Vol. 10, issue 1 (Jan-Jun 2000)

Abstracts

• Ioannis Meladiotis (Laboratoire de Géologie, Departement du génie civil, Université Aristote de Thessaloniki, GR-540 06 Thessaloniki, Grèce): «Identification et détermination par méthode géoradar des caractéristiques géométriques des couches conglomératiques stériles du gisement de lignite au Bassin de Sarigiol». Mining & Metallurgical Annals, vol. 10, issue 1, Jan-Jun 2000, pp. 15-26.

(RÉSUMÉ) Au cadre du probleme qui pose la présence de formations conglomératiques «dures» intercalées des formations stériles «tendres» au gisement de lignite du Bassin de Sarigiol lors d'exploitation, on a réalisé une campagne de prospection géophysique au moyen d'un géoradar. Le but essentiel de ce projet de note est de présenter les résultats de cette technique pour la détermination des caractéristiques géométriques des couches conglomératiques. La méthode géoradar basse sur la réflexion d'ondes électromagnétiques de hautes fréquences était bien adaptée au terrain d'étude et on a permis de localiser clairement les couches conglomératiques entourées des formations sablo-argilomarneux tendres. (Article en grec.) © Mining & Metallurgical Annals, Hellenic Society of Mining & Metallurgical Engineers, 2000.

• Konstantinos Komnitsas (National Technical University of Athens, Laboratory of Metallurgy GR-157 80 Zografos, Attica, Greece): "Methodology for the assessment of pollutants risk at industrial and hazardous waste disposal sites." Mining & Metallurgical Annals, vol. 10, issue 1, Jan-Jun 2000, pp. 27-44.

Most mining, metallurgical and chemical activities pose high risk and very often cause considerable harm to humans, other receptors and the ecosystem in general. The present paper aims to present the methodology for the quantitative assessment of risk related to hazardous pollutants at industrial and hazardous waste disposal sites. The methodology used is based on the following stages: (a) identification of the sources of pollution and of the most hazardous pollutants, (b) estimation of the exposure, related to the recep-tors at risk and the pollutants under study (by taking into account the environmental routes by which pollutants from the site can reach receptors), (c) assessment of the toxicity for each pollutant under study (using quantitative indices whenever possible), and (d) the characterisation of the risk (by assessing the magnitude of the consequences and the degree of uncertainty). The calculation of doses of the different pollutants, defined as administered, absorbed and target or effective, to which receptors are potentially exposed, is performed with the use of equations having as parameters the concentration of the pollutants on the exposure points, the daily intake of pollutants, the frequency and the duration of exposure, the body weight of the receptors and the averaging time (the averaged period over the exposure duration). The toxicity of the pollutants, which are characterised as carcinogens and non carcinogens, depends on the concentration of each pollutant at each exposure point. Finally, risk is calculated with the use of equations having as parameters the daily intake and the reference dose or the carcinogen slope factor for each pollutant under study. Risk calculation, in the present paper, is shown with characteristic examples. (Article in Greek.) © Mining & Metallurgical Annals, Hellenic Society of Mining & Metallurgical Engineers, 2000.

• Antonios Peppas¹, Dimitrios Filippou¹, Nikolaos Katiforis², Nymphodora Papassiopi¹, Katerina Adam³, Dimitrios Karatzovalis⁴, Theophilos Zambetakis⁴ (¹National Technical University, Laboratory of Metallurgy, GR-157 80 Zografos, Attiki, Greece; ²Hellenic Aerospace Industries SA, Greece; ³ TVX Hellas SA, Greece; ⁴Grecian Magnesite SA, Greece): "Process simulation of a pilot plant producing magnesium hydroxide by magnesia hydration." Mining & Metallurgical Annals, vol. 10, issue 1, Jan-Jun 2000, pp. 45-64.

The present paper deals with the simulation of a pilot plant producing magnesium hydroxide Mg(OH)₂, with specific quality specifications, by hydration of magnesia (MgO) originating from roasting of natural magnesite (MgCO₃). Three alternative pilot plant circuits were designed according to the specifications concerning the uses of magnesium hydroxide. The circuits were analysed using the METSIM software, which can compute accurately flow rates and can assist in selecting the equipment to be used. METSIM also allowed for the analysis of process stability. Thus, it was found that a hydration circuit with three reactors operating continuously in series and one batch reactor (for the hydration of partially hydrated coarse magnesia) is the best choice that offers high productivity and enhanced process stability. (Article in Greek.) © Mining & Metallurgical Annals, Hellenic Society of Mining & Metallurgical Engineers, 2000.

• Athina Tsetsekou (Dept. of Mineral Resources Engineering, Technical University of Crete, Campus of the Technical University of Crete, GR-731 00 Chania, Greece), Christos Agrafiotis (Dept. of Materials Science and Engineering, University of Ioannina Campus of the University of Ioannina, GR-471 10 Ioannina, Greece): "Ceramic filters." Mining & Metallurgical Annals, vol. 10, issue 1, Jan-Jun 2000, pp. 65-80.

The current environmental regulations together with stricter technological demands for the clean-up of gases and liquids from suspended particles have promoted extensively the use of ceramic filters and membranes. The present article gives an overview of the main types of ceramic filters, which have found industrial applications in the fields of hot gas clean-up and molten metal filtration. The technological solutions proposed are discussed, together with the methods and the materials of manufacturing and the advantages and disadvantages of each filter type. The current research trends in the field are presented, as well as the status of the ceramic filters market, both in Greece and abroad. © Mining & Metallurgical Annals, Hellenic Society of Mining & Metallurgical Engineers, 2000.

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