Search

High purity magnesia refractories have been tested for their resistance to iron-rich converter slags of ferronickel production. Laboratory tests were performed using crucibles made from magnesia refractories filled with slag at temperatures up to 1700 °C and contact times of 1, 2, 4, or 8 h. SEM observations and microanalyses performed on both refractories and slag indicated the progressive substitution of Mg in magnesia refractories by iron and production of magnesiowustite ((Mg, Fe)O), thus forming an affected intermediate zone with a depth depending on contact time and temperature. At the most aggressive conditions investigated, i.e., temperature 1700 °C and 8 h contact time, the maximum depth of the intermediate affected zone measured was 1.57 mm. Thermodynamic simulation of the system with FactSage 7.0 confirmed the formation of magnesiowustite with progressively higher rates of Mg substitution by Fe that decreases the melting point of (Mg, Fe)O, resulting in the progressive corrosion of the converters' lining. [ABSTRACT FROM AUTHOR]

Copyright of Scientific Journal Systemy Wspomagania w Inzynierii Produkcji is the property of P.A. Nova S.A. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Metallurgical wastes are deposited in landfills or are being recycled, mainly as material used for engineering work. They are also sources of pollution in the groundwater environment. For this reason, it is necessary to explore environmentally safe ways of using them. Environmental impact assessments of waste can be made on the basis of static or dynamic laboratory tests. The alternative is to carry out lysimetric research. However, this kind of research is rarely performed due to the degree of complexity, cost and duration. This paper presents the preliminary results of a 12-year lysimetric research project concerning the metallurgical waste deposited at the landfill site Lipowka in Strzemieszyce Małe, Southern Poland. The research investigated the quantity and chemical composition of the leachates and rainwater. Measurements were conducted in 2005, 2008/2009, 2014/2015 and 2016/2017. The preliminary results confirm the significant negative impact of leachates from the Lipówka landfill site on groundwater quality in its vicinity. This risk is caused mainly by leaching from as sulfates, potassium, chlorides and nitrogen compounds. Mn, Ba, Sr, As, Hg, Sb, B were also found in the initial phase of the study. After 20 years of experiment, the leaching of the examined substances decreased up to 20 times. [ABSTRACT FROM AUTHOR]

Field research conducted in the southern slopes of the rock massif Sinite Kamani in Sliven Stara Planina Mt revealed numerous traces of ancient and medieval iron mining and metallurgy: remains of ancient mines, rock dumps from ore processing and rolled cinder, аnd metallurgy slags indicating the sites of ore processing, as well as and other artifacts associated with these activities. Analysis of local iron ore and slags from ancient iron mining shows that a hematite ore and limonite manifestations found in the area were used as sources for these activities. The ore was obtained by open mining and processed to metal in primitive furnaces by direct reduction by charcoal. Extraction of metal was low, as evidenced by the composition of the slags, which differs from those originating from late medieval furnaces by the higher content of residual iron oxides, which is an evidence for primitive early iron processing. The remains of antique and medieval ore and metallurgical settlement were found in the Yurta locality in the eastern part of the Sinite Kamani massif near the iron ore deposits operated in the antiquity. Byzantine written historical sources suggest that these are the remains of the fortified medieval village of Kamena. The finding of traces of ore mining and metallurgy in a large area lead to the conclusion that during Late Antiquity and the Bulgarian Middle Ages there existed a center for iron ore mining, processing and metallurgy. The beginnings of this activity should be referred to an early age. This area of iron mining and processing was guarded by fortresses, which simultaneously protected the important roads passing there. It is proposed that the early development of this industrial activity was one of the preconditions for the rise of the early Byzantine town and episcopal center Tsoida there, as well as for the economic and cultural prosperity of the medieval city Istlifinus (actual Sliven), which in Bulgarian Middle Ages was famous with his monastic community known as “Little Athos” or “Sliven small Mount Athons”. [ABSTRACT FROM AUTHOR]