Vol. 14 (Jan-Dec 2004)

Abstracts

• Panagiotis J. Chrissochou (Labor der Technische Geologie Fakultat Bauingenieure, Aristoteles Universitat von Thessaloniki GR-540 06 Thessaloniki Griechenland): "Analysieren und Praktisch Anwenden Einer Verfahren für der Bestiemmung des Mittleren Normalabstandes Zwischen Klüften In Gesteinmassiv." Mining & Metallurgical Annals, vol. 14, Jan-Dec 2004, pp. 21-32.

Früheren geologisch-tektonische Untersuchungsmessungen fur statistischen Analysen der Klüften in Marmor gebiete der Südlichen Rhodopen Massivs, fand mit Hilfe eines planmaâigen Verfahrens statt.

Die Häufigkeit der Klüften (Diaklasen) in stark zerklüfteten Marmorlagerstätten des Zonen-Massivs, ergab die Möglichkeit der praktischen Anwendung eines Planmäßigen geometrischen Verfahrens für die Bestimmung des mittleren Normalabstandes zwischen Klüften mit idendischen tektonischen Daten.

Bei Untersuchungen in Marmorrsteinbrüchen des Süd-Westlichen Gebietes der tektonischen Zone, hat man versucht die Methode praktisch anzuwenden um genauere Ergebnische zu erreichen. (Article in Greek with summary in German.) © Mining & Metallurgical Annals, Hellenic Society of Mining & Metallurgical Engineers, 2004.

• Agoro Dimadi and Ioannis Meladiotis (Laboratory of Engineering Geology, Departement of Civil Engineering, Aristotle Univercity of Thessaloniki, GR-540 06 Thessaloniki, Greece): "Use of the Eraso software to locate drilling positions for productive water wells in the rocky underlying formations of the western perimetrical zone of the Sarigiol basin (Kozani, Greece)." Mining & Metallurgical Annals, vol. 14, Jan-Dec 2004, pp. 33-44.

The fieldwork and laboratory research done in the western perimetrical zone of the Sarigiol bassin (Kozani Prefecture, Greece) proved the presence of subterranean aquiferous circulation in the underlying rocky formations along the communities Pontokomi and Mavrodendri. In order to locate the positions for drilling productive water wells in these rocky formations, we applied a methodology that allows for the identification of the principle directions of subterranean drainage of aquiferous circulation, in the aforementioned formations, with the use of the software Eraso. This software takes into account the geometrical characteristics of faulted microstructures such as conjugated microfaults and stylolites conjugated with feather joints or with microfaults.

With the application of the aforementioned methodology, eight positions were finally identified for drilling productive water wells. The drilling results were very successful. All the eight wells, either alone or in both of two, perforated independent exploitable aquifers systems developing into the fractured miocen conglomerates and karstified Triassic-Jurassic limestones. (Article in Greek.) © Mining & Metallurgical Annals, Hellenic Society of Mining & Metallurgical Engineers, 2004.

• Anastassios Grammatikopoulos (University of Patras, Department of Geology, Section of Earth Materials, GR-265 00 Patras, Greece), Vasilios Tsikouras (University of Patras, Department of Geology, Section of Earth Materials, GR-265 00 Patras, Greece) and Konstantinos Salonikis (Otavi Minerals GmbH, 14th km Athens-Lamia Nat. Road, PO Box 51528, Athens, Greece): "The application of mineralogical studies of gold deposits in metallurgical processing." Mining & Metallurgical Annals, vol. 14, Jan-Dec 2004, pp. 45-60.

Quantitative process mineralogy has become an integral part in gold exploration and metallurgical operations. Gold occurs in different forms and it has been used in process mineralogy to describe the different chemical states in which gold is encountered in ore deposits. The most commonly known form is that of gold minerals and alloys, submicroscopic gold, which is invisible under the optical microscope (i.e., less than 1 μm in diameter), including solid solution gold, colloidal size particulate gold and surface bound gold. Exploration companies and contemporary gold mining operations generally deal with very low-grade ores, in the order of a few grams per tone, in which gold is often fine-grained and commonly associated with polymetallic ores. These difficulties cause problems in the understanding of the gold mineralogy, processing and recovery, but also complicate the mineralogical studies to characterize gold, on which the process development flowsheet should be based. A comprehensive understanding of the gold mineralogy of an ore is a valuable tool not only in selecting the most appropriate gold extraction process but also for optimizing gold metallurgy, and in some cases may provide useful information for developing the genetic model. (Article in Greek.) © Mining & Metallurgical Annals, Hellenic Society of Mining & Metallurgical Engineers, 2004.

• Marios Leonardos (Public Power Corporation, Valtinon 76, GR-114 74 Athens, Greece): "The significance of the soil residual shear strength for the stability of slopes in mining excavations." Mining & Metallurgical Annals, vol. 14, Jan-Dec 2004, pp. 61-78.

The significance of the soil residual shear strength for the development of progressive failure in mining slopes is treated. The mechanism of progressive failure occurs in the high mining slopes not only when soft material is excavated but also in the case of hard rock mining operations. Direct shear tests, with conventional and in precut samples, are used for soil residual shear strength determination. The ring shear apparatus was recently used and the results from slow shearing in these tests were in better agreement with back analysis calculations. The soil residual shear strength is well correlated with the plasticity index (PI) and the clay fraction (CF). When a soil has plasticity index (PI) > 25 or clay fraction (CF) > 50, it should be tested for residual shear strength in the ring shear apparatus. The use of the residual shear strength does not imply a conservative slope design but it must be considered as a actual condition. Special care should be exercised in slope modelling during stability calculations in order to simulate the progressive failure with acceptable accuracy. The stability calculations must also consider the progressive failure within layers, prone to develop such a condition, even when they are located well below the final pit level. (Article in Greek.) © Mining & Metallurgical Annals, Hellenic Society of Mining & Metallurgical Engineers, 2004.

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