Technical Sessions

Frank Lloyd Wright Ballroom CD

Chair: Georgios Kolliopoulos, Université Laval, Québec, QC, Canada

8:30 AM

Recovery of Valuable Metals from LIBs Black Mass by Nickel Pre-loaded Extractants

Yeon Chul Cho, Daejin University; Ki Hun Kim, Daejin University; Junmo Ahn, Jeonbuk National University; Jaewoo Ahn, Daejin University

Recycling of valuable metals from waste Li-ion batteries(LIBs) has recently attracted significant attention. A leaching solution obtained by leaching LIBs black mass with sulfuric acid contains copper, aluminum, manganese, cobalt and nickel. In order to remove Cu, Al and Mn from the leaching solution and recover Co and Ni, experimental work was performed using solvent extraction with Ni-D2EHPA and Ni-PC88A as extractants. The effects of various process parameters on pre-loading and extraction were investigated. Based on experimental designs, the parameters with the largest effects on the process performance were determined to be organic phase saponification, nickel concentration and phase ratio for pre-loading.

9:00 AM

Imaging Spectroscopy from Unmanned Aerial System (UAS) for Monitoring Heap Leach Pad Operations

Jinping He, Dean Riley, Isabel Barton, University of Arizona, Tucson, AZ

Unmanned Aerial Systems flying imaging spectrometers are a potential solution for hydrometallurgy operations to monitor heap leach pad operations, maintenance, and design. Heap leach pads are active geochemical systems and mapping mineralogical changes with background confusers such as pipes, ponded lixiviant, and other materials makes it difficult for ground truth sampling. We are using unsupervised learning with subject matter expertise and matched filtering to improve material mapping on leach pads. Early results indicate that mapping background materials as well as constraining the analytical methodology to the individual leach pads improves computational performance and allows for comparative analysis between leach pads.

10:00 AM

Recycling of Bauxite Residue (Red Mud) for Recovery of Metallic Values

Himanshu Tanvar, Material Science and Engineering, Worcester Polytechnic Institute; Brajendra Mishra, Material Science and Engineering, Worcester Polytechnic Institute

Bauxite residue is an industrial by-product generated during alumina production through the Bayer process. The worldwide stockpiles of bauxite residue are expected to reach 10 billion tons by 2050 if not processed effectively. Limited industrial-scale processing (3-4 %) of bauxite residue is mainly due to complex physical and chemical characteristics. High alkalinity and multiple elements make the recycling process complicated and expensive. The following work presents a hydrometallurgical approach for effectively recycling bauxite residue to recover high-purity metal oxide products, including magnetite, alumina, titanium dioxide, and scandium oxide. A pyrometallurgical method based on smelting for recovery of pig iron and subsequent processing of slag for value recovery is also discussed. A comparative analysis of hydro and pyrometallurgical processes is carried out to highlight the key differences and potential for large-scale application.

10:30 AM

Metal Leaching from Spent LIBs Using Deep Eutectic Solvents

Yeongran Hong, Jaehoon Lee, Eunjin Jung, Hyung Sub Eum, Younwoo Park, Go-Gi Lee, Industrial Materials Research Group, Research Institute of Industrail Science and Technology, Pohang, Korea 

Current technologies for the valuable metal recovery from spent LIBs are limited in terms of environmental point of view due to the use of strong acids, alkalis and organic solvents. Deep Eutectic Solvents (DESs) are a class of ionic liquids which can be formed by simply mixing hydrogen bond donors and acceptors above their eutectic temperatures. In this study, the DESs were applied to extract the valuable metals such as nickel, cobalt, lithium and manganese from black mass of the spent LIBs. The composition of DESs and the reaction conditions were explored to achieve eco-friendly metal leaching.  

11:00 AM

Solvometallurgical Recycling of Lithium-Ion Battery Components

Halimeh Askari Sabzkoohi, Department of Mining, Metallurgical, and Materials Engineering, Université Laval, Québec, Québec, G1V 0A6, Canada; Georgios Kolliopoulos, Department of Mining, Metallurgical, and Materials Engineering, Université Laval, Québec, Québec, G1V 0A6, Canada

E-waste generation, including spent lithium-ion batteries (LIBs), is a significant problem facing the world that can be turned into a critical and strategic metal recycling opportunity. Although hydrometallurgy offers a sustainable pathway to extract and recover these metals, the extensive use of aqueous solutions generates toxic effluents and raises concerns over the social acceptability of such projects. In this study, we report on a new solvometallurgical process paradigm to recover metals from lithium-ion battery components using green selective anhydrous solvents, namely deep eutectic solvents. Our approach promises to minimize water use and effluent generation in process circuits, thus improving the overall efficiency of metal recycling processes.

Frank Lloyd Wright Ballroom AB

Chair: Junmo Ahn, Jeonbuk National University

1:30 PM

Comprehensive Analysis of Cathode Stripping Behavior: Simulation by the Finite Element Method and Experimental Results

Almeida, N.G.S, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil; Ciminelli, V.S.T., Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil; Cetlin, P.R., Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil; Majuste, D., Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil

The main goal of this work is to improve the fundamental understanding of the stripping behavior of electroplated metals in an attempt to better control metal sticking in industrial practice, thus minimizing its impact on cost and productivity.

2:00 PM

Reverse Osmosis Treatment of In-situ Copper Leach Solution

Lingyu Zhang, Florence Copper, LLC

This paper summarizes the development of Reverse Osmosis treatment to concentrate low grade copper leach solution which produces high quality permeate for use as electrowinning process make up water. The demand for sustainability in the copper hydrometallurgy process is to increase sharply due to the water crisis especially in dessert area like Arizona and the significant growth of copper usage in electrical industries such as semiconductor or electrical car manufacturing. A review of RO plant optimization practices including acid RO design, fouling and scaling problems, pH control, multimedia filter management strategies, membrane selection, and clean in place frequency is given in this paper.

Frank Lloyd Wright Ballroom AB

Chair: Junmo Ahn, Jeonbuk National University

2:30 PM

Heap Leaching of Rare Earth Deposits – Hydrodynamic Characterization

Amado Guzman and Toren Olson, HydroGeoSense Inc; Randolph Scheffel, Independent Metallurgical Consulting; Tim Harrison, Ionic Rare Earths; Harley Davies, Ultramet Ltd and Grant Colligan, and Juan Illescas, USA Rare Earths Inc

Heap leaching has been used for centuries to process low-grade ores containing significant amounts of gold and copper. As the electric age progresses and new metals and elements, such as Rare Earths, become essential, our understanding of how to process the typically low-grade deposits must improve. For successful leaching processes, an integrated evaluation of the physical (geotechnical), hydraulic, and metallurgical ore responses is necessary.

3:30 PM

Extraction of Critical Elements from Sulfuric Acid Solutions

Weston C Hartzell, Missouri University of Science and Technology, Rolla, MO; Michael S Moats, Missouri University of Science and Technology, Rolla, MO

To address the supply risk of critical semiconducting materials, sustainable resources need to be developed. A zinc leach residue originating from electric arc furnace dust contains gallium (Ga), germanium (Ge), and indium (In). The residue can be leached with sulfuric acid to extract Ga, Ge, and In into an aqueous solution, however a process is needed to separate and concentrate these elements for recovery. The extraction of these critical elements from sulfuric acid solutions were examined using commercially available solvent extraction extractants and ion exchange resins. Distribution ratios and separation factors of these products are reported. A potential flowsheet to recover these critical electronic elements from a zinc leach residue is presented.

4:00 PM

Kupferglimmer – Its Identification and Leaching in Copper Anode Slimes

Shijie Wang, Coeur Mining, Inc., Chicago, IL

Kuferglimmer is a copper-nickel-antimony oxide phase contained in some copper anode slimes. It is difficult to effectively leach copper from kupferglimmer due to its refractory nature. This paper identifies and analyzes kuferglimmer for the first time as a needle-shape mineral in slime samples. This paper presents the mineralogy results, describes how to leach kuferglimmer during slimes processing, and shows the kuferglimmer composition before and after the leach.

4:30 PM

Stabilization of Arsenic Byproduct from Decopperization Process to Scorodite Using Methanesulfonic Acid

Junmo Ahn, The Department of Mineral Resources & Energy Engineering, Jeonbuk National University, Jeonju, South Korea; Jiajia Wu, The Department of Mining Geological Engineering, University of Arizona, Tucson, AZ, USA; Jaewoo Ahn, The Department of Advanced Materials Science and Engineering, Daejin University, Pocheon, South Korea; Jaeheon Lee, The Department of Mining Engineering, Colorado School of Mines, Golden, CO, USA

Arsenic (As) is a toxic byproduct from copper smelter. Arsenic immobilization is critical to prevent detrimental impacts on the environment. Arsenic compounds from decopperization requires to be dissolved and stabilized into scorodite. However, conventional lixiviant, H2SO4 limits As leaching, so methanesulfonic acid (MSA), an alternative lixiviant was investigated for arsenic leaching and scorodite crystallization. Results of arsenic trioxide leaching show that arsenic extraction with MSA was above 90% at 80oC within 4 hours. In addition, arsenic removal in scorodite was 98% at 80oC, and scorodite was successfully crystallized at MSA medium of pH 0.5. Overall, MSA was proven to be an alternative lixiviant to treat arsenic byproduct and feasible to precipitate arsenic into scorodite in MSA medium.

5:00 PM

Copper Extraction from Chalcopyrite in Various Hydrometallurgical Systems

Jaeyeon Kim, Department of Mining Engineering, Colorado School of Mines. Kroll Institute for Extractive Metallurgy, Colorado School of Mines; Junmo Ahn, Department of Mineral Resources and Energy Engineering, Chonbuk National University; Jaeheon Lee, Department of Mining Engineering, Colorado School of Mines. Kroll Institute for Extractive Metallurgy, Colorado School of Mines

Copper sulfide concentrate leaching, particularly chalcopyrite or other primary copper sulfides, has been investigated as an alternative to the conventional smelting. The grand challenge for copper industry is to improve copper extraction from the primary sulfides such as chalcopyrite. A newly developed method using activated carbon showed almost 99% copper extraction from a chalcopyrite concentrate containing 85% chalcopyrite and 8% pyrite. The system used sulfuric acid and ferric ion as a stock solution with activated carbon as an additive. In the absence of the activated carbon, only 19.2% copper extraction was observed for 96 hours at 65℃. With 10 g/L activated carbon increased the copper extraction up to 98 % for 48 hours at 65℃ in 10 g/L H2SO4. The activation energy of the H2SO4-activated carbon leaching system was 127.47 kJ/mol from the 25-65℃ temperature range, indicating the reaction is controlled by the chemical reaction. The system enhanced the copper extraction without surface passivation under the conditions used because the solution potential has been maintained lower than 640 mV vs. SHE. This leaching system is also compatible with the current solvent extraction and electrowinning process without any modification.

Frank Lloyd Wright Ballroom CD

Chair: Mike Free, University of Utah, Salt Lake City, UT

2:00 PM
On The Feasibility of Forward Osmosis and Freeze Concentration: A Process Simulation and Cost Analysis
Runlin Yuan, Chemical Engineering & Applied Chemistry, Institute for Water Innovation, University of Toronto; Vladimiros G. Papangelakis, Chemical Engineering & Applied Chemistry, Institute for Water Innovation, University of Toronto

Forward osmosis and freeze concentration (FO-FC) is a hybrid membrane-thermal process for water recovery. To fully understand its energy savings compared to conventional evaporative technologies, a thermodynamic process model was built using the OLI Flowsheet software. By simulating the operating conditions of a realistic FO-FC process and incorporating some basic heat integration, the energy cost was calculated to be 19 kWh/m3. It was also shown that the FC unit must be able to produce high purity ice otherwise the chemical cost of replenishing the lost draw solute can be prohibitive to the FO-FC process.

2:30 PM
Rare Earth Elements Separation Principles and Methods
Michael L. Free, University of Utah; Prashant K. Sarswat, University of Utah

Rare earth elements are critical to many modern devices. REEs are not as rare in ores as many common elements, but many of them are rare in applications because of their cost and availability. Much of their low market availability and relatively high cost are related to their similarities in properties, which make them difficult to separate. This paper provides a brief overview of various fundamental principles, such as reaction free energies, equilibrium constants, and electrochemical potentials as well as application methods that can be used to separate rare earth elements. The principles that establish what is possible in terms of extraction, separation, and recovery of rare earth elements and critical elements are based on the atomic level properties of the elements as well as the processing methods with related time, temperature, and mass transport parameter effects. Correspondingly, the main tools for separating elements are generally related to selective complexation, precipitation, oxidation/reduction, and mass transport.

3:30 PM
Copper Refinery and Impurity Control
Bradford C. Wesstrom, Freeport-McMoRan Copper & Gold, El Paso Refinery, 897 Hawkins, El Paso, Texas

Copper refining requires the removal of impurities that can build up in the electrolyte. This is typically done by removing a small amount of electrolyte from the refinery. This paper will cover the control methods used at the Freeport-McMoRan Refinery in El Paso, Texas for these soluble electrolyte impurities.

Frank Lloyd Wright Ballroom CD

Chair: Mike Free, University of Utah, Salt Lake City, UT

4:00 PM
Assessing the Suitability of Mine Tailings as a Geopolymer Precursor Material for Subsurface Engineered Barriers for In-Situ Recovery Operations
Godfrey Mawire, Curtin University, Commonwealth Scientific and Industrial Research Organisation; Robbie McDonald, Commonwealth Scientific and Industrial Research Organisation; Lionel Esteban Commonwealth Scientific and Industrial Research Organisation; Abhijit Mukherjee, Curtin University; Navdeep Dhami, Curtin University

Introducing artificial barriers to contain lixiviants within in-situ recovery operations is critical for economic and environmental reasons. Geopolymers which offer high acid resistance and rapid strength development were investigated as barrier materials. A range of mix designs were used to study tailings from two sites, CMT1 and CMT2. The reaction stages were quantitatively analysed with isothermal calorimetry. Under representative of subsurface pressure and temperature conditions, all permeability measurements were made at 3.5 MPa confining pressure (or 1.72 MPa effective pressure) and 22ºC; and converted into apparent hydraulic conductivity assuming water physical properties at the subsurface pressure and temperature conditions. The best hydraulic conductivity was found at 2.74×10-11 m/s for CMT1 and 3.62×10-11 m/s for CMT2 corresponding to a period ~ 1150 and 875 years respectively to displace lixiviants through 1-meter of such artificial barrier.

4:30 PM
Sustainable Water Recovery from Hydrometallurgical Effluents Using Gas Hydrate Based Desalination-29 OR 30
Seyed Mohammad Montazeri, Department of Mining, Metallurgical, and Materials Engineering, Université Laval, Québec, Québec, Canada; Georgios Kolliopoulos, Department of Mining, Metallurgical, and Materia ls Engineering, Université Laval, Québec, Québec, Canada

Hydrometallurgical processes generate large volumes of aqueous effluents. These effluents are deposited in tailings ponds, after being treated to remove impurities and recover water for reuse in process circuits. Effluent desalination is key to attain a zero liquid discharge future in the industry. In this study, we report on hydrate based desalination (HBD), which is an innovative, energy-efficient, and sustainable desalination technology, capable to treat hydrometallurgical effluents to recover water in the form of gas hydrates by consuming CO2, which is a harmful greenhouse gas. Therefore, HBD meets the criteria of an eco-friendly effluent treatment technology, especially compared to conventional methods.

5:00 PM
In Pursuit of Zero Discharge: Forward Osmosis and Freeze Concentration for Hydrometallurgical Wastewater Recycling
Noel Devaere, University of Toronto; Vladimiros Papangelakis, University of Toronto

To address the growing need for improved water capture for recycling in the hydrometallurgical industry, we are developing a hybrid process to treat aqueous wastes and intermediate streams by Forward Osmosis (FO) and Freeze Concentration (FC). The proposed FO-FC process has energy advantages over traditional precipitation and evaporative technologies, particularly for cold climates. This work describes the FO-FC proof-of-concept results and developments to date. 

5:30 PM
A Novel Process for Synthesis of TiO2 and Application for the Photocatalytic Remediation of Water
Trenin Bayless, Gary Wilson, Courtney Young, Department of Metallurgical and Materials Engineering, Montana Tech, Butte, MT

A novel process for synthesizing carbon-doped TiO4 at ambient temperature has been studied as a potential alternative to other techniques. During the synthesis, titanium tetrachloride (TiCl4), commonly referred to as "tickle" (i.e., TiCl), is exposed to UV radiation in an oxidizing environment to precipitate TiO2 particles. The study investigated the impact of the absence and presence of different UV wavelengths, oxygen source, and either carbon tetrachloride (CCl4) or graphene-oxide as carbon-doping agents.  Characterization was accomplished using UV-vis spectroscopy, Raman spectroscopy, calorimetry, scanning electron microscopy (SEM), and X-ray diffraction (XRD).  Bandgaps were therefore determined along with the presence of anatase and rutile.  Photocatalytic activity was measured by comparing the rates at which azo dye was degraded under UV as measured by its colorimetric intensity.  The dye was used as a substitute for organic contamination.  It was found that UV exposure favors synthesis through the oxygen-rich route while depressing production through the routes deprived of oxygen. The preliminary production of an anatase TiO2 supports future research into scaling and methods of improving efficiency.