Applications of Process Engineering Principles in Materials Processing, Energy and Environmental Technologies: An EPD Symposium in Honor of Professor Ramana G. Reddy: Modeling and Simulation
Sponsored by: TMS Extraction and Processing Division, TMS Light Metals Division, TMS: Energy Committee, TMS: Hydrometallurgy and Electrometallurgy Committee
Program Organizers: Shijie Wang, Rio Tinto Kennecott Utah Copper; Michael Free, University of Utah; Shafiq Alam, University of Saskatchewan; Mingming Zhang, Arcelor Mittal; Patrick Taylor, Colorado School of Mines

Thursday 2:00 PM
March 2, 2017
Room: 15B
Location: San Diego Convention Ctr

Session Chair: Mingming Zhang, ArcelorMittal Global R&D

2:00 PM  
Phase-Field Modeling of Internal Oxidation: Youhai Wen1; 1National Energy Technology Laboratory
    An electrochemistry based phase-field model for external oxidation has been developed that shows capability to continuously simulate oxidation kinetics across a wide range of lengths and times. External oxidation is, however, not the only mode for alloy oxidation. In some situations oxidation may proceed predominantly by inward penetration of oxygen through the alloy matrix and new oxide is formed internally with a much faster rate. Understanding internal oxidation and its transition to external oxidation is equally important especially in design of Fe-, Ni- and Co-base structural alloys. Important issues involved in internal oxidation modeling will be discussed, such as dilatation caused by oxide particles, plastic deformation, and coherency state of the interfaces, and how their interplay can be modeled by phase-field approach.

2:25 PM  
HPC4Manufacturing Program: A National Laboratory - Industry Partnership in High Performance Computational Simulations for Energy EfficiencyUntitled: Robin Miles1; Peg Folta1; Jeff Roberts1; 1Lawrence Livermore National Laboratory
    The HPC4Manufacture program is a new EERE-sponsored program with the aims of introducing industry to High Performance Computing for advanced science and engineering simulations, transferring advanced simulation techniques developed at the National Laboratories to industry and reducing industrial energy usage. The three partner national laboratories have been working with a variety of large and small companies in a variety of energy intensive industries to improve manufacturing processes and enhance product design. Examples include optimizing steel-making furnaces to reduce energy and coke usage and advanced CFD modeling of turbines used for aerospace and energy generation. Many companies are interested in advanced simulation as a way to reduce costs associated with product/or and process testing. Projects will be highlighted as demonstrations of how HPC can be used to reduce energy and enhance industrial competitiveness. Interactions can be used to gage industrial needs in the area of computational simulation at large scales.

2:50 PM  
Metal Silicides for High-Temperature Thermoelectric Application: Mallikharjuna Bogala1; Ramana Reddy1; 1The University of Alabama
    Transition metal silicides have good potential for converting waste heat into electrical energy at higher temperatures. Transition metal silicides are used as thermoelectric alloys at higher temperatures because of their low toxicity, high natural abundance, good transport properties, and better thermal stabilities. In this article, thermodynamic, and thermoelectric properties of promising metal silicides are reviewed, calculated, and compared for waste heat recovery application. Higher manganese silicide (Mn4Si7) was produced from easy one-step self-propagating high-temperature synthesis (SHS) procedure of arc-melting technique. Characterization of the alloy phases were done using X-ray diffraction (XRD). In this study, lattice constants, Vickers microindentation hardness, and thermoelectric (TE) properties (Seebeck coefficient, electrical conductivity, thermal conductivity, and figure of merit) of Mn4Si7 alloy were experimentally determined, and compared with the reported literature values.

3:15 PM  
Computational Fluid Dynamic Based Process Modeling of Reverberatory Furnaces Used for Lead Recycling: Alexandra Anderson1; Patrick Taylor1; Gregory Bogin1; 1Colorado School of Mines
    A common type of furnace used for the production of secondary lead is a reverberatory furnace in which the burden is heated through direct contact with the flame as well as radiant heat transfer from the walls and combustion gases. The impingement of the flame on the burden can facilitate large amounts of heat transfer, leading to greater production rates, but can also cause areas of high velocity turbulent flow and hotspots within the refractory lining. These phenomena can lead to excessive erosion and thermal stresses and thereby prematurely shorten the lifetime of the refractory. A computational fluid dynamic (CFD) model has been developed to simulate various reverberatory furnace conditions typical of secondary lead processing with the goal of increasing refractory lifetime. Several simulations were performed to examine the relationship between the burden height, burner location and burner orientation and how these parameters affected the conditions within the furnace.

3:40 PM Break

4:00 PM  
CFD Modeling of Slag-Metal Reactions and Sulfur Refining Evolution in an Argon Gas-Stirred Ladle Furnace: Qing Cao1; April Pitts2; Laurentiu Nastac1; 1University of Alabama; 2Nucor Tuscaloosa.
    Accurate prediction of the desulfurization behavior of steel is of great importance for process control during ladle metallurgical furnace (LMF) steel refining. A CFD model capable of simulating multiphase flow with bulk and free surface turbulence phenomena, slag-metal reactions and desulfurization behavior in the gas-stirred ladle has been developed. The fluid flow behavior shows that slag and metal try to entrap each other, forming a two-phase mixing zone. The resulting substantial contact area between the two phases will provide very favorable kinetic conditions for chemical reactions. For reaction kinetics model, the reactions in the metal/slag bath mixing zone as well as the entrapped droplet surface are included. Predicted results show that the sulfur content changing with time in the ladle agrees well with the industrial-scale experimental measurements. The effects of the gas flow rate, slag layer thickness, slag basicity and initial steel contents on the desulfurization efficiency were also investigated.

4:25 PM  
Numerical Study of the Fluid Flow and Temperature Distribution in DC Non-transferred Arc Thermal Plasma Reactor: Yudong Li1; Ramana Reddy1; 1University of Alabama
    A Numerical model was developed to simulate a thermal plasma reactor for material synthesis process. In this work, detailed design of the DC arc torch was approximated by defining the temperature and velocity profile of the argon gas at nozzle exit. The turbulence of plasma jet as well as coupled heat transfer phenomenon in the reactor were taken into account in this model to better predict the gas flow and temperature distribution. The temperature profile obtained from this model showed a great agreement with the experimental measurements. The influence of plasma torch input power as well as the plasma gas flux on the temperature distribution were studied using this model. The mechanism of ultrafine composites (including TiC-Al, TiC-Fe, TiN-Fe composites) synthesizing process was proposed based on the calculated temperature profile and velocity distribution.