Flotation '23: a summary of the technical presentations

Flotation '23 was MEI's 11th International Flotation Conference, and the first face-to-face flotation event since Flotation '19 post-Covid.

The conference was held at the Vineyard Hotel, Cape Town, from November 6-9, attended by 336 delegates from 32 countries. Following is a very brief summary of the presentations made in the technical sessions over the four days.  This summary is intended to guide you to the extended abstracts associated with the presentations, including the poster presentations, most of which are available online as open-access. Unfortunately not all presenters responded to requests for drafts, but for those that did their names are linked directly to the online Proceedings.

The drafts have not been refereed, but all the presenters have been invited to submit their final papers for peer-review to a virtual special issue of Minerals Engineering.

Monday November 6th

Session 1

The conference got off to a perfect start with a keynote lecture from Graeme Jameson, Distinguished Emeritus Professor at the University of Newcastle, Australia, who is probably our profession's most prolific and respected innovator in froth flotation. In 2018 he was honoured by one of the most prestigious organisations in the world, the Royal Society, which boasts a fellowship of 1,600 of the world’s most eminent scientists. Fellow of the Royal Society, FRS, a rare and distinguished honour, is decided by a peer-review process based on excellence in science, and this was bestowed on Prof. Jameson for his work on fluid and particle mechanics, and especially the flotation process. In his keynote “Mostly froth and bubble – a lifetime of flotation research” he talked about his involvement with flotation since he first saw a flotation cell when he took his first job in the assay laboratory of a tin smelter in Sydney, Australia seventy years ago.

Graeme Jameson with his grandson, Samuel

One of Prof. Jameson's inventions is the Concorde Cell, a high-intensity pneumatic cell dedicated for treating ultrafines and rheologically-challenging ores, which is licensed to conference sponsor Metso, and Nathalie Kupka, of Metso Finland, discussed the metallurgical performance of the Concorde Cell at industrial scale. Nathalie is a mining geologist by training and worked at the German Geological Survey on conflict minerals in the Democratic Republic of the Congo. She then did her PhD and postdoc on froth flotation and process mineralogy at the Helmholtz Institute Freiberg for Resource Technology in Germany. Since 2021, she has been working with Metso as a technology manager and R&D project manager for the Concorde Cell.

Also representing Metso was Berivan Tunc, and she looked at the effect of operational changes in gas dispersion in the Concorde Cell. Berivan began her career at the Istanbul Technical University, Turkey, as a research assistant in the mineral processing department and currently she is with Metso as a process metallurgist, specialising in ultrafine flotation, surface chemistry and process design.

Berivan Tunc (left) and Nathalie Kupka with Metso colleagues

The Reflux Flotation Cell (RFC) is another innovation from the University of Newcastle, invented by Prof. Jameson's colleague Kevin Galvin.  Three presentations on the RFC followed the Concorde Cell presentations.

The RFC is licensed to conference sponsor FLSmidth and Lance Christodoulou, the Global Product Manager-Reflux Technologies at FLSmidth, USA, showed that results from extensive laboratory, pilot and industrial testing are showing that the RFC is transforming the hydrodynamics of traditional flotation and proving to meet the challenge of delivering as a high efficiency flotation technology. He presented an overview of the results of a testing campaign in an operating copper concentrator.

Lance Christodoulou (centre) with FLSmidth colleagues

Two presentations on the RFC were made by workers from the University of Newcastle. Subhasish Mitra's work involves complex hydrodynamics of multiphase flow systems related to mineral flotation with a specific focus on understanding role of turbulence in the bubble-particle interaction process. He explained that the RFC achieves fast flotation without a froth zone, however current understanding of the complex multiphase hydrodynamics of this system is quite limited. His work aims to characterise the two critical hydrodynamic variables of the RFC system – gas volume fraction and bubble size distribution.

Siân Parkes is a PhD candidate at the University of Newcastle, supervised by Kevin Galvin, and she specialises in developing benchmarks and optimising the RFC technology for low-grade battery and critical minerals and ion flotation applications. She holds a Bachelor of Chemical Engineering from the University of Newcastle, and has studied at INSA Lyon and Lund University and collaborated on mineral processing and renewable energy projects in Timor Leste, with the CSIRO and NIER in Australia, and HZDR and TU Dresden in Germany. Her presentation investigated the impact of feed gangue concentration on flotation kinetics and recovery in the RFC.

Siân Parkes with Luke Crompton of University of Newcastle and Mehdi Safari of Mintek

Imhoflot pneumatic flotation was introduced to the mining industry more than 25 years ago by conference sponsor Maelgwyn Mineral Services (MMS), UK. Over the years the flotation cell design has been optimised for different applications, including vertically fed (V-Cell), tangentially fed (G-Cell), hybrid (H-Cell) and VC-Cell as the latest design for coarser particles.

Imhoflot cells have over 180 installations globally covering coal, potash, kaolin, magnesite, copper, gold, PGMs, molybdenum, lead-zinc and reverse flotation of silica from iron ore. The main advantage of the Imhoflot system is the improved grade-recovery curve and the increased range of mineral particle sizes which can be recovered (both ultrafine and coarse). This is achieved through the higher energy dissipation for the bubble-particle attachment and the superior froth draining which reduces gangue entrainment.

Ahmad Hassanzadeh is the Chief Research Officer at MMS and holds a post-doctoral research fellow position at the Norwegian University of Science and Technology and he was the recipient of the 2020 MEI Young Person's Award. He presented a comparative study between Imhoflot and mechanical flotation cells.

Ahmad Hassanzadeh with Irina Bremerstein of UVR-FIA, Germany

Duong Hoang is also working in both academia and industry, at the Helmholtz Institute Freiberg for Resource Technology, Germany as a postdoc and at MMS as an Applied R&D lead. He discussed the application of the pneumatic Imhoflot G-Cell in recovering fine particles at Poland's KGHM Polkowice plant, one of the biggest copper concentrators in Europe. 

Duong Hoang (centre) with Helmholtz colleagues

Till Zürner received his Masters degree in Physics from the University of Technology Dresden in 2015. He obtained his engineering PhD from the University of Technology in Ilmenau, Germany in 2019 and then spent two years in France, studying the sedimentation motion of particles in water at the engineering school ENSTA Paris. In 2022 he joined the High Potential Programme at the Helmholtz-Zentrum Dresden Rossendorf, working in the department of Transport Processes at Interfaces investigating multiphase flows in flotation experiments. In his presentation he described bubble generation by a plunging jet in the column of a pressurised pneumatic flotation cell.

Till Zürner (right) with Helmholtz colleagues

Taking us to the lunch break were three papers on fluidised bed flotation cells (FBFCs), developed for coarse particles flotation, as they provide a quiescent environment, separating particle-bubble aggregates based on their density and minimising detachment. 

Diego Mesa has a PhD in Mineral Processing from Imperial College London and an MSc in Extractive Metallurgy from Universidad de Chile and is a Research Associate at Imperial College. He described the quantification of the multiphase fluid dynamics of the CoarseAir, a 2m tall laboratory-scale FBFC. The measurements were obtained using PEPT, a non-invasive technique that tracks the motion of a radiolabelled tracer and which was the largest PEPT experiment to date. 

The Eriez HydroFloat FBFC has demonstrated the ability to recover much coarser and less-liberated particles than a traditional mechanical cell, but where the effects of parameters such as bubble size are yet to be established. Konuray Demir, Projects & Development Superintendent at Newcrest, Australia described work on assessing the bubble size produced in a pilot HydroFloat Cell and its effects on flotation.

Isabella Verster is a Senior Research Fellow at the University Of Queensland and has a Bachelor of Engineering Honours degree in Control Engineering from the University of Pretoria, South Africa. She described the development of a small-scale fluidised bed flotation device for ore amenability testing. Currently the smallest available fluidised bed flotation units require 100kg of sample for a single test. This high sample requirement often prohibits the execution of small-scale ore flotation performance optimisation tests using this technology. The development of a small-scale device is vital to enable rapid and efficient testing for important operations and Isabella described the design and development of a  device that uses just 1-2kg of sample per test.

With Isabella Verster (2nd Left) and UQ colleagues

Session 2

Following the lunch break, mechanical flotation machines were the subject of a number of papers, beginning with Steve Merrill, Product Line Manager for Flotation at FLSmidth, USA, who compared FLSmidth's two main product lines for mechanical flotation machines: the WEMCO which is self-aspirated and the NextSTEP which is externally aerated (forced-air). He showed that although thousands of these machines have been installed throughout the world and both machines are effective at concentrating hydrophobic minerals, each has unique benefits in operation.

Steve Merrill (centre) with FLSmidth colleagues

Dariusz Lelinski of FLSmidth, USA, has been working in flotation for 31 years and his flotation experience covers wide range of subjects, from basic flotation research, through CFD analysis, scale-up methodology, to industrial process and mechanical flotation machine design. He was the keynote speaker at Flotation’13 in Cape Town and today he described the development and performance of the WEMCO II at pilot and industrial scales compared with the traditional WEMCO.

Dariusz Lelinski (left) with Ronney Silva of Locus Mining, USA

Shen Zhengchang is the chief scientist, professor, and doctoral supervisor of Beijing General Research Institute of Mining & Metallurgy (BGRIMM) and is a member of the Chinese Academy of Engineering. He presented research on a 680m3 ultra-large flotation machine based on flotation kinetic region reconstruction.

Kevin Galvin is the inventor of the Reflux Classifier (RFC) and also the Reflux Flotation Cell. He is a Laureate Professor at the University of Newcastle, Australia and Fellow of the Australian Academy of Science and Australian Academy of Technology and Engineering, and previous recipient of the Antoine Gaudin Award in mineral processing. He is Director of the ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals. He presented work demonstrating the efficacy of the RFC hydrodynamics in upgrading slow floating minerals using a reduced footprint, while rejecting the hydrophilic ultrafine particles.

Kevin Galvin (right) with Kirsten Corin and Cyril O'Connor of UCT

Afshin Jalili is Product Manager, Flotation Innovation and Development at Metso, Canada. He discussed recent advancement in froth management for large flotation cells, showing how there are several industrial designs to enhance froth management and suitable launder and crowder selection can be defined during the engineering phase of a greenfield project.

Afshin Jalili (2nd right) with Metso colleagues

Adrian Bill is a Senior Process Consultant with Ausenco, Canada, and a graduate of McGill University. He showed how the accurate sizing of flotation cells is critical for the optimal performance of flotation circuits and mineral processing plants. The sizing of conventional flotation cells and circuits is generally well understood but the demand for plants with higher throughput and smaller footprints has increased interest in alternative flotation technologies. Adrian argued that the sizing of these newer technologies needs to be better understood and established and he presented an analysis of cell sizing techniques, specifically focusing on their application to non-conventional flotation cells.

Mazen Draw is a Civil and Computational Engineer with experience in Computational Fluid Dynamics. He has a Master's degree from the Ruhr-University of Bochum and is currently a PhD candidate at the Technical University of Dresden, working at the Helmholtz-Zentrum Dresden-Rossendorf on the Eulerian simulation of flotation processes, the subject of his presentation.

Mazen Draw (left) with Helmholtz colleagues

Benmansour Mohammed Rida is a third-year PhD student at Université Cote d'Azur, France, and Mohammed VI Polytechnique University, Morocco, specialising in developing the ion flotation process for industrial applications, specifically within the phosphate industry and its related products. He described work on ion flotation process development for heavy metals extraction from aqueous and acidic solutions for industrial application.

Benmansour Mohammed Rida (right)

Luke Crompton is a PhD student at the University of Newcastle, Australia and he described work applying a new algorithm to the coarse particle flotation achieved in a simple bench scale mechanical cell. This work provides a robust and effective way to explore the benefits of changes in feed preparation, for example, from changes in crushing and grinding, or reagent delivery, to be easily quantified.

In 2012 Sebastian Maaß was awarded the young research award from the European Federation of Chemical Engineers in the field of mixing. During his PhD at the Technische Universität Berlin  he received several national and international grants and he is a founding member of two companies. One of which is SOPAT GmbH, where he is the CSO overseeing the company strategy. The Smart Online Particle Analysis Technology (SOPAT) has received several research and business awards and his presentation looked at do’s, don’ts and have to’s in the use of image analysis tools to record bubble size distributions in highly concentrated flotation applications.

Sebastian Maaß (3rd left) in the Mecosa booth

Han Dengfeng is a professor in flotation technology at BGRIMM, China, and he has developed the world's largest 680 cubic meter flotation machine. He described exploratory research into the implementation and sorting performance of a new technology based on reverse collision flotation.

With Han Dengfeng (2nd right) and his colleagues

Leon Knüpfer is a Research Fellow with the Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden-Rossendorf and TU Dresden, Germany. His main research interests include the development of experimental techniques for characterization of liquid foam and froth. He described neutron radiographic investigations on liquid and particle dynamics in a froth column.

More on Day 1

Tuesday November 7th

Session 3

Modelling dominated the morning session, which bgan with a fine keynote lecture, "a probabilistic approach to understanding particle collection in flotation" from Glenn Dobby, co-owner and Senior Consultant for Woodgrove Technologies Inc., Canada. From 1991 to 2005 Glenn was co-owner and VP of MinnovEX Technologies Inc, where he was primarily responsible for the direction of technology development in flotation equipment, flotation modelling, comminution modelling and geometallurgy. He has a BEng and a PhD in metallurgical engineering from McGill University and from 1984-1991 was Professor in the Metallurgy and Materials Science Department at the University of Toronto.

Glenn Dobby (right) with Juan Yianatos and Jim Finch

Raimund Bürger is a full professor of applied mathematics at Universidad de Concepción, Chile. He holds a doctoral degree from Universität Stuttgart, Germany. He is interested in models formulated in terms of time-dependent partial differential equations, their mathematical and numerical analysis, and applications in mineral processing, wastewater treatment, and related areas. His presentation described a degenerating convection-diffusion model of a flotation column, the theory, numerics and applications.

Raimund Bürger and Fernando Betancourt from Universidad de Concepción

Stephen Neethling is Professor of Minerals Processing at Imperial College London and has attended all MEI's flotation conferences. His main area of interest is in the modelling and simulation of multiphase systems, with the modelling of flotation being a particular interest. He discussed the modelling of flotation cells using Smoothed Particle Hydrodynamics.

Stephen Neethling with Rodrigo Serna of Aalto University

Ali Hassan is an industrial PhD student with FLSmidth, Helmholtz Institute Freiberg, and TU Dresden as part of EU-MSCA-EID FlotSim project. The focus of his work is to utilize state-of-the-art process mineralogical approaches to understand flotation hydrodynamics. Unfortunately Ali could not attend the conference so the paper was presented by his c-author, Martin Rudolph,  who discussed the effect of hydrodynamics on flotation kinetics of complex particles using particle-based separation modelling.

Martin Rudolph with Gabriela Budemberg of BASF, Brazil

Saeed Chehreh Chelgani is the Director of the Swedish School of Mines at Luleå University of Technology and is in the top 2% in the scientists worldwide list. He described a “conscious lab (CL)” concept for modeling flotation responses, based on the most advanced explainable AI models.

Pablo Brito-Parada is a Reader at Imperial College, UK. Since the beginning of this year Pablo is the Editor-in-Chief of Minerals Engineering and he serves on the International Mineral Processing Council (IMPC). He presented an economic model predictive control for a rougher flotation cell, using a physics-based model approach.

Luis Vinnett is with the Universidad Técnica Federico Santa María, Chile, having obtained a PhD from McGill University, Canada. He looked at the use of stretched exponentials to characterize flotation kinetics.

Luis Vinnett (right) with Juan Yianatos, Paulina Vallejos and Ahmad Hassanzadeh

Lucas Pereira is a researcher and group leader at the Helmholtz Helmholtz-Zentrum Dresden-Rossendorf, Germany, with a masters degree in georesources engineering and PhD in particle-based separation models. He discussed the application of convolutional neural networks to quantify the process behaviour of complex individual particles in froth flotation.

Lucas Pereira with Jim Finch

Benedikt Tiedemann is a PhD student at the Institute of Fluid Mechanics at Technische Universität Dresden, Germany. He is actively involved in the EID FlotSim project, a collaborative effort between FLSmidth and Technische Universität Dresden, aimed at enhancing flotation recovery rates through scientific advancements. He presented a new analytical model for particle-bubble collision in flotation processes.

Benedikt Tiedemann with colleagues

Mehdi Safari is Head of Flotation in the Mineral Processing Division of Mintek, South Africa. He discussed ion flotation and prediction of its kinetics using a new empirical model.

Mehdi Safari (centre) with his Mintek colleague
Musawenkosi Buyani Edison Diame (right) and Adrian Singh

Milad Eftekhari received his B.Sc. and M.Sc. in Petroleum and Chemical Engineering from Tehran University, Iran, and is working as a researcher at Helmholtz Zentrum Dresden, Germany. He discussed his research interests which focus on the dynamic interfacial properties of multiphase systems. In his current research, he is using particle image velocimetry and imaging techniques to understand the interaction of particles and bubbles in a modelled stirred cell.

Kirsten Corin is currently an Associate Professor and leads the Flotation Chemistry and Reagent Research Groups at the University of Cape Town. She discussed the use of simple analytical techniques to assess surface oxidation of sulphide ores which can have a negative impact on the flotation performance.

Kirsten Corin (right) with Margeth Tadie and Wonder Chimonyo

Labone Lorraine Godirilwe is an Assistant Professor at Akita University, Japan. She obtained her undergraduate degree in Chemical Engineering from Laurentian University, Canada and her PhD from Akita. She described and Investigation into the adhesion of sphalerite to air bubbles for suppressing sphalerite during the flotation of zinc-containing copper ore.

Labone Lorraine Godirilwe (left) at an evening sundowner

Session 4

The first presentation in the afternoon session was from Seda Ozcelik, a PhD student at Hacettepe University, Turkey. She discussed the surface chemistry and flotation of gold contained in pyrites with different textures.

Miguel Maldonado has a Master's degree in electrical engineering from the University of Concepcion in Chile and a PhD in electrical engineering from Laval University, Canada on the supervision and control of flotation columns. Later he moved to McGill University as a Postdoctoral Fellow under Professor Jim Finch's supervision, specializing in gas dispersion, frothers, and flotation banks. He is now a full professor at the Department of Metallurgical Engineering at the University of Santiago, Chile and he described a novel multivariable submersible sensor for the supervision, control, and optimization of flotation systems.

During his time at ProcessIQ, Australia, the digital division of Molycop, Bradley Williams has played a key role in improving grinding and flotation processes through advanced instrumentation and control. Recently, his research has been dedicated to enhancing the stability of interactions between flotation cells and banks. This involves utilising froth cameras to analyse flow velocities and effectively mitigate anomalous conditions. Bradley's expertise in Computer Vision and Artificial Intelligence has been invaluable in developing an AI-based approach for detecting anomalies, which was the subject of his presentation.

Thália Maria Checon Frade has been a process engineer at Anglo American Iron Ore, Brazil since 2019 and she has a Master's degree in Metallurgy, Materials and Mining Engineering from UFMG. Thália’s contribution spans across various areas, leading to improved processes and efficiency but her passion is flotation processes advancements and she looked at the analysis of froth flotation velocity from Anglo American Minas-Rio according to the ore in the plant feed and the benefits of its measurement.

Thália Maria Checon Frade with Jenni Sweet of Anglo America, South Africa

Nicolas Miranda was representing SCM Minera Lumina Copper, University of Santiago and Santa Maria University, Chile and he discussed flotation bank optimization through online gas holdup measurement on self-aerated cells.

Annelette Coetzee received a Master's degree from Stellenbosch University in 2020. She is currently a Process Data Analyst at Stone Three, South Africa, a digital company that helps the mining industry to improve productivity by providing expert services. She described an industrial application of an image classification model for detection of undesirable pulping, when pulp flows with the froth over the flotation cell launder lip.

Annelette Coetzee (centre) with Lidia Auret and Matt Lloyd of Stone Three

Egemen Guney graduated from Hacettepe University, Turkey in 2022 and is now a Master of Science student. His main research areas are sulphide mineral flotation, optimization studies of flotation plants and reagent schemes, metallurgical accounting and simulation of flotation circuits. He looked at the analysis of froth Structure and flotation performance in different types of flotation cells.

Hifsa Pervez is currently a PhD student in Technische Universität Dresden, Germany under the European Industrial Doctorate Program “FlotSim”. The FlotSim innovation program aims to educate the next generation of experts on flotation. As part of her PhD, Hifsa has had experience in flotation fundamentals and testing with FLSmidth in Denmark and USA. Her current research focuses on flotation hydrodynamics, specifically, on modeling the bubble size distribution in a flotation cell, the subject of he presentation.

Hifsa Pervez with colleagues

The last presentation of the day was from Stefan Geldenhuys, a research officer at the University Of Cape Town since 2014. He received a bachelor’s degree in chemical engineering from Stellenbosch University in 2011, after which he joined the metallurgy team at Anglo American Platinum where he completed the graduate development program. His presentation looked at the digital twinning of flotation processes, including a business case and potential challenges.

More on Day 2.

Wednesday November 8th

Session 5

Luis Cisternas is a well known face at MEI Conferences. He is a Professor and Director of the Doctoral Program on Mineral Processing Engineering at Universidad de Antofagasta, Chile. He got the day off to a fine start with a keynote lecture on the sustainable design of polymetallic flotation circuits.

Luis Cisternas and his keynote co-author Yesica Botero

This led nicely onto a presentation by another very well known face, MEI's flotation consultant Jim Finch, Emeritus Professor at McGill University, Canada, who compared circuits over time in Canadian practice.

Paulina Vallejos is a Researcher at the Universidad Técnica Federico Santa María, Chile and the recipient of the IMPC 2020 Young Author Award. She works with Prof. Juan Yianatos, the co-author of her paper on the effect of particle size and liberation on the mineral collection rate of industrial cells.

Paulina Vallejos (right) with her co-author Juan Yianatos

Diana Kasymova is preparing her doctoral thesis at Aalto University, Finland, while  working for Metso, Finland. She looked at the climate-induced variation in electrochemical behavior of low-grade Cu-Ni-PGM ore, using Kevitsa concentrator plant as a case study.

Natalie Shackleton is a Metallurgical Consultant for AECI Mining Chemicals, South Africa. She has 40 years’ experience in the mining industry in analytical chemistry, hydrometallurgical processes, mineral processing and mineralogy. Her main area of specialization is flotation, in particular, surface chemistry and reagent development for flotation for PGM ores. She discussed where chemistry and mineralogy meet during PGE and BMS flotation.

Natalie Shackleton with Margeth Tadie of Stellenbosch University

The Kamoa-Kakula greenfield copper project is located west of Kolwezi in the DRC and the flowsheet development and commissioning of the Project was described by Norman Lotter, a Distinguished CIM Lecturer in 2010. who is President and Consulting Engineer for Flowsheets Metallurgical Consulting in Canada.

Norman Lotter with Vongani Lucky Nkuna of Ivanhoe Mines, South Africa

R. Manenzhe

Resoketswe Manenzhe is a PhD Candidate at the University of Cape Town, as well as an award-winning novelist, and she described a stepwise study on the characterisation and processing of South African platinum group tailings.

Yesica Botero is a researcher at the University of Antofagasta, Chile. She has double degrees from the University of Antioquia, Colombia and the University of Limoges, France, and PhD in Minerals Engineering from the University of Antofagasta and the University of Quebec in Abitibi Temiscamingue (Canada), a convention Double degree between these two universities in 2023. She discussed the use of desulfurization by flotation for acid mine drainage prevention of a porphyry copper waste rock.

Rakan Rahbani is Director -mineral Processing at Aurubis AG, Germany. His presentation focused on optimising the Aurubis smelter by introducing mineral processing technologies that focused on improved metal recoveries. These include using floatation technology targeting graphite in the Aurubis hydrometallurgical flowsheet used for the recycling of Li Ion battery Black Mass.

Rodrigo Serna joined Aalto University in 2015 as the leader of the Mineral Processing and Recycling research group. Since then, Prof. Serna has researched new flotation technologies for the recovery of valuable materials from primary and secondary sources and his presentation described a characterization study on lithium-ion battery active materials flotation products using microscopic and tomographic techniques.

Ezgi Akyildiz is a PhD candidate at the Norwegian University of Science and Technology and she discussed a mineralogical study of rare earth elements bearing minerals to develop a selective flotation process.

Ezgi Akyildiz (left) with NTU colleagues

Inzhu Sandybekova is the Sulphide Plant Operations Superintendent at Kaz Minerals Bozshakol, Kazakhstan. The Bozshakol mine contains two distinct ore bodies, one is a simple copper sulphide ore, primarily chalcopyrite. The other ore, the clay ore, is a fine grained Cu and Au ore with very complex and extremely variable mineralogy. Copper is contained in the full spectrum of copper minerals, including primary, secondary and oxide copper minerals. Inzhu discussed methods to improve the recovery of valuable minerals by flotation, by performing an industrial trial with a technology based on paramagnetic ore characteristics in order to agglomerate the fines, which significantly improved copper and gold recoveries whilst maintaining the concentrate grades and process stability.

Inzhu Sandybekova (2nd left) with the MEI and Kaz Minerals teams

Session 6

Following the lunch break Chloé Korbel, a PhD Student at the Université de Lorraine, France looked at mineralogical insights in the flowsheet development for the selective flotation of lepidolite from the Beauvoir granite, a world-class lithium deposit containing significant amounts of lepidolite, cassiterite, and colombo-tantalite, which should all be beneficiated.

Chloé Korbel (centre) with Juliette Lainé and Josué Mesquita

Alireza Rezvani is a metallurgical engineer who graduated from the University of Tehran and continued his research at Curtin University, Australia. He began his professional career as a metallurgist at IGO Mining Company and later worked for three years at Anglo Gold Ashanti Gold Mine, where he evaluated industry problems in copper-gold flotation. He is now a PhD student at the University of Queensland, working on a project related to the depression and activation of pyrrhotite in copper-gold flotation. His presentation discussed the quantification of the distribution of different pyrrhotite types in copper-gold ore flotation using synchrotron X-ray diffraction.

With Alireza Rezvani (right) and his UQ colleagues

Maria Sinche Gonzalez is a doctor and engineer in mineral processing from the University of South Australia and San Agustin University, Philippines. She worked 12 years in the mining industry for several companies, such as Panamerican Silver, the Trafigura Group, the Newmont-Yanacocha mine, and BHP Billiton in the Olympic Dam mine. Maria has been working in research and teaching for 13 years, working at the University of South Australia, the Technical University of Lulea and currently at the University of Oulu in Finland. Her presentation revealed the process mineralogy of sub-microscopic gold-bearing refractory sulphides and their interpretation by SEM-based automated mineralogy and machine learning.

Josué Mesquita is a Process Engineer with over a decade of experience in the iron ore industry. He has an MSc in Mineral Technology from UFMG, Brazil and is currently a PhD candidate at Université de Lorraine, France. His expertise lies in the field of iron ore mineral processing, and he is currently working as a Senior Researcher at ArcelorMittal Mining and Mineral Processing R&D Centre. France. He discussed the evaluation of flotation for producing a DRI pellet feed from a Canadian low-grade iron ore.

Andrew Hobert graduated from Virginia Tech with a BSc and MSc in Mining and Minerals Engineering in 2014 and has since worked over nine years with Eriez Flotation in the USA. With Eriez, he has held the roles of Process Engineer, Technical Services Manager, Operations Director - USA, and his current role as Global Business Development Manager. In these roles, Andrew has contributed to the development, improvement, and adoption of Eriez' HydroFloat, StackCell, and Column Flotation technologies within the sulfide and industrial minerals industries. He looked at he use of HydroFloat coarse particle flotation in Quebec Iron Ore’s Bloom Lake low silica upgrade circuit.

With Andrew Hobert (right) and the Eriez team

The cationic reverse flotation route is one of the main processes to remove silicates from iron ore, and etheramines are the most common surfactants used to modify the hydrophobicity of silica surfaces to make them floatable. Wendel Rodrigues, Sales Manager at Clariant, Chile described how the performance of three types of etheramines in the flotation of quartz was investigated in order to understand the influence of the chemical structure of these collectors on the floatability of silicate minerals.

Wendel Rodrigues with Gilmara Lopes and Andreia Henriques

Borhane Ben Said is a PhD candidate at the Helmholtz Institute Freiberg for Resource Technology, Germany. He studied chemical engineering at the Niederrhein University of Applied Sciences in Germany. As part of his PhD, he is investigating flotation processes with a particular focus on the flotation of calcium minerals, testing new reagents to improve selectivity, and working on a methodology to optimize and upscale the process to industry scale, the subject of his presentation.

Borhane Ben Said (right) with Helmholtz colleagues

Sancho Nyoni is a Mineral Processing PhD Candidate at the University of Cape Town. He described his research, which considers how the milling environment can be harnessed, at a chemical level, to help improve ore metallurgy in flotation. Furthermore, it considers the possibility of water recycling in the presence of some common and problematic ionic species and how any subsequent adverse effects on mineral recovery and grade may be circumvented.

Renji Zheng received his PhD degree in mineral engineering from Wuhan University of Technology in 2019. He is now a senior lecturer at Central South University, China. His presentation considered the quantitative evaluation of collector flotation performance and the creation of a flotation index based on mineral recovery.

Mayeli Alvarez Silva, a researcher at Corem, Canada, presented the development of novel bio-collectors for sulphides, specifically chalcopyrite. Two peptides selected due to their high selectivity towards chalcopyrite were subsequently modified with a hydrophobic domine to act as collectors. Testwork on chalcopyrite and quartz proved the effectiveness of the peptide-base collectors comparable to xanthate. This work opens interesting alternatives in the selection and development of peptide-type collectors (or depressants and other reagents) having great affinities towards different minerals.

Minsu Hwang is currently pursuing a PhD degree in flotation at the University of Queensland and prior to this he completed a Master's degree in mineral processing engineering in South Korea, where his research focused on utilizing mineral processing techniques for recycling industrial waste. He looked at the changed behaviour of xanthate in saline water, which has emerged as a strategy in flotation plants to address water scarcity concerns.

Minsu Hwang (left) with UQ Colleagues

Tarun Bhambhani is Principal Scientist at Solvay Mineral Processing Chemicals Research and Innovation, USA, where for the past 16 years he has engaged in design, development and commercialization of novel flotation reagents to enable mineral separations and recovery of value metals from challenging ores. He discussed improving cleaner circuit operations using novel frother technology.

With Tarun Bhambhani and Bravo Mbao of Solvay Zambia

Ronney Silva has BS, MS and PhD degrees in Mining Engineering from Federal University of Minas Gerais, Brazil. He started his career in 2001 as a Process Engineer at the research center of iron ore giant Vale. In 2008, he joined FLSmidth, USA where he held the positions of R&D Engineer, Group Leader – Flotation, and Sr. Process Engineer. In 2014, he worked at Magnetation Inc. (Iron Ore Producer) as a Sr. Process Engineer. In 2017 he moved to Clariant as a New Business Development Manager, later returning to FLSmidth as R&D Project Manager II, and in 2021 moved to customer services as a Global Service Line Manager. In 2022 he joined Locus Mining Solution, USA as the Director of R&D and Metallurgy and his presentation evaluated biosurfactants as frothers.

Ronney Silva (right), with Dariusz Lelinski of FLSmidth

The last paper of the day was presented by Syamsundar Menon Murali Mohan, of the University of Newcastle, Australia. He looked at the effect of surfactants on rising dynamics of coarse particle-laden bubbles in turbulent flows.

More on Day 3

Thursday November 9th

Session 7

Diana Drinkwater, of Metcelerate, is a mineral processor with over 30 years’ experience in mining operations, engineering and consulting. Her principal interest is professional education and technology transfer, and she has delivered targeted education programs in Australia, Africa, the Americas and Europe. She has served on the board of the Australian Institute of Mining and Metallurgy  and currently chairs the Education Commission of the International Mineral Processing Council which is overseeing a global review of Mineral Processing education.

In her keynote lecture this morning Diana spoke of how organisations need to manage their people like any other asset, to ensure best possible condition, use, and performance. Human resource departments run excellent programs to develop skills in communication, leadership, and social responsibility. The skills needed to make good decisions include the ability to collect and manage data, numerical skills, awareness of best practice, and knowledge of analytical tools. Some of these skills are learned at university, but they can only be fully developed and refined in the workplace. Several studies conducted in the last decade have highlighted significant challenges in delivering quality professional development including rapidly changing workplaces, changing technology and changes to tertiary education. In her presentation Diana expanded on some of these studies, and reviewed the development pathways emerging to enable effective management of the “people” asset.

Diana Drinkwater (centre) with her Metcelerate colleagues
Jenny Wiese and Katja Freitag

Belinda McFadzean is an Associate Professor at the University of Cape Town and her research focuses on the flotation process and ranges from molecular surface interactions to plant-scale optimisation techniques. She discussed the analysis of dispersant efficacy in overcoming challenges posed by alteration minerals in flotation.

Mustafa Guner finished his bachelor's and master's degree at the Department of Mineral Processing Engineering, Istanbul Technical University. He worked as an R&D metallurgist at Koza Gold Coop, Turkey for two years before beginning his PhD at the Norwegian University of Science and Technology. His presentation looked at the synergism of mixed collectors in the flotation of copper in a Reflux Flotation Cell.

Mustafa Guner (centre) with NTU colleagues

Kosei Aikawa is a postdoctoral researcher in the Division of Sustainable Resources Engineering, Hokkaido University, Japan. His presentation was on the depression of sphalerite in the flotation of copper ores based on estimation of the degree of copper activation of sphalerite.

Ngoni Mhonde is an early career mining industry technical consultant at Nalco Water, working to drive the success of Nalco Water flotation chemistries within Sub Saharan Africa. Before Nalco Water, he was at Aalto University, Finland, as part of the EU Horizon 2020, ITERAMS work group, where he researched on water issues in flotation and in his presentation he examined the effectiveness of polysaccharide pyrite depressants in Cu flotation. He highlighted that polysaccharide pyrite depressants are effective but there is a poor understanding of how the depressants can be implemented and what changes are required in the plant philosophy. He shared Nalco Water's experience in the practical use of polysaccharide depressants in copper flotation.

Ngoni Mhonde (3rd left) at the Nalco booth

Prior to the coffee break, Lina Uribe, an Associate Professor at the Universidad de Talca, Chile, evaluated the use of polymeric nanoparticles as a collector of chalcopyrite in the presence of clays.

Leopoldo Gutierrez is a metallurgical engineer who graduated from the University of Concepción Chile. He has degrees of PhD and Master of Applied Science in froth flotation and surface chemistry both obtained from the University of British Columbia, Canada. He is currently Associate Professor at the University of Concepcion and he discussed the effect of polymer mechanical degradation and anionocity on molybdenite flotation in the presence of polyacrylamides.

Lina Uribe (centre) and Leopoldo Gutierrez (2nd right) with Chilean colleagues

Ilhwan Park is an Associate Professor in the Division of Sustainable Resources Engineering at Hokkaido University, Japan. He presented a microencapsulation-based surface modification for improving flotation separation of Cu-Zn mixed sulfide minerals with high Cu/Zn ratio which often  prove difficult due to undesired activation of sphalerite by pyrite.

The role of depressant and pH in the selective flotation of copper and zinc ore and insights from mineralogy was discussed by Refilwe Magwaneng, a researcher at the Metals Technology Center at the Japan Organization for Metals and Energy Security and at Akita University, Japan.

Samuel Hartikainen, a Doctoral Researcher at the Oulu Mining School, University of Oulu, Finland, presented work on synthesized bisphosphonates as non-toxic collectors in the flotation of massive Cu-Zn-Fe sulphide ore.

Dzmitry Pashkevich is a graduate of the joint European master's program EMerald with a professional focus in geometallurgy. He has several years of work experience in mineral processing projects in Germany and is currently a PhD student at McGill University, Canada. He presented a froth flotation study of a Pb-Zn ore under different temperature constraints.

Dzmitry Pashkevich (left) with McGill staff and alumni

Taking us to the lunch break, Richard Lee, a research scholar at the School of Chemical Engineering, the University of Queensland, Australia, looked at methods for depressing high-concentration pyrite in copper flotation.

Richard Lee with his UQ colleague Wonder Chimonyo

Session 8

Lam Ian Ku is a PhD candidate at the JKMRC, Australia. Her project focuses on developing novel, bioinspired flotation collectors for targeting arsenic-containing minerals during froth flotation, potentially opening the doors to a new generation of environmentally friendly reagents for mineral processing applications. She looked at the separation of arsenic minerals using a novel peptide collector.

With Lam Ian Ku (left) and her JKMRC colleagues

Tatsuhiro Ono is a researcher in the Japan Organization for Metals and Energy Security. Currently, he is a first year PhD student in the Graduate School of International Resource Sciences of Akita University, Japan, where he also obtained his Master of Engineering in 2019. He discussed the selective flotation of arsenic bearing copper sulfide minerals from non-arsenic copper sulfide minerals using a new collector reagent.

Bradley Nemutudi, a PhD candidate at the University of Limpopo, South Africa, presented results of an investigation into the effect of pH on the adsorption behavior of xanthate, dithiocarbamate and s-triazine collectors on sperrylite using computational and experimental techniques.

Linda Mahlangu is Regional Metallurgist for Clariant Southern Africa with more than 20 years experience in flotation. Her career started at Mintek where she gained experience in minerals processing specializing in flotation then later joined Clariant in 2011 as technical lead responsible for research and development for projects in the Sub-Sahara Africa region. She talked about Clariant's specialty collectors for PGM flotation.

Linda Mahlangu (forefront) with Clariant colleagues

Avuyile Wali, a PhD Candidate at the University of Cape Town described a surface and solution characterization study investigation into the effect of Eh and pH on the adsorption of a xanthate collector on sperrylite (PtAs2).

Avuyile Wali (2nd left, back)

Juhani Wallenius has a Masters degree from Aalto University, Finland and nearly a decade of experience in depressant development and application in sulfide flotation. As a senior researcher at Nouryon, Finland he has taken new products from lab scale application testing to plant scale industrialisation at concentrators as well as been involved in development of novel test equipment for reagents. He described how tailored carboxymethyl cellulose depressant has been used for managing carbon recovery in refractory gold ore flotation.

Juhani Wallenius (left) in the Nouryon booth

Pongsiri Julapong is a mining engineer and PhD student in Georesources and Petroleum Engineering at Chulalongkorn University, Thailand. He has BEng and MEng degrees in mining engineering from Prince of Songkla University, Thailand and he described an investigation on the effects of cationic and anionic moieties on ionic liquids as collectors for the flotation of monazite, xenotime, and zircon.

Johanna Sygusch is a chemist by training. She is currently doing her PhD at the Helmholtz Institute Freiberg for Resource Technology, investigating the flotation of ultrafine particles with special focus on the influence of the particle properties of size, shape and wettability on the separation. She presented work on gallium recovery by ion flotation using amphiphilic siderophores as a novel flotation reagent.

Johanna Sygusch with Helmholtz colleagues

Aliza Salces is a PhD student at the Helmholtz Institute Freiberg for Resource Technology, specialising in the recycling of lithium-ion batteries (LIBs). She presented an evaluation of the bio-based Cyrene™ as a sustainable pre-treatment solvent for the effective froth flotation-based separation of fine valuables from spent Lithium-ion batteries. Congratulations also to Aliza for winning the prize for best student poster at the conference.

Aliza Salces with me and Jim Finch

Juliette Lainé works with Université de Lorraine and ArcelorMittal, France, on the flotation of iron ores and focus particularly on the removal of kaolinite fine particles. She presented work aimed at unravelling the interaction between amine collectors and kaolinite through adsorption isotherms and molecular modelling.

Juliette Lainé with Josué Mesquita and Yann Foucaud

And so ended 4 days of 97 technical presentations, but supplementing these were 60 poster presentations, many of which have associated extended abstracts contained in the online Proceedings.  

More on Day 4

The next flotation conference, Flotation '25, will be held at the Vineyard Hotel again from November 17th-20th, 2025.

This thread links to all the daily reports and photos on the conference and a complete album of photos is available for personal use. If you would like to use any photos on a company website, please acknowledge the source (MEI Blog).

Finally a massive thanks to all who made this conference a great success, sponsors, exhibitors, presenters and all delegates, and not forgetting the wonderful staff at the Vineyard Hotel.

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