Simple steps for the detection and classification of different lamprophyric rocks: a case study from Greece

This study aims to help non-expert geologists in locating, classifying and analyzing lamprophyres, the exotic and complex rocks. The process includes three basic steps, a macroscopic study of the formation, petrographic microscopy and lastly whole-rock and trace element analyses of the samples. Fourteen Greek lamprophyric rocks with distinct characteristics were used. Conventional lamprophyres were considered along with rarer alkali minettes, meta-lamprophyres, lamproschists, appinites and para-lamproites.

The effect of porosity on the reactivity of calcium sorbents

The current work presents the results of seven sorbent samples investigated with respect to SO2 capture. The sorbents’ reactivity and capacity indexes were determined, and the tests were carried out in accordance with the ‘classical’ procedure for limestone sorbents. The reactivity indexes (RIs) of the tested samples were in the range of 2.57 and 3.55 (mol Ca)/(mol S), while the absolute sorption coefficients as determined by the capacity index (CI) varied between 87.9 and 120.6 (g S)/(kg of sorbent). Porosimetric analysis was also carried out and the specific surface area of the samples was found to be between 0.2 and 1.7 m2/g. The number of micro-, meso- and macro-pores in individual samples was determined from the corresponding pore size distribution histograms, and the values of sorbent RIs and CIs were correlated with the samples’ total porosity and specific surface.

Sorption of oil products on the synthetic zeolite granules

In this work, lightweight granules of zeolite Na-P1 based on expanded glass aggregates were synthesized for the application in oil products’ sorption. The sorption of gasoline, diesel and silicone oil tests were also conducted for raw expanded glass, zeolite A, clinoptilolite and mineral sorbent available at a fuel station. All sorbents were also characterized in terms of the phase composition (X-ray diffraction) and structure (infrared spectroscopy). The zeolite Na-P1 granules achieved the highest values of sorption capacities (1.8, 2.1 and 2.6 g/g, respectively), which makes them promising materials for oils’ removal.

Activated Carbon as a Support of Catalysts for the Removal of Nitrogen Oxides

Activated carbon was oxidised with concentrated nitric acid and impregnated with urea to form nitrogen-containing groups. Such a support was impregnated with cobalt, copper or silver nitrates to obtain catalysts for the selective catalytic reduction of nitrogen oxides with ammonia. Infrared spectra confirmed the formation of carboxylic and other organic oxygen-containing groups during oxidation. Nitrogen-containing species resulted from urea thermal decomposition. The metal-containing samples were hydrophilic. Cobalt and copper were present in the samples as small Co3O4 and CuO crystallites, while silver occurred in the form of large metallic crystallites, as seen from the X-ray diffraction patterns. Low temperature N2 sorption revealed that all samples were microporous solids, and the chemical and thermal treatment did not change their textural properties. The copper admixture caused the highest NO conversion, but worsened the selectivity and thermal stability of functionalised carbon support.

Analysis of selected mineral and waste sorbents for the capture of elemental mercury from exhaust gases

Several mineralogically, chemically and texturally diverse minerals and waste materials were selected for the testing of elemental mercury capture in exhaust gas, namely tyre char resulting from the burning of pyrolytic rubber tyres, class C fly ash, mesoporous material type MCM-41 and glauconite. Each material’s mineralogical, chemical and textural characteristics were explored. In order to conduct experiments in conditions similar to those during the contact of sorbent with real coal exhaust fumes at a temperature of about 110-120°C, the experiments were carried out using a test device consisting of a furnace for burning powdered coals, a thermostatic cage for sorbent reactors and mercury gas analysers, which are able to measure and compare the effects of individual sorbents with exhaust gas. The study found that the best results for mercury sorption in the exhaust atmosphere were obtained for class C ash resulting from brown coal combustion.

Synthesis and application of natural sorbents with silver nanoparticles in reducing the emission of odours

The paper concerns the applicability of silver nanoparticles for reducing the emission of odours. Silver nanoparticles were successfully adsorbed on three different dolomitic limestone samples. In the next stage, wastewater from the meat industry was mixed with sorbents modified with a variable content of silver nanoparticles. After 4 days and 7 days, the concentration of ammonia was examined spectrophotometrically. Also, the degree of reduction of total odour concentration by olfactometric method was carried out. Depending on the concentration of the silver nanoparticles on the sorbents, the concentration of ammonia was 15-42 μg/cm3 for nAg content equal to 0.08%, while for sorbents containing approximately 36% of nAg the concentration of ammonia was 0.09-16 μg/cm3. A leaching test of nanosilver from sorbents confirmed that the particles were bound with the sorbents by strong bonds. The percentage of eluted silver increased from 0.67% to 11%, with increased initial concentrations of nAg on the sorbents from 0.18% to 0.37%.

Geochemistry, mineral chemistry and P-T evaluation of metasediments of Bahram-Gur complex, ES Sanandaj-Sirjan zone, Iran

The Bahram-Gur area in the southeastern part of the Sanandaj – Sirjan metamorphic zone, contains metabasites and metasediments. The metasedimentary rocks are mainly garnet schists and garnet-staurolite schists that were metamorphosed under amphibolite facies conditions. The rocks consist of garnet ± staurolite, biotite, muscovite, chlorite and quartz. The geochemistry of the Bahram-Gur metasediments classifies them as quartziferous sedimentary rocks. The protoliths of the metasedimentary rocks were close to greywackes from an ensialic arc basin depositional setting, with a source comprising mostly mixture of acid and intermediate magmatic rocks in the upper continental crust. The metamorphic conditions of formation of the Bahram-Gur metasedimentary are investigated by geothermobarometric methods. The results show that the metasedimentary rocks formed at temperatures of 600-750°C and pressures of 5-7.5 kbar.

Lamprophyric rock locations in Greece

Twenty-four areas with lamprophyric formations have been located through a bibliographic search in Macedonia, Thrace, the islands and Attica. Most lamprophyre types have been identified including rare “alkali minette”. In most localities the dikes/sills appear to be late mantle products associated with deep faulting following extensional activity in granitoids.

Synthesis and characterization of cadmium chlorapatite Cd5(PO4)3Cl

One of the most effective methods for the immobilization of toxic metals involves the use of minerals from the apatite supergroup. The formation of cadmium chlorapatite may lead to successful entrapping of cadmium; thus, it is important to examine the solubility constant to determine the stability of cadmium in the the apatite structure. Cadmium chlorapatite was synthetized and characterized by X-ray diffraction, infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy. The solubility constant (log) Ksp of cadmium chlorapatite was -65.58. The Gibbs free energy of formation of cadmium chlorapatite reached -3950.48 kJ mol−1. The solubility constant turned out to be low but was enough for cadmium chlorapatiteto be considered a very stable compound..

Coke and coal as reductants in manganese ore smelting: An experiment

The effect of coke and bituminous coal on the reduction of medium-grade manganese ore in ferromanganese production was investigated. Charges of 30 kg medium grade manganese ore, 12 kg limestone and varied amounts of coke and coal were smelted in a Submerged Electric Arc Furnace (SAF) at temperatures of 1300°C to 1500°C. The composition of the ferromanganese and the slag were determined by X-Ray Fluorescence. It was found that using coke as a single reductant resulted in a 96% yield of ferromanganese which was higher than by using coal either as a single reductant or in a mixture of coal and coke. It was also found that using coke as a single reductant resulted in the lowest specific energy consumption. Using coal as reductant produced ferromanganese containing high sulfur and phosphorus.