Dr. Georgios Triantafyllou Mineral Resources Engineer, M.Sc.Technical University of Crete School of Mineral Resources Engineering Exploration and Positioning Division Laboratory of Petrology and Economic Geology Phone: +00306945668651 Address: 6H PARODOS AGIOU ONOUFRIOU KOUNOUPIDIANA, POBOX 557
International Conference on Raw Materials and Circular Economy, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Biogenic limestones from the area of Herethiana, Western Crete, have been examined in order to ev... more Biogenic limestones from the area of Herethiana, Western Crete, have been examined in order to evaluate their properties as hydraulic lime raw materials. Samples of three different horizons, X1, X2, and X3 have been investigated using X -ray diffraction (XRD), X - ray fluorescence spectroscopy (XRF), optical and scanning electron microscopy (SEM) and calcimetry analyses. According to the XRD analyses the main component is calcite variying between 80% and 84%. Illite, quartz, albite and goethite are also present in minor amounts. Representative samples, with a particular grain size of the different horizons, were burned at 900°C for 12 hours, to produce hydraulic lime. The analysis of the calcined products showed that larnite, portlandite and lime appear in all samples. Quartz and hematite are also present in minor amounts. The abundance of amorphous silica in the form of silica sponges and diatoms offers the necessary active silica to form, together with an appropriate portion of fr...
This study was designed to determine the physical and technical characteristics of the building s... more This study was designed to determine the physical and technical characteristics of the building stones and mortars of the Koule Castle Heraklion, in order to use compatible materials in future restoration works. Five core samples of rocks and masonry mortars have been extracted from different parts of the monument. Both mortar and rock samples have been studied by optical microscopy and X-ray diffraction (XRD). Their morphological characteristics, granulometry and mineralogical composition have been determined. In the old mortars a thermogravimetric analysis was carried out, while mortar samples have also been studied by scanning electron microscopy. The building stones of Koule Castle are in their majority biomicritic breccia limestones and bioclastic limestones. The binder of the studied mortars consists of calcite, as a result of the lime carbonation. The inert material of the mortars consists mainly of calcite and secondarily of quartz. The inert to binder material ratio was det...
pressure shadows, kinking of the phyllosilicates, and mechanical reorientation of the mineral com... more pressure shadows, kinking of the phyllosilicates, and mechanical reorientation of the mineral components along s 1 . Preferred orientation of the phyllosilicates and slaty cleavage (s 1) have developed, and represent one of the most pronounced structures along which the rock prefers to split. It was shown that in all cases a good correlation exists between the average point load strength index of the rock samples, the direction of loading, and the petrographic/fabric type in the samples without pre-failed surfaces. Failures in the slate and metasiltstone follow concentrations of preferred oriented phyllosilicates of the s 1 slaty cleavage in the first place. Other parameters (e.g. average grain size, granoblastic texture, quantity of quartz etc.) are of secondary importance and find principal expression in homogeneous rocks and in cases when they were loaded transversely to the main discontinuity. In the pre-failed rocks, the direction of loading played the major role. The relevance...
The industrial sector, including cement production, is responsible for approximately one-third of... more The industrial sector, including cement production, is responsible for approximately one-third of global CO2 emissions. Cement is a basic material for building and civil engineering construction that today tracks the overall economic situation very closely. The European Commission Integrated Pollution and Prevention Control (IPPC) bureau in co-operation with the cement industry, national authorities and NGOs, has defined the Best Available Techniques (BAT) in order to improve its environmental performance. Actually the cement industry is one of the very first sectors the IPPC directive deals with. The present paper outlines the current status of the cement industry and defines the most important issues required towards improvement of sustainability, such as cleaner production methods and enhanced environmental performance through establishment of objective environmental indicators. Improvement of efficiency, use of alternative fuels, production of blended and alternative cements are...
Hydraulic limes are traditional construction materials and were the primary hydraulic binders use... more Hydraulic limes are traditional construction materials and were the primary hydraulic binders used in mortars prior to the development of ordinary Portland cement. They have strongly re-emerged in 21st century as a restoration material, since compatibility with the original structures is one of the fundamental principles of modern conservation. Natural hydraulic limes result from burning of marly limestones at relatively low temperatures (below 1250 • C) with reduction to powder by slaking with or without grinding. Chemically, hydraulic lime might be classified as being intermediate between lime and Portland or natural cement. It possesses considerable free lime (CaO, or CaO + MgO) so that the product hydrates and slakes in water converting to calcium hydroxide. At the same time, it contains sufficient calcium silicates to give the binder its hydraulic properties. The degree of hydraulicity of these limes varies considerably and thus they are classified as feebly, moderately and emi...
Cement industry is facing growing challenges in conserving materials and conforming to the demand... more Cement industry is facing growing challenges in conserving materials and conforming to the demanding environ-mental standards. Therefore, there is great interest in the development, investigation and use of binders alternatives to Portland cement. Natural hydraulic lime (NHL) binders have become nowadays materials with high added value, due to their advantages in various construction applications. Some of them include compatibility, suitability, workability and the versatility in applications. NHL binders are made from limestones which contain sufficient argillaceous or siliceous components fired at relatively low temperatures, with reduction to powder by slaking with or without grinding. This study is focused in developing technology for small-scale production of cementitious binders, combining the knowledge and experience of geologists and mineral resources engineers. The first step of investigation includes field techniques to the study the lithology, texture and sedimentary stru...
Twenty eight Greek low rank coals (peat, peaty lignites, lignites of both matrix and xylite-rich ... more Twenty eight Greek low rank coals (peat, peaty lignites, lignites of both matrix and xylite-rich lithotypes, and subbituminous coals) were physically activated by pyrolysis in order to increase their adsorptive surface area. Results show that the surface area of activated Greek low rank coal (lignite) samples increased substantially and in some cases more than that of commercial products. The increase in surface area was higher for higher carbon content and for lower the ash content. The adsorption capacity of activated coals for NO, SO 2 C 3 H 3 and a mixture of light hydrocarbons (CH 4 , C 2 H 6 , C 3 H 8 and C 4 H 10) at various temperatures, as well as the adsorption of phenols and the decrease of COD (Chemical Oxygen Demand) in olive oil mill waste disposals was measured in selected samples. For the gases the results show a positive correlation between the surface area and the gas adsorption. In contrast, the gas adsorption is inversely correlated with temperature. The maximum recorded adsorbed values are: NO = 8.22 x 10-5 mol/g at 35 o C; SO 2 = 38.65 x 10-5 mol/g at 60 o C; C 3 H 6 = 38.9 x 10-5 mol/g at 35 o C: and light hydrocarbons = 19.24 x 10-5 mol/g at 35 o C; The long chain hydrocarbons are preferentially adsorbed on activated lignites as compared to the short chain hydrocarbons. The maximum recorded adsorption of phenol was 30.6 mg/g of activated lignite, while the commercial one (HOK) adsorbed 16mg/g of activated lignite. The COD reduction was 1262 mg of COD/g of activated lignite while in the commercial one the reduction was 439 mg of COD/g of activated lignite. The results also suggest a positive correlation between the surface area and the content of the telohuminite maceral subgroup above the level of 45%.
... 03NT41987, Doe/netl Mercury Control Technology Conference, December 11-13, 2006, Pittsburg, P... more ... 03NT41987, Doe/netl Mercury Control Technology Conference, December 11-13, 2006, Pittsburg, PAmercury/presentations/Dombrowski presentation--121106.pdf ... 9. Kelessidis, VC, C. Tsamantaki, A. Michalakis, GE Christidis, P. Makri, C. Papanicolaou, A. Foscolos, 2007a. ...
Lime is a product with several uses. The most important are in metallurgy, in the manufacture of ... more Lime is a product with several uses. The most important are in metallurgy, in the manufacture of paper, glass, paints and sugar, for construction and environmental uses. At the present study the contribution of lime in the protection of environment is described. The lime industry product constitutes a significant segment of the environment industry with future prospects of growth. The treatment of municipal potable water, the treatment of urban sewages, the contribution in the neutralization of acid industrial discharges and the flue gas desulfurization, constitute the main environmental applications of the lime industry products. It is appreciated that the continuously increasing demand of products and technologies friendly to the environment over the next decade will have as a consequence the increase of lime production, particularly after the increasing application of stricter environmental legislation in national, as well as in global level.
Η άσβεστος είναι ένα προϊόν με πάρα πολλές χρήσεις. Οι κυριότερες περιλαμβάνουν τη χρήση ασβέστου... more Η άσβεστος είναι ένα προϊόν με πάρα πολλές χρήσεις. Οι κυριότερες περιλαμβάνουν τη χρήση ασβέστου στη μεταλλουργία, στην παραγωγή χαρτιού, γυαλιού, χρωμάτων και ζάχαρης, στον κλάδο των κατασκευών και σε περιβαλλοντικές εφαρμογές. Στην εργασία αυτή γίνεται περιγραφή των σημαντικότερων χρήσεων της ασβέστου σε διεργασίες σχετικές με την προστασία του περιβάλλοντος. Το περιβάλλον αποτελεί τον τομέα διάθεσης των προϊόντων της βιομηχανίας παραγωγής ασβέστου με τις πιο σημαντικές προοπτικές ανάπτυξης. Η επεξεργασία του πόσιμου νερού, η επεξεργασία των αστικών λυμάτων, η συμβολή στην εξουδετέρωση όξινων απορροών και η αποθείωση των καπναερίων αποτελούν τις κυριότερες περιβαλλοντικές εφαρμογές της ασβέστου. Εκτιμάται πως η ολοένα αυξανόμενη ζήτηση προϊόντων και τεχνολογιών φιλικών προς το περιβάλλον την επόμενη δεκαετία, θα έχει ως συνέπεια την αύξηση της παραγωγής της ασβέστου, ιδιαίτερα μετά και από την εφαρμογή των διαφόρων νομοθεσιών για το περιβάλλον τόσο σε εθνικό, όσο και σε παγκόσμιο επίπεδο.
Με βάση πρώτες ύλες από μονάδα παραγωγής αδρανών υλικών και ασβέστου από την περιοχή Φονέ Αποκορώ... more Με βάση πρώτες ύλες από μονάδα παραγωγής αδρανών υλικών και ασβέστου από την περιοχή Φονέ Αποκορώνου του νομού Χανίων, έγινε σύνθεση δομικών κονιαμάτων για διάφορες χρήσεις. Επιλέχθηκαν διαφορετικές κοκκομετρικές κατανομές των αδρανών υλικών και εξετάστηκε η επίδραση της περιεχόμενης παιπάλης. Ως συνδετικές κονίες χρησιμοποιήθηκαν υδράσβεστος κόνεως τύπου CL 80 και λευκό τσιμέντο. Πραγματοποιήθηκε έλεγχος των τεχνικών χαρακτηριστικών των παρασκευασθέντων δοκιμίων με προσδιορισμό της αντοχής σε μονοαξονική θλίψη μετά από διαφορετικούς χρόνους ωρίμανσης, καθώς και μελέτη τεχνητής γήρανσης. Βάσει των αποτελεσμάτων ποιοτικού ελέγχου τα δομικά αυτά κονιάματα κατατάσσονται στις κατηγορίες Μ1, Μ2, Μ2.5, CSI και CSII, κατά ΕΝ 998.02.
Νεογενείς ασβεστόλιθοι από τη Δυτική Κρήτη αξιολογήθηκαν ως προς την καταλληλότητά τους για την π... more Νεογενείς ασβεστόλιθοι από τη Δυτική Κρήτη αξιολογήθηκαν ως προς την καταλληλότητά τους για την παρασκευή φυσικής υδραυλικής ασβέστου. Δείγματα πετρωμάτων από διαφορετικούς ορίζοντες εξετάστηκαν ορυκτολογικά με περιθλασιμετρία ακτίνων-Χ (XRD), οπτική και ηλεκτρονική μικροσκοπία σάρωσης (SEM) και χημικά με φασματοσκοπία ακτίνων-Χ φθορισμού (XRF) και ασβεστιμετρία. Τα δείγματα περιέχουν κυρίως ασβεστίτη που κυμαίνεται από 74 έως 86% και σε μικρότερες αναλογίες, χαλαζία, αλβίτη, καλιούχο άστριο, παραγωνίτη και αργιλικά ορυκτά όπως ιλλίτη, μοντμοριλλονίτη και καολινίτη, η παρουσία των οποίων πιστοποιήθηκε στο αδιάλυτο υπόλειμμα. Αντιπροσωπευτικά δείγματα συγκεκριμένης κοκκομετρίας, χρησιμοποιήθηκαν για την παραγωγή υδραυλικής ασβέστου μετά από έψηση για χρονικό διάστημα δώδεκα ωρών σε θερμοκρασία 900 °C. Η ανάλυση των προϊόντων έψησης έδειξε ότι οι σχηματισθείσες φάσεις είναι κυρίως πορτλανδίτης και οι μορφές β και α΄ του πυριτικού διασβεστίου. Τα προϊόντα της έψησης χαρακτηρίζονται ως φυσικές υδραυλικές άσβεστοι μέτριας (CI 0.7) και υψηλής υδραυλικότητας (CI 1.4 - 1.6).
Δείγματα νεογενών βιοκλαστικών ασβεστολίθων από την περιοχή Αγίας Βαρβάρας Ηρακλείου Κρήτης, αξιο... more Δείγματα νεογενών βιοκλαστικών ασβεστολίθων από την περιοχή Αγίας Βαρβάρας Ηρακλείου Κρήτης, αξιολογήθηκαν με ορυκτολογικές και χημικές μεθόδους ως προς την καταλληλότητά τους για την παραγωγή υδραυλικών κονιών. Οι πρώτες ύλες περιέχουν ικανοποιητικά ποσοστά οξειδίου του ασβεστίου και διοξειδίου του πυριτίου. Μετά την έψησή τους σε θερμοκρασία 900 °C για χρονικό διάστημα 12 ωρών και στην συνέχεια αέρια σβέση τους, προέκυψαν η υδραυλική φάση του λαρνίτη (β-C2S) και πορτλανδίτης σε διαφορετικές ποσοστιαίες αναλογίες, για τα δείγματα των διαφορετικών οριζόντων. Έγινε σύνθεση κονιαμάτων υδραυλικής ασβέστου με κατάλληλα αδρανή υλικά και ελέγχθηκε η μηχανική τους συμπεριφορά με δοκιμές ανεμπόδιστης μονοαξονικής θλίψης σε διαφορετικούς χρόνους ζωής των δοκιμίων. Σύμφωνα με τις αντίστοιχες ευρωπαϊκές προδιαγραφές οι παραχθείσες κονίες χαρακτηρίζονται σαν φυσικές υδραυλικές άσβεστοι χαμηλής (NHL 2) και υψηλής (NHL 5) υδραυλικότητας.
Within the framework of a research supported by the 18 th ephorate of Byzantine antiquities for t... more Within the framework of a research supported by the 18 th ephorate of Byzantine antiquities for the preservation and restoration of the castle of Arta, a total of sixteen representative samples of late Byzantine and Ottoman pottery dated from the 13 th to 19 th century were analyzed. This research aims to determine the firing techniques applied in the manufacturing technology of the ceramics and shed light on the provenance (siliceous or calcareous) of the raw materials used in their production. The potsherds fall into bodies and bases of common ware samples, either glazed or unglazed. As the castle plays a significant role during the medieval and modern history of the city, the pottery collected during the survey carried out in its interior, is an important source of evidence for cultural and technological transformations that occurred within the local society. A multi-analytical approach including petrographic, mineralogical and chemical investigations by means of optical microscopy, powder X-Ray Diffraction (XRD) and X-Ray Fluorescence Spectroscopy (XRF) was used for the determination of the morphological, mineralogical and chemical characteristics of the potsherds. Diagnostic features like color, shape, decorative style, glaze and/or engobe were also taken into account. Powder diffraction patterns of all samples are dominated by reflections of quartz. Specific phases detected by XRD, primary like anorthite, diopside and gehlenite are considered to be neoformed minerals during the stage of production and serve as firing temperature markers. The presence of hematite in most samples suggests that the artefacts were manufactured by firing in an oxidizing atmosphere. The results of the bulk chemical analysis proved that the ceramic materials are categorized as rich in SiO 2 (average of 57.8 %), followed by lower amounts of Al 2 O 3 (average of 14.7 %), Fe 2 O 3 (average 7.6 %), CaO (average 6 %) and MgO (4 %). According to the plotting to triangular CaO+MgO -Al 2 O 3 -SiO 2 compositional system diagrams, the examined potsherds are derived mainly from Ca-poor clay raw materials. Based on the experimental results, a distinction between two main different firing procedures characterizes the production of the samples. Those produced in relatively low firing conditions (from 700 to 850°C) and pottery fired at higher temperatures (above 900 and up to 1050°C).
International Conference on Raw Materials and Circular Economy, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Biogenic limestones from the area of Herethiana, Western Crete, have been examined in order to ev... more Biogenic limestones from the area of Herethiana, Western Crete, have been examined in order to evaluate their properties as hydraulic lime raw materials. Samples of three different horizons, X1, X2, and X3 have been investigated using X -ray diffraction (XRD), X - ray fluorescence spectroscopy (XRF), optical and scanning electron microscopy (SEM) and calcimetry analyses. According to the XRD analyses the main component is calcite variying between 80% and 84%. Illite, quartz, albite and goethite are also present in minor amounts. Representative samples, with a particular grain size of the different horizons, were burned at 900°C for 12 hours, to produce hydraulic lime. The analysis of the calcined products showed that larnite, portlandite and lime appear in all samples. Quartz and hematite are also present in minor amounts. The abundance of amorphous silica in the form of silica sponges and diatoms offers the necessary active silica to form, together with an appropriate portion of fr...
This study was designed to determine the physical and technical characteristics of the building s... more This study was designed to determine the physical and technical characteristics of the building stones and mortars of the Koule Castle Heraklion, in order to use compatible materials in future restoration works. Five core samples of rocks and masonry mortars have been extracted from different parts of the monument. Both mortar and rock samples have been studied by optical microscopy and X-ray diffraction (XRD). Their morphological characteristics, granulometry and mineralogical composition have been determined. In the old mortars a thermogravimetric analysis was carried out, while mortar samples have also been studied by scanning electron microscopy. The building stones of Koule Castle are in their majority biomicritic breccia limestones and bioclastic limestones. The binder of the studied mortars consists of calcite, as a result of the lime carbonation. The inert material of the mortars consists mainly of calcite and secondarily of quartz. The inert to binder material ratio was det...
pressure shadows, kinking of the phyllosilicates, and mechanical reorientation of the mineral com... more pressure shadows, kinking of the phyllosilicates, and mechanical reorientation of the mineral components along s 1 . Preferred orientation of the phyllosilicates and slaty cleavage (s 1) have developed, and represent one of the most pronounced structures along which the rock prefers to split. It was shown that in all cases a good correlation exists between the average point load strength index of the rock samples, the direction of loading, and the petrographic/fabric type in the samples without pre-failed surfaces. Failures in the slate and metasiltstone follow concentrations of preferred oriented phyllosilicates of the s 1 slaty cleavage in the first place. Other parameters (e.g. average grain size, granoblastic texture, quantity of quartz etc.) are of secondary importance and find principal expression in homogeneous rocks and in cases when they were loaded transversely to the main discontinuity. In the pre-failed rocks, the direction of loading played the major role. The relevance...
The industrial sector, including cement production, is responsible for approximately one-third of... more The industrial sector, including cement production, is responsible for approximately one-third of global CO2 emissions. Cement is a basic material for building and civil engineering construction that today tracks the overall economic situation very closely. The European Commission Integrated Pollution and Prevention Control (IPPC) bureau in co-operation with the cement industry, national authorities and NGOs, has defined the Best Available Techniques (BAT) in order to improve its environmental performance. Actually the cement industry is one of the very first sectors the IPPC directive deals with. The present paper outlines the current status of the cement industry and defines the most important issues required towards improvement of sustainability, such as cleaner production methods and enhanced environmental performance through establishment of objective environmental indicators. Improvement of efficiency, use of alternative fuels, production of blended and alternative cements are...
Hydraulic limes are traditional construction materials and were the primary hydraulic binders use... more Hydraulic limes are traditional construction materials and were the primary hydraulic binders used in mortars prior to the development of ordinary Portland cement. They have strongly re-emerged in 21st century as a restoration material, since compatibility with the original structures is one of the fundamental principles of modern conservation. Natural hydraulic limes result from burning of marly limestones at relatively low temperatures (below 1250 • C) with reduction to powder by slaking with or without grinding. Chemically, hydraulic lime might be classified as being intermediate between lime and Portland or natural cement. It possesses considerable free lime (CaO, or CaO + MgO) so that the product hydrates and slakes in water converting to calcium hydroxide. At the same time, it contains sufficient calcium silicates to give the binder its hydraulic properties. The degree of hydraulicity of these limes varies considerably and thus they are classified as feebly, moderately and emi...
Cement industry is facing growing challenges in conserving materials and conforming to the demand... more Cement industry is facing growing challenges in conserving materials and conforming to the demanding environ-mental standards. Therefore, there is great interest in the development, investigation and use of binders alternatives to Portland cement. Natural hydraulic lime (NHL) binders have become nowadays materials with high added value, due to their advantages in various construction applications. Some of them include compatibility, suitability, workability and the versatility in applications. NHL binders are made from limestones which contain sufficient argillaceous or siliceous components fired at relatively low temperatures, with reduction to powder by slaking with or without grinding. This study is focused in developing technology for small-scale production of cementitious binders, combining the knowledge and experience of geologists and mineral resources engineers. The first step of investigation includes field techniques to the study the lithology, texture and sedimentary stru...
Twenty eight Greek low rank coals (peat, peaty lignites, lignites of both matrix and xylite-rich ... more Twenty eight Greek low rank coals (peat, peaty lignites, lignites of both matrix and xylite-rich lithotypes, and subbituminous coals) were physically activated by pyrolysis in order to increase their adsorptive surface area. Results show that the surface area of activated Greek low rank coal (lignite) samples increased substantially and in some cases more than that of commercial products. The increase in surface area was higher for higher carbon content and for lower the ash content. The adsorption capacity of activated coals for NO, SO 2 C 3 H 3 and a mixture of light hydrocarbons (CH 4 , C 2 H 6 , C 3 H 8 and C 4 H 10) at various temperatures, as well as the adsorption of phenols and the decrease of COD (Chemical Oxygen Demand) in olive oil mill waste disposals was measured in selected samples. For the gases the results show a positive correlation between the surface area and the gas adsorption. In contrast, the gas adsorption is inversely correlated with temperature. The maximum recorded adsorbed values are: NO = 8.22 x 10-5 mol/g at 35 o C; SO 2 = 38.65 x 10-5 mol/g at 60 o C; C 3 H 6 = 38.9 x 10-5 mol/g at 35 o C: and light hydrocarbons = 19.24 x 10-5 mol/g at 35 o C; The long chain hydrocarbons are preferentially adsorbed on activated lignites as compared to the short chain hydrocarbons. The maximum recorded adsorption of phenol was 30.6 mg/g of activated lignite, while the commercial one (HOK) adsorbed 16mg/g of activated lignite. The COD reduction was 1262 mg of COD/g of activated lignite while in the commercial one the reduction was 439 mg of COD/g of activated lignite. The results also suggest a positive correlation between the surface area and the content of the telohuminite maceral subgroup above the level of 45%.
... 03NT41987, Doe/netl Mercury Control Technology Conference, December 11-13, 2006, Pittsburg, P... more ... 03NT41987, Doe/netl Mercury Control Technology Conference, December 11-13, 2006, Pittsburg, PAmercury/presentations/Dombrowski presentation--121106.pdf ... 9. Kelessidis, VC, C. Tsamantaki, A. Michalakis, GE Christidis, P. Makri, C. Papanicolaou, A. Foscolos, 2007a. ...
Lime is a product with several uses. The most important are in metallurgy, in the manufacture of ... more Lime is a product with several uses. The most important are in metallurgy, in the manufacture of paper, glass, paints and sugar, for construction and environmental uses. At the present study the contribution of lime in the protection of environment is described. The lime industry product constitutes a significant segment of the environment industry with future prospects of growth. The treatment of municipal potable water, the treatment of urban sewages, the contribution in the neutralization of acid industrial discharges and the flue gas desulfurization, constitute the main environmental applications of the lime industry products. It is appreciated that the continuously increasing demand of products and technologies friendly to the environment over the next decade will have as a consequence the increase of lime production, particularly after the increasing application of stricter environmental legislation in national, as well as in global level.
Η άσβεστος είναι ένα προϊόν με πάρα πολλές χρήσεις. Οι κυριότερες περιλαμβάνουν τη χρήση ασβέστου... more Η άσβεστος είναι ένα προϊόν με πάρα πολλές χρήσεις. Οι κυριότερες περιλαμβάνουν τη χρήση ασβέστου στη μεταλλουργία, στην παραγωγή χαρτιού, γυαλιού, χρωμάτων και ζάχαρης, στον κλάδο των κατασκευών και σε περιβαλλοντικές εφαρμογές. Στην εργασία αυτή γίνεται περιγραφή των σημαντικότερων χρήσεων της ασβέστου σε διεργασίες σχετικές με την προστασία του περιβάλλοντος. Το περιβάλλον αποτελεί τον τομέα διάθεσης των προϊόντων της βιομηχανίας παραγωγής ασβέστου με τις πιο σημαντικές προοπτικές ανάπτυξης. Η επεξεργασία του πόσιμου νερού, η επεξεργασία των αστικών λυμάτων, η συμβολή στην εξουδετέρωση όξινων απορροών και η αποθείωση των καπναερίων αποτελούν τις κυριότερες περιβαλλοντικές εφαρμογές της ασβέστου. Εκτιμάται πως η ολοένα αυξανόμενη ζήτηση προϊόντων και τεχνολογιών φιλικών προς το περιβάλλον την επόμενη δεκαετία, θα έχει ως συνέπεια την αύξηση της παραγωγής της ασβέστου, ιδιαίτερα μετά και από την εφαρμογή των διαφόρων νομοθεσιών για το περιβάλλον τόσο σε εθνικό, όσο και σε παγκόσμιο επίπεδο.
Με βάση πρώτες ύλες από μονάδα παραγωγής αδρανών υλικών και ασβέστου από την περιοχή Φονέ Αποκορώ... more Με βάση πρώτες ύλες από μονάδα παραγωγής αδρανών υλικών και ασβέστου από την περιοχή Φονέ Αποκορώνου του νομού Χανίων, έγινε σύνθεση δομικών κονιαμάτων για διάφορες χρήσεις. Επιλέχθηκαν διαφορετικές κοκκομετρικές κατανομές των αδρανών υλικών και εξετάστηκε η επίδραση της περιεχόμενης παιπάλης. Ως συνδετικές κονίες χρησιμοποιήθηκαν υδράσβεστος κόνεως τύπου CL 80 και λευκό τσιμέντο. Πραγματοποιήθηκε έλεγχος των τεχνικών χαρακτηριστικών των παρασκευασθέντων δοκιμίων με προσδιορισμό της αντοχής σε μονοαξονική θλίψη μετά από διαφορετικούς χρόνους ωρίμανσης, καθώς και μελέτη τεχνητής γήρανσης. Βάσει των αποτελεσμάτων ποιοτικού ελέγχου τα δομικά αυτά κονιάματα κατατάσσονται στις κατηγορίες Μ1, Μ2, Μ2.5, CSI και CSII, κατά ΕΝ 998.02.
Νεογενείς ασβεστόλιθοι από τη Δυτική Κρήτη αξιολογήθηκαν ως προς την καταλληλότητά τους για την π... more Νεογενείς ασβεστόλιθοι από τη Δυτική Κρήτη αξιολογήθηκαν ως προς την καταλληλότητά τους για την παρασκευή φυσικής υδραυλικής ασβέστου. Δείγματα πετρωμάτων από διαφορετικούς ορίζοντες εξετάστηκαν ορυκτολογικά με περιθλασιμετρία ακτίνων-Χ (XRD), οπτική και ηλεκτρονική μικροσκοπία σάρωσης (SEM) και χημικά με φασματοσκοπία ακτίνων-Χ φθορισμού (XRF) και ασβεστιμετρία. Τα δείγματα περιέχουν κυρίως ασβεστίτη που κυμαίνεται από 74 έως 86% και σε μικρότερες αναλογίες, χαλαζία, αλβίτη, καλιούχο άστριο, παραγωνίτη και αργιλικά ορυκτά όπως ιλλίτη, μοντμοριλλονίτη και καολινίτη, η παρουσία των οποίων πιστοποιήθηκε στο αδιάλυτο υπόλειμμα. Αντιπροσωπευτικά δείγματα συγκεκριμένης κοκκομετρίας, χρησιμοποιήθηκαν για την παραγωγή υδραυλικής ασβέστου μετά από έψηση για χρονικό διάστημα δώδεκα ωρών σε θερμοκρασία 900 °C. Η ανάλυση των προϊόντων έψησης έδειξε ότι οι σχηματισθείσες φάσεις είναι κυρίως πορτλανδίτης και οι μορφές β και α΄ του πυριτικού διασβεστίου. Τα προϊόντα της έψησης χαρακτηρίζονται ως φυσικές υδραυλικές άσβεστοι μέτριας (CI 0.7) και υψηλής υδραυλικότητας (CI 1.4 - 1.6).
Δείγματα νεογενών βιοκλαστικών ασβεστολίθων από την περιοχή Αγίας Βαρβάρας Ηρακλείου Κρήτης, αξιο... more Δείγματα νεογενών βιοκλαστικών ασβεστολίθων από την περιοχή Αγίας Βαρβάρας Ηρακλείου Κρήτης, αξιολογήθηκαν με ορυκτολογικές και χημικές μεθόδους ως προς την καταλληλότητά τους για την παραγωγή υδραυλικών κονιών. Οι πρώτες ύλες περιέχουν ικανοποιητικά ποσοστά οξειδίου του ασβεστίου και διοξειδίου του πυριτίου. Μετά την έψησή τους σε θερμοκρασία 900 °C για χρονικό διάστημα 12 ωρών και στην συνέχεια αέρια σβέση τους, προέκυψαν η υδραυλική φάση του λαρνίτη (β-C2S) και πορτλανδίτης σε διαφορετικές ποσοστιαίες αναλογίες, για τα δείγματα των διαφορετικών οριζόντων. Έγινε σύνθεση κονιαμάτων υδραυλικής ασβέστου με κατάλληλα αδρανή υλικά και ελέγχθηκε η μηχανική τους συμπεριφορά με δοκιμές ανεμπόδιστης μονοαξονικής θλίψης σε διαφορετικούς χρόνους ζωής των δοκιμίων. Σύμφωνα με τις αντίστοιχες ευρωπαϊκές προδιαγραφές οι παραχθείσες κονίες χαρακτηρίζονται σαν φυσικές υδραυλικές άσβεστοι χαμηλής (NHL 2) και υψηλής (NHL 5) υδραυλικότητας.
Within the framework of a research supported by the 18 th ephorate of Byzantine antiquities for t... more Within the framework of a research supported by the 18 th ephorate of Byzantine antiquities for the preservation and restoration of the castle of Arta, a total of sixteen representative samples of late Byzantine and Ottoman pottery dated from the 13 th to 19 th century were analyzed. This research aims to determine the firing techniques applied in the manufacturing technology of the ceramics and shed light on the provenance (siliceous or calcareous) of the raw materials used in their production. The potsherds fall into bodies and bases of common ware samples, either glazed or unglazed. As the castle plays a significant role during the medieval and modern history of the city, the pottery collected during the survey carried out in its interior, is an important source of evidence for cultural and technological transformations that occurred within the local society. A multi-analytical approach including petrographic, mineralogical and chemical investigations by means of optical microscopy, powder X-Ray Diffraction (XRD) and X-Ray Fluorescence Spectroscopy (XRF) was used for the determination of the morphological, mineralogical and chemical characteristics of the potsherds. Diagnostic features like color, shape, decorative style, glaze and/or engobe were also taken into account. Powder diffraction patterns of all samples are dominated by reflections of quartz. Specific phases detected by XRD, primary like anorthite, diopside and gehlenite are considered to be neoformed minerals during the stage of production and serve as firing temperature markers. The presence of hematite in most samples suggests that the artefacts were manufactured by firing in an oxidizing atmosphere. The results of the bulk chemical analysis proved that the ceramic materials are categorized as rich in SiO 2 (average of 57.8 %), followed by lower amounts of Al 2 O 3 (average of 14.7 %), Fe 2 O 3 (average 7.6 %), CaO (average 6 %) and MgO (4 %). According to the plotting to triangular CaO+MgO -Al 2 O 3 -SiO 2 compositional system diagrams, the examined potsherds are derived mainly from Ca-poor clay raw materials. Based on the experimental results, a distinction between two main different firing procedures characterizes the production of the samples. Those produced in relatively low firing conditions (from 700 to 850°C) and pottery fired at higher temperatures (above 900 and up to 1050°C).
Uploads
Papers by Georgios Triantafyllou