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Geochemical impact of a bloomery : Tracing a bloomery furnace in peat records with geochemistry in central SwedenThöle, Philine January 2016 (has links)
The aim of this study was to work out whether bloomery activities might have left a geochemical imprint in two mires close to a known bloomery and identify differences between the geochemical signals in the mires. Therefore two peat profiles (140 cm deep) and a series of bulk samples (composite of 10-60 cm) were taken near the remains of a bloomery close to Ängersjö, Hälsingland, which has one documented radiocarbon date of AD 1300-1435. One profile was taken in the fen closest to the bloomery, the other profile was taken close to a nearby lake. Geochemical analysis of the peat samples was performed with X-ray fluorescence spectroscopy (XRF). The results were combined with previously taken data from a sediment profile from the lake ~120 m away and a pollen profile close to the bloomery. The results showed that the activities of the bloomery were visible in the geochemical signals of the peat core closest to the bloomery with two peaks in Pb and Zn, which coincide with the previous reported times of operation (1. AD 1030-1060; 2. AD 1300-1435), which also fits with the pollen record from the nearby peat record. The mire close to the lake, which is hydrologically not connected with the area where the bloomery was, did not show these increases in elements associated with iron processing and only a small peak of Pb was visible. Furthermore, the geochemistry of the bulk samples showed that a disturbance of the mire surrounding the lake was responsible for the geochemical changes observed in the lake,particularly as a source of increases in inferred biogenic Si observed in the sediment record (as increased Si/Al ratios) in association with human-related disturbance in the sediment record during AD 800-1200. Si concentrations in the bulk peat samples in the fen adjoining the lake range as high as 14% (≤23% as SiO2).
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The technology of ancient and medieval directly reduced phosphoric ironGodfrey, Evelyne January 2007 (has links)
After carbon, phosphorus is the most commonly detected element in archaeological iron. The typical phosphoric iron range is 0.1wt% to 1wt%P. The predominant source of phosphorus in iron is the ore smelted. Around 60% of economic UK rock iron ore formations contain over 0.2%P. Under fully reducing conditions, both in liquid-state (cast iron) and solid-state bloomery smelting (direct reduction) processes, such rock ores would be predicted to produce phosphoric iron, and bog iron ores even more so. Ore-metal-slag phosphorus ratios for bloomery iron are derived here, by means of: laboratory experiments; full-scale experimental bloomery smelting; and analysis of remains from three Medieval and two Late Roman-Iron Age iron production sites in England and the Netherlands. Archaeological ore, slag, metal residues (gromps), and iron artefacts were analysed by metallography, SEM-EDS, EPMA, and XRD. The effects of forging and carburising on phosphoric iron were studied by experiment and artefact analysis. The ore to slag %P ratio for solid-state reduction was determined to range from 1:1.2 to 1: 1.8. The ore to metal %P ratio varied from 1:0.2 to 1:0.7-1.4, depending on furnace operating conditions. Archaeological phosphoric iron and steel microstructures resulting from non-equilibrium reduction, heat treatment, and mechanical processing are presented to define the technology of early phosphoric iron. Microstructures were identified by a combination of metallography and chemical analysis. The phosphoric iron artefacts examined appear to be fully functional objects, some cold-worked and carburised. Modern concepts of 'quality' and workability are shown to be inapplicable to the archaeological material.
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The Technology of Ancient and Medieval Directly Reduced Phosphoric Iron.Godfrey, Evelyne January 2007 (has links)
After carbon, phosphorus is the most commonly detected element in archaeological
iron. The typical phosphoric iron range is 0.1wt% to 1wt%P. The predominant source of phosphorus in iron is the ore smelted. Around 60% of economic UK rock iron ore formations contain over 0.2%P. Under fully reducing conditions, both in liquid-state (cast iron) and solid-state bloomery smelting (direct reduction) processes, such rock ores would be predicted to produce phosphoric iron, and bog iron ores even more so.
Ore-metal-slag phosphorus ratios for bloomery iron are derived here, by means of:
laboratory experiments; full-scale experimental bloomery smelting; and analysis of
remains from three Medieval and two Late Roman-Iron Age iron production sites in
England and the Netherlands. Archaeological ore, slag, metal residues (gromps), and iron artefacts were analysed by metallography, SEM-EDS, EPMA, and XRD. The effects of forging and carburising on phosphoric iron were studied by experiment and artefact analysis. The ore to slag %P ratio for solid-state reduction was determined to range from 1:1.2 to 1: 1.8. The ore to metal %P ratio varied from 1:0.2 to 1:0.7 ¿ 1.4, depending on furnace operating conditions. Archaeological phosphoric iron and steel microstructures resulting from non-equilibrium reduction, heat treatment, and mechanical processing are presented to define the technology of early phosphoric iron. Microstructures were identified by a combination of metallography and chemical analysis. The phosphoric iron artefacts examined appear to be fully functional objects, some cold-worked and carburised. Modern concepts of 'quality' and workability are shown to be inapplicable to the archaeological material.
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Examination of Ancient Scandinavian Archaeological Findings : From Tortuna in Västerås, SwedenBlinke, Jacob, Geiger, Evelynne, Edlund, Amanda January 2018 (has links)
This study concerns the examinations of archaeological steel-objects from the Iron Ages, found in Tortuna outside Västerås, Sweden. Not many metallurgical analyses have been made on steel objects from the Iron Ages, most likely in order to preserve the findings. Therefore, very little knowledge about old steel materials exists.The main goal of this study was to investigate how steel-made items from the Iron Ages were created, what they have been used for, and determine what kind of metallurgical knowledge the blacksmiths of the Iron Ages had. The experiments were conducted with light optical microscopy in order to investigate the morphology of the materials and with Vickers hardness test, to investigate the hardness of the materials. The investigation gave varying results for the different iron-made objects. All of the objects have been forged in some way. Most of the objects, were made of heterogeneous low carbon steel with a mainly ferritic structure. Some items also showed a martensitic structure with a ferritic core, which concludes that the smiths probably knew how to quench and temper steel. Due to heavy corrosion on many ofthe items, further investigation is needed to strengthen the conclusions made in this report. / Denna studie behandlar undersökningar av arkeologiska stålobjekt från järnåldern,hittade i Tortuna utanför Västerås, Sverige. Det har inte gjorts många metallurgiska analyser på stålobjekt från järnåldern, troligen för att bevara föremålen. Därför finnsdet lite kunskap om gamla stålmaterial. Huvudsyftet med denna studie var att undersöka hur föremål i stål från järnåldern tillverkades, vad de har använts för och bestämma vilken typ av metallurgisk kunskap dåtiens smed besatt. Experimenten utfördes med hjälp av ljus optisk mikroskop för att undersöka materialets morfologi och med hjälp av Vickers hårdhetsprov för att undersöka materialens hårdhet. Undersökningen gav olika resultat för föremålen. Alla föremål är smidda på något sätt. De flesta föremålen bestod av heterogent kolstål med huvudsakligen ferritisk struktur. Vissa föremål visade också en martensitisk struktur med en ferritisk kärna,vilket visar på att smeden troligen visste hur man härdar och anlöper stål. På grund av stor korrosion på många av föremålen krävs ytterligare analyser för att stärka slutsatserna i denna rapport.
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To Make Iron of Iron : A Comprehensive Analytical Study of Spade Shaped Iron BarsPappas Adlreburg, Nickolas January 2017 (has links)
This thesis aims to provide adequate analytical information on the spade shaped iron bars of Norrland and central Sweden. While their significance has been thoroughly debated for decades, analytical research on them has been confined to cases of single artefacts or theoretical interpretations of their value, meaning and origin. In this study a comprehensive approach is taken into consideration. Based on X-Ray fluorescence (XRF), scanning electron microscopy (SEM) and metallographical analysis this thesis seeks to facilitate new interpretations on quality, production centres and usage based on analytical results. Aiming to settle some of the long lasting questions regarding the artefacts while producing results which can further the discussion by raising new questions, previously unasked.
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