Summary The effect of sintering on the maximum capture efficiency of CO2 is studied, using a carbonation/calcination cycle for a series of samples with different stoichiometries of dolomite and calcite. For the materials that belong to the categories of limestone and dolomitic limestone, sintering decreases the extent of carbonation significantly at the two different highest temperatures studied. The extent of carbonation for the same maximum heating temperature depends mainly on the percentage of dolomite. Sintering is negligible in the dolomitic rocks, especially at the maximum heating temperature of 1005°C. The composition of the carrier gas does not seem to play a significant role. The reduction of the extent of carbonation at the second heating /cooling cycle in limestone, and the durability after enough successive cycles of calcination/carbonation in the dolomitic rocks, does not seem to be affected by the maximum temperatures of calcination that were used at the experiments.
The objective of this research was to investigate the effect of different clay composition and concentrations on the thermal
behaviour and kinetics of heavy crude oil in limestone matrix by thermogravimetry (TG/DTG). In TG/DTG experiments, three distinct
reaction regions were identified in all of the crude oil + limestone mixture known as low temperature oxidation (LTO), fuel
deposition (FD) and high temperature oxidation (HTO) respectively. Addition of clay to porous matrix significantly affected
the reaction regions. Significant reduction of activation energy due to addition of clay to crude oil indicates the catalytic
effect of clay on crude oil combustion.
The activity concentrations of 40K, 232Th, and 238U in the characteristic rocks of the Modane-Aussois region (Western Alps, France) were determined using an HPGe gamma-ray
spectrometry system. The activity concentrations of 40K varied from 18 Bqkg−1 (limestone dolomite) to 392 Bqkg−1 (calcschist), while those of 232Th varied from 0.7 Bqkg−1 (limestone dolomite) to 18 Bqkg−1 (calcschist). The activities associated with 238U ranged from 9 (quartzite) to 29 Bqkg−1 (dolomite). In the investigated rock samples, concentrations of 238U (ppm) and 40K (%) had a strong negative correlation.
A high temperature volatilization technique was applied to lower the detection limit for the determination of mercury in mineral samples by neutron activation analysis to the 10–15 pg range. Activated charcoal was used to trap evaporated mercury. Geologic standard samples and weathering crusts from limestone buildings were analyzed. The data obtained indicate how the concentration of air pollutants varies.
Authors:S. Meloni, N. Genova, M. Oddone, F. Oliveri, and R. Vannucci
The geochemical behavior of REE has been tested in the Umbro-Marchean (Italy) pelagic sequences of Cretaceous-Paleocene age. REE were determined by INAA in a number of limestone, marl and clay samples. Both chondrite and shale normalized patterns are discussed: the observed REE amounts and distributions are mainly attributed to highly complex diagenetic processes.
A thermogravimetric method has been developed and is suggested for both the qualitative and quantitative phase analyses of
high-calcium lime and calcium speciation as well. Two complementary TG measurements are proved to be satisfactory for the
determination of moisture, calcium oxide, calcium hydroxide and calcium carbonate contents as well as total mineral impurities
in high-calcium limes: quicklime, hydrated lime and limestone.
Twenty elements (Sm, U, As, Sb, La, Ce, Yb, Th, Cr, Eu, Hf, Ba, Cs, Tb, Sc, Rb, Fe, Zn, Ta, Co) have been determined by instrumental
neutron activation analysis in GSJ/AIST carbonate reference samples, JCp-1 (Coral) and JCt-1 (Giant Clam), together with JLk-1
(Lake Sediment), JDo-1 (Dolomite) and JLs-1 (Limestone) reference samples.
Investigations of the water regime of the plant species
L. (Scrophulariaceae) were conducted to examine ecological characteristics and the physiological status of the species from different geological substrates of its habitats (from the serpentine, andesite, dacite, limestone) in the flora of Serbia.
Authors:R. Piasentin, M. Armelin, O. Primavesi, and P. Cruvinel
Instrumental neutron activation analysis (INAA), followed by gamma-ray spectrometry, was used to determine the concentration
of K, Ca, Mg, Na, Zn, Fe, Mn, Mo, Co, Cr, La, Eu and Th in six species of legumes and three species of grasses. Each species
of forage was cultivated on two differet oxisols, that is, a red yellow Latossol and a dark red Latossol, with the aim of
comparing the influence of the soils in the mineral extraction. Besides, on each kind of soil, two different limestone concentrations
were used in order to verify how the soil pH correction could influence the elemental absorption in each species, and at the
same time; to search for an optimum value of limestone concentration for each soil.
Museum collections include many French medieval limestone sculptures of unknown origin. To localize the source of their stone, the composition of samples from such sculptures has been determined by neutron activation analysis (INAA). Using multivariate statistics, we compared their compositional profiles with groups of samples from French monuments and from quarries known to medieval craftsmen. This process has suggested a provenance for some sculptures and allowed us to assign others to a region or a quarry that provided stone for their production.