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Design in structural steelwork to EN 1993 and EN 1994
Published in Chanakya Arya, Design of Structural Elements, 2022
In 1784, a method known as ‘puddling' was developed which could be used to convert pig iron into a tough and ductile metal known as wrought iron. Essentially this process removed many of the impurities present in pig iron, e.g., carbon, manganese, silicon and phosphorus, by oxidation. However, it was difficult to remove the wrought iron from the furnace without contaminating it with slag. Thus, although wrought iron was tough and ductile, it was rather soft and was eventually superseded by steel.
Field Water Regimes
Published in Shingo Iwata, Toshio Tabuchi, Benno P. Warkentin, Soil-Water Interactions, 2020
Shingo Iwata, Toshio Tabuchi, Benno P. Warkentin
Puddling of paddy fields is important to make soil soft for transplanting and impervious for percolation control. The soil surface should remain flat to keep a uniform water depth and to drain surface water rapidly at harvest time. Puddling breaks down large soil clods and soil aggregates, and decreases transmission pores. The permeability of the puddled soil generally depends on soil texture, especially clay content (Fujioka and Nagahori, 1964), but also depends on puddling method and frequency (Osari, 1988). The disadvantages of puddling (Sharma and De Datta, 1985; Koga, 1992) include a high labor requirement, a high water requirement for puddling, difficult regeneration of soil structure, and impeded root development.
Integrating Spatial and Temporal Models: An Energy Example
Published in Robert M. Peart, R. Bruce Curry, Agricultural Systems Modeling and Simulation, 2018
The third factor in estimation of CWm is the infiltration loss I for wet cultivated crops. Soil is thoroughly worked and its structure destroyed during wetland preparation for planting. This operation is commonly known as puddling. Two main aims of the puddling operation are to loosen the soil to facilitate transplanting and to reduce the infiltration rate. The infiltration loss was estimated on a daily basis using the equation () I=I0/ki
Characterization and Joining of an Historical Ferrous Tie-Rod
Published in International Journal of Architectural Heritage, 2019
P. Matteis, G. Scavino, G. Ferro
During and after the 18th century, the bloomery and finery processes were gradually abandoned, and, in the 19th century (and until the early 20th century), wrought iron was fabricated mainly with the puddling process. This process was similar to the finery one, but the pig iron was usually fabricated by using coke, instead of charcoal, resulting in comparatively higher sulphur and phosphor levels, and the final decarburization was performed in a reverbatory furnace, avoiding direct contact between the charge and the fuel (Aston and Story 1941; Bowman and Piskorowski 2004; Rutz et al. 2018; Tylecote 1992; Walker 2002). Puddled wrought iron was, however, similar to earlier bloomery and finery wrought iron in the fact that it retained a large volume fraction of slag inclusion, which were elongated during forging (Aston and Story 1941; Bowman and Piskorowski 2004; Walker 2002).
The life and work of John Baildon, the man who took British 18th century iron innovations to Prussia between 1793 and 1836
Published in The International Journal for the History of Engineering & Technology, 2020
John Baildon (1772–1846) achieved fame, fortune and social standing by taking the nascent British industrial revolution to what became modern Germany. He had a hand in the first coke-fired blast furnace, the first iron structures, the first (modern) rolling mills, the first Boulton and Watt steam engines, sophisticated machine tools, cannon, early Prussian zinc works and early puddling works. He worked first for the Prussian state itself and then with a number of private individuals, being rewarded in the latter situation by receiving equity for his expertise, but increasingly investing his own money as well. His family married into the nobility and in turn were ennobled themselves.
Comparison of iron ores upgraded with Falcon concentrator and magnetic separators assisted by coal reduction-conversion process
Published in Particulate Science and Technology, 2020
Hüseyin Vapur, Soner Top, Mahmut Altiner, Şükrü Uçkun, Musa Sarikaya
Iron ore is the most important raw material among many natural raw materials used for iron and steel production in terms of tonnage and value (Yang, Li, and Wang 2017). Problems such as sintering difficulties experienced in specularite as a hematite ore limit the number of types of ore that can be used for the iron and steel industry (Zhu et al. 2018). Magnetite (Fe3O4), hematite (Fe2O3), limonite (FeO(OH)·nH2O), and ilmenite (FeTiO3) are the most important commercial iron oxide minerals (Zeng et al. 2017; Yu et al. 2017a; Ponomar 2018; Wu et al. 2018). These are followed by carbonated and sulfide iron ores such as siderite (FeCO3), pyrite (FeS2), and pyrrhotite (Fe1-xS (x = 0-0.2)) (Hao et al. 2018; Jin et al. 2018; Liu et al. 2018). Throughout the history, the development of the iron and steel industry has evolved from primitive puddling furnaces to today's modern arc and blast furnaces (Du Puy 1881; Smith 2017). The economic development indicators of countries may be measured by per capita iron and steel consumption as well as per capita gross national product (Hernandez, Paoli, and Cullen 2018; Khaki et al. 2018). However, the rapid increase in iron demand in the industry and the gradual reduction of the ore that can be directly loaded into blast furnaces have necessitated evaluation of low-grade iron ores (Ponomar, Dudchenko, and Brik 2018). Besides, impurities must be reduced to certain levels. There are special limits for alumina, PbO (increasing fuel consumption), sulfur (increasing brittleness) ZnO, TiO2, etc. (MTA 2017). The minimum grade of iron ore must exceed 56% Fe (80% Fe2O3) in order to be used in the iron and steel industry (Isnugroho and Birawidha 2018). Iron ores can be physically enriched by taking advantage of their magnetic susceptibility and heavy density features (Seifelnassr, Moslim, and Abouzeid 2013; Ezhov and Shvaljov 2015; He et al. 2017). The flotation method is accepted to be costly in enriching iron ores. In this method, either iron minerals or gangue minerals (reverse flotation) are floated (Quast 2017; Shrimali et al. 2018). The roasting and microwave irritation methods to increase the magnetic susceptibility of iron ores were investigated in other recent studies (Peng et al. 2017; Yu et al. 2017a). Leaching may be used as an alternative method to reduce sulfur and phosphorus contents (Yong-Shi et al. 2006; Rezvani Pour et al. 2016). Enhanced gravity separators such as Kelsey Jig, MGS (Multi gravity separator), and Falcon separators have also been used for beneficiation of iron ores with fine particle sizes (Nayak and Pal 2013a; Sharma, Sharma, and Mandre 2015; Chaurasia and Nikkam 2017).