A CASE STUDY OF DIFFERENT LIMESTONES DURING QUICK LIME AND SLAKED-LIME PRODUCTION

We have examined 5 different limestones in order to study their behavior i) during calcination at different temperatures (900, 1050 and 1200°C for 30 min) and ii) after hydration of quick limes derived to slaked lime. Quick limes calcined at 900°C show the lower reactivity values. This could be related to the low calcination temperature or to the short calcination time of 30 min which was unable to produce enough lime. The samples calcined at temperatures of 1200°C are less reactive compared to the hydrated limes which were prepared by hydration of quick lime calcined at 1050°C, indicating by parameters such as the (CaO+MgO)Lime, the time required to become the temperature maximum and the reactivity rate. These, probably could be due to crystal growth at relative high temperatures

A case study of lime`s behavior during slaking with different set of natural water: implications for industrial water treatment technologies for light brackish waters

Two samples were collected from different quarries from Greece; one sample is characterized as calcitic limestone and the other as dolomitic limestone. The samples were calcined at 1050 0C. We investigated the effective role of the water anions on the reactivity and slaking rate on the basis of laboratory-produced quicklime. The ultimate scope of the present work is to place constraints on the brackish-water treatment processes as potential guidelines, marking the cost-benefits of pointless investments

Assessment of the quality of calcination of marbles from Thassos Island using Raman spectroscopy and X-Ray Diffraction

The degree of calcination of a dolomitic and a calcitic marble from Thassos Island, was investigated, by combining both Raman spectroscopy (RS) and X-Ray diffraction (XRD) techniques. The samples were prepared in isometric 2 cm cubes and calcined at three different temperatures, 900, 1050 and 1200 0C for 2 hours in order to produce quick lime. RS was applied at the lime sample's surface and inner (near core) part after gently crushing. XRD was applied on the bulk rock specimens in order to verify the transformation process during heating of the raw material. Quality control of the applied calcination procedure is provided through the hydration of quick lime. The rise in solution temperature suggests the chemical "reactivity" of the produced slaked lime. Raman and XRD results revealed the presence of unburned quantities of calcite and dolomite on samples that were calcined at 900 0C. Furthermore, temperatures of 1050 and 1200 0C have shown comparable mineralogical features signifying evenly the conversion of carbonate minerals to their oxide equivalents, proving the completion of the calcination process. Finally, reactivity tests showed that the highest reactivity value of the produced quicklime, for both marbles is observed at the temperature of 1050 0C

A mineralogical study of pigments used in two Iakovidis paintings: Verification of artwork authenticity using Raman micro-spectroscopy method.

For the purpose of the current study, we examined two paintings, an original and a fake one, entitled "Still life with grapes", and claimed both to be created from the Greek Painter G. Iakovidis. The current Research Project has been carried out at the Centre Nikias, an innovative Research Centre specialised on certification, maintenance and restoration of art works. Raman spectroscopic analysis has been carried to verify the authenticity of the used pigments and also the originality of the two paintings. The Raman spectra acquired confirmed four different colours in both painting`s pigments: red, blue, white and yellow. For the first painting Cinnabar for the red pigment, Ultramarine for the blue pigment, White earths for the white pigment and Yellow ochre for the yellow pigment. In the second painting the colours used verified as synthetic pigments. We identified the presence of Cadmium red for the red colour, Cobalt blue for the blue pigment, Zinc white for the white and Cadmium yellow for the yellow one

Hydrogeochemical characteristics and genetic implications of Edipsos thermal springs, north Euboea, Greece

Edipsos area, situated in northern Euboea, has been well known since ancient times for the existence of thermal springs. In order to assess the hydrogeochemical conditions, thermal and cold water samples were collected and analyzed by ICP method for major and trace elements. The results revealed the direct impact of seawater, a process which is strongly related to the major tectonic structures of the area. Seawater impact was confirmed by the Cl/Br and Na/Cl ionic ratios, as well as from statistical processing and graphical interpretation of the analytical results, which classified the sampled waters into three groups (two for cold waters and one for the thermal ones). Trace element ranges for thermal waters are: As (44-84 ppb), Pb (23-154 ppb), Ag (1-2 ppb), Mn (31-680 ppb), Cu (61-97 ppb), Cs (66-244 ppb), Se (0-76 ppb), Li (732-3269 ppb), Fe (0-1126 ppb), Sr (14000-34100 ppb), B (4300-9600 ppb).Compared with the chemical composition of other thermal springs from the Hellenic Volcanic Arc, Edipsos thermal waters are enriched in Ca2+, Na+, Cl-</ sup>, SO42-, Li, B and K+, reflecting the influence from seawater. Cold waters are free of heavy metals compared with other natural waters and are characterized by good quality based on the major element chemistry. Finally, several geothermometers were applied in order to assess the reservoir temperatures, but none of them appear to be applicable, mainly due to the impact of seawater on the initial hydrogeochemistry of the geothermal fluids

Device and materials for in vitro evaluation of forces developed to teeth and periodontal structures during dental practices

This study aimed at providing a gauge device (Ekontak et al Gauge K-Device) in order to analyze the forces applied to teeth and periodontal tissues during dental practices in vitro. This force gauge device can be used in the investigation of the possible defect generation to tooth structures when overloaded forces are applied during dental procedures in vitro. Ekontak et al Gauge K-Device consists of three units: the specimen's holder, a high-performance digital force gauge, and the support frame. The holder was fabricated by an Al alloy providing a steady detachable attachment between the specimens and the force gauge's pin connector. The clinical simulation was achieved with the use of a proper silicone material, selected to provide similar elastic behavior with the human periodontal ligament and to join the teeth inside a solid matrix of an acrylic resin. The digital force gauge is a high-speed collection and recording (1000 Hz) product coupled with data recording software. The forces developed to 15 specimens' root canals during lateral condensation and vertical compaction of cold gutta-percha obturation procedures were monitored, saved as graphs, CSV, and excel files and presented over time. The forces developed during vertical compaction (mean maximum force per obturation circle = 13.22 N) were more excessive than those during lateral condensation (mean maximum force per obturation circle = 10.14 N). In conclusion, Ekontak et al Gauge K-Device is provided as a modern gauge device, capable of performing clinical simulation in vitro, under the terms of its protocol. © The Author(s) 2013

Influence of natural water composition on reactivity of quicklime derived from Ca-rich and Mg-rich limestone: Implications for sustainability of lime manufacturing through geochemical modeling

We studied the effects of water quality on the hydration of quicklimes prepared from calcitic limestone and dolomitic limestone during calcination at 1050 °C. At a low total chloride and sulfate content, reactivity is insensitive to concentration and no effect on quicklime slaking is seen. At higher concentrations, however, we observe a chromatographic effect for chlorides and sulfates. Concentrated chlorides react with the slaking water, forming products such as CaCl2 that are much more soluble than Ca(OH)2, which facilitates transformation of quicklime to slaked lime. In the range of sulfate concentrations in natural waters we observed no effect of sulfates during quicklime hydration. Consequently, in natural waters and their mixtures (conductivity < 2600 μS cm-1), only chloride concentrations are found to promote quicklime hydration. These results suggest that water treatment technologies, applied to natural light brackish water compositions, will not lead to quality improvement for lime-industry products. This journal is © The Royal Society of Chemistry 2016