Cast Shop Technology: Recycling and Furnace Operations
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Samuel Wagstaff, Oculatus Consulting
Tuesday 2:00 PM
March 16, 2021
Room: RM 29
Location: TMS2021 Virtual
Session Chair: Kjerstin Ellingsen, SINTEF; Jean-Francois Desmeules, Dynamic Concept
2:00 PM
Introductory Comments: Cast Shop Technology: Samuel Wagstaff1; 1Oculatus
Introductory Comments
2:05 PM
Impact of COVID-19 on the British Foundries: Prateek Saxena1; Pam Murrell2; Tharmalingam Sivarupan3; Konstantinos Salonitis1; Mark Jolly1; 1Cranfield University; 2Cast Metals Federation; 3The University of Queensland
COVID-19 has emerged as a global pandemic in the past few months. It has impacted not only the health of the people but also the global economy is hit to a large extent. This has imposed severe threats and challenges on businesses. In the context of the UK, the British government has launched various schemes to identify and combat the new scenarios developed as a result of the pandemic. This paper aims to assess the impact of COVID-19 on foundries in the UK. A detailed survey will be conducted and the response of small, medium, and large foundries will be recorded. The short and long term action plan of the foundries will be identified. The data recorded will further be analyzed and quantified. The current status, challenges, and future direction of the UK foundries will be discussed and presented in this work.
2:25 PM
Effect of Steam on Aluminium Packaging Multilayers: Martin Syvertsen1; Anne Kvithyld1; Birgitte Vågenes1; Stephan Kubowicz1; Rune Gaarder1; 1SINTEF Industry
Aluminium multilayer packaging systems have the recent years become increasingly popular due to its performance for food preservation. These material systems often consist of two or more layers of organic material (PP, PE, PET etc.) and a layer of aluminium. Up until recently there has not existed any environmental friendly technique for separation of these materials so that the aluminium can be recycled with satisfactory metal yield. This paper present laboratory scale experiments where steam (i.e. water vapour) at elevated temperature and pressure has been shown to liberate the organic layers from the aluminium. The results show different type of organic material behave differently and that the aluminium does not oxidize significantly at least up to 3 h of treatment at 174 °C and 8 bar pressure.
2:45 PM
Compaction of Aluminium Foil and Its Effect on Oxidation and Recycling Yield: Alicia Vallejo Olivares1; Harald Philipson1; Mertol Gökelma2; Hans Roven1; Trond Furu3; Anne Kvithyld4; Gabriella Tranell1; 1Norwegian University of Science and Technology; 2İzmir Institute of Technology; 3Norsk Hydro; 4SINTEF
Improving the circularity of aluminium is vital to meet current environmental and resource efficiency goals. One of the main challenges when recycling aluminium is its oxidation and consequent loss during re-melting. This problem is critical for the thin sheet/foil materials used for food packaging applications. Compacting the scrap into briquettes before re-melting may partly reduce such losses in addition to facilitate transport and storage.Shredded aluminium sheets of different thicknesses (15-300 µm) were compacted into briquettes by uniaxial pressure or moderate-pressure torsion. A sub-set was subsequently oxidized at 650 °C, while a sub-set was left untreated. Finally, both briquettes and loose shreddings were re-melted under molten protective salt flux. Higher bulk density and reduced specific surface area resulted in increased coalescence and yield for the oxidized thinner foil, but did not significantly affect the metal yield of the thicker sheets and the extent of briquette oxidation.
3:05 PM
Influence of Mg Concentration on the Inhibiting Effect of CO2 on the Oxidation Rate of Aluminum Alloys 5182 and 6016: Cathrine Solem1; Egil Solberg2; Gabriella Tranell1; Ragnhild Aune1; 1Norwegian University of Science and Technology (NTNU); 2Alcoa Norway ANS
Oxidation of aluminum alloys during production is a well-known problem and contributes to significant metal losses. As small additions of CO2 in the atmosphere has proven to inhibit the oxidation rate for high-Mg (≥ 5wt%) aluminum alloys, the present study has aimed at evaluate its effect on alloys with varying Mg concentration, i.e. 5182 (AlMg4.6Mn0.4 ) and 6016 (AlSi1.2Mg0.4 ). Experiments were performed by STA using three different cover gases, i.e. 80% synthetic air and 20% argon, 99.999% argon and 4% CO2, 20% argon and 76% synthetic air, while monitoring the mass change and heat flux at 750°C for 7 h. A significant inhibiting effect was observed for the 5182 alloy during exposure to CO2 when compared to the results obtained for synthetic air and argon. A similar effect was observed for the 6016 alloy to a lesser extent due to the lower Mg concentration.
3:25 PM
Automated Chemical Analysis of Liquid Aluminum for Process Control: Sveinn Hinrik Gudmundsson1; Halldor Gudmundsson2; Kristjan Leosson1; 1DT Equipment; 2Nordural ehf.
We report on automated analysis of the trace element content of liquid metal, implemented in a casthouse of a primary aluminum smelter. The automated analysis involves robotic sampling from transport crucibles followed by a direct measurement of the chemical content of the liquid metal using laser-induced breakdown spectroscopy (LIBS). Experiments were carried out on-site over a period of several months, sampling hundreds of crucibles and comparing the LIBS analysis with conventional laboratory spark-OES analysis of solid samples collected from the same crucibles. We discuss the predictive power of LIBS analysis for different trace elements, in pure aluminum as well as in 5000 and 6000 alloys, confirming that automated analysis of the molten metal can replace manual laboratory analysis for process control for many common trace and alloying elements.
3:45 PM
Characteristic Impurities of Silicon Metal SI-441 as Additive Material to Produce Aluminium Foundry Alloy A356.2: Reggy Zurcher1; Rainaldy Harahap1; Edi Mugiono1; M. Yasir Parapat1; Masrul Ponirin1; 1PT Indonesia Asahan Aluminium
Quality assurance of material is a critical parameter to prevent an increasing reject rate production. As all unacceptable product cause of impurities involves rework or rejection, which directly lead to production losses. Aluminum with silicon will impact of Fluidity. According to the content of some impurities, silicon metal can be divided into different grades.INALUM uses silicon metal grade 441 to produce foundry alloy A356.2 with a maximum iron content of 0.12 wt %. An unidentified silicon metal method will impact impurities' undefined content, such as iron content (Fe). Although still unable to identify the distribution of iron content in each bag, several works have been developed. In this work, a new method with high accuracy of characteristic material with composite and homogeneity tests has been proven to reduce the reject rate of products and discussed to seek the opportunity to expand a complex method by using machine learning.
4:05 PM
Molten Aluminium Transfer: Review and Comparison of Different Technologies: Olivier Dion-Martin1; Robert Dumont1; Jean Francois Desmeules1; 1Dynamic Concept
In the casthouse, from the raw materials to the finished products, aluminium undergoes a series of treatments ranging from furnace charging and alloying, degassing, filtration and casting. One common denominator between all these treatments is that molten metal must be transferred in a way or another. Sometimes the transfer method is obvious but there are many occasions where there are different methods available. Open launders, covered launders, pouring, multi level launders are common open channel methods for transferring molten metal. Gravity siphoning, aspiration siphoning and pressure siphoning are less common but increasingly used in the industry. All have different influences on molten metal temperature, oxidation and cleanliness. The purpose of this paper is to compare different molten metal transfer methods and provide guidelines to select and size the most appropriate method according to the process requirements.
4:25 PM Question and Answer Period