S2 E60: Revolutionizing Rare Earth Separation: A Chemical Engineer’s Perspective

Dustin Olsen (00:40)
Hi everyone, welcome to the Rare Earth Exchanges podcast. I am Dustin, your host joined by my cohost Daniel, and we have our special guest, Lynn Ding, who is a chemical engineer and is gonna talk to us more about the separation process in the rare earth sector. Lynn, welcome to the podcast. How are you doing?

Daniel O'Connor (00:56)
Okay.

Lingyang Ding (01:00)
And they're Thank you very thank you. Like inviting here to recording the podcast.

Dustin Olsen (01:05)
Absolutely. ⁓ Lynn, ⁓

Daniel O'Connor (01:06)
Okay.

Dustin Olsen (01:09)
to kind of kick things off, to help introduce you to the audience, can you give us a quick summary of your background and how you got started in chemical engineering?

Lingyang Ding (01:18)
OK, so I'm a PhD in rare separation and also extraction. I just graduated from University of Toronto last October and I'm actually looking for some engineer process and unit jobs in Canada and the US. And I choose chemical engineering because in senior high school I'm interested in the chemical reactions and then I choose chemical engineering for my undergraduate and during the undergraduate I realized that.

The experiment we did in the lab looks beautiful, but as we scale it up in the industrial, it might cause serious pressure to the environmental problems. So now I realize I need to do something important or meaningful to the society. So now in the PhD, I start to pursue my hydrometeorology PhD degree. It's because I know that the metal extraction and separation is very energy and chemical intensive.

Daniel O'Connor (01:56)
you

Lingyang Ding (02:11)
And the waste can put a lot of pressure on the environment. So I choose the hydrometallurgy. And the reason why I choose the rare earth element is because currently, the popular critical metals, we

can say, battery metals, including lithium, carbon, nickel, manganese, and also the manganese metals, the rare earth element. And among all these metals, the rare earth element faces the most energy-intensive and chemical-intensive and also

Daniel O'Connor (02:27)
. .

Lingyang Ding (02:40)
will need to deal with most of the wasted treatment. Also, the rear earth face the most challenging technical hurdle for

the separation. I chose rear earth because I know it's very important and I like to do something that is difficult. I asked a professor to give me this rear earth project. Now I go to the area of the earth. I think that's a summary.

Daniel O'Connor (03:08)
I will jump in here. Very important. We're so excited that you've gone down this path because it's needed. We write a lot about the need for more chemists, engineers, metallurgists. And so the fact that you've studied this and gotten your PhD is very exciting.

We picked up your paper and we did an article about it. So that's how we got to know you. Do you want to maybe just explain at a high level for the viewers, what was your paper about and what did you discover?

Lingyang Ding (03:39)
Do you want to discuss about the extraction or the separation because they are different?

Daniel O'Connor (03:44)
Let's look at first the extraction, OK, at high level to start.

Lingyang Ding (03:48)
OK, OK.

OK, OK, so we got a new rare resources from the North America like Chile and we start to discover like what minerals it has and what kind of metals it has and we find that there are rarest elements on the surface of the clay and we investigate very mild leaching process like using pH larger than three.

acidic solution and also use an ammonia solvent at least Lexilien agent to leach the air from the surface of the particle at room temperature and atmosphere. And then we also optimize the process. we also, so that was engineering part. For a scientific part, we do investigate the mechanism that how the layers absorb on the clay and how the layers dissolved from the clay. So that's the, for the extraction part.

Daniel O'Connor (04:40)
Excellent. And the extraction happens to be a key first big part of the problem. And then of course, there's a separation separating each element away from each other and from the other material. So what do you see first if we look at

Lingyang Ding (04:55)
Yes.

Daniel O'Connor (04:58)
extraction and separation, what do you see as more complex first in the lab and then in the real world?

Lingyang Ding (05:03)
Okay.

In both in the lab and in the real world, separation will be definitely much more difficult than extraction for the real-life elements.

Daniel O'Connor (05:14)
Right, right.

Lingyang Ding (05:14)
That's

Daniel O'Connor (05:15)
And so with that in mind, could you, what's your understanding of why separation is so difficult?

Lingyang Ding (05:24)
OK, so it's because the readers, you know it is a series of 70 elements. They like their clothes in the periodic table, including exclude like it's it's read and scanning. They're maybe a little bit higher in the location, but they're they have very similar physical and chemical properties. I can just the same example. For example, we have three people here and we are totally different so you can identify. Other can identify as very easily, but if we have three people.

Japanese, Chinese, Korean, it might be difficult to identify them. in another case, if we have three triplets, like if we have three triplets, they look almost the same. They have almost the same appearance. So we need to check their fingerprint. Rears, neighbor rears like twins and also triplets, their appearance looks very similar and they have very similar characteristics. So it's very different to tear them apart and separating them even more harder.

Daniel O'Connor (06:17)
Makes total sense. Makes total sense. So in your paper, how did that part of the experiment in your studies come along? Was there anything that you observed that was surprising? You all had a hypothesis, and you tested, and you did the experiment, and you wrote it up. Could you share any notable findings that interested you?

Lingyang Ding (06:40)
Okay, my finding is that even though they have very similar properties, but we still can find some key leading agents. They have different affinity preference to the key leading agent. So this kind of key leading agent, let's say HEDTA, EDTA, DCTA, something like this, this can combine with different rare elements with different affinity. For example, the DCTA can combine, for example, we have one more of the neodymium, one more of the

dysprosy, they are very important to the manganese. And they have totally different preference to combine with the DCTL or EDTA. The heavier of the layers, so the dysprosy will more likely to combine with the EDTA, but neodymium will be less. Because neodymium and dysprosy, are far away in the table. Neodymium is light and dysprosy is heavy. So their preference will be

Daniel O'Connor (07:27)
Mm.

Lingyang Ding (07:33)
a lot different like times. But for the neighbor arrears, for example, pre-ZioDEMI and Neodymium, these are also the many arrears, their preference are very similar, only like 10 % differences. So it's very difficult to separate the pre-ZioDEMI and Neodymium, like the twins.

Daniel O'Connor (07:45)
You

Yes, yes, and we've heard that. now from that standpoint, there's a one Essex, they call it, a way that they go about separating. At the university where you're at, were you looking at other alternative approaches? What methodology were you using?

Lingyang Ding (08:11)
I'm using chelation-assisted electrodialysis. So the chelation-assisted means just what I say uses. Sorry, it's chelating-assisted electrodialysis. So chelation-assisted, that's what I say. We use EDT or DCTA to combine the heavy-ray earth element. And electrodialysis is a mature technology that has already been widely used in wastewater treatment, like desalination. So we do some adjustment to this.

Daniel O'Connor (08:15)
Say it, can you say that again?

Okay.

Lingyang Ding (08:39)
mature technology to apply this new technology to separate the rarest elements. So that is what I do. But I also know that there are some other research about, for example, on-exchange. some that they are like design often sign some proteins as scaling agent for better selectivity. But I have no idea how specifically they are doing.

Daniel O'Connor (08:43)
Okay, okay.

Right, yes, yes. it's complex and we're not chemists, but we write about ⁓ some of these processes and we've interviewed a few other people. What about in terms of the approach that you worked on, can you speak a little bit about the energy involved, units of energy and also environmental?

factors just to have a better understanding of this process from your perspective.

Lingyang Ding (09:24)
OK, so we use electric balances. The point of using electric balances is because we want to use electricity to replace the organic solvent. So our technology, we use water to replace the organic solvent. And we also use electricity to replace the very corrosive strong acid use.

Daniel O'Connor (09:45)
Mm-hmm.

Lingyang Ding (09:45)
So we

use water and electricity to replace the organic solvent and the corrosive highly acidic solution. And for another key point for our technology is we use less chemicals. And because we use less chemicals, so we will generate much less waste. So that is very environmentally friendly. It's totally environmentally friendly. No organic solvent, less chemical, less waste.

Daniel O'Connor (10:08)
Very important. I mean, that's what caught our attention, to be honest with you, was that. And of course, these different approaches have not necessarily been proven at scale, right? But you've got to start somewhere, right? So you want to talk about, you finished your PhD.

Lingyang Ding (10:21)
Yes.

Yeah, I finished like last October.

Daniel O'Connor (10:30)
Okay, you've finished your PhD and, you know, what are, just out of curiosity, you know, with other students, PhD students that are studying this, I mean, there must be a growing interest, right? Because the supply chains have to be rebuilt, right? We all know that mainland China has sort of, has a monopoly pretty much on the refining, the separation, extraction separation.

Lingyang Ding (10:46)
Mm-hmm.

Daniel O'Connor (10:55)
of these rare earth elements. was there a sense at your university, is there more interest in this topic? Are there more people going into chemistry programs, for example? Is that becoming more of an interest in the university level, do you think?

Lingyang Ding (11:10)
The separation of rare elements come to the research like five years ago or six years ago, maybe five years ago. And all the funding is from the government. I remember there is a company that wants to support the rare separation, but they may find it's too difficult or they may find that the payback period will be too long.

They overestimate the difficulty of rare stem, so they just give up the project. But the government sponsor allowed to the rare separation. know, yeah, Canadian government do it, our University of Toronto do it, but right now I only know two groups doing rare separation in electrolysis. There might be some other groups in the US or other labs, maybe most of in the US to do some other, like the protein, synthesize or some ion exchange, but

Daniel O'Connor (11:42)
Yeah.

Lingyang Ding (12:02)
But the scale is very small, not like AI or others.

Daniel O'Connor (12:04)
Yeah,

understood. ⁓ What were the two in Canada, what are the two centers that are doing this type of separation?

Lingyang Ding (12:14)
One is our lab, like Azimi's lab, Azimi's Strategic Material Lab. And the other is NRCan, I'm not sure, like, Canadian government. They are all own research teams. And we collaborate sometimes.

Daniel O'Connor (12:16)
Of course.

Okay.

So,

and there are a couple companies or organizations in Canada that are setting up rare earth separation refining operations, including Saskatchewan Research Council, right? So it's called SRC, Saskatchewan Research Council, and they have government funding in Canada, and they are actually separating rare earth elements.

Lingyang Ding (12:43)
⁓

Daniel O'Connor (12:53)
I'm.

Lingyang Ding (12:53)
Which type

of technology are they using?

Daniel O'Connor (12:56)
I think they're using SX, I think. I'm pretty sure. We can check on that.

Lingyang Ding (13:01)
Okay.

Dustin Olsen (13:03)
From your experience going through your studies, this is a follow on question to what Daniel is asking. Are you finding more and more people being interested in being a part of the rare earth industry, either from like a mining separation perspective such as yourself, or do you feel like they're struggling to

Lingyang Ding (13:08)
Mm-hmm.

Dustin Olsen (13:20)
to gain students interested in the programs to learn more, where do you find that balance to be?

Lingyang Ding (13:27)
OK, I think for the rare extraction, like more companies, like startups try to do some about extraction. But for the separation, not too much, maybe because they haven't reached that stage to consider about the separation. They need to deal with the extraction first. Yeah, but yes, governments pay attention to both extraction and the separation.

And the universities, I did not notice that they are like pay more attention to the mirrors because we because actually the university should have funding from industry or from the government. Only when government or industrial have interest in this type of research, then they will have money to give us to do it. Yes.

Dustin Olsen (14:11)
We have noticed we're starting to see a change in that effort from a government perspective. They're trying to re-industrialize their own countries to bring things in-house, so to speak. And so they need more talent. They need people who understand these things. Are you starting to see some of that show up?

Lingyang Ding (14:20)
Mm-hmm.

Yes.

Dustin Olsen (14:34)
Obviously, I know here in the United States, a lot of businesses are getting funding to grow and scale their operations. Do you see, have you seen a trend towards universities? Do you think they're next in terms of getting funding?

Lingyang Ding (14:41)
Mm-hmm.

OK, so for the extraction, I see the trend. So for the extraction, many companies, they find, for example, new resources of some like in this area, in that area, then they send these to our lab to help them to see, could you help us to design a process to extract the rarest elements? The trend of the extraction is increased, but for the separation, not yet.

Dustin Olsen (15:10)
So through the university program, have you guys partnered with other businesses to help them do the research, develop the technology?

Lingyang Ding (15:11)
Yeah.

Yes, so our lab will collaborate with some companies, for example, some engineering companies like the Hatch, something like this, and also collaborate with some mining or mineral companies to directly help them to design the process or optimize the process.

Dustin Olsen (15:34)
Okay.

Lingyang Ding (15:36)
Yeah, I hope more funding will go to the separation because the separation is the point that you need to spend more money, more time to. Like breakthrough, not extract extraction is just. As it reaches.

Dustin Olsen (15:48)
So let's talk a little bit more about that. The extraction, that's, from what I'm hearing, that's easy, right? We've been doing it for a long time. Separation, however, is not. That's a lot more complicated. what are some of the, let's first talk about what are the limitations you've found with separation, and then what are some of the breakthroughs you have discovered through your studies?

Lingyang Ding (15:57)
Mm-hmm.

Okay, so the limitations, you want to the solvent extraction or other technologies?

Dustin Olsen (16:15)
just whatever you've learned through your your research.

Lingyang Ding (16:18)
OK, so for the solvent extraction, the limitation is like high demand of the chemicals, the solvent and the chemicals. And for example, for the solvent, it is toxic, volatile, flammable. So we need to design very complicated risk management, like VOC, ⁓ control system, something like this. And also, because for the rear, it's very

difficult to separate and you need reach up to hundreds of stages. So this number is very huge, hundreds of stages. So you need a lot of solvent and a lot of other acid. the process will be very, like, the plant will be very, big and very complicated. And you will generate a lot of waste because we will use a lot of chemicals. And the dealing with these

waste is also a problem. the final waste will be like the salt solutions, the acid solutions, and also the solid waste and might be radioactive. And how to deal with waste can also be a problem. And also the transportation of these toxic corrosive chemicals. So you need to find a plant that is close to the manufacturer that can give you a cheap acid and the lower transportation fee.

It's very, very complicated. For my tech knowledge, the breakthrough is, there is a breakthrough for all technologies, the selectivity. But selectivity is the most difficult one to break through because right now we can only base on the low selectivity right now to design many different technologies.

can find some p-elating agents that has very good selectivity, then we can decrease the number of stages a lot. Like, it will be no problem for the rare separation. If you can find or design or synthesize a chemical or protein that can have very high selectivity. But now, we cannot. So we can only, based on our current low selectivity to design solvent extraction or electrolysis or other unexchange,

process. And for first session, just said before the bad thing is like the solvent and the corrosive acid. for the electrolysis, the chemical feasibility is having demonstrated, but for the economic analysis, like techno economic analysis, we haven't done it. And I'm not sure if it can beat

the solar exertion, but I'm confident about it because after you optimize the process, you can decrease the cost in operation and also the capital cost. And also the most beautiful thing about the air traffic is just less chemical, wasted treatment. It will save a lot of money in the chemical and waste treatment, but it will spend more money on the, for example, the membrane cost.

the electricity, but electricity is not such high if you choose a location like in Quebec, Canada. And for the membrane, I hope some labs can do research to produce or manufacture, to like to, to, to, to, to, to, to,

Dustin Olsen (19:30)
a lot of information, lot of interesting information about, now that I think it's, I think it's educational to understand some of the nuances that go into separation. So a moment ago you talked about being able to find a protein to help with the separation, but it doesn't exist yet.

Lingyang Ding (19:34)
Sorry, I speak too much.

Mm-hmm.

It can be protein or can be chemical molecules like EDT or DCT. So it can be discovered or synthesized, but we haven't found it.

Dustin Olsen (19:52)
So.

So is the limitation, is it current technology, like we can't develop it, or is it funding and there's just not enough money to put towards that sort of research so that we can?

Lingyang Ding (20:13)
We can. So some bio labs, are doing such kind of experiments. For example, in the US, there are some labs doing that kind of research to generate, to like cultivate batteries or something else to, and to generate some proteins. And they use protein as, as killing agents. So for me, I use chemical molecules, EDTA, DCTA. They use proteins as a killing agent to increase the activity.

Yes, but for the chemicals, for them, or what do we do? We can justify the chemicals very easily, but for their proteins, they need to cultivate batteries or they need to produce the proteins. It will be another tough job to do it. So it's more like it's to scale them up. think it actually does. It's much easier than the proteins to scale up because if you introduce bio, there will be a lot of other

tough work to do.

Dustin Olsen (21:08)
Yeah, so let's dive into that just a little bit more, this scaling issue, because when we're talking to a lot of people from universities, they do a lot of research, a lot of things sound great in the lab, but in terms of economically scaling a solution for commercial use is a bit hard, hard because there's just not enough

Lingyang Ding (21:14)
and

Mm-hmm.

Mm-hmm.

Right, right.

Dustin Olsen (21:33)
resources to even make it work, right? So can you give us more insight into how what you've been studying, what you know, how does that scale?

Lingyang Ding (21:36)
Yes.

OK, so for example, let's say the electrolysis is what I'm doing right now. So for my electrolysis cell, it's very small. And we use constant voltage. So constant voltage is a version like how we operate the electrolysis. It's very safe, because as the concentration of solution decreases, the current will be zero. So there will be no current. It's very safe. But for the inductor scale,

they usually use the constant current, which means that if the concentration in the solution decrease, they need to keep the current at the same value. So in that case, the voltage will increase a lot. If the voltage increase rapidly, there might be some risk like the file, header, some other dangerous things happen. So like first one is 50.

In the lab, it's but in the industrial scale, it might not need other safety control or risk management to make the process safe. Another one is in the lab, we use batch process. in the chemical engineering, there is batch process and continuous process. In our small lab, we use batch process. And we can do the experiments day by day. can test the state. So we have hundreds of stages.

and we can pass a stage one by one. But in the data skill, they need to use the continuous process to decrease the cost, like operational cost. So in the continuous process, you cannot do the stage one by one. You have to set hundreds of stages together, and they need to work together simultaneously. So hundreds stages.

work simultaneously, it's very difficult to ⁓ control all the stages. So in addition to the equipment to do the separation, they need a control system to control all the stages. And the control system is difficult to design because you have hundreds of stages, and you have a lot of pH to measure, or you have a lot of concentration to measure. So design and application of the control process control system will be another difficult thing to do.

Because in our life, don't need to do it because we are a person to control the process. We only have one stage at one experiment, so it's much easier. And so that's the second one. The third one. OK, I think that's the two. Like we need to consider the safety and the process control.

Dustin Olsen (24:08)
Very interesting. And I could see definitely, you know, hundred different stages would be a lot to manage, much less do it at a volume that would be economically viable for a business to adopt. So as someone who's looking at the research level, what do you think the industry sometimes underestimates about

Lingyang Ding (24:15)
Yeah.

Yes.

Mm-hmm.

Dustin Olsen (24:33)
separation chemistry, like where they may be misunderstanding something.

Lingyang Ding (24:38)
I think maybe overestimate, not underestimate. Yes, if they underestimate this technology, they do not need to do any research. They just grab this technology and use it, scale up it, and just do it. But if they overestimate it, they might think that it's too difficult for them to do it right now.

Because if it's too difficult, they need to invest a lot of money, a lot of time to this, they may, OK, we spend a lot of money, spend a lot of time, but finally we may fail. So they just give it up. And do not invest it. Or maybe they did not overestimate or underestimate. They just did not notice that problem because currently most companies in the US and in Canada and Europe, they just focus on finding new resources of real-world and extraction of real-world elements.

And after they extracted the rarest, they just sell the whole rarest to some companies to do the separation. So they haven't reached the stage to consider about the separation problem. But finally, they will meet this problem.

Dustin Olsen (25:41)
Interesting. Okay, so your perception is that they take for granted or they overestimate the ability to adopt some of this technology without maybe fully understanding its own limitations or things like that. Is that a fair summary to say?

Lingyang Ding (25:58)
Mm-hmm.

Yes, yeah, think so. But because for me, I think I kind of like to overestimate it. Because currently in our lab, we only take several stages of separation. But in the real case, we need 200 stages. And I cannot even imagine how I can do the whole 100 stages by myself in the lab scale. So for me, I.

I probably overestimated, but for the company, I'm not sure they overestimate or underestimate. They maybe just haven't noticed this problem.

Dustin Olsen (26:38)
Okay. And looking into the future, what are some things that give you hope or give you optimism about the future of rare earth processing technologies?

Lingyang Ding (26:41)
Mm-hmm.

OK, I think I'm positive about it because I'm that, as you say before, more funding from the government to the industrial and then from the industrial to the universities. So if you spend more funding to cultivate more engineers, PhD students, expertise, then definitely this area will be like very like positive to have better technologies in where both.

extraction and separation. Definitely because patterned people will do a lot of work.

Dustin Olsen (27:19)
Yeah, we have the same optimism as businesses and governments become more invested in the need to restore their own domestic supply chains that we're going to see a lot of renewed interest, renewed or even new companies being built to help support this effort. And we hope that that will

Lingyang Ding (27:26)
Mm-hmm.

Mm-hmm.

Mm-hmm.

Dustin Olsen (27:42)
transcend down to the university level where ⁓ people are learning the skills that they need to be a part of this industry, whether they're metallurgists, chemists, you name it. So we're looking forward to that.

Lingyang Ding (27:44)
Yes.

Yes, and yeah.

Yet and I strongly suggest to fund the collaboration between industrial and the university universities, because if you only found a university, we only have students that have very limited industrial skills and our thinking problem matter will be different from any years. So if we if we have engineers, PhD students, expertise, professors work together, we can definitely speed up the research process.

And also think of better technologies. That is what I'm saying, what I feel. Because for my own experience, I'm the only person to do the old experiment in the lab. And I have very limited industrial ⁓ experience. I think if some people join me from an industrial side, I think I can do the project much better than now.

Dustin Olsen (28:43)
Yeah, I think that's a great call to action. we need more involvement from the businesses and universities together to, mean, funding will be great. know, having money to do this research would be great, but you need the experience of those who are out in the field, who've done this work, who can share their knowledge to help accelerate.

Lingyang Ding (28:46)
Mm-hmm.

Yes.

Mm-hmm.

Mm-hmm.

Dustin Olsen (29:09)
additional research. I, so I would agree that collaboration amongst universities and the industry would do wonders. And we've reported on other businesses in Europe that have created those collaborations. They've, know, publicly announced collaborations with other universities. And I think it's a smart, smart thing to do. So hopefully we see that happen more.

Lingyang Ding (29:29)
Mm-hmm.

Mm-hmm. Yes.

Dustin Olsen (29:32)
⁓ sooner than later in, in

other countries around the world, because, the talent, you know, sharing the talent, the knowledge will be extremely vital. ⁓ so as we kind of come to the end of our show here, Lynn, if you were to just quickly summarize everything for, for us, what, what is one thing you would like people to understand about?

Lingyang Ding (29:41)
Yes.

Dustin Olsen (29:54)
the research you've done, the work you're trying to do, and things like that.

Lingyang Ding (29:59)
I want people to know that separation with earth element is very difficult, technically difficult. the current technology for extraction is energy intensive, chemical intensive, and will generate amounts of waste. And my project will delete the use of the organic solvents and also use less chemicals, generate less waste. And I hope governments, industrial, can do, sponsor more.

I give more funding about the electrolysis and in addition to the research, but also to the scaling up and optimize the process.

Dustin Olsen (30:36)
I think that's a great summary. And Lynn, as we move on today, we do wish you the best of luck as you are trying to make your mark in society, as you were saying earlier, to make a difference in this space. We fully support that initiative that have for yourself.

Lingyang Ding (30:37)
Yeah.

Dustin Olsen (30:53)
We look forward to seeing other publications that you've put out there as you continue to learn more and share with the world what you're learning.

Lingyang Ding (31:01)
Thank you so much, Darsie. I will.

Dustin Olsen (31:03)
Great. Thanks, Lynn. And thanks for being on the podcast with us today. It was very educational.

Lingyang Ding (31:08)
Thank you very much.