Toward a Multidisciplinary Strategy for the Classification and Reuse of Iron and Manganese Mining Wastes

The aim of this paper is to evaluate an integrated multidisciplinary strategy for the characterization of mining waste, their possible recycling and reuse. The use of Fe-Mn rich wastes in arsenic removal and phosphorus recovery from water and the phytoextraction potential of metals and their possible recovery from biomass are evaluated

Multi-scale geological evaluation for quarrying activities in ophiolitic rocks: Implications for asbestos-related legislation

This study illustrates the importance of undertaking a multi-scale geological approach when assessing ophiolites which may contain harmful asbestos. A case history from an active quarry in the Carinthia region of Austria is presented. The data obtained indicated four main zones within the heterogeneous rock mass. The study identified those horizons which could be used for commercial purposes, notably railway ballast and road sub-base. Extensive testing was undertaken which confirmed that asbestiform amphiboles were not present in the quarry. Attention is drawn to the ambiguities in current legislation regarding the presence of asbestos. \ua9 2013 Springer-Verlag Berlin Heidelberg

The assessment of particulate matter emitted from stone-crushing industry by correlating rock textures with particles generated after comminution and dispersed in air environment

The generation and emission of particulate matter from abrasion industry are subjects of the pollution monitoring by multidisciplinary study involving earth sciences and engineering disciplines. This work investigates the correlation between textural properties of in situ rock with class size distribution and morphology of particles generated after rock comminution and particles emitted in the air. A special comminution-dust sampling architecture was realised. The combined use of scanning electron microscopy and particle size analyser was considered in performing digital image analysis on both crushed products and airborne particles collected onto membrane filters. The results show that the size and morphology of crushed particles are linked to the petrographic rock properties. In particular, particles with fibrous morphology are prominent in rocks showing foliated textures where elongated minerals occurred, with implication for asbestos-bearing rocks. For what concerns the airborne particles, the results show that their aerodynamic diameters are independent of the crusher operating conditions. External parameters probably intervene in the distribution of the airborne particles emission, including the dynamic air fluxes, or environmental conditions. By applying mathematical models, the morphology and size range of airborne particles following the comminution processes can be predicted, and results has implication for pollutants contamination due to particulate matters emitted by crush stone industry. \ua9 2012 Springer-Verlag Berlin Heidelberg

The assessment of particulate matter emitted from stone-crushing industry by correlating rock textures with particles generated after comminution and dispersed in air environment

The generation and emission of particulate matter from abrasion industry are subjects of the pollution monitoring by multidisciplinary study involving earth sciences and engineering disciplines. This work investigates the correlation between textural properties of in situ rock with class size distribution and morphology of particles generated after rock comminution and particles emitted in the air. A special comminution-dust sampling architecture was realised. The combined use of scanning electron microscopy and particle size analyser was considered in performing digital image analysis on both crushed products and airborne particles collected onto membrane filters. The results show that the size and morphology of crushed particles are linked to the petrographic rock properties. In particular, particles with fibrous morphology are prominent in rocks showing foliated textures where elongated minerals occurred, with implication for asbestos-bearing rocks. For what concerns the airborne particles, the results show that their aerodynamic diameters are independent of the crusher operating conditions. External parameters probably intervene in the distribution of the airborne particles emission, including the dynamic air fluxes, or environmental conditions. By applying mathematical models, the morphology and size range of airborne particles following the comminution processes can be predicted, and results has implication for pollutants contamination due to particulate matters emitted by crush stone industry. © 2012 Springer-Verlag Berlin Heidelberg

Studio geologico-strutturale per l'ottimizzazione della coltivazione di rocce ofiolitiche: il caso della cava "Tana dei Banditi" in localit\ue0 Carpenara (Genova)

Exposures of ophiolitic rocks define extractive sites with geological complexities that may influence the quarrying activities. This study concerns the "Tana dei Banditi" quarry located in the Carpenara village (Genoa), managed by the Frantoio del Tigullio Company. Using a multidisciplinary approach that integrated geological-structural and minero-petrographic analyses, we assessed: (I) the geological-structural setting of the quarry, (II) the geological-structural relationships between the extracted lithotype (Capenara metagabbro) and the surrounding units, (III) the petrographic characteristics, (IV) the geometry, distribution, and kinematics of the main deformation structures, and (V) the relationships between deformation structures and secondary mineralization. Our results can: (I) improve the quarry activities through the individuation of specific sectors in the deposit, and (II) provide a firstorder methodology for evaluating critical factors related to quarrying in ophiolitic rocks

Experimental study of coarse soil properties influencing soil abrasivity

The paper reports selected results of a study on tool wear for mechanized tunnelling in coarse soil. Several laboratory soil abrasion tests were performed and the results correlated with mineralogical composition, shape and surface roughness of the grains and the grain size curve of the soils. The analysis of the results clearly confirms the well-known correlation between soil abrasivity and quartz content and, for the soils tested, can quantify the relevant influence of grain size and grain roughness. We also report and discuss results useful for quantifying the positive effect of the addition of different chemical agents, injected as foams in a process known as soil conditioning, commonly performed in mechanized tunnel excavation using tunnel boring machines whit earth pressure technology to minimise tool consumption

Two-phase flow field in a cylindrical hydrocyclone with tangential discharge

The two-phase, air-water flow pattern in a DynaWhirlpool type centrifugal separator is investigated using time-dependent, three-dimensional numerical simulation. The air-water interface is captured by the Volume-Of-Fluid approach, while the unresolved turbulence fluctuations are modeled via a second-order differential-stress turbulence model. The methodology is validated with available laser-Doppler data acquired on a similar separation device. The velocity field within the cyclone is thoroughly characterized for a single operating condition, revealing the presence of a stable air core that flows axially faster than the surrounding water

Asbestos fibre identification vs. evaluation of asbestos hazard in ophiolitic rock mélanges, a case study from the Ligurian Alps (Italy)

In recent years, the high incidence of harmful health effects through inhalation of airborne asbestos from amphibole-bearing rock mélanges has been thoroughly documented. Here, we present a field-based, multi-scale geological approach aimed at illustrating the occurrence of amphibole fibrous mineralisation in an ophiolitic suite from the Ligurian Alps (Italy) and discussing the implication on in situ determination of the asbestos hazard. The rock mélange is composed of plurimetre-sized blocks of different lithotypes (metagabbro, serpentinite, chloritoschist) juxtaposed by the meaning of tectonic structures. The geological-structural survey revealed that the fibrous mineralisation is localised in specific structural sites of the rock volume, including veins and schistosity. Both micro-chemical and crystal structure analyses on selected fibrous samples revealed that actinolite fibres grow in veins within the metagabbro and in chloritoschists, while fibrous tremolite occurs in serpentinite schistosity. The morphological features of these amphibole fibres have been analysed in TEM images and used for classifying them as "asbestiform" or "non-asbestiform". The results show that the asbestos hazard determination is not unequivocally identified when different procedures for asbestos fibre identification and classification are applied. This may have impact on normatives and regulations in defining environmental hazards due to asbestos occurrence. © 2014 Springer-Verlag Berlin Heidelberg

Asbestos fibre identification vs. evaluation of asbestos hazard in ophiolitic rock m\ue9langes, a case study from the Ligurian Alps (Italy)

In recent years, the high incidence of harmful health effects through inhalation of airborne asbestos from amphibole-bearing rock m\ue9langes has been thoroughly documented. Here, we present a field-based, multi-scale geological approach aimed at illustrating the occurrence of amphibole fibrous mineralisation in an ophiolitic suite from the Ligurian Alps (Italy) and discussing the implication on in situ determination of the asbestos hazard. The rock m\ue9lange is composed of plurimetre-sized blocks of different lithotypes (metagabbro, serpentinite, chloritoschist) juxtaposed by the meaning of tectonic structures. The geological-structural survey revealed that the fibrous mineralisation is localised in specific structural sites of the rock volume, including veins and schistosity. Both micro-chemical and crystal structure analyses on selected fibrous samples revealed that actinolite fibres grow in veins within the metagabbro and in chloritoschists, while fibrous tremolite occurs in serpentinite schistosity. The morphological features of these amphibole fibres have been analysed in TEM images and used for classifying them as \u201casbestiform\u201d or \u201cnon-asbestiform\u201d. The results show that the asbestos hazard determination is not unequivocally identified when different procedures for asbestos fibre identification and classification are applied. This may have impact on normatives and regulations in defining environmental hazards due to asbestos occurrence