Episode Description

In the very first Sepro Podcast, we sat down with Erin Bobicki, an Assistant Professor at the University of Toronto, to talk about the future of mineral processing. Erin is collaborating with Sepro on a microwave-assisted comminution project, which has shown to improve ore sorting efficiency and energy savings of up to 70% in comminution circuits. We also discuss her career, education, and other mineral processing projects that will impact the future of our industry. 


Also available on Spotify, RadioPublic, PocketCasts and Breaker

Full Transcript

Hi, I’m Andrew Gillis with Sepro Mineral Systems. You are listening to the first and, depending on how this goes, maybe the only Sepro podcast ever recorded. Today I am talking with Professor Erin Bobicki from the University of Toronto. She is the Assistant Professor of Materials Science and Engineering, and in addition to that, she is collaborating on a research and development project with Sepro and a few of our partners. 


We decided to talk today about Erin’s background, the current project, as well as some of the things that Erin sees as exciting areas in the future of [mineral processing] research. If you enjoy this podcast, we will endeavour to produce more like it. And, as always, feedback is welcome. Hope you enjoy.


Thanks for talking to me today Erin. If you don’t mind, talking a little bit about where you grew up.

Okay, well I grew up in Kelowna, BC not too far from Sepro. I was certainly not involved in the mining or mineral processing industry at the time. I didn’t really have a clue about anything going on in engineering. Engineering was not on my radar until I went to university, and then discovered I was not super keen on science. But I ended up at UBC I guess roughly around the same time as you [Andrew] and ended up switching into environmental engineering as a new program that was being offered. 


I’ve always been a bit of an environmentalist so it was an interesting fit. [The program] was offered jointly with UNBC [University of Northern British Columbia] in Prince George so there was a bit of an adventure there,  checking out some new territory in British Columbia. So that’s really how I got involved in engineering in the first place. But as a young person, it was not something that was on my radar at all.


 What got you interested in engineering?

Again, it was particularly this program in environmental engineering that was being offered and it was a mix of environmental science but it also had the engineering side. I was in first-year residence at UBC and making new friends, meeting people and they were in engineering. I liked the applied side of it. I like to solve problems and build things so I thought it was a good way to use some of my passion for environmental issues to solve some of the problems that were out there.


 What happened after you graduated?

I definitely took kind of a right-hand turn when I was an undergrad. I did a lot of co-op but it was all forestry and geotechnic-related. In my final year, I received a call from Inco [Vale]. They were recruiting and looking for people from different disciplines and they thought based on the work that I had done in geotechnics, I could apply that to tailings research. 


Coming from Kelowna, I had never been on a plane before I went to university. Going to Toronto on a big trip for an interview was pretty exciting, so that’s how they were able to entice me to go to that interview⏤and then ultimately it worked out. It was a really interesting two-day process. They had a lot of senior people there and they convinced me that I can make an impact working in the mining industry⏤specifically on tailings⏤so they hired me to work in their mineral processing group at their research centre in Mississauga.


Okay, so what was the move after that for you?

Well, when I first started there, it was kind of a battery pilot power plant. So I didn’t work on anything tailings or environment related but I certainly got the bug for piloting and starting new processes and troubleshooting. I was the only technical lead onsite right-fresh out of school, that was pretty exciting. And after eight months, once we finished commissioning, I went back to the mineral processing group and got to work on all different things that were really related to a lot of the research I do today. 


I did quite a bit of ore sorting work, stuff on ultramafics, and a lot of tailings work. A lot of this stuff has led to the research projects we have now. After doing that for a number of years, Voisey’s Bay was looking for a metallurgist and I had begun to think that I needed some operations experience to be able to make some more practical decisions in the research that I was doing and also the recommendations that I was making at the research centre. A big component of what we did actually was site support and troubleshooting as well. So, it was a good fit for me at the time.


I was recommended for the position so I ended up at Voisey’s Bay for a couple years as a newer metallurgist and really enjoyed it. It was a life experience. I lived in a coastal Inuit community at the time and also I was running the mill so it was pretty exciting. The nickel price was high and it was a good time.


Oh good, but that didn’t last so long.

Well you know when you’re doing a really good job as a metallurgist and you have a nice ore body and a new mill, it runs pretty easily, you know? So, after a few years, I began to think I’d like to get back into a technical role. And at about the same time the steelworkers went on strike (the strike ended up lasting for two years). During that time we started operating the mill with the management team. Which was pretty exciting at first because as management you don’t get to touch anything and then all of the sudden you’re the Comminution Operator, Dewatering Operator, and Flotation Operator. So I was getting a lot of hands-on experience but at the same time not getting to do any of the technical work that I really enjoy.


I wanted to do graduate studies from the time that I finished my undergrad but it just didn’t work out with what was going on in my life. So I started to talk to a few people about what opportunities might be out there. I talked to a few professors at different universities in Canada about the research they were working on, about what opportunities were available and ultimately I decided to go back to university in Edmonton at the University of Alberta to do my PhD in chemical engineering.


What attracted you to U of A?

Well, the person that ended up being my PhD supervisor, Zhenghe Xu, was friends with my boss at the research centre in Mississauga so I had worked with him for a number of years on some different projects and knew him well. But also the facilities there were excellent. It was a large research group. There were a lot of different things going on and it just seemed like a good fit all around. 


Inco, or it would have been Vale by that time, was starting to sponsor a project on ultramafics


And so I spent a lot of time working on ultramafics while I was at Inco and had dreamed up this project with my former supervisor around storing carbon in ultramafic tailings. So it was a combination of resources, the facilities, as well as the project was interesting to me.


That was a fair bit of years of working in the industry before you went and did your PhD, which I think is a little bit unusual. Do you have any comments around the pros and cons of working before your PhD, and having for a gap like that between academic studies?

Well it’s definitely an unusual path. I think it was really good for me because I had a lot of perspective on what the industry, and particularly mining operations, was interested in…what their problems were, what types of solutions could be implemented versus those that could not…I also had good experience managing research projects so I knew how to plan and I knew how to execute. I was able to do my work quite quickly in comparison to the other students. 


One of the cons is obviously going back to do a full-time PhD, you quit your job. That’s not a decision you make without some financial hit, you know? You don’t go back to school to do your PhD because you’re going to make the money back. It’s something you do because you’re interested and that’s the path that you want to take. It could be hard for people as they get into their careers and they start families. But part of it⏤and I didn’t mention before but⏤part of the decision to leave working at a remote site is that I wanted to have a family and that wasn’t going to work, working two on, two off at a fly in, fly out camp. So it kind of came together for me and it was a really good fit, but yes you’re right, it’s not a typical path people take.


Okay so you finished your PhD, and then what happened?

Well I went back with the idea that I would go back into mineral processing research, potentially go back to Vale.


So at the time, you weren’t planning on pursuing an academic path?

No. I didn’t go back and think, “Gee, I’m going to be a professor.” That didn’t really cross my mind until the end of my PhD⏤that I would like teaching, and like doing research. I had this industry mindset the whole time. Even as I was finishing my PhD and looking at options, companies like Vale laid off a large number of people at their research centre. Mining companies were closing their research centres. There were very few opportunities in mining research at the time and I did start to explore opportunities at different [academic] institutions. 


I had discussions with a number of different universities, but also opened things up more broadly to see what else was out there. I ended up being recruited by Intel, which many people thought was an odd choice. I had some reservations initially when they were making offers, until the company that makes semiconductors [spoke with me]. I did not see at the time how my skill set fit into what they were trying to do. 


One of the professors in the department⏤he’s now the department chair, Ken Cadien, had a background in metallurgy, had worked at Intel, and had become a senior fellow before coming back to the university [as a professor]. He convinced me that a lot of the same fundamental science that is used in metallurgy, particularly in mineral processing around surface and interface sciences, is absolutely applicable to semiconductors, although, you’re working on vastly different scales. 


So I took that risk and moved to the States to their research centre near Portland, Oregon and worked on semiconductor development for a few years.  It was really, from a work culture perspective, a really interesting place at Intel. But also very cutting-edge research and development that was going on. It was a very different approach than I had experienced before so I really enjoyed my time there. After a few years, looking to come back to Canada, [I] again sort of poked my nose out to see what was around and speaking to some people, I found out that U of T [University  of Toronto] was looking for somebody in mineral processing. I had a few kids by that time and thought maybe taking a step back from the 24/7 workflow at Intel might be a good plan. And so they ultimately invited me for an interview and I ended up at U of T where I am now.


Okay really interesting path, very unusual.

Yes, I don’t take the straight and narrow.


So at U of T what are your current areas of research?

Well everything is structured around mineral processing. If you’re not in mineral processing that might seem like a very specific area but when I start to describe the things that I do in mineral processing, people are surprised at how broad it is. 


Everything I do is still focussed on this sort of environmental aspect: how to reduce water and energy and processing, how to reduce waste, how to reprocess waste. Basically [it’s] all about sustainability of operations. I can group the different research projects into about four broad areas but there’s a ton of overlap. Of course we do quite a bit of microwave work… that’s sort of one of the general themes. I do quite a bit of bio-work, bio-processing. I do a lot of work on clays and clay minerals and how they impact mineral processing and also quite a bit of work on tailings and effluent and waste utilisation…so different clusters we work on there but [it] spans everything from rock coming out of the ground and how do we break it – to now we’ve generated tailings and what do we do with them? How do we better manage them?


Well, since we have the common interest of the microwave, we’ve been involved in a project together along with some other collaboration partners. Do you want to talk a little bit about the microwave work, the principles behind it, some of the results, and some of the potential you see in it?

Sure. So there is certainly the microwave project that we are collaborating on together and this is around scaling up microwave-assisted comminution and sorting. I first became interested in microwave treatment during my PhD. Even though it was focussed on carbon storage, with this mineral processing mindset, I decided to look at pretreatments that could improve the carbon storage in the tailings but also improve the processing. And so one of the things that’s been well researched but certainly came out in my PhD work too, is that you can really improve the grindability of different ores by exposing them to microwaves. Ores are of course composed of different minerals and these different minerals have different properties including different microwave responsiveness. So we lump those together as permittivities. 


Fortunately for us, it tends to be the valuable minerals, the sulfides, and some various types of oxides⏤iron oxide, chromium oxide, manganese oxide, etc. that are very highly microwave responsive. 


So, if you expose them to microwaves, they heat very very quickly, whereas things like silica, alumina, and various other gangue minerals, are largely microwave transparent. And so when you take a piece of rock and expose it to microwaves, you get this intense heating response from those valuable minerals in comparison to a non-heating response from the gangue minerals that surround it. This results in a differential thermal expansion, so the valuable minerals will expand as they heat and the microwave transparent gangue minerals will stay at status quo. So you get this stress and strain across the boundaries that results in fracture. This  reduces the competency of the ore, so when we grind it, [and compare] untreated or versus microwave-treated ore, under ideal conditions you’ll get greatly enhanced grindability because the competency is reduced. 


Also because you’re cracking across the grain boundaries exactly where you want, you don’t have to grind it as fine. So it’s really interesting as far as comminution. And then with this CanMicro project that we’re working on together as well⏤because these valuable minerals are the ones that are responding to microwaves, we’re using that to sort the ore. So basically, rocks that contain valuable minerals will heat versus rocks that don’t contain valuable minerals, they won’t heat. And then we’ll be able to sort on that basis using a thermal camera. It’s pretty interesting. 


It’s the first time that people have tried to combine the two technologies: the microwave-assisted comminution and the sorting. It’s non-trivial. Typically you expose ore to high-power microwaves for a short period of time at very high power for compound fracture, but for ore sorting historically longer exposure times have been used. But we’re trying to combine the two by finding the operational overlap. We’re able to get the benefits from both so we can reduce our competency, increase mineral liberation, as well as reject waste and sorting. So that’s pretty exciting and there’s lots of benefits for downstream processing as well. We can reduce the comminution energy, and we can also improve the separation in flotation and leaching and gravity separation, as well as reduce the amount of tailings that we’re generating in the water that we use in processing. There’s really a huge potential here to improve the overall sustainability of operations.


Potentially remove fines, make tailings dewatering easier, perhaps enable dry stacking or quicker dropout in tailings ponds to improve tailings management. That’s a lot of potential benefits.

Absolutely, yeah.


Okay so, to close off maybe you could talk a little bit about what you see as potential areas of research that are either just starting to be pursued, or areas that you think are an open path for future research that you might be interested in doing or that you look forward to seeing other people take up?

Certainly within the microwave space for CanMicro we selected this ex-situ microwave-assisted comminution and sorting treatment because we felt it was the most sort of developed process and this project is around scaling up. But I think future applications that are really exciting involve microwave treatments underground and at the face for selective cutting. That’s something that I’m interested in and talking to partners about and that’s really I think for me, that’s the next iteration of microwave technology at least on the comminution side. I mean, I think more generally you know trends in industry are the interest in improving process efficiency and reducing water and energy and waste is going to continue there certainly is an increasing focus on reducing tailings production so these types of research projects are going to continue. Microwaves definitely fit well…they touch on each of those areas. Other than that, looking at new ways to process low-grade complex ores, and particularly how to separate colloidal and fine particles. 


We’ve been relying on flotation for the separation of sulfides now for 120 years and now with ore texture getting finer and finer, we’re losing valuables in the slimes fraction because we just don’t have a good way to separate them. So there are a couple different avenues that I’m looking at to separate fine particles… looking at different bubble sizes, different bioseparations…I mentioned the bio stuff, and I didn’t go into much detail but using bacteria to separate mineral particles is very exciting. Actually I do see biology as a big area of development in mineral processing. It’s used⏤I don’t want to say extensively⏤in hydrometallurgy, but certainly has been explored more in hydrometallurgy. 


I think there’s a ton of potential both in generating reagents, separation and developing new separation techniques but also managing tailings because one of the big challenges we face now is around tailings ponds and tailings dams. Best practice for sulfide-containing tailings is to store them underwater to prevent acid rock drainage and that’s a real problem if we’re concerned about the stability of these dams and managing risk. So figuring out how we can store sulfide tailings on the surface by dry stacking, as you say, a lot of that revolves around how do we shut off the bacteria that is catalyzing the acid rock drainage generation. So that’s a big project that we’re getting into starting as well. 


There’s a ton of stuff going on and certainly looking for additional ways to do comminution, how do we break bonds in a more efficient way other than smashing…that’s a continued area of research. There’s certainly a lot of interesting things here. It’s a really good industry for young people to get involved in because there are so many challenges, and so many interesting things to work on. A lot of the ways that we’ve done things and the practices that are still used have been around for a hundred if not hundreds of years so I think personally there’s a lot of low-hanging fruit in terms of developing new technology.


Yeah for better or for worse, there’s no shortage of opportunity for innovation in the mining industry, that’s for sure. Okay well I really appreciate you taking the time today, Erin. It’s been a pleasure chatting, thanks for sharing so much about your background and your current work experience and what you see upcoming. 

Thanks Andrew!
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