Synthesis of zeolite NaP with controllable morphologies

Huo, Zhiping; Xu, Xiangyu; Lu, Zhi Hong; Song, Jiaqing; He, Min; Li, Zhaofei; Wang, Qian; Liang, Yan

doi:10.1016/j.micromeso.2012.03.026

Cited by 120 publications

(83 citation statements)

References 9 publications

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“…3f)-consistent with that expected for a Na-P synthetic zeolite 43,44 -shows two mass losses. The first 13 wt% loss in the 25-200°C range is likely a loss of physisorbed water.…”

Section: Unseeded Leaching Testssupporting

confidence: 84%

“…42 The IR spectrum corresponds to that expected for a synthetic Na-P zeolite. 43,44 The outer surface of these almost spherical seeds was evaluated by laser diffraction (Supplementary Fig. 3.e): particle size distribution shows (i) a bimodal distribution with maxima at 7 and 18 µm and (ii) the numbers of particles with a size less than 3 µm or greater than 100 µm are negligible.…”

Section: Unseeded Leaching Testsmentioning

confidence: 99%

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Contribution of zeolite-seeded experiments to the understanding of resumption of glass alteration

et al. 2017

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Understanding the origin and the consequences of glass alteration regimes is necessary for the prediction of nuclear glass durability. The so-called "stage 3" or "resumption of alteration regime" of glasses used to sequester nuclear waste by vitrification, is characterized by a sudden acceleration of glass alteration rate arising from the precipitation of secondary minerals, mainly zeolites. To study this process, a promising approach is developed, based on seeding by synthesized zeolite seeds. This study quantitatively links the alteration of a six-oxide reference borosilicate glass (ISG) and the precipitation of zeolites that affects concentrations of key species-in particular aluminum-and thus the glass dissolution rate. The characterization of stage 3-easier at alkaline pH-can now be extended to pH conditions more representative of those found in a geological repository thanks to seeding that reduces, or even eliminates, the latency period preceding a resumption of glass alteration. The resumption occurrence and glass dissolution rate are related with temperature and pH. This study shows that the detrimental effect of zeolite precipitation decreases with decreasing pH and temperature, until it is no longer detectable at a pH around 9 imposed by the dissolution of the ISG glass. Even for both high temperature and high pH, the resumption rate is lower than the initial alteration rate, which remains the fastest kinetic regime.npj Materials Degradation (2017) 1:17 ; doi:10.1038/s41529-017-0018-x INTRODUCTION Like the United Kingdom, Japan, Russia and India, France has chosen to reprocess spent nuclear fuel. Ultimate waste arising from this recycling process-consisting of fission products and minor actinides-are confined by vitrification. The reference solution for the management of these waste packages over geological time scales is their storage in a deep, low-permeability and stable geological formation.In contact with water, the vitrified product of waste, usually called "nuclear glass", undergoes both dissolution and irreversible transformation into more stable phases; the rate of this transformation strongly depends on geochemical conditions. Formation of a passivating layer (also called "gel") causes the reduction of the initial alteration rate r 0 -due to the hydrolysis of the vitreous network by nucleophilic substitution of hydroxide ions-until the persistence of a residual rate. For a glass, this gel can exhibit a great variability in composition-and thus in properties-depending on the environmental parameters, in particular pH, temperature and solution composition. Gel stability and its passivation properties allow-under the most favorable conditions-a glass package lifetime of hundreds of thousands to millions of years. However, a resumption of alteration (RA, also called "stage 3" in the literature)-i.e., a sudden acceleration of the glass alteration rate-can occur.1,2 Resumptions of alteration have been observed in specific experimental conditions, particularly in alkaline environments-as a conseque...

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“…3f)-consistent with that expected for a Na-P synthetic zeolite 43,44 -shows two mass losses. The first 13 wt% loss in the 25-200°C range is likely a loss of physisorbed water.…”

Section: Unseeded Leaching Testssupporting

confidence: 84%

Section: Unseeded Leaching Testsmentioning

confidence: 99%

Contribution of zeolite-seeded experiments to the understanding of resumption of glass alteration

et al. 2017

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“…3a, b) clearly indicates the presence of both the cactus-like and diamond-like morphologies. These morphologies show the NaP phase in the composite, and it is similar to what previously reported [30] and the size of diamond-shape particle is about 1-2 µm. Figure 3c, d shows that the particle size of HAp in the composite is about 40-70 nm.…”

Section: Semsupporting

confidence: 89%

Removal of heavy metals and bacteria from aqueous solution by novel hydroxyapatite/zeolite nanocomposite, preparation, and characterization

2016

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In this study, a HAp/NaP nanocomposite was prepared by adding a synthesized nano-hydroxyapatite to zeolite NaP gel in the hydrothermal condition and used for the removal of lead(II) and cadmium(II) ions from aqueous solution. HAp/zeolite nanocomposite was then characterized by Fourier transform infrared spectroscopy, X-ray diffraction and Rietveld method, scanning electron microscope, energy-dispersive X-ray analysis, and surface area and thermal analyses. Results suggested that the nanocomposite crystals of HAp were dispersed onto the zeolite external surface and/or encapsulated within the zeolite channels and pores. The potential of the composite in adsorption of heavy metals was investigated by using batch experiment. The metal concentration in the equilibrium Ce (mg/g) after adsorption with nanocomposite of HAp/NaP was analyzed using flame atomic adsorption spectrometry. The adsorption experiments were carried out at pH of 3–9. The influences of contact time, initial concentration, dose, and temperature on the adsorption of lead and cadmium ions were also studied. Results show that these nanocomposites have further adsorption related to NaP and HAp. They have great potential (about 95 %) for Pb(II) and Cd(II) adsorption at room temperature. The equilibrium process was described by Frendlich, Langmuir, Temkin, and Dubinin–Radushkevich (D-R) models. The kinetics data were successfully fitted by a pseudo-second-order model. The in vitro antibacterial activity of these composites was evaluated against Bacillus subtilis (as Gram-positive bacteria) and Pseudomonas aeruginosa (as Gram-negative bacteria) and compared with standard drugs that show inhibition on bacterial growth

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“…This fact was in agreement with the XRD results. In this sense, different morphologies for NaP1 have been obtained depending on the synthesis conditions which are documented in the literature [6,8]. SEM images of NaP1 magnified at: (left) x2200; (right) x10000.…”

Section: Resultsmentioning

confidence: 73%

“…The high microporosity present in these materials ("molecular sieve"), the number of documented methods to obtain them and the possibility to introduce variations on their compositions as well as morphologies [6] allow a huge number of applications in interesting fields such as catalysis, ion exchange, chemical separation, membranes, etc. Inside this group of porous materials, NaP and analcime are recognized by their excellent properties as ion exchangers.…”

Section: Introductionmentioning

confidence: 99%

Industrial aluminum hazardous waste as a new raw material for zeolite synthesis

López‐Delgado

Rodríguez

Padilla

et al. 2014

WIT Transactions on Ecology and the Environment

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In Spain, the secondary aluminum industry is a mature activity which produces 35% of the total aluminum production. This industry generates slag (black dross) with a valuable content of aluminum which is recovered by dry milling processes in the aluminum tertiary industry. The powdered fine solid is trapped in the sleeve filter suction system of the aluminum slag milling process. This solid is considered as a hazardous waste within the 10 03 21 group in the European Waste Catalogue (EWC), because of the very fine grain size (x 50 < 50 µm) and the presence of dangerous substances (metallic aluminum, AlN, heavy metals, etc.). The high aluminum nitride content, ranging between 2 and 24%, is remarkable and it releases ammonia gas in the presence of environmental humidity. The aim of this work was to evaluate the complete recovery of the fine powders coming from the sleeve filters in the aluminum tertiary industry, as a zeolite. Two types of zeolite, analcime and NaP were obtained by hydrothermal processes from the aluminum waste and silica as raw materials. Different compositions of wastes and parameters such as time and temperature were assayed to study their effects on the obtained zeolites. The materials were characterized by X-ray diffraction and scanning electron microscopy.

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Synthesis of zeolite NaP with controllable morphologies

Cited by 120 publications

References 9 publications

Contribution of zeolite-seeded experiments to the understanding of resumption of glass alteration

Contribution of zeolite-seeded experiments to the understanding of resumption of glass alteration

Removal of heavy metals and bacteria from aqueous solution by novel hydroxyapatite/zeolite nanocomposite, preparation, and characterization

Industrial aluminum hazardous waste as a new raw material for zeolite synthesis

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