Advances in Environmental Technologies: Recycling and Sustainability Joint Session: Advances in Environmental Technologies: Characterization and Uncertainty
Sponsored by: TMS Extraction and Processing Division, TMS Light Metals Division, REWAS Organizing Committee, TMS: Pyrometallurgy Committee, TMS: Recycling and Environmental Technologies Committee
Program Organizers: John Howarter, Purdue University; Mark Kennedy, Proval Partners SA; Naiyang Ma, ArcelorMittal; Elsa Olivetti, Massachusetts Institute of Technology; Randolph Kirchain, Massachusetts Institute of Technology

Monday 8:30 AM
February 27, 2017
Room: 14B
Location: San Diego Convention Ctr

Session Chair: Naiyang Ma, Arcelor Mittal; Randolph Kirchain, MIT

8:30 AM  
Understanding Scrap Recycling and the Potential of Hand-held Elemental Analyzers: Teija Mortvedt1; Adam Gesing2; Subodh Das3; Gabrielle Gaustad1; Elsa Olivetti4; 1Rochester Institute of Technology; 2Gesing Consultants; 3Phinix, LLC; 4Massachusetts Institute of Technology
    The scrap metals market is a multi-billion-dollar global industry. Currently, total ferrous scrap supply rests below demand for construction steel where higher impurity tolerances facilitate scrap absorption. However, by 2100 forecasts suggest that total scrap supply will match 96% of total demand. This eventuality necessitates progress towards scrap sorting and processing improvements. Current inspection methods are based largely on visual inspection and inexpensive non-quantitative testing. Hand Held (HH) elemental analyzers hold promise to address the lack of quantitative evaluation in scrap processing. This research aims to study the flow of valuable elements in the scrap industry, and evaluate HH-XRF and LIBS systems for their potential worth. A description of unit strengths, limitations, accuracy, precision, and sensitivity will be presented both qualitatively and quantitatively. These analyzers will be evaluated based on their potential value-adds to the system and conditions for beneficial use in a dynamic market.

8:50 AM  
Characteristics of Municipal Solid Waste Incineration Bottom Ash with Particulate Matters PM2.5 ~PM10: Ahn Ji Whan1; Thenepalli Thriveni2; 1KOrea Research Institute of Geoscience and Mineral Resources(KIGAM); 2Korea Research Institute of Geoscience and Mineral Resources(KIGAM)
    Numerous reports and researches address the various environmental issues about the municipal solid waste incineration waste management of heavy metals and other particulate matters with the range of 2.5 ~10. Although in many developing and industrialization countries landfill with the disposal of municipal solid waste, open incineration has become a common practice. Bottom ash contains heavy metals including particulate matters. The investigation of size distribution for the heavy metals and particulate matters in the bottom ash is essential. However, ultra-fine particle size and heavy metal stabilization are the most important requirements for ecofriendly by products. There are wide variety commercial technologies available for monitoring PM10, PM2.5 and ultra-fine particles. In this paper, we reported the studies on physical and chemical characteristics of municipal solid waste incineration (MSWI) bottom ash containing particulate matter whose particulate sizes are lower than PM10 and PM2.5 and heavy metal stabilization method by carbonation were investigated.

9:10 AM  
Development of Open Source Software Tool for Life Cycle Assessment of Rare Earth Elements Production: Ehsan Vahidi1; Praneet Arshi1; Fu Zhao1; 1Purdue University
    A handful of life cycle assessment studies on rare earth elements (REEs) have been published, however, these studies either cover a small portion of the REE life cycle or suffer from data quality and transparency issues. Given the importance of REEs in clean energy technologies, an LCA software tool that is well documented, easily accessible, and open to customization and updates while covering different REEs production pathways is highly desirable. The paper introduces the development of a modularized open source MS Excel based LCA software tool to support environmental performance analysis of REEs production. The software tool is organized in a layered structure with unit processes of input materials and energy used forming the base layer. The subsequent layer combines the environmental impacts (TRACI and ILCD) of these unit processes which form REE production pathways. All unit processes have an XML version that can be imported into commercial LCA software.

9:30 AM  
Scoping the Potential of Coal Ash as a Source of Rare Earth Elements: Gabrielle Gaustad1; Vasken Xhaxhollari1; Eric Williams1; Saptarshi Das1; 1Rochester Institute of Technology
    It has been well known for decades that coal ash contains both hazardous and valuable metals. However, a majority of secondary uses for both fly and bottom ash, for example as cement and concrete additives, do not attempt to extract these materials. Current concerns about lack of diversity in supply of critical materials have spurred research into utilizing domestic sources, particularly from waste streams. This work combines material flow analysis and techno-economic modeling to explore the resource and economic potential for coal ash to become a valuable source of rare earth elements (REE). Results show that while REE concentrations in the ash are significantly lower than currently economically extractable ores in most mines, the magnitude of materials available could meet current REE demand even at fairly low extraction yield rates. A combination of higher REE commodity prices, improved yields, and scale-up factors would be required for economic profitability.

9:50 AM Break

10:10 AM  
Addressing Criticality in Rare Earth Elements through Strategic Recycling: Cajetan Nlebedim1; 1Ames Laboratory, US Department of Energy
    Approaches for recycling rare earth element (REE)-based intermetallic alloys will be presented. Recycling offers alternative/supplementary manufacturing materials sources by reinserting manufacturing wastes or end-of-life products into the manufacturing chain. Since manufacturing wastes are generated in manufacturing facilities, they help to eliminate difficulties in collecting recycling feedstock materials. Swarfs are wastes generated during cutting/grinding/polishing operations. During manufacturing, 30%–70% of REE magnet alloys can be generated as swarfs. Magnet swarfs are often contaminated and oxidized and therefore difficult to be directly reinserted into the manufacturing process. This talk will present metallurgical approaches for recycling magnet swarfs including directly reusing the swarfs for magnet manufacturing. Approaches for removing surface contaminations to facilitate direct reuse will be discussed. Acknowledgement: This work was supported by the Critical Materials Institute, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office.

10:30 AM  
Environmental Implications of Laser Metal Deposition: The Role of Feedstock Powder and Material Utilization Fraction: Kaka Ma1; Julie Schoenung2; 1Colorado State University; 2University of California Irvine
    Metal additive manufacturing (AM) has emerged as a new sustainable metallurgical processing technique attributed to its capability of creating near-net shapes in a single-step, reducing the need for machining. More than 80% of the feedstock, however, does not go into the final metal part and becomes waste powder. The present work aims to evaluate the environmental implications of laser assisted direct metal deposition, a representative category of AM techniques, paying particular attention to the impact of producing feedstock powder and the actual material utilization fraction. A model taking into account a weighting factor to incorporate the environmental impact of the waste powder was applied to evaluate material/energy consumption. Results indicate that recycling the waste powder is important to improve the environmental sustainability of laser metal deposition. To explore the potential to reuse the waste powder for subsequent deposition, waste powder was collected for microstructural characterization.

10:50 AM  
Development of a Separation Process of NBR/ HNBR Rubber from Metal Substrate: Mariana Nascimento1; Sarah Scardelatto1; 1Centro Universitário Fundação Santo André
    The objective of this project consists in the development of a process for separating the rubber NBR/ HNBR from the metal substrate. The methodology will consist in choosing, presentation, separation, identification and classification of the material; performing cryogenic and solubility tests, record the results, quantitative and economic survey, data processing, analysis and discussion of the results and preparation, structuring and presentation of the report and the thesis. The results showed that a bath in polar acetic acid, above room temperature, followed by a wash in a basic pH bath and further drying, generates the expected results, with complete separation of the parts without attack the steel and with little change on the structure of rubbers. With this, the process becomes attractive because, in addition to the considerable decrease in the volume of discarded material, the by-products can be reused in the process itself, with recycling and reuse of materials.

11:10 AM Poster Session Preview