Based on geological, mineralogical, physical, chemical and technological investigations in the Tamnava Tertiary Basin near Sabac town (western Serbia), deposits of ceramic clays were studied. These ceramic clays are composed of kaolin-illite with a variable content of quartz, feldspars, mica, iron oxides and hydroxides, and organic matter. Four main types of commercial clays were identified: i) red-yellow sandy-gravely (brick clays); ii) grey-white poor sandy (ceramic clays); iii) dark-carbonaceous (ceramic clays); and iv) lamellar (?interspersed?) fatty, poor sandy (highly aluminous and ferrous clays). Ceramic clays are defined as medium to high plastic with different ranges of sintering temperatures, which makes them suitable for the production of various kinds of materials in the ceramic industry. [Projekat Ministarstva nauke Republike Srbije, br. OI-176016]
The results of perennial research of several Serbian zeolitic tuffs enriched with HEU-type minerals are presented in this paper. There are several recognized zeolitic tuff deposits containing HEU-type minerals: Zlatokop, Igros, Beocin, Toponica, Slanci, but their comparative mineralogical and crystallochemical features have not been studied in detail so far. These zeolitic tuff deposits are spatially and genetically connected to volcanic and pyroclastic rocks of marine and lake environments of Senonian and Eocene, and Neogene age, respectively. As a result of devitrification and diagenesis process of volcanic glass within zeolitic tuffs hypocrystalline porphiry and vitroclastic textures occur. The studied zeolitic tuffs are mainly composed of heulandite occuring in a form of needle- to plate-like crystals of 0,1 do 100 ?m in length, associated with other silicates. Depending on the type and content of exchangeable cations as well as the thermal stability of these raw materials, 24 clinoptilolite-Ca and heulandite-Ca can be distinguished. The values of cation exchange capacity and surface area capacity range from 96 to 166 meq/100 g, and from 8,0 to 10,5 meq/100 g, respectively. HEU-type minerals can be distinguished either by a Si/Al ratio or arrangement of extra framework cations within the crystal structure of these minerals. [Projekat Ministarstva nauke Republike Srbije, br. TR 34013: Osvajanje tehnoloskih postupaka dobijanja ekoloskih materijala na bazi nemetalicnih mineralnih sirovina i br. 45012: Sinteza, procesiranje i karakterizacija nano strukturnih materijala za primenu u oblasti energije, mehanickog in?enjerstva, zastite zivotne sredine i biomedicine]
Data on thermally induced transformations of Mn exchanged zeolites LTA and FAU topology are presented in this paper. Thermally induced phase transformation of Mn-exchange zeolites are followed in the range from 700 to 1300?C. Both frameworks collapse into amorphous intermediate products after heating between 600 and 650?C. Prolonged heating of the intermediate product above 1100?C results directly in formation of a disorder Mn-anorthiteLTA and Mn-anorthiteFAU. The parameter of unit cell of Mn-anorthiteLTA and Mn-anorthiteFAU, in temperature range between 700 and 1300?C, was observed in space group C-1. The phase conversions in the temperature range investigated were followed by thermal, X-ray powder diffraction and FT-IR analyses
This study presents investigations of zeolitic tuff samples from the ?Igros- -Vidojevici? deposit. The aim of the research was to determine the quality of samples taken from all deposit parts. Thus, samples were taken from the footwall (?Zeolit 1?), and four samples from the central deposit part (?Zeolit 2?, ?Zeolit 3?, ?Zeolit 4? and ?Zeolit 5?). Characterization of the samples included chemical analysis, determination of the adsorption coefficient for methylene blue dye and cation-exchange capacity (CEC), X-ray powder diffraction analysis (XRPD), differential thermal and thermogravimetric analysis (DTA and TGA), and Fourier transform Infrared spectroscopic analysis (FTIR). Results have shown that the footwall consists mostly of clays, whereas zeolite minerals dominate in the rest of the deposit. XRD analysis of the ?Zeolit 1? sample confirmed presence of smectite and kaolinite clays, while zeolite of analcime type and quartz are present as smaller fractions. Chemical composition analysis and determination of heavy metal contents showed a significant amount (7.58%) of Fe2O3 in this sample. Therefore, further research can be pursued to find a method for removal of magnetic impurities in this deposit portion in order to utilize the clay fraction. On the other hand, according to XRD, FTIR, DTA/TGA and SEM/EDS analyses, samples which belong to the central deposit part (?Zeolit 2?5?) consist of clinoptilolite zeolite type, while clays are present in less than 10%. Thus, clays (smectites and kaolinite) accompanied with analcime and quartz are the most abundant footwall minerals while central deposit parts contain predominantly clinoptilolite accompanied with small amounts of clays. Mineragenetically, zeolites are most abundant in the ?Zeolit 2? and ?Zeolit 3? samples. The smallest value of CEC was determined for the ?Zeolit 1? sample (46.98 mmol/100g). According to CEC values determined for ?Zeolit 2? and ?Zeolit 3? (141.99 and 121.01 mmol/100 g, respectively) these samples are of the best quality, and could be utilized as adsorbents of inorganic pollutants from contaminated waters. Moreover, they could be potentially used for removal of mycotoxins from cattle feed. ?Zeolit 4? and ?Zeolit 5? samples have shown slightly lower CEC values (89.48 and 83.75 mmol/100 g, respectively), which implies lower quality, and, therefore, could be used for soil quality improvement. Finally, determination of the external CEC has revealed a significant difference between ?Zeolit 1? and ?Zeolit 5? samples (17.9 and 5.31 mmol/100 g, respectively). [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR34013 and Grant no. TR33007]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.