Cast Shop Technology: EHS and Cast House Products
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Johannes Morscheiser, Novelis Koblenz GmbH
Monday 2:30 PM
February 24, 2020
Room: 1B
Location: San Diego Convention Ctr
Session Chair: Jean-Francois Desmeules, Dynamic Concept
2:30 PM Introductory Comments
2:45 PM
Hands-free-casting at AMAG Casting GmbH – It is Possible!: Bernd Prillhofer1; Rudolf Dobler1; Thomas Mrnik1; 1AMAG casting GMBH
The start-up of the aluminum rolling slab casting process is one of the most critical procedures in terms of casthouse-safety. In many casthouses, it is common practice that the staff works directly at the launder system and on the casting table during the whole start-up. Operators are needed along the launder system (furnace spout con-trol, opening of launder gates, CFF check etc.) and on the casting table (priming of the distribution bag, filling control etc.), but there are a lot of risks, which can have a tremendous adverse impact on human health: Wet starter-blocks, bleed-outs, hand-ups etc. can lead to very harmful situations and therefore it’s best for the operators to start the process from a save place. This paper deals with all needed mechanical and automation systems, as well as casting techniques, to enable the casthouse staff to control the start-up at a safe place.
3:05 PM
User-friendly Surveillance Tools to Prevent Bleed-out During Cast Start: Mark Badowski1; Daniel Krings1; Gerd-Ulrich Gruen1; Werner Droste1; Philip Meslage2; Benjamin Jaroni1; 1Hydro Aluminium Rolled Products; 2Aluminium Norf GmbH
Insufficient or deviating cooling conditions in the water curtain of the secondary cooling zone are common causes for bleed-outs, especially during cast start with the risk of water-melt explosions. They typically rely on the flow conditions in the sump, the stress-strain conditions in the solidifying shell and insufficient water supply for cooling. Hydro’s “water tester” is a robust tool to check the water flow rate and distribution in the water curtain of all types of casting molds. It is well accepted by operators due to its easy and ergonomic use. The thermopile-array based “bleed-our detector” represents an even more detailed analysis tool of the cooling features of the used molds. It is a cost-efficient tool visualizing the water and temperature distribution in the secondary cooling zone suitable to trigger alarms or even automatic cast aborts.This paper describes the technological approach and application cases for both tools.
3:25 PM
Beryllium Reduction Potential in AlMg Cast Alloys: Jan Steglich1; Alexandra Basa1; Anne Kvithyld2; Nichloas Smith2; Ines Zerbin1; 1Trimet Aluminium Se; 2SINTEF
Beryllium is used in many aluminium-magnesium alloys to minimize molten metal oxidation. As beryllium containing dust and fumes have detrimental effects on health, its use has to be limited. The reduction potential of beryllium has been investigated for AlMg3, AlMg5 and AlMg10 cast alloys as well as Al99,85 by thermogravimetric analysis (TGA). The samples were alloyed with Be contents between 2 – 56 ppm to measure the oxidation inhibiting effect over time. During TGA, the weight gain by oxidation of each sample was measured continuously for 21 hours at 750 °C in laboratory scale. The results show that the Be inhibiting effect is lost after a period of time. The samples were analysed by X-ray Photoelectron Spectroscopy (XPS) and electron microscopy to further understand the oxidation mechanism. Finally, the results were used to derive a predictive model for the required Be content to protect an AlMg alloy.
3:45 PM
Accurate Real-time Elemental (LIBS) Analysis of Molten Aluminum and Aluminum Alloys: Sveinn Hinrik Gudmundsson1; Jon Matthiasson2; Kristjan Leosson1; 1DT Equipment; 2Innovation Center Iceland
Real-time LIBS analysis for monitoring and process control in a primary aluminum smelter is reported. Chemical analysis was carried out directly in a casting launder as well as with robotic sample feeding at a crucible skimming station. For a number of trace elements, quantification limits down to 10ppm or lower have been demonstrated, exhibiting measurement repeatability for direct melt measurements of the same order as observed in OES analysis on corresponding solid samples. Furthermore, LIBS analysis allows the time-varying concentration of elements in the melt to be monitored on a minute-by-minute basis. Our results confirm that for many technologically important elements, LIBS analysis represents a competitive alternative to laboratory OES, provided that suitable access to the liquid aluminum can be ensured. This approach improves plant safety by reducing the need for manual sampling of liquid metal, eliminates operator-related errors in chemical analysis and is critical for automation of casthouse operations.
4:05 PM Break
4:20 PM
Industrial Verification of Two Rotor Fluxing in Large Crucibles: Terje Haugen1; Arild Hakonsen1; Vegard Innerdal1; 1Hycast AS
Crucible fluxing is a well known method to reduce the alkaline metal content in potroom metal in an Aluminium smelter. By doing this the need to perform melt treatment inside the casthouse furnace will normally be eliminated. Hycast has beed supplying crucible fluxing (RAM) to the Aluminium business for three decades. Recently Hycast has developed a solution for crucible fluxing in large crucibles with a closed lid used for crane tapping. This paper is about the different technical solutions and the measured performance during industrial operation.The AlF3 addition rate, rotor speed, and the effect of one versus two rotors are investigated. Halftimes of Sodium (Na) for the two-rotor version is ~0.3min/mt. For the one-rotor version the half time of Sodium is ~0.5min/mt. The temperature loss was lower than expected and the rotor torque higher than expected for the two-rotor RAM stations.
4:40 PM
Dynafeed: An Improved Crucible Transfer System: Jean Francois Desmeules1; André Tremblay1; Martin Dubois1; 1Dynamic Concept
Tilting tables are commonly used as a means from transferring metal from crucibles to furnaces or other types of equipment, including open mold casting machines such as sow casters.Transferring metal from crucibles often requires a series of non-productive tasks including moving the crucibles manually with an overhead crane. The Dynafeed tilting table was developed to eliminate the requirement for an overhead crane, accepting the crucible directly from the transport truck. A first version was developed for a sow casting machine, allowing for the use of larger crucible while eliminating the overhead crane. Other configurations are used for transfer to furnaces and contingency sow casting
5:00 PM
Metal Transfer from Furnace to Furnace – A Case Study: Olivier Dion-Martin1; Jean Francois Desmeules1; Pierre Jeanroy1; 1Dynamic Concept
Siphoning is a well known method to transfer metal from a container to another without generating dross. It is often used to transfer the metal from crucibles to furnaces or from furnace to furnace. Many existing systems suffer from siphon blocking or slow cycle times. A system was recently designed and supplied to transfer metal from a melting furnace to a casting furnace. Fully automated operation allows for the transfer of a full load at the touch of a button. The unit is totally autonomous, featuring a preheating system and a positioning mechanism that detects the condition of the siphon during transfer. A full scale prototype was designed and built to test the control system with water prior to the commissioning.The purpose of this paper is to describe the application its challenges and the solutions applied to ensure that performances were above expectations.
5:20 PM
Heavily Loaded Areas in Aluminum Melting Furnaces and Possible Refractory Solutions: Thomas Schemmel1; Rüdiger Pfaar1; Uwe Kremer2; 1Refratechnik Steel Gmbh; 2Trimet Aluminium S.E.
Due to the trend to modern melting and recycling furnace technologies, the requirements for the refractories in the Aluminum Casthouse are increasing constantly. The operating temperatures have increased and the chemical attack is more intense. Especially in the areas of the belly band, ramp slope and sill the established lining concepts have reached their limits. The previously well-proven anti-wetting agents of wear-lining material decomposes earlier and the concrete infiltrates with liquid Aluminum. We have responded to these challenges by developing a novel monolithic wear lining refractory with an inorganic binder and a very effective anti-wetting agent. This special additive is highly temperature stable and thus still effective at increased process temperatures. By using the novel material, the life time of the refractory lining was increased significantly. This paper shares theoretical aspects of the refractory technology as well as practical experience and results of the collaborative work with Trimet Aluminum SE.