Zeolitized tuffs in pedotechnique for quarry restoration: evaluation of phytonutritional efficiency in ^AUP model horizons

A study was started aiming at assessing the suitability of zeolitized tuff as optimal mineral Human Transported Materials (HTMs) in pedotechnologies for quarry restoration

Use of zeolite-rich rocks and waste materials for the production of structural lightweight concretes

This paper aims at testing the use of mixtures constituted by natural zeolitized products and SiC-bearing industrial wastes (sludge deriving from polishing of porcelain stoneware tiles, hereafter DPM) for the production of lightweight expanded aggregates as constituents of structural and/or thermo-insulating lightweight concretes. Two commercial products have been used as zeolite natural source: Cab70 (Yellow facies of Campanian Ignimbrite) and IZclino (Turkish clinoptilolite-rich epiclastite). Different amounts of a calcareous material (Pozzano limestones - hereafter CP) from the Sorrento peninsula (Naples - Italy) were also added to a Cab70 - DPM mixture. All raw materials were characterized by means of mineralogical (XRPD) and chemical (XRF) analyses. All the products and mixtures were tested from a technological point of view by means of fusibility and firing tests in order to evaluate the expanding properties. It was evidenced that the expansion of the mixture was deeply depending on the occurrence of SiC in the industrial waste. The addition of CP (10 wt.%) to the mixtures accounts for an even increased expansion, though this is accompanied by a worsening of the mechanical features of the material. These results along with literature data allowed to select 3 mixtures (70% Cab70-30% DPM, 70% IZclino-30% DPM, 60% Cab70-30% DPM-10% CP) and each of them was used for the preparation of 5 l of lightweight aggregates afterward employed for the manufacture of lightweight concretes. It was remarked that natural zeolitized materials mixed with DPM (30 wt. %) can provide lightweight aggregates with densities ranging between 0.8 and 1.0 g/cm3 suitable for the preparation of structural lightweight concretes. The addition to the mixture of CP (10 wt.%) produces less dense aggregates (0.6-0.7 g/cm3) potentially useful for the manufacture of thermo insulating lightweight concretes

Lava stones from Neapolitan volcanic districts in the architecture of Campania region, Italy

Abstract Results of a research carried out on the lavas from Campi Flegrei and Somma-Vesuvius volcanic districts are reported here. The lavas have been widely employed, since Roman age, in several important monumental buildings of the Campania region, mainly in the town of Naples and in its province. They are classified as trachytes (Campi Flegrei products), tephri-phonolites and phono-tephrites (Somma-Vesuvius complex) from a petrographical point of view. Sampling was carried out from well-known exploitation districts. A substantial chemical difference between the products of the two sectors was confirmed, while petrophysical characterization evidenced similarity among the two different materials, although some differences were recorded even in samples coming from the same exploitation site

Italian zeolitized rocks of technological interest

Large areas of Italian territory are covered by thick and widespread deposits of zeolite-bearing volcaniclastic products. The main zeolites are phillipsite and chabazite spread over the whole peninsula, and clinoptilolite recorded only in Sardinia. A trachylic to phonolitic glassy precursor accounts for the formation of the former zeolites characterized by low Si/Al ratios (≤3.00), while clinoplilolite is related to more acidic volcanism. The genesis of most of these zeolitized deposits is linked to pyroclastic flow emplacement mechanisms characterized by quite high temperatures and by the presence of abundant fluids. The main utilization of these materials has been and still is as dimension stones in the building industry. Currently, limited amounts are also employed in animal farming (dietary supplement, pet litter and manure deodorizer) and in agriculture as soil improvement and slow-release fertilizers. New fields of application have been proposed for these products on account of their easy availability, very low cost, their high-grade zeolites (50-70%), and good technological features such as high cation exchange capacities and adsorption properties

Ceramica altomedievale dal castrum di Cuma (Campi Flegrei): aspetti peculiari di una produzione

International audienc

Byzantine ceramic production from Cuma (Campi Flegrei, Napoli)

International audienceSamples of table and cooking ware, dating back to the Byzantine period of the ancient Greek colony of Cuma, were analysed by optical microscopy, X-ray diffraction, X-ray fluorescence and scanning electron microscopy, in order to reconstruct the main technological properties of these manufactures. The comparison of minero-petrographical data from these samples with those of some kiln wastes allowed us to hypothesize a local manufacture for most of the investigated specimens and to confirm the relative reference groups. A restricted number of samples did not link with the main groups, indicating a regional (or maybe extra-regional) production, in agreement with the widespread circulation of this high-medieval ceramic production in southern Italy

Evaluation of natural phillipsite and chabazite as cation exchangers for copper and zinc

Chabazite and phillipsite, two zeolites widespread in many volcaniclastic deposits in central-southern Italy, were evaluated as cation exchangers for the removal of copper and zinc from aqueous solution. Equilibrium and kinetics of copper and zinc exchange reactions for sodium were investigated in order to verify the selectivity and the uptake rate of both zeolites for these heavy metals. Thermodynamic quantities, such as equilibrium constant, K-a, and Delta G degrees, as well as rate constant, K, were computed, and they showed that Na-chabazite displays a moderate selectivity and a favorable kinetics for copper, whereas in ail the other cases uses in wastewater treatment are not recommended