Materials Processing Fundamentals: New Processes and Insights
Sponsored by: TMS Extraction and Processing Division, TMS Materials Processing and Manufacturing Division, TMS: Process Technology and Modeling Committee
Program Organizers: Samuel Wagstaff, Oculatus Consulting; Alexandra Anderson, Gopher Resource; Adrian Sabau, Oak Ridge National Laboratory
Thursday 8:30 AM
March 23, 2023
Room: 29B
Location: SDCC
Session Chair: Samuel Wagstaff, Oculatus Consulting
8:30 AM Introductory Comments
8:35 AM
Scaling Up of Contactless Ultrasonic Cavitation: Catherine Tonry1; Christopher Beckwith1; Valdis Bojarevics1; Georgi Djambazov1; Koulis Pericleous1; 1University of Greenwich
Ultrasonic Treatment (UST) of liquid metals has shown great potential for both grain refinement and degassing. Current UST methods use an immersed sonotrode to treat the melt. This approach has limitations due to impurities being introduced. A high frequency electromagnetic coil placed in proximity to the melt surface, induces ultrasound, avoiding contact, while adding heat and vigorous mixing. To ensure the resulting pressure waves reach the level required for cavitation it is necessary to tune the system for acoustic resonance. The cavitation zone then resides deep in the melt, avoiding the gas shielding problem of immersed probes and allowing the treatment of larger volumes. Extensive studies in aluminium, have shown that this technique can produce grain refinement and enhance degassing. Recent modelling work has suggested that by using higher resonant modes of the system, a larger crucible can be resonated leading to the possibility of treating much larger volumes.
8:55 AM
Reductant Formation Enthalpy in DC Ferrochrome Smelting: Merely Academic or Fundamental to Operation: Harmen Oterdoom1; Markus Reuter2; Johan Zietsman1; 1University of Pretoria; 2SMS Group
The start-up and operation of DC furnaces for ferrochrome and titania slag proved more challenging than anticipated. A combination of few furnaces in operation, a limitation on shared operational experience, quick response times between operational decisions and consequences, and a limited fundamental understanding of process mechanisms is a part of the causes for the results. Understanding the process chemistry, energy balance and interactions between them are fundamental to investigating the mechanisms taking place in a DC furnace. As part of a PhD investigation of process mechanisms and behaviour of DC ferrochrome furnaces, this paper will describe the potential operational consequences of ignoring the formation enthalpy of reductants. Reductant is used as an example to demonstrate that fundamental understanding of process chemistry is required for designing, operating, and studying DC furnaces. The paper will conclude with a brief discussion of the presented results, and how these relate to the PhD study.
9:15 AM
Measuring and Processing of Electrical Parameters in a Submerged Arc Furnace: Hakon Valur Haraldsson1; Halldór Traustason1; Yonatan Tesfahunegn1; Merete Tangstad2; Gúðrún Sævarsdóttir1; 1Reykjavík University; 2Orwegian University of Science and Technology
Electric arcs are necessary for high Si yield operation in Submerged Arc Furnaces (SAFs) for Si/FeSi production, and a certain fraction of heat dissipation in the arc enables optimal operating conditions. Directly measuring the arc is impossible due to hostile conditions inside the SAF, so controlling the heat dissipation is both a science and an art. The arcs exhibit non-linear electrical characteristics and behave in a complex manner so by implementing a data acquisition (DAC) system to collect current and voltage waveforms, typically on the electrodes or transformers connections combined with appropriate signal processing offers an estimate the actual arc parameters, enabling improved understanding of the arcing in the furnace, and improve furnace operation. In this paper a DAC system gathering data from a FeSi SAF will be discussed, the data is processed and used to determine various furnace conditions including arc and charge current as well as harmonics.
9:35 AM
Virtual Reality for Die Casting Industry Workforce Preparation: John Moreland1; Cristina Cabascango1; Kyle Toth1; Chenn Zhou1; 1Purdue University Northwest
High-Pressure Die Casting involves forcing molten metal into a mold cavity where it solidifies and is ejected. The die casting industry seeks to attract and train skilled operators for die casting machines and melting furnaces. A virtual reality simulator has been developed to enable rapid and in-depth preparation of die casting operators and related personnel. The simulator covers an introduction to die casting machine and melting furnace equipment, virtual hands-on instruction of machine startup, troubleshooting, operating parameters, furnace charging and tapping, and cleaning procedures. Development, functionality, and in-plant testing and evaluation are discussed.
9:55 AM Break
10:15 AM
Machining Fluid Filtration and Particle Count Measurement: Chaitanya Ruhatiya1; Brajendra Mishra1; 1Worcester Polytechnic Institute
Disposal of cutting fluids is a major problem for machining and manufacturing industries. Primarily due to high disposal cost and issues with production downtime and, unscheduled maintenance for large central machine shops. While it is also important to maintain the quality of machining fluid for a high-quality manufacturing and, extended tool and workpiece life. Moreover, the imposition of stringent pollution norms has forced the large machining plants to search for a dependable process that will help extend the life of machining fluids. One such process which can solve this waste disposal problem is onsite recycling and reuse of machining fluid. This work focuses on problems related to recycling of machining fluids in a central filtration facility with primary focus on standardization of sample collection, processing, and accurate particle count measurement for establishment of correct filter-system location and count-process relationship.
10:35 AM
Comprehensive Recovery of Elemental Sulfur and Sulfide Minerals from Pressure Acid Leaching Residue of Zinc Sulfide Concentrate with an Integrated Flocculation Flotation-hot Filtration Process: Guiqing Liu1; Bangsheng Zhang2; Zhonglin Dong3; Fan Zhang2; Fang Wang2; Jintian Wu3; Tao Jiang3; Bin Xu3; 1Northeastern University; 2Jiangsu BGRIMM Metal Recycling Science & Technology Co. Ltd; 3Central South University
An efficient flocculation flotation-hot filtration process was developed to recover elemental sulfur and sulfide minerals from a pressure acid leaching residue of zinc sulfide concentrate. The particle size distribution of the residue indicated that the portion of thin particle with the size of -37 um reached 67.65% and 36.27% of sulfur in the residue was distributed in this size fraction, necessitating the flocculation flotation for recovering the elemental sulfur and sulfide minerals. 94.59% of the sulfur was recovered with the flotation process of one-time blank rougher, two-time agent-added roughers and two-time blank cleaners with Z-200 as the collector and polyacrylamide as the flocculant. After hot filtration for the flotation concentrate at 145 °C for 2 h, 85.32% of the elemental sulfur in the concentrate was recovered and its product purity reached 98.64%. The filter cake of sulfide minerals can be returned to the leaching stage for zinc recovery.