Aluminum Waste Management and Utilization: Aluminum Waste Management and Utilization
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Pernelle Nunez, International Aluminium Institute; Lavinya Kugaswaran, International Aluminium Institute
Tuesday 8:55 AM
March 21, 2023
Room: 31A
Location: SDCC
Session Chair: Miles Prosser, International Aluminium Institute
8:55 AM Introductory Comments
9:05 AM
Recovery of Value Added Products from Bauxite Residue: Himanshu Tanvar1; Brajendra Mishra1; 1Worcester Polytechnic Institute
The growing stockpiles of bauxite residue and associated environmental hazards require a sophisticated process flowsheet for sustainable residue management and value recovery. Considering the association of multiple elements (Fe, Al, Si, Ca, Ti, V, Sc) within bauxite residue, metal extraction is of prime interest. The complex association of different elements and physical and chemical characteristics makes the extraction and purification process expensive and challenging. The present study focuses on developing a novel hydrometallurgical flowsheet for subsequent recovery of base metals and critical elements from bauxite residue. The major elements present in bauxite residue are recovered as high purity magnetite, alumina, titania, silica and calcium carbonate. Whereas critical elements (such as V and Sc) are recovered in the liquid stream generated after the recovery of base metals
9:30 AM Invited
Current Status and Proposed Economic Incentives for Higher Utilization of Bauxite Residue to Enhance Sustainability of the Aluminum Industry: Subodh Das1; Muntasir Shahabuddin2; 1Phinix LLC; 2Worcester Polytechnic Institute
The three-stage aluminum production chain from ore to casting is complex and consumes large amounts of energy and input materials. The process also results in undesirable by-products, such as bauxite tailings and bauxite residues or red mud. From a holistic perspective, the overall sustainability of the aluminum industry is dependent on several factors that go beyond the recent focus on the low carbon drive across the companies and regions. Globally, some 3 billion tons of bauxite residue (red mud) are now stored in massive waste ponds or dried mounds, making it one of the most abundant industrial wastes on the planet. Alumina refining plants generate an additional 150 million tons each year. The industry produces 0.5-2 tons of bauxite residue per ton of aluminum. Although actively globally pursued, the current utilization of bauxite residues is less than 4%. In the author’s published analysis, mitigation and utilization of bauxite residue are the number one sustainability-enhancing factor. The objectives of this paper are: 1. Review of bauxite residue utilization status 2. Assess the feasibility and prospects of current efforts underway3. Suggest economic incentives to encourage higher utilization
9:55 AM Invited
Aluminium Bahrain (Alba) SPL Sustainable Solution from Landfill to Valuable Feedstock “HiCal30”: Nabeel Al Jallabi1; Khalid Ahmed Shareef1; Bernie Cooper2; Mohsen Qaidi Ghulam1; Fuad A. Hussain Alasfor1; Vijay Rajendran1; 1Aluminium Bahrain Bsc; 2Regain Technologies
Spent pot lining (SPL) is one of the largest solid waste generated from the primary aluminium production process. Around 23kg of SPL is generated per ton of aluminum. ALBA, the largest aluminum smelter in the world outside China, produces 1.56 MT of aluminum (2021), where SPL generated becoming very significant. SPL classified as hazardous material contaminated with cyanide and fluorides. The traditional way of handling SPL is either stockpile around smelters facility or landfilling, which is not sustainable solution. ALBA has taken the initiative to construct its own one of kind SPL treatment plant through partnership with Regain Technologies to process, detoxify, and convert SPL into useful feedstock into cement industry.This paper discusses the journey of Alba toward sustainable solution of converting SPL into valuable product called HiCal30. Moreover, this paper focuses on the process flow, detoxification heat treatment process, the final product specification and usages
10:20 AM Break
10:35 AM
Valorization of Treated Spent Potlining in Cement Industry: Laurent Birry1; Jean Lavoie1; Victor Brial2; Claudiane Ouellet-Plamondon2; Hang Tran3; Luca Sorelli3; David Conciatori3; 1Rio Tinto Aluminium; 2Ecole de Technologie Superieure, Montreal; 3Universite Laval, Quebec
Spent potlining (SPL) is a hazardous waste produced by aluminum smelters. It is classified as a hazardous waste because of its contamination with fluorides and cyanides and its reactivity with water, generating explosive gases. After the industrial and hydrometallurgical treatment by the Low Caustic Leaching and Liming (LCL&L) process, the refractory part of SPL becomes an inert non-hazardous material, called LCLL Ash. The cement industry is a major emitter of greenhouse gases. One of the best options for reducing the carbon footprint of concrete is the use of supplementary cementitious materials or filler to replace part of the cement in the concrete. This article presents the conditions for LCLL Ash to be a suitable and value-added material for cement industry. The results were obtained during the last 4 years R&D project at Ecole de Technologie Superieure (Montreal) and Laval University (Quebec), with support of Rio Tinto and Ciment Quebec.
11:00 AM
Aluminum Recycling and Recovery of Other Components from Waste Tetra Pak Aseptic Packages: Ilgım Baltaci1; Selcuk Kan1; Ahmet Turan2; Onuralp Yücel1; 1Istanbul Technical University; 2Yeditepe University
Tetra Pak packages which are multi-layered composite materials (approximately 75% cardboard-cellulose, 20% LDPE and 5% Al by weight) facilitate the distribution of particular food products and aid to preserve some food properties for a long time. In this study, experiments were proceeded to separation of the layers of Tetra Pak aseptic packages efficiently from each other and their recycling. Hydropulping process were carried out for the separation of the celluloses part which is paper for this material; then, hydrometallurgical and pyrometallurgical treatments were followed through for partition of polyethylene and aluminum (PEAl) fractions from each other. In hydrometallurgical pathway, PEAl samples were put in vegetable oil, observed according to increasing temperature, time and solid/liquid ratio parameters, at the end the LDPE and Al phases were purified. The pyrometallurgical studies (pyrolysis) were carried out with various time and temperature combinations, and efficiency of Al recovery from PEAL fraction were investigated.