Important Key Process Simulations in the Field of Steel Metallurgy

During the last decade, the chair for ‘Simulation and Modelling of Metallurgical Processes’ (SMMP) has worked on different metallurgical processes with the highlights of the following five industrial relevant topics: (i) modelling the as-cast structures of large steel castings; (ii) exploring the formation mechanisms of macrosegregation; (iii) describing magnetohydrodynamic and electrochemical phenomena in remelting processes, (iv) understanding how solidification and flow can be influenced by magnetohydrodynamics during steel continuous casting; and (v) describing nozzle clogging in steelmaking processes. In this contribution, the main achievements from the group on the above five topics are briefly described.

Production of Sustainable Hydrogen and Carbon for the Metallurgical Industry

Hydrogen will presumably become an important substitute for carbon as a reductant in the metallurgical industry for processes such as steel production. However, the challenge to supply enough CO2-free hydrogen for metallurgical processes has not been resolved yet. This paper reviews different production technologies for hydrogen and their advantages and drawbacks. Additionally, it will highlight the development of plasma technology to produce hydrogen and carbon black which has been taking place at SINTEF during the last 30 years.

From Mineral Processing to Recycling: The Case of End-of-Life Printed Circuit Boards’ Physical Processing

The treatment of end-of-life printed circuit boards (EoL PCBs) presents a contemporary recycling challenge with significant environmental, economic and social dimensions. This reality has attracted interest in the development of sustainable treatment processes, founded on mineral processing and metallurgical processes. The present paper reviews the applications of mineral processes in the treatment of end-of-life printed circuit boards (magnetic, electromagnetic, gravity and flotation processes), highlighting their strengths, weaknesses and limitations in the processing of EoL PCBs.

The Symbolic Use of Whetstones and Their Role in Displaying Authority over Metallurgical Processes and Trade

Whetstones of the Viking Age can have a conspicuous design, but not much is understood about the specific use of more unusual specimens, or their place in rituals. This article proposes a new interpretation of whetstones, based on novel studies of a well-known whetstone from Lejre, and miniature pendants from Tissø. Our examination of the prominent whetstone from the Lejre hoard with an x-ray fluorescence (XRF) scan, did not reveal any metal traces, which suggests that it was unused. At Tissø, the find distribution of so-called stafflike pendants – made of iron, bronze, or silver – links them to a metal-working area, and since their morphology resembles full-scale whetstones we suggest that they may be symbolic, miniature whetstones. Finally, we argue that the overarching meaning of the ritual use of whetstones is more related to the authority over – and control of – metallurgical processes, as well as the trade of metal goods, and only by proxy to the smith himself.

Thermal Conductivity of Sodium Silicate Glasses and Melts: Contribution of Diffusive and Propagative Vibration Modes

The thermal conductivity of silicate melts and glasses is an important physical property for understanding the temperature distribution in high-temperature metallurgical processes; however, the mechanism of heat conduction in these non-crystalline materials remains unclear. Two types of vibration modes must be considered to understand the mechanism of heat conduction, namely, propagative and diffusive vibration modes. In the present study, we carefully derived the thermal conductivity of pure silica and sodium disilicate glasses and melts, and estimated the contribution of the diffusive vibration mode using a recently developed model. The results indicated that the diffusive vibration mode was not dominant in the silicate non-crystalline materials, whereas the propagative vibration mode (i.e., phonons) was dominant in the heat conduction of silicate glasses and melts, which is in contrast with borate glasses.

Processing of industrial waste by plasma-chemical method

In this paper, the results of the processing of magnesium fluoride by plasma-chemical method to obtain periclase and a solution of hydrogen fluoride (hydrofluoric acid) were presented. For the industrial implementation of plasma technologies, it is necessary to study the main parameters of plasma processes for obtaining reducing gases and processing metal oxides with them, to solve the issues of their hardware design, to increase the service life of plasma torches for their use in continuous metallurgical processes. The purpose of this work was to determine the conditions for the plasma-chemical process of processing magnesium fluoride. Thermal analysis of magnesium fluoride on a TGA/DSC2 thermogravimetric analyzer was performed. Thermogravimetric analysis showed that in the temperature range under consideration the process is endothermic, and at a temperature of ~1280°C a phase transition of the 1st kind is observed due to the melting of magnesium fluoride. The fractional composition of MgF2 and MgO powders was studied using the Analysette-22 Nanotech laser diffraction analyzer. The results of the evaluation of the fractional composition of powders have a significant difference. At the same time, the convergence of the data obtained using laser diffraction and electron microscopy methods was found.