.15 μm/h at 150 °C to 0.396 μm/h at 225 °C, and are consistent with an apparent activation energy of analcime growth ( E a,g) of 77.1 ± 9.4 kJ/mol. These nucleation and growth parameters are combined to successfully model the evolution of analcime particle size distributions. The experimental methods developed in this study demonstrate the use of hydrothermal flow-through methods in the study of zeolite transformations.

Hydrothermal Conversion of Trachytic Glass to Zeolite. 3. Monocationic Model Glasses

AbstractExperiments on zeolitization were conducted on four synthetic monocationic glasses (Na, K, Ca, or Mg-rich glass) with Si/Al molar ratios of 2.67, similar in acidity to many volcanic glasses of partially zeolitized Italian tuffs. The products of the hydrothermal treatment at 100, 150, and 200°C of single glasses or glass mixtures with deionized H2O or monosaline solutions (NaCl, KCl, CaCl2) were characterized by X-ray diffraction, thermal, microscopic and chemical analyses. Chemical analyses of mother liquors were also performed. Mineral assemblages, containing chabazite, phillipsite, analcime, and K-feldspar, very similar to those found in altered, volcaniclastic alkali-trachytic or trachytic glass deposits were produced. Potassium was essential to chabazite and phillipsite crystallization, although phillipsite was obtained also in Ca-Na mixed systems. Sodium was necessary for analcime formation. Calcium plays only a secondary role in zeolitization, and magnesium does not favor zeolite crystallization but promotes the formation of smectite. Glass composition determines the mineral assemblages obtained and hence in those commonly found in nature.

水熱条件下におけるトスダイトの変質に及ぽす磨砕効果

Li-bearing tosudite has a regularly interstratified structure consisting of chlorite and smectite layers. Hydrothermal treatment of unground and ground Li-tosudite was carried out under 150°C to 250°C in a distilled water and various concentrations of NaOH solutions, and the reacted products were examined by XRD, ethylene gricol treatment and methylene blue absorption capacity.The final reacted products obtained from the both of unground and ground Li-tosudite were mainly analcime, and swelled Li-tosudite was also formed as a by-product. The formation temperature of analcime using ground Li-tosudite was low compared with that using unground Li-tosudite, and its temperature was also related to concentration of NaOH solution. The analcime formation temperature become low with increasing NaOH concentration in the both cases of unground and ground Li-tosudite.Heterogeneous substitution of interlayer cation (Na+) was considered to be occurred on the basis of different features of XRD profile after ethylene gricol treatment and under various relative humidity states.The interlayer structure of Li-tosudite was altered into complex interlayer structure of swelled Li-tosudite, and analcime was readily obtained as a final product from the unground Li-tosudite compared with the ground Li-tosudite. These facts suggest that the reacted products of hydrothermal treatment reflect an original crystal structure of the starting material.

Zeolitic diagenesis of late Quaternary fluviolacustrine sediments and associated calcrete formation in the Lake Bogoria Basin, Kenya Rift Valley

ABSTRACTLate Quaternary fluviolacustrine siltstones, mudstones and claystones (Loboi Silts) on the northern margins of the saline, alkaline Lake Bogoria in the Kenya Rift Valley contain up to c. 40% authigenic analcime and minor natrolite. The zeolitic sediments are reddish brown and up to 1 m thick. The amount of analcime increases upward in the profile, but decreases with distance from the lake. The altered sediments show many pedogenic features including zeolitic root mats, rootmarks, concretions and carbonate rhizoliths. Residual patches of calcrete locally cap the zeolitic rocks. The profile is interpreted as an exhumed palaeosol and land surface on the former margins of the lake.The analcime occurs as submicroscopic (0–5–2–5 μ.m) subhedral and euhedral crystals, which have an average Si/A 1 ratio of 2–33 (as determined by X‐ray microanalysis) or 2–18 (d‐value of 639 analcime peak). The analcime formed in lake marginal sediments (soils) by reaction of silicate detritus with Na2CO3 rich pore waters concentrated close to the land surface by evaporative pumping and evapotranspiration. Poorly ordered clay minerals were probably the main reactants. Authigenic illite may have been a by‐product of the reactions. Chemical analyses suggest that pore waters supplied some of Na+, and possibly K+ and SiO2. The associated calcrete and rhizoliths were formed during or shortly after the main period of zeolitic alteration. The Ca2+ may have originated from infiltrating dilute runoff and groundwater. Authigenic smectite was precipitated in open porosity following analcime formation. The zeolitic alteration at Lake Bogoria provides a relatively recent analogue for lake marginal zeolites found in many ancient saline, alkaline lake sediments.

Clay mineral diagenesis in two East African lake sediments

AbstractThe vertical clay mineral distribution pattern in two sediment cores taken from two East African lakes has been studied in detail. In the core from Lake Albert (Mobutu Sese Seko) a clay assemblage consisting principally of smectite with some illite and kaolinite in the uppermost segment of the core changed with depth into first a mixed-layer illite-smectite dominated clay and then at 6·60 m into an iltite dominated clay. Lower in the core there was again a transition towards interlayer mixtures, and in the bottom segment towards smectite. These changes are interpreted as a diagenetic transformation of smectite into illite, effected by saline palaeo-lake water with an unusually high K/Na ratio. Three smectite→illite-smectite→illite transition cycles were recognized in a 56 m deep sediment core from Lake Manyara. The sections in which illite dominated contained silt-sized analcime, while those with interlayer mixtures contained alkaline zeolites. The diagenetic illitization of smectite appeared to parallel the process of analcime formation, the K necessary for illitization being released during K,Na-zeolite→analcime transformation. These occurrences suggest that high temperature and pressure may not constitute absolute prerequisites for the diagenetic illitization of smectite.

A New and Important Occurrence of Sedimentary Analcime

ABSTRACT Considerable quantities of sedimentary analcime have been found in the rocks of the Chubutian Group (Senonian) of the anticline of the Senguerr River (Chubut, Argentina). These analcime-bearing rocks are pyroclastic, mostly tuffs that vary in grain size from claystones to conglomerates, sandstones being the most frequent type. Analcime occurs as replacement of the tuffaceous matrix, but also as crystals, fillings of cavities, veinlets, cement etc. Analcime distribution is concentrated in the lower or Castillo Formation, part of the Chubutian Group. The mineral is authigenic and its origin is closely related to environmental and climatic factors (lacustrine or paludal conditions under arid or semiarid climate); volcanic ashes, or their alteration products, seem to be essential in analcime formation. Sedimentary analcime may be more abundant in continental pyroclastic deposits than has hitherto been thought, since it can easily be mistaken for opal. Some partial references in the Argentine geological literature seem to point in this direction.