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Clayey soils are treated with binding agents to improve their mechanical properties, as these soils are widely used in construction. The production of binding agents is an energy-intensive process and emits significant amounts of CO2. In addition, the interest in recycling industry waste materials has increased, and the management of significant waste from biomass power plants remains an issue. We used three biomass ashes derived from pellet, olive, and grapevine combustion as stabilizing agents of a clayey soil. The mechanical effects of the treatment on clay-ash mixtures were evaluated using confined compressive tests. The mixtures' chemo-mineralogical evolution was evaluated through X-ray powder diffraction and quantitative Rietveld analysis, Fourier transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy coupled with scanning electron microscopy (EDS-SEM). The FT-IR spectra showed an evolution of the Si-O-Si/Al features, with shifting band positions due to polymerization of the tetrahedral units. The EDS-SEM analysis showed an evolution of the Ca/Si distribution and the growth of pozzolanic reaction products, such as C-S-H nanocrystals and gels. This evidence confirms that the pozzolanic reaction occurs by dissolution of clay minerals and/or the amorphous phase of the ash, which affects the macroscopic behavior of clayey soils in terms of stiffening and strengthening, as confirmed by mechanical tests, albeit these effects are non-homogenous and continuous. [ABSTRACT FROM AUTHOR]

This paper described a baseline for a multidisciplinary approach to the mineralogical and chemical characterization of eighteen fragments of archaic transport amphoras (7th-6th centuries BC) found at Gravisca archaeological site (Lazio, Italy) attributed to an Eastern Aegean provenance (six from Samos, three from Miletus, three from Chios and three from Klazomenai). The samples have been typed on the evidence concerning archaic manufactory techniques by using X-ray powder diffraction (XRPD) associated with quantitative phase analysis (QPA), optical (OM) and electron microscopy (SEM). Following Inductive Coupled Plasma Spectroscopy (ICP), compositional data analysis has been for the first time applied to selected geochemical proxies combining rare earth elements and selected heavy metals concentration in Hierarchical Agglomerative Cluster (HAC). This innovative approach allows to distinguish different sources of the raw materials used from different geological and geographical areas. Multivariate statistical treatments via Principal Component Analyses (PCA) open the possibility to group the sherds into clusters, comparing the results with the HAC application allowing to validate the methodology. Two distinct centres associated with Samos manufactory appear to be operating during 7th-6th centuries BC, which could be related to different production periods or even different production areas. The new data concur with a more straightforward historical reconstruction of archaic Poleis manufactory and commercial activity toward Etruria and the Mediterranean and with a new methodological approach to archaeometry. [ABSTRACT FROM AUTHOR]

Ferri-kaersutite, ideally NaCa2(Mg3TiFe3+)(Si6Al2)O22O2, is a new oxo-amphibole from Harrow Peaks, Northern Victoria Land, Antarctica. It occurs as brown prismatic crystals, up to 200 μm in length, with a vitreous luster, and a perfect {110} cleavage. Ferri-kaersutite is associated with forsterite, diopside, and Cr-bearing spinel. Chemical analyses, by a combination of electron microprobe, SIMS, and 57Fe Mössbauer spectroscopy, gave the following results (in wt%): SiO2 41.69, TiO2 5.30, Al2O3 13.65, Cr2O3 0.09, Fe2O3 4.52, MgO 15.54, CaO 11.03, MnO 0.11, FeO 2.83, Na2O 2.88, K2O 0.96, H2O 0.70, F 0.24, Cl 0.08, O=(F,Cl) -0.12, sum 99.50. On the basis of 24 anions per formula unit, the formula is (Na0.816K0.179)S0.995(Ca1.726Fe2+0.258Mn0.014)S1.998(Mg3.383Fe2+0.088Ti0.582Fe3+0.497Al0.439Cr0.011)S5.00(Si6.089Al1.911)S8.00O22[O1.187(OH)0.682F0.111Cl0.020]S2.00. Ferri-kaersutite is monoclinic with space group C2/m. Its unit-cell parameters are a = 9.8378(8), b = 18.0562(9), c = 5.3027(4) Å, β = 105.199(9)°, V = 908.99(13) Å3, Z = 2. The five strongest reflections in its X‑ray powder diffraction pattern [d in Å (relative visual intensity, hkl)] are: 8.4 (s, 110), 3.379 (ms, 131), 3.115 (ms, 310), 2.707 (s, 151), 2.598 (ms, 061). The crystal structure of ferri-kaersutite has been refined on the basis of 1783 observed reflections [Fo > 4σ(Fo)] with a final R1 = 0.038. The relatively large equivalent isotropic displacement parameter at M(1), with respect to those at M(2) and M(3) sites, together with the short M(1)-O(3) distance, suggest the occurrence of Ti4+ at the M(1) site, whereas the small octahedral distortion at this site suggests a low Fe3+ occupancy. This element is mainly hosted at the M(2) and M(3) sites. The occurrence of amphiboles in the magma source region is notably relevant. The melting of Ti-rich amphibole in the lithosphere and subsequent degrees of melt/host peridotite reactions are able to produce melts that account for the compositional spectrum ranging from extreme alkaline lavas to the most common alkaline basalts. In particular, when this amphibole is formed by reaction between a peridotite matrix and metasomatic melts/fluids with high Fe3+/Fetot ratio, its subsequent melting can influence primary volatile contents and ultimately magma rheology. [ABSTRACT FROM AUTHOR]

A new technology was tested to improve the cooking efficiency of the raw mixture for Portland clinker production by the use of nano-Ca(OH) 2 . A decrease in the free lime concentration after the firing of approximately 35% and 55% in the nano-added clinkers burned at 1350 °C and 1450 °C, respectively, with respect to the standard Portland clinkers was observed. Moreover, in the nano-added clinkers, a slight decrease in alite (C3S), of approximately 2-4 wt%, and increase in belite (C2S), of approximately 5-6 wt%, were observed. Despite these variations, the C2S and C3S abundance lies within the ranges for standard Portland clinkers. The results showed that the nano-addition leads to an increase of the raw mixtures' cooking efficiency. The relatively low energy required for the clinker firing could be used to increase the plant productivity and decrease the CO 2 emissions during clinker burning. The decrease of the work index of the clinkers produced by the use of the nano-Ca(OH) 2 also contributes to the energy saving during clinker grinding. Differences were also found in the pore size distribution among nano-added clinkers and the standard Portland clinker. The smallest porosities with the modal volume lying in the class of 3∙10 -6 mm 3 were found to increase by the use of nano-Ca(OH) 2 . However, the pore volumes higher than 2.0∙10 -5 mm 3 decreased in the nano-added clinkers., Competing Interests: The authors declare no conflict of interest.