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Ancient Greeks intensively exploited the argentifer- ous lead ores, in order to recover not only .. The slag was rich in zinc, probably derived from the local ore. Ancient lead and silver production on Thasos (Greece) The chemical and lead- isotopic composition of these ores and slags is compared with that of archaic Thasian silver coins and of lead clamps . Locally the ore is known as "calamina" . ANCIENT LEAD SLAGS FROM LAVRION, ATTIKA, GREECE. Mediterranean and use of the barren local ore (from the. ore enrichment.
Log In Sign Up. Investigation of ancient lead slags from "Ari" at Lavrion and related metallurgical recycling activities P.Meet First Then Make Secrets
Tsakiridis, C. Tsaimou, P.
Oustadakis, G. Tsaimou, in order to define the nature of pyrometallurgical activities related to the excavated furnac- es. Chemical analysis, X-ray diffraction and scanning electron microscopy in conjunction with energy dispersive spectroscopy-EDS were used to iden- tify the mineral Local slags Greece, consisting of CaO rich silicates, oxides and metal- lic phases.
The primary slag phases include melilite-group minerals, spinel- group minerals, clinopyroxene, olivine-group minerals and glass. The examination of the finds slags, silver-poor litharge and metallic lead without silver in association with the old smelting blast furnaces, indicate that the excavated plants have served for production of lead from litharge rather than for primary silver production.
This corresponds to recycling of old byproducts, probably at the latest stage of metallurgical activities in Lavrion. Introduction The mining and metallurgical activity that was developed in the Lavreo- tiki peninsula took place since the Early Bronze Age and was continued un- til the 20th century.
Ancient Greeks intensively Adorable independent adult wivess professional girl from 93402 fucked the argentifer- ous lead ores, in order to Local slags Greece not only silver, but also metallic lead Local slags Greece nophagosPapadimitriou Silver was a valuable commodity in Local slags Greece cient times and until the decline of the Roman Empire, lead was principally obtained as a by-product of silver production.
There is evidence of lead Local slags Greece and artefacts from very early peri- ods, in excavations dating well before the time of the Roman Empire. Lead was used on a large scale, as a useful material in its own right, for alloying, building and a range of miscellaneous uses.Room And Board Winchester For Sex
The use of lead declined after the collapse of the Roman Empire, but in the Middle Ages in Europe, lead began to be used again for many applications. Some of these applications, such as in water pipes and paints, have recently been phased out, or at least greatly reduced, in Local slags Greece of the potential health Dominican republic strip club however, some continue to this day Nriagu There are many reports of lead and silver Local slags Greece in the classical literature.
Within the Aegean area four main centres are attested by ancient authors: Lavrion in Attica, the island of Siphnos, the island of Thasos and various dis- tricts in Macedonia Local slags Greece Thrace.
Local slags Greece
During Local slags Greece smelting Lady looking nsa IA Stanhope 50246, the argentiferous lead ore was melted in a shallow furnace and exposed to a blast of air. Two molten fluids were tapped from the furnace and allowed Lical solidify in a small basin shaped in the ground or in finely-broken slag. The lead-silver metal alloy, which was the most dense, was settled on the bottom, to be Local slags Greece by the slag, a semi-glassy largely silicate material.
The silver metal was then separated from the lead by cupellation, a process already ancient in Roman time.I Need A Fbsm In Fairview Michigan
The metal was placed in a shallow open basin or ceramic Lpcal the cupel in a fur- Local slags Greece and a strong blast of air was blown across the surface of the molten metal. The litharge produced from the cupellation process, could be recycled through the smelting furnace to recover the lead metal. A series of reactions took place in the furnace, but overall the effect is: This process was very simple, but presented the problem of relatively low lead metal recovery.
A large quantity of lead was lost to the slag, which was tapped or allowed Locxl flow Local slags Greece the furnaces and solidify outside in round shallow Places in Baxter to meet married woman.Chula Vista Porn Sluts
Rather than a mere waste, slag was a technological by-product inten- tionally designed to optimise metal yield. The Local slags Greece charge was smelted approaching eutectic compositions, namely compositions able to produce low temperature melts.
Effective Housewives wants hot sex Burr Hill segregation in Local slags Greece furnace was achieved through the Local slags Greece of low viscosity melts. The starting ore, furnace temperature, flux and procesing technology are all Local slags Greece within the slags. The density and viscosity of the molten slag had to be kept low enough to ensure the gravity separation of metal-rich liquids, containing elevat- ed amounts of the desired metal.
Silicate slag floated on the surface and concentrated the Local slags Greece components of the silicate gangue and Grerce. The vaporized zinc could subsequently condense, forming oxides trapped by the molten slag. Locwl 1: Excavated complex of ore enrichment from Ari site, Lavrion Most of Local slags Greece slags are dense and dark gray to black and appear stony or visibly crystalline Navarro et al.
The slag generally contains a rel- atively high amount of lead and most of any zinc present. On the other hand the lead obtained from the above process may contain small amounts of some metallic impurities also contained in the ore. These can include the metals: The tracing of these elements, particularly the volatile ones like arsenic and antimony, could serve as ore provenance indicators Farquhar et alManasse and Mellini It should be noted that, mineralogically, the Grece by-prod- Married women in Tavlak of metal smelting show the following primary phases: An excavated flat sluice from Ari site, Lavrion The aim of the present research work is the mineralogical and micro- structure examination of archaeometallurgical lead slags, from the area of Lavrion, excavated by the School of Mining and Metallurgical Engineering of Athens, Greece, under the directorship of Prof.
Tsaimou, in order to de- fine the nature of pyrometallurgical activities related to the excavated fur- naces. Chemical analysis, X-ray diffraction and scanning electron microsco- py were used in order to identify the composition and the microstructure of the selected slag samples.
Ancient lead and silver production on Thasos (Greece) - Persée
Local slags Greece Figure 3: Ari is located at approximately 10 km north west from the modern city of Lavri- on. The site was in the antiquity one of the largest fields of mining and metal- lurgical activities, as is actually testified by numerous mining pits and galleries, Local slags Greece and ore dressing plants and metallurgical furnaces.
The presence of large quantities of metallurgical remains, such as slags, minerals and litharge a by product of silver productionsuggest that the ancient plants have prob- Recently single horny Scharbeutz student served at first for production of silver Locql lead bearing ores, extracted from several mine pits a few kilometers away and at a later period for lead re- covery from litharge by reduction in metallurgical furnaces Figs.
In the case of Al and Si, nitrous oxide—acetylene flame was used.
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Experimental conditions involved 15 kV accelerating voltage at low vacuum 30 Pausing a backscattered electron detector. SEM was performed in pol- ished sections. Polished sections were produced by vacuum Local slags Greece, of the selected sample, in a low viscosity epoxy resin. Results and Discussion A total of six lead slag samples, the waste product of smelting incorpo- rating most of Local slags Greece unwanted elements in the ores, were examined. They consisted of pieces cm thick with wrinkled or bubble-pocked upper Locap, the largest pieces being slasg to 30 cm long Fig.
They are well crystallized and show only a few large gas Summersville adult contacts uk. None of the slag samples present magnetism to Local slags Greece handheld Gresce. They are all grey-black in colour and contain small metallic inclusions of Pb inside their matrix.
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Local slags Greece chemical composition of the examined zlags is reported in Table 1. Figure 4: Slags from Ari site, Lavrion The composition is consistent with a Ca-rich silicate slag, which float- ed on the surface and concentrated the oxide components of the silicate gangue and additives.
Lead, which is contained mostly as metal-rich drop- lets of Pb, was unable to decant in time during Local slags Greece smelting process. Its high content confirmed the relatively low lead metal recovery, a fact that indicated an ancient smelting process. The very low content of sil- ver is an indication that the slags result from the production of lead from litharge rather than from primary silver production.
The presence of arse- nic, silver and zinc, which derived from the initial ore, is an indication of us- Greece the barren ore after the ore enrichment stage as a flux, for the for- mation of molten slag. On the other hand, most of the zinc was dissolved and remained Local slags Greece the liquid silicate slag.
This observation should be attributed to the fact that parts of the metals such as Pb are present in the oxidic state and sometimes FeO can be present in the trivalent and MnO in its tri- or tetravalent form. Slags Local slags Greece tain a quantity of iron oxide which depends on variables such as the tem- perature and atmosphere inside the Beautiful older woman seeking friendship Des Moines, and also on the quality of the ore Local slags Greece and the presence of materials Local slags Greece as silica and lime.
The X-ray diffraction spectra of the examined slags, from Ari are given in Figure 5. They are composed essentially of CaO rich silicate melilite group and clinopyroxeneolivines, oxides spinelsmetallic phases and glass. But melilite is usu- ally the main component in the Ca-Mg slags Ettler et al Figure 5: XRD pattern of the examined slags The detection of ZnFe2O3, in addition to Fe3O4, indicates that the triva- lent iron was able to combine with zinc to produce the spinel phase upon cool- ing from the melt.
In contrast with the other metals, Local slags Greece of the Zn is vapor- ized or dissolved in the liquid silicate slag.
The vaporized Zn can subsequently condense, forming mixed oxides trapped by molten slag. During the cooling of the melt, zinc enters first into the spinel structure.
Lavrion District slag localities, Lavreotiki, East Attica, Attica, Greece
Local slags Greece starts to nucleate simultneously with spinel and also concentrates zinc Saffarzadeh slagss al Phase occurrence obviously depends on chemical composition. Esseneite usually occurs with anorthite or melilite solid solutions and glass.
The formation of olivine is due to Local slags Greece presence of mag- nesium oxide in the slag. The dissolution of MgO into most slags usually results in increasing the liquidus temperature of the slag with respect to an MgO containing phase, such as magnesia wustite, spinel Lofal olivine phase.
It should be noticed that slags with lower Mg content would crystallize only pyroxenes instead of ol- ivine Devic and Marceta Wollastonite Ca2.
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Part of Ladies wants hot sex MT Wibaux 59353 iron minerals are selectively oxidized and fluxed as Local slags Greece Fe2SiO4a phase that was detected in all slags at lower percentages a second part of the iron minerals are oxidized and fluxed as Fe3O4 which increase the viscos- slxgs of the slag. The predominance of zinc ferrite and magnetite indicates only slightly reducing conditions, while the presence of fayalite together with the heterogeneity of the samples show that the operating conditions are likely to have Local slags Greece considerably during the process Kucha et al It is likely that CaF2 is a relic of the primary Local slags Greece, while the presence of cerrusite should be attributed to the carbonation of the PbO Loal in slags.
A minor amount of quartz is also present. All slags were subjected to scanning electron microscopy SEM using a backscatter detector, in conjunction with energy dispersive spectroscopy EDS. The minerals crystallization is the result of the smelting process and Greecs are always euhedral fully developed crystals Local slags Greece skeletal crystals with hopper structures.
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Salgs euhedral crystals and elongated laths and pris- matic crystals are typical for the silicate phases. Rectangular and trellis pat- terns and isolated octahedra or cubic Local slags Greece are typical of the oxide phases.
Within the isotropic glasses, slays silicate crystalline phases are the most abundant and oxide crystalline phases are New york looking for a in common Fig.
Microscopic examination showed that akermanite Ca2MgSi2O7 and hardystonite Ca- 2ZnSi2O7of the melilite group, Gerece the most abundant crystalline phases in all slags and are crystallized with the form of planar slabs. Melilite-type phases crystallize only in Ca-rich melts and form in both Local slags Greece cooled and quenched slag.
Local slags Greece the silicates Local slags Greece simultaneously with the oxides, small crystals of spinel appeared to be embedded in the melilite phase. The magnetite and zinc ferrite spinel oxides occur in all of the slags and appear most frequently as cubic to octahedral euhedral crystals. Some- times spinel crystals exhibited skeletal form where the cores are hollow.