Tools to Qualify Experiments With Bloomery Furnaces*

Senn, Marianne; Gfeller, Urs; Guénette-Beck, Barbara; Lienemann, Peter; Ulrich, Andrea

doi:10.1111/j.1475-4754.2009.00461.x

Cited by 20 publications

(11 citation statements)

References 3 publications

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“…In ancient times, from the Iron Age to the appearance of cast iron and blast furnaces in the Middle Ages (10th century BC-20th century AD) iron was obtained by the direct solid-phase reduction method, also called "bloomery" method. In the bloomery, the iron oxides from the ore are processed in one step in a furnace with carbon-based fuel where charcoal acts as reducing agent reaching temperatures of about 1200 • C. [1][2][3][4][5][6]. Inside the furnace, carbon monoxide (CO) gas emanating from the charcoal reacts with iron oxide (FeO) in the ore to form solid iron particles and carbon dioxide (CO 2 ) gas [7].…”

Section: Introductionmentioning

confidence: 99%

Mineralogical Characterization of Slags from the Oiola Site (Biscay, Spain) to Assess the Development in Bloomery Iron Smelting Technology from the Roman Period to the Middle Ages

et al. 2020

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The Oiola archeological site, located in the mining complex of La Arboleda (Biscay, North Spain) was an important iron smelting center from the Roman Period to the Middle Ages and even in more current times (19th–20th centuries). Tap-slags and some plano-convex slags were identified as smelting slags. Samples were analyzed by optical microscopy, X-ray powder diffraction, scanning electron microscopy coupled with electron-dispersive spectroscopy and Raman microspectroscopy to perform a mineralogical and textural characterization. Additionally, thermogravimetric and thermodiffraction analyses were carried out to determine furnace operating temperatures. The mineral assemblage reflects furnace temperatures and cooling rates and the addition of quartz as the main flux to decrease the melting temperature of the iron ore. The comparison of slags from the Roman Period and the Middle Age reveals changes in the pyrometallurgical process through time.

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Section: Introductionmentioning

confidence: 99%

Mineralogical Characterization of Slags from the Oiola Site (Biscay, Spain) to Assess the Development in Bloomery Iron Smelting Technology from the Roman Period to the Middle Ages

et al. 2020

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“…In ancient times, from the Iron Age to the appearance of blast furnaces and cast iron in the Middle Ages (10th century BC -20th century AD), iron was obtained by the direct solid-phase reduction method, also called "bloomery" method and a posterior smithing (forging) process. In the bloomery process, the iron oxides from the ore are processed, in one step, in a furnace with carbon-based fuel and reducing agent (usually charcoal) at temperatures of about 1200 °C [1][2][3][4][5][6]. Inside the furnace, carbon monoxide (CO) gas emanating from the charcoal reacts with iron oxide (FeO) in the ore to form solid iron particles and carbon dioxide (CO2) gas [7].…”

Section: Introductionmentioning

confidence: 99%

“…The metallic product, called bloom, is a heterogeneous spongy mass, more or less consolidated and with a large number of pores. The reduction of the metals starts at temperatures of around 800 °C but metal never reaches its molten condition (as high as 1540 °C) and remains solid [2,5,[9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Mineralogical Characterization of Slags from Oiola Site (Biscay) to Assess the Development in Bloomery Iron Smelting Technology from the Roman Period to the Early Middle Ages

Portillo-Blanco¹,

Zuluaga²,

Ortega³

et al. 2020

Preprint

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Oiola archeological site, located in the mining complex of La Arboleda (Biscay, North Spain) was an important iron smelting center from the Roman Period to the Early Middle Ages and even in more current times (19th-20th centuries). Tap-slags and some plano-convex slags were identified as smelting slags. Samples were analyzed by optical microscopy, X-ray powder diffraction, scanning electron microscopy coupled with electron-dispersive spectroscopy and Raman microspectroscopy to perform a mineralogical and textural characterization. Additionally, thermogravimetric and thermodiffraction analyses were carried out to determine furnace operating temperatures. The mineral assemblage reflects furnace cooling rates and temperatures and the addition of quartz as the main flux to decrease the melting temperature of the iron ore. The comparison of slags from the Roman Period and the Early Middle Age allows to observe changes in the pyrometallurgical process through time.

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“…Identification of ore resources that were exploited in the past, therefore, has a particular significance as it can contribute to the understanding of the socio-technological factors affecting development of craft-production in the past societies. This identification can be achieved through the study and comparison of chemical and mineralogical composition of archaeological slags and ores, as well as through experimental smelting of ores from local geological outcrops to determine feasibility of their exploitation in the bloomery process [13][14][15][16] The epigenetic and hypogene iron mineralization are associated with major trending faults related to the Dead Sea transform (DST). Epigenetic ores mostly occur in the northern Negev region, Israel [23,25,26], while hypogene ores are known from the upper Jordan valley in the Ajloun region, in north-western Jordan [27,28].…”

Section: Introductionmentioning

confidence: 99%

Assessing the Quality of Iron Ores for Bloomery Smelting: Laboratory Experiments

2019

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There is fragmentary knowledge of iron ore sources exploited in the past for many regions including the Southern Levant. This missing information has the potential to shed light on political, economic, craft-production, and trading patterns of past societies. This paper presents the results of smelting experiments performed in graphite crucibles and a muffle furnace, using 14 iron ore samples from the Southern Levant, in an attempt to determine their suitability for smelting using ancient techniques. A range of analytical techniques, including optical and electron microscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction, and portable X-ray fluorescence were used to comparatively investigate the mineralogy and composition of the precursor iron ores and their smelting products: Iron bloom and slag. Several parameters attesting to the ability of a given ore to be successfully reduced and consolidated into a solid metal mass were quantified. The generated results highlight the significance of a 'correct balance' between iron oxides and other major elements in the smelting system in order to form fluid slag and a well-consolidated bloom. These data contribute to the understanding of factors, potentially influencing choices of iron ore exploitation by past human societies in the Southern Levant.The assaying (i.e., small-scale experimentation to determine quality of an ore) has always been an important component of ancient technology, as it represented an easy and resource-efficient technique to predict and coordinate subsequent large-scale processing and smelting [17]. For past societies, this was an advantage, given that properties of materials could be grasped only empirically and use of metallic resources was often associated with high resource and labor costs (e.g., extraction, transportation, and processing of the ore and fuel, cf. iron production in Africa [18]). The assay furnaces described by Agricolla [19] are a historical example of methods traditionally used for cupellation of small amounts of costly argentiferous ores to predict the outcome of large-scale cupellation performed in larger furnaces set to a greater consumption of raw materials.Determining the iron content and the quality of iron ores, prior to large-scale bloomery smelting, thus, is highly advantageous. Significantly, despite the common occurrence of iron ores in nature, knowledge about the types of deposits exploited in the past often remains limited and poorly understood. In fact, for some regions of the Ancient Near East, for example, south-eastern Arabia and Cyprus, there is still a lack of evidence about indigenous iron ore exploitation, although certain types of iron-rich rocks (e.g., gossans) exist in these regions [20][21][22][23]. Whereas in other regions, such as the southern Levant, evidence of past ore exploitation is only known so far from the Mugharet el-Wardeh deposit in the Ajloun, Jordan [5,24], although this is certainly not the only ore deposit in the region.In this paper, we present the results of a ser...

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Tools to Qualify Experiments With Bloomery Furnaces*

Cited by 20 publications

References 3 publications

Mineralogical Characterization of Slags from the Oiola Site (Biscay, Spain) to Assess the Development in Bloomery Iron Smelting Technology from the Roman Period to the Middle Ages

Mineralogical Characterization of Slags from the Oiola Site (Biscay, Spain) to Assess the Development in Bloomery Iron Smelting Technology from the Roman Period to the Middle Ages

Mineralogical Characterization of Slags from Oiola Site (Biscay) to Assess the Development in Bloomery Iron Smelting Technology from the Roman Period to the Early Middle Ages

Assessing the Quality of Iron Ores for Bloomery Smelting: Laboratory Experiments

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