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Abstract  

The firing temperature of a Persian-period kiln excavated at Tel Michal (Makmish), on the Mediterranean coast north of Tel Aviv, Israel, is estimated from the composition of its pottery, using X-ray diffraction and IR spectroscopy methods. The kiln was built with two chambers: an upper one where the vessels were fired and a lower one for the burning. Storage jars that had been fired and remained inside the kiln are composed of lime tempers and quartz sand in a fired clay matrix that contains amorphous material and the high-temperature Ca-silicates gehlenite and anorthite. The tempers are composed of re-formed calcite. Thermal simulation indicates that the composition is compatible with a heating temperature of 800–900°C, which represents the firing temperature in the upper chamber of the kiln.

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Abstract  

Guadiana River Chalcolithic middle basin (Badajoz, Spain) pottery was in many cases decorated with bone, which suffers a hydroxyapatite to β tri-calcium phosphate transformation while firing. The evolution of physico-chemical characteristics of bone decorations and experimentally heated fossil bone as a function of temperature through 1) major XRD planes, and 2) OH librational mode at 630 cm–1 in the FTIR spectra let us establish a correlation between the physico-chemical features and firing temperature, allowing the estimate of firing temperatures for bone decorated pottery. What is a reliable criterion to differentiate over potters behavior and skill during the pottery production.

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Abstract  

The study of a limestone and clay mixture using Mössbauer spectroscopy, and X-ray powder spectrometry (XRD) for different firing temperatures are presented. This type of mixture is used in raw minerals in order to obtain industrial clinker. This study permits to know the changes of the iron present during the clinkerization process, its mineralogical transformation with the temperature, and the minimal temperature necessary to obtain a good quality clinker.

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Journal of Thermal Analysis and Calorimetry
Authors: M. Franquelo, M. Robador, V. Ramírez-Valle, A. Durán, M. Jiménez de Haro, and J. Pérez-Rodríguez

Abstract  

Roman ceramics of two hydraulic mortars used to build the pond and water channel of Mithraeum house from Mérida (Spain) have been studied. The sizes of the ceramic fragments found were different in both of the samples studied, showing different behaviour in the reactions with the lime. The X-ray diffraction of the ceramic shows the presence of quartz, mica (biotite), anorthite and hematite accompanied by amorphous phase, being observed scarce vitrification. The presence of mica confirms a firing temperature for manufacturing the ceramic below 900°C. In one of the ceramics studied, X-ray diffraction did not show calcite. However, in the FTIR appear bands that could be assigned to carbonates absorptions and likewise, carbonates were identified in the DTA-TG curves. Ca and small quantities of Si and Al were also identified by SEM-EDX on the surface of the pores that could be due to an amorphous phase formed in the reaction of lime with the Si and Al of the ceramic. On the other hand, in other ceramic samples carbonates (about 10%) were detected. The carbonates have been found filling the pores, sometimes accompanied by a new calcium-aluminium-silicate phase produced by the reaction between the lime and the amorphous phase of the ceramic. The carbonates and the new phases formed inside the pores are responsible for the decrease of the porosity and for the formation of new phases during the heating of the ceramics.

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the thermal products. The firing temperature and the advantage of using calcareous raw materials in the manufacture of ancient pottery are discussed. Materials and methods Pottery Iron Age pottery

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for the estimation of the original firing temperature of the ceramics [ 9 – 13 ]. On the other hand, the chemical composition of ceramics is related to the raw materials and can be successfully used for the classification of ceramics into groups of

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. It was noticed that the micro- and mesopores are reduced in frequency by increasing the firing temperature but the macropores do not change to a great extent [ 27 ]. For this reason, macropore volumes were not determined. Since the specific micro and

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Journal of Thermal Analysis and Calorimetry
Authors: Dmitar Zorić, Dušan Lazar, Ognjen Rudić, Miroslava Radeka, Jonjaua Ranogajec, and Helena Hiršenberger

fired at three temperatures has a complex internal void structure. The apparent particle density values increase along with the firing temperature increase, while the water absorption decreases, Table 4 . The apparent particle density and the open

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Abstract  

In the present work 39 ancient ceramic sherds from the archaeological excavation of Abdera, North-Eastern Greece, dating to 7th century B.C., and 11 local raw clay bricks, fired at temperatures ranging from 500 to 1000C, were characterized by ICP-AES, powder X-ray diffraction (PXRD) and thermal analysis (TG-DTA) techniques. It has been found that the mineralogical composition of the most studied sherds is quartz, feldspars and micas, which is in agreement with the composition of the local bricks. Chlorite is also present in a few samples, while there is one completely different sherd, which belongs to the Ca-rich clays. From the simultaneous TG/DTG and DTA data, under nitrogen atmosphere in the temperature ranges ambient to 1000C, we comment on the possible firing temperature and distinguish between samples of different origin. The existence of muscovite or illite in most of the samples denotes that the firing temperature was lower than 950C, while the existence of chlorite means that the firing process in these samples stopped before 700C. A very different thermogram gave the Ca-rich ceramic sherd, due to the existence of calcite, denoting that the firing temperature was about 700C.

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Abstract  

Waste compromises environmental preservation as well human health in many countries. Recycling is an alternative that sometimes represents the only economical activity for a significant population in the big cities. Almost 3% of waste materials in Brazil are vitreous. Ceramic production adding waste glass is possible with advantages of costs reduction associated to decrease on firing temperatures and to the raw material itself. At present paper up to 80 mass% of waste glass was added to clay. The sintering temperature decreased linearly and the shrinkage increased with glass content, an effect more pronounced for high glass amount.

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