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The objective of this work was to formulate and prepare alkyd paints with new anticorrosive pigments based on exchanged mordenite, friendly with the environment. The electrochemical characterization of painted steel was done by: conductivity measurements, linear polarizations essays and corrosion potential measurements. The paint film tested in this case was removed and the steel surface analysed by scanning electron microscopy and energy dispersive X-ray analysis. The results showed that the new pigments incorporated in the paint have acceptable anticorrosive properties, taking into account their low environmental impact and the use of a low-cost natural resource. [ABSTRACT FROM AUTHOR]

This work presents a comprehensive study on chromate ions (CrO42-) removal from aqueous solutions for different levels of alkalinity in the natural mordenite zeolite from Palmarito de Cauto deposit. The Surface charge density and zero charge point (p.z.c.) values of the zeolite were determined, which lead to outline that these ions are adsorbed on this mineral in a specifically form and it was associated with the formation of an electric layer double. Through atomic emission spectroscopy, infrared spectroscopy (FT-IR) and scanning electron microscopy (MEB) with EDX was showed that this zeolite removes chromium from the aqueous solutions of chromate ions and it occurs independently of its basicity level. The mineral has a significant neutralizing effect on alkaline solutions. The results provide information that expands the useful potential of an abundant natural resource, with low cost and great accessibility. [ABSTRACT FROM AUTHOR]

In this work, zeolite beta (Zβ) was synthesized using fly ash (CV) from coal-fired Power Plant, Termopaipa, at Paipa, Boyacá (Colombia). The silicon and aluminum were extracted from fly ash, which performed by means an acid pretreatment followed by hydrothermal process with NaOH. To obtain the zeolite beta, silicon source and aluminum source of gel mother and crystallization time were varied, keeping a nominal composition, so that 50SiO2: 1Al2O3: 25TEAOH: Na2O: K2O: 17H2O. In the first experiment, the CV provided the aluminum source, while the silicon source was obtained by CV and fumed silica, which were prepared by hydrothermal synthesis, kept at 170 °C for 40 h, which led to obtain ZSM-5 together with a secondary phase of Mordenite. In the second experiment, the CV provided the source of silicon and were necessary the addition of aluminum sulphate octadecahydrate to complete the amount of aluminum source, which were prepared by hydrothermal synthesis, kept at 170 °C for 60 h, which led to a phase of beta zeolite (Zβ) highly pure. The zeolitic phases were characterized using DRX, FTIR, and SEM and by XRF. The zeolites were modified using (3-aminopropyl) triethoxysilane (APTES) and hexadecyltrimethylammonium bromide (HDTMA-Br). The results show that the zeolite Zβ-APTES with an adsorption capacity of 5 mmol NO3 - /100g have the mayor potential for controlled fertilizer release. [ABSTRACT FROM AUTHOR]

The objective of the investigation was to evaluate the capacity of natural zeolite from Palmarito de Cauto as ionic exchanger. This zeolite was characterized by completing chemical, roentgenographic and thermal analyses. The crystal chemical formula of the mineral was also obtained based on volume of unit cells and density. The results indicate that the peculiarity of the modernite allows the extraction of Cr(III) and Cr(IV). The theoretical capacity for ionic exchange was demonstrated in practice using the wastes from the fibrocement plant of Santiago de Cuba. The concentration of chrome in these wastes exceeds the established standards for discharge to the ecosystem of the coast. It was concluded that the zeolite from Palmarito de Cauto can be used for removing the chrome contained in industrial wastes, which leads to a reduction in the pH of the wastes. [ABSTRACT FROM AUTHOR]

This work is a survey of zeolitic rocks in Palmarito de Cauto deposit, consisting mainly of mordenite-type zeolite, to identify basic magnetic phases and other potential phases associated with iron contained in this rock, and propose methods to eliminate it. In this study, samples with different particle sizes (-0,09 + 0,05 mm; -0,05 + 0,038 mm and -0,038 + 0 mm) were subjected to magnetic and gravimetric separation to extract non-zeolite phases associated with iron. The samples were analysed to determine the iron content and magnetic susceptibility and by X-ray diffraction both before and after each separation. The interpretation of the survey results allowed for identifying magnetite as the main magnetic phase (ferromagnetic); which is associated with iron present in zeolitized rocks in Palmarito de Cauto. It was demonstrated that non-zeolitic mineral phases associated with iron present in this natural zeolite can be separated (removed) by using gravimetric and magnetic methods. A greater amount of iron was separated by using a gravimetric method and with a particle size ranging from -0,05 + 0,038 mm; which is close to the average particle size (0,04 mm) of cemented crystallites in natural zeolites. [ABSTRACT FROM AUTHOR]

Copyright of Superficies y Vacío is the property of Sociedad Mexicana de Ciencia y Tecnologia de Superficies y Materiales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Sociedad Química del Perú is the property of Sociedad Quimica del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Different Cuban natural zeolites, as well as the effect caused by the thermical treatment and the ionic exchange were studied using the 29Si-MASNMR technique. The process of hydrothermal transformation of natural clinoptilolite into Y-and-P1 type zeolites reported in [1] is also monitored. It is shown how with the help of this technique mordenite, clinoptilolite and heulandite can be easily identified as well as the Si/AI relationship can be estimated in some cases. [ABSTRACT FROM AUTHOR]

It is reported for the first time the proton magnetic resonance spectra of the clinoptilolite and mordenite between 220 K and 440 K. In mordenite it was observed that all water molecules have so an intensive diffusive movement, that they are completely delocalized. In clinoptilolite below 390 K, only a part of the water molecules are completely delocalized. Over 390 K all water molecules become delocalized. This particular behavior of the water molecules in clinoptilolite and mordenite is confronted with those structural models proposed by D. W. Breck. The concept of non-localized quantum state is introduced in order to explain the difference observed with the structural models [ABSTRACT FROM AUTHOR]

El artículo describe un método para la esterificación metílica de los ácidos grasos libres del aceite de soja en presencia de zeolita con 85% de mordenita como catalizador. Dicho método permite la reducción de los ácidos grasos libres aún en aceites de soja con altos contenidos de estos.