XRF technique

2019 ◽  
Vol 4 (8) ◽  
Author(s):  
Pasquale Acquafredda

Abstract The techniques of chemical investigation by X-ray fluorescence (XRF) are widespread since the 50s of the last century. Depending on the accuracy of the desired data and on the artifact characteristics, they can be used as partially destructive or as absolutely non-destructive and non-invasive techniques. The archeomaterials that can be analyzed are the most disparate: minerals, rocks, metals, building materials, pigments, and so on; practically almost everything that is solid, liquid or gelatinous can be analyzed by XRF. The theoretical physical principles and the main components of X-ray spectrometers, in energy dispersion (ED) and wavelength dispersion (WD), are described, also comparing the advantages and disadvantages of each analytical technique. In the last decades, the diffusion of the ED silicon drift detectors, together with the development of very accurate and high specialized software for quantitative analysis, has given a new impulse to the diffusion of the portable spectrometers offering new possibilities for in situ and very rapid archeomaterial characterizations. Case studies related to different artworks, like ceramics, necklaces, coins, obsidians and other lithic artifacts will also be presented: they show the important contribution that X-ray spectrometer technique gives to solve problems related to the characterization, restoration and to the source identification of the raw materials.

2019 ◽  
Vol 23 (11) ◽  
pp. 32-37
Author(s):  
N.A. Konovalova ◽  
O.N. Dabizha ◽  
P.P. Pankov ◽  
E.A. Rush

The article investigated the compositions of road-building materials containing screenings of rock crushing, Portland cement, hydrolyzed lignin, modified by the stabilizing additive “Element”. The road-building compositions containing screenings of rock crushing, Portland cement, hydrolyzed lignin modified with the stabilizing additive "Element" were investigated. The optimal content of raw materials has been established, which allows to obtain soil-cements with a strength mark of at least M 60 - M 75. Using a model experiment, it was shown that the stabilizing additive “Element” is active and can interact with each of component of the raw materials. Using the methods of scanning electron microscopy, infrared spectroscopy, X-ray phase analysis, it has been experimentally shown that the processes of hydration, carbonization and increasing the connectivity of orthosilicate anions play a significant role in the structure formation of soil-cements.


2020 ◽  
Vol 3 (3) ◽  
pp. 40-46 ◽  
Author(s):  
V. Men'shikova ◽  
L. Demina

the paper raises questions about the search for the possibility of obtaining a construction ceramic material using a special type of raw material component. Diopside concentrate was chosen as the basis for the ceram-ic masses due to its positive parameters necessary to improve the strength properties of the material and to support local deposits of raw materials in the East Siberian region. To reduce the optimal firing temperature, an aqueous-alkaline solution of sodium silicate was used in small quantities. The chemical composition of the diopside rock showed mainly the presence of silicon oxides. X-ray diffraction analysis revealed the presence of diopside, quartz and calcite. Sodium-silicate glass is characterized by a full content of silica and a modulus of 3. Using the state diagram of three-component systems, the temperature limits necessary for sintering ceramic masses are established. The fusibility curves show that at a temperature of 1040oC, the values of the primary melt for various compositions are 4-14%, and the total melt content is observed at 1475oC. The parameters of physical and mechanical properties of the ceramic material were determined, where at the firing temperature of 1000-1100oC the value of fire shrinkage was no more than 1%, water ab-sorption up to 10%, and compressive strength up to 31 MPa. Moreover, with an increase in the amount of diopside to 90% by weight, the strength increases, and shrinkage decreases. X-ray phase analysis of the compositions determined mainly analytical lines of diopside, which begin to decrease by 1000oC, which de-termines the relationship with the liquid glass. The DTA and TG curves of the thermogram showed endo-thermic and exothermic effects due to the release of adsorbed water and crystallization of glass. The possi-bility of obtaining high-strength low-shrink ceramics using diopside raw materials as the basis of ceramic masses when adding sodium-silicate glass in the form of a melt is established.


2002 ◽  
Vol 712 ◽  
Author(s):  
C. Montoya ◽  
J. Lanas ◽  
M. Arandigoyen ◽  
I. Navarro ◽  
P.J. García Casado ◽  
...  

ABSTRACTTen ancient mortars of dolomitic origin, used in the construction of the church of Santa María de Zamarce in Navarre, Spain, have been studied in order to define their composition and to characterize the type of binder employed. A complete characterization has been carried out including: morphological examination (visually and using optical microscopy); mineralogical studies (X-ray diffraction, XRD); chemical analysis (main components and soluble salts); grain size distribution and thermal studies (thermogravimetric and thermodifferential simultaneous analysis, TGA-DTA). Dolomite and calcite, as binders, and quartz, as aggregate, have been found as the main phases. The important variability of the studied samples has confirmed that the choice of the raw materials and their preparation were not taken carefully. Thermal behavior of the samples has shown the endothermic peaks related to calcite and dolomite decarbonations. No hydromagnesite phases have been detected. Finally, the approximate indications of the original composition of the raw materials mixtures are presented.


2020 ◽  
pp. 0734242X2093517
Author(s):  
Raheleh Talavari ◽  
Shokoufe Hosseini ◽  
GR Moradi

With the production of renewable biofuels, concerns about the end of fossil fuels have been partially eliminated. On the other hand, the utilization of low-cost and waste materials to provide the raw essential substances to manufacture these fuels is of paramount importance. Biodiesel is one of these fuels and the required raw materials for the reaction are oil (triglycerides), alcohol and catalyst. In this work, travertine stone powder (as waste in the manufacture of building materials) was used as a catalyst and waste frying oil as a source of triglyceride for biodiesel production. Using thermogravimetric and X-ray diffraction analysis, optimum temperature for catalyst calcination was selected at 900°C. Furthermore, X-ray fluorescence, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, transmission electron microscopy and scanning electron microscopy analyses were performed. Using the design of experiments Response Surface Methodology, the optimum reaction conditions for biodiesel production yield of 97.74% were: reaction temperature 59.52°C (~60°C), time 3.8 h (228 min), catalyst concentration 1.36 wt.% and the methanol to oil molar ratio of 11:6. After reusing four times, the catalyst efficiency was reduced a little, and the biodiesel yield was 89.84%, indicating high strength and stability of the catalyst.


2018 ◽  
Vol 35 ◽  
pp. 30-61
Author(s):  
Ruta Švinka ◽  
Visvaldis Švinka

Vēsturiski viena no silikātu tehnoloģijas katedras pamattēmām vienmēr ir bijusi celtniecības materiālu pētīšana un jaunu materiālu izstrāde. Tie ir gan keramikas materiāli, gan materiāli uz neorganisko javu saistvielu bāzes. Ir analizētas un salīdzinātas šo materiālu īpašības: siltuma vadāmība, līdzsvara mitrums, mehāniskās īpašības. Salīdzinātas rūpnieciskos apstākļos un laboratorijā iegūtu dažādu Latvijas mālu keramikas materiālu īpašības un struktūra. Aprakstīta dažu rūpniecisko atkritumu ietekme uz keramikas materiālu īpašībām. Aprakstīta arī jauna keramikas materiāla keramzīta ražošanas tehnoloģija – vienas stadijas paņēmiens, kas ļauj paplašināt keramzīta ražošanai izmantojamo izejvielu bāzi un variēt keramzīta īpašības atkarībā no paredzamā pielietojuma. Pētīta dažādu Latvijas mālu noderība porainu keramisku sorbentu iegūšanai, par poru veidotājiem izmantojot organiskas dabas ražošanas atkritumus. Analizēta keramikas virsmas apstrāde, piemēram, apstarošana ar paātrinātajiem elektroniem un nanodaļiņu pārklājumi, keramikas granulu sorbcijas spējas palielināšanai un noderība fotokatalītiskai organisku piesārņotāju sadalīšanai.Building Ceramics, Expanded Clay, and Ceramic SorbentsInvestigation and development of new building materials historically was one of base research fields in the Institute of Silicate Materials. These are ceramic materials and materials based on inorganic binders. These materials have both advantages and disadvantages. Properties of these materials, such as thermal conductivity, equilibrium humidity and mechanical properties, are analysed and compared. Properties and structure of ceramic materials produced from Latvian clays in the laboratory and industrially were compared. Influence of addition of some industrial waste on the properties of ceramic materials was described. A new technology for obtaining expanded clay pellets was developed. It is a one-step technology that makes it possible to extend the basis of raw materials for production of expanded clay pellets and to produce pellets with different properties depending on the possible practical use. Usefulness of different Latvian clay for the production of porous ceramic sorbents was investigated. Organic industrial waste was added to function as pore former. A treatment of ceramic surface by irradiation with accelerated electrons or coating with nanoparticles was analysed. An increase of sorption activity of ceramic pellets or usefulness for the photocatalytic decomposition of organic pollution was the goal of the aforementioned treatment.Keywords – ceramics, expanded clay, equilibrium moisture, thermal insulation, ceramic granules, sorbents.


2021 ◽  
Vol 14 ◽  
Author(s):  
Xiaoyu Guo ◽  
Yajing Mao ◽  
Lizhai Pei ◽  
Chuangang Fan

Background: A large amount of phosphogypsum occupies the land and causes the environmental pollution. It is of great research significance and urgency to utilization of the phosphogypsum. Methods: The influence of the ratio of the cementing materials and phosphogypsum (C/P ratio) on the compressive strength, water absorption, softening coefficient and freeze-thaw stability of the phosphogypsum baking-free bricks was investigated. The consolidation process of the phosphogypsum baking-free bricks was analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results: XRD patterns show that the phosphogypsum baking-free bricks curved for 28 d are mainly composed of monoclinic CaSO4•2H2O and hexagonal Ca6Al2(SO4)3(OH)12•26H2O (Aft) phases. SEM observation shows that the phosphogypsum bricks consist of Aft nanorods and irregular microscale particles. The softening coefficient, water-resistant performance and freeze-thaw stability of the phosphogypsum baking-free bricks remarkably decrease with decreasing the C/P ratio. 28 d compressive strength decreases from 26.42 MPa to 15.58 MPa with the change of the C/P ratio from 1:1 to 1:2.5. The optimal ratio of the cementing materials and phosphogymsum is 1:1. The phosphogypsum baking-free bricks exhibit good stability after 18 freeze-thaw cycles. Conclusion: Phosphogypsum baking-free bricks were prepared by natural curing process using phosphogypsum as the raw materials, cement, slag, fly ash and silica fume as the cementing materials. The phosphogypsum baking-free bricks exhibit great application in the field of the building materials.


MRS Advances ◽  
2018 ◽  
Vol 3 (34-35) ◽  
pp. 1969-1983 ◽  
Author(s):  
S.N. Panya panya ◽  
A.H. Galmed ◽  
M. Maaza ◽  
B.M. Mothudi ◽  
M. A. Harith ◽  
...  

AbstractLIBS is a developing analytical technique, which is used to perform qualitative and semi-quantitative elemental analysis of materials (solid, liquid and gas). Recently LIBS became an attractive technique to be used for geological samples, due to its advantages such as fast data collection and the lack of sample preparation. This study is done to improve analytical methods for geochemical analysis of samples during different exploration phases (Mining, filed analysis, etc.), to be used in the future as a real-time analysis method to save money and time spent in labs. In this work, LIBS has been used to differentiate between some geological samples gathered from different areas: South Africa and Namibia. Using principal component analysis (PCA), it was found that LIBS was able to differentiate between the samples even those of the same area. The results from the LIBS technique were correlated with subsequent analysis of the same samples by Particle-Induced X-ray emission (PIXE).


2014 ◽  
Vol 1618 ◽  
pp. 97-107
Author(s):  
Emiliano R. Melgar Tísoc ◽  
José Luis Ruvalcaba

ABSTRACTIn the Great Temple at Tenochtitlan, the archaeologists found more than 150 offerings with thousands of pieces, most of them made on foreign raw materials to the Basin of Mexico. Among these votive contexts, the Chamber III of stage IVa (AD 1440-1469), buried during the government of Moctezuma I, is one of the most richness offerings of the temple. Inside this context, the quantity of greenstone beads is huge, and among them, there is a group of translucent appearance that resembles the green calcite objects from the Huastec region. The purpose of this research is to confirm or discard this probable cultural origin and technological manufacture of these beads. To do that, we perform different analysis with neither non-destructive nor invasive techniques like X-Ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FTIR), Raman, Optic Microscopy (OM), and Scanning Electron Microscopy (SEM). By this way we could confirm the similarities among Huastec pieces and these beads, both at mineralogical and technological levels. Based on that, and supported with some written sources from the Colonial period, we propose that these pieces could be war prizes and looted objects by pillage during the Aztec campaigns against Huastec sites; furthermore some of these goods were deposited as victory´s gifts to the gods at the Great Temple of Tenochtitlan.


Author(s):  
C. Wolpers ◽  
R. Blaschke

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.


1986 ◽  
Vol 84 ◽  
Author(s):  
Masahiro Okamoto ◽  
Koichi Chino ◽  
Tsutomu Baba ◽  
Tatsuo Izumida ◽  
Fumio Kawamura ◽  
...  

AbstractA new solidification technique using cement-glass, which is a mixture of sodium silicate, cement, additives, and initiator of the solidification reaction, was developed for sodium borate liquid waste generated from pressurized water reactor (PWR) plants. The cement-glass could solidify eight times as much sodium borate as cement could, because the solidifying reaction of the cement-glass is not hindered by borate ions.The reaction mechanism of sodium silicate and phosphoric silicate (initiator), the main components of cement-glass, was studied through X-ray diffraction and compressive strength measurements. It was found that three- dimensionally bonded silicon dioxide was produced by polymerization of the two silicates. The leaching ratio of cesium from the cement-glass package was one-tenth that of the cement one. This low value was attributed to a high cesium adsorption ability of the cement-glass and it could be theoretically predicted accordingly.


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