The Green Horizon: Innovations in Tailings Filtering and Sustainable Mining with BOKELA's Jürgen Hahn

Speaker A: Hi mining community. Welcome back to another episode of the Dig Deep, the mining podcast, the show that brings you the latest insights, thought leadership and stories from across the global mining industry. In today's episode episode we have Jurgen Han, who's the managing director of Bocula, who is a company renowned for its expertise in advanced filtration, dewatering and process technologies for the mining and mineral sector. With more than three decades of experience and a strong scientific background, Jurgen has played a key role in the development of innovative tailings management solutions and authored numerous technical papers on. On this particular subject, we're going to discuss the growing importance of tailings filtration and the balance between operational cost and long term sustainability and how the industry is responding to increasing environmental and regulatory pressures. We're also going to look ahead to the future of mining, covering topics such as recycling and the role mining will play in supporting the global energy transition. And finally, Jurgen will share key insights and advice for professionals working in tailings management and mine waste stewardship. So Jurgen, great to have you on the podcast. How are you?

Speaker B: Oh, I'm really feeling fine. Although there have been a few, let's say, um, physical hurdles in the last two or three years.

Speaker A: Yeah, yeah, well we're going to discuss all those kind of things uh, obviously during this episode. But before we start, um, and obviously you're an avid listener and I wonder if you can just tell us a little bit about your career. As I mentioned, um, you've been in the career for uh, uh, for, for a while now. So I just wonder if you can just give us a step by step how your career sort of developed, um, how you got into the industry to what it is currently today.

Speaker B: Well, I mean my career is pretty much linked with Bukela because I already worked as a student for the company. I was a student assistant at uh, the Institute of Werner Stahl in Karlsruhe. And uh, then one of the founders, I mean the three founders is Bott, Kern, Langelow, Boki La, this is where the name comes from. And they asked me whether I wanted to continue in the Institute of Werner Stahl or whether I joined the company as a student already. And I did that and I was involved in, I did mainly all these lab testing stuff and uh, that finally led to the uh, diploma thesis about how to use lab results to do a proper sizing of filters and a proper process guarantee of filters. And right after that I basically started with Bokehla. So that was three years uh, after the foundation of Bokehla in uh, 1989 and then I was involved in lots of filter retrofits. We retrofitted filters in the Netherlands on uh, sodium bicarbonate, in Sweden on iron ore concentrates, in Australia on alumina, uh, seed course and fine seed filters. And with that of course we gained a lot of knowledge where bottlenecks are in existing filter systems. And then there was for me a little beauty because uh, there was a dispute between the three owners and Robert Kern left the company that was in the mid-90s and I got responsible for all these retrofitting jobs and uh, so I learned a lot about that. And then that gave us the opportunity to um, design uh, let's say what we call then the high performance filter, which already includes all the knowledge about bottlenecks and how to overcome the bottlenecks. And uh, that put me in a position when we got a bit of structure within Bukela to um, lead or to head the sales department for almost 20 years. And a couple of years back when I got closer to retirement, I said I want to reduce my. And then um, the management said okay then you should not uh, be heading a department anymore. And my responsibility is now product and business development. And that's pretty much what I did the last couple of years. And that gets me into all these conferences presenting a paper papers about what is a good design or how can you improve your filter systems by just using science, um, and uh, by that making your filters more efficient. Yeah, and this is where I am and I'm still here for the next three. Three years. Yeah.

Speaker A: Good, that's good. So one, if you could just tell us a little bit about the company. Bekela, obviously like you said you've been with the company for a long time so a lot of things have happened. Um, but why don't you just give us a snapshot of the company so our audience uh, know a little bit about the business.

Speaker B: Well as I mentioned, company was founded in 1986 and we started basically with consulting work and consulting work for us had a major focus on filter retrofits, um, but also on filter developments. So we did uh, um, 100 bar ring press development for the company SimpliComp in the mid-90s, uh, intended to do um, to dewater sludges, uh, are from uh, chemical applications with um, basically toxic and all sorts of that because the depositing costs would be very, very high. Then the wall came down, deposition costs dropped to a tenth of what they were expected. So that business completely disappeared. And um, we had a copper, then we had a Cooperation with Palwood. They wanted to diversify at that time and uh, were looking for high bar technology or hyperbaric technology. But finally we didn't move into hyperbaric technology. We basically moved into the supplies of our first filters because we were still um a consulting company but um, then we got that um, retrofitting job at Oginish and uh, Oginish Alumina refinery. They said okay, uh we decided not to do a retrofit of our filters. We want to buy two new filters. And we said okay, we have the knowledge, we did the basic design but we needed a partner, a partner with experience of well project management, manufacturing and all that. And so that was Paul Wood for us to start with. And um, we did the first two of these high performance disk filters for the Oginis Alumina refinery. And that was in 1997. And um, that was basically the start because then Alcoa got uh, um interested in the design. And uh, two years later we got uh, orders for Aluminary Nalco, for Wagerup and also for uh Worsley in Australia. And then from that point on we could actually say now we are filter supplier and this is we grow big in the alumina. Then the next step was moving into coal. Um that worked in Germany, that worked in Australia pretty well. Uh all the others were more looking for hyperbaric uh solutions or filter presses. And then after that around 2005, 2006 then we also started into terephthalic acid with our high bar drum filter. And that was also a major step because on the one side we had our vacuum disk filters as um a top seller. And then in the terephthalic acid area, um which is the base material for polyester and pet. Um this was then also our second leg uh and uh our next top seller that we had. And this is still a strong area we have uh, in the last five years we have had uh record order intakes because of lots of filters going into terephthalic acid mainly in China. But then there was a big change uh that goes back to I think 2013 when the remaining two founders, uh spot and Langalu, I've uh got to my age that I am now and then there was, I mean we do a turnover between 20 and 40 million euro a year and there was nobody in the family um who could actually run a company this size. And so they decided uh to sell. And um, Rainer Weidner the managing director of Pokela at the moment, he was actually involved in that sales process. And uh, so we got now 100% owned by Tsukishima holding which is based in Tokyo, Japan. And we are pretty happy with that because I think the thinking of Japanese guys and German guys is pretty much very similar. And so from a mentality point of view it's a good fit and uh, we are happy with the situation. And also Tsukishima holding seems to be happy with with the ah, good figures that we had in the last five years.

Speaker A: Um, tailings management is obviously a critical component and challenge for obviously mining companies. And you've published uh, quite a few scientific papers on tailings management. What was your sort of path into that particular area? And also how has the whole talens management changed over the last sort of few years or within the last decade or so?

Speaker B: Um, as I mentioned we grew big with our uh, high performance disk filter in the alumina. This is where the basic design is coming from. And we did the move uh at the early 2000s into coal. But in the mid ah, so around between 2005 and 2010 um, there was very little happening in that area. And so we were looking for other areas where our filter would fit into. And so we uh, got then involved in base metals and all that. But we identified that vacuum filtration is not good for concentrates. But at that time there was more and more talk about tailings. And uh, primarily we got actually into the Cellopetch mine in Bulgaria which is a ah, copper and gold mine. And they were the first using our high performance disk filters. And this is a backfill operation. And we identified that uh, our filter design is already pretty good and it works. And later on but I think we get to that we started to optimize the design in particular for tailings operations. But that's basically how we got into tailings because we were looking for another big market similar to alumina and coal, um, um, to get filter orders. And I think when I think back to that time um, there was very little discussion about um, what all can happen. I mean at that time I was not aware that there is uh, wet disposal with potential of dam breakage and all that stuff. For me and for Bukele, tailing was just anything like um, a production plant where you just treat one of the products. And uh. But then from these backfill operations um, where we have in the meantime a fair bit of references then we understood that there is also dry stacking or filter tailing. Stacking. And then we really got involved into all these issues. How important is it Is um, what. Um, that there is basically every year there is a breakage of a dam. And, uh, that there is a tendency to move, um, to safer solutions. Let me call it that way. Um, so we got more and more aware of that. And then also our focus moved more and more in that direction. How can we on vacuum disk filter produce lower moisture? Because in backfill operation, everybody is happy with 20% moisture or more because you mix with cement. Anyway, um, we have a new guy, Dr. Timo Doppler, with us. And, uh, he will actually take my role in the future. And he has a much bigger focus at the moment on tailings. Also talking to geotechnical engineers. Because I think this is the key, um, to a safe deposit. That you really understand what geotechnical engineers require. But also geotechnical engineers should understand, um, what is really needed to really produce a safe stack. And I think, um, Timo is actually working in areas where he is also, uh, doing not just filtration laboratory test work. But also working, um, with the Casagande test. Which is actually, uh, something that, uh, identifies the, uh. Uh, when m at what moisture is a filter cake Relique. And this is one of the big questions when it comes to dry stack or filter tailing. Stacking, um, under which condition is it actually relique. And I think, uh. So we are moving, um. We are including more than just, uh, laboratory filtration testing. We also think about how can we support geotechnical engineers in their work. And how can we probably get a better understanding so that, um, we are getting out of the fear factor and getting to the facts factor. Yeah,

Speaker A: um, I guess some people in operations may think tailings filtration seems quite expensive to, uh, implement. Um, why should someone invest more money into, uh, tailings filtration?

Speaker B: I mean, we've already mentioned, um, if I have a wet disposal, I think we still have one dump breakage once a year. So although there is a lot of knowledge gained in the meantime, Although there is, uh, um, good, uh, operational practice. There are specifications and guidelines and all that. It still happens. And so the best way to get out of that, um, risk of fatalities, uh, because of, uh, dam breakage. Is to filter the tailings. But I think we should also have a bit of a closer look. Because everybody says, yeah, um, filtering the tailings is more expensive than any wet disposal. But I think we should include, um, more in the calculation. Because, um, the land, the ground that you need to build a wet disposal. Is about three times bigger than what you need for A filter, tailing, stack. And um, okay, in some areas, um, property is very cheap. In some areas it's not. But is that really going into the real calculation? When we talk, for example about a life cycle calculation and what is the cost for rehabilitation, what do you have to do on a wet disposal to finally have trees growing or anything else to make sure and you still have that ongoing control of the drainage water. So there is other costs. And I think, um, when a decision is made about uh, filtering the tailings and doing stacking versus um, having wet disposal, I think we should talk more about life cycle cost and include all that into the real calculation. Because at the moment I think it's more a question of what's the equipment that I need for a wet disposal and what will be the operational cost versus what's the equipment for stacking, uh, operation and the operational cost for stacking. And I think things would change if we really talk about life cycle cost.

Speaker A: Uh, Thailand's management is also an environmental issue, obviously with some countries, such as, uh, Brazil already having strict regulations in this area. Do you think net zero emissions is important for mining? And also what about recycling? Is there an alternative, uh, to the whole mining industry?

Speaker B: I mean, I think first of all, yes, I think net zero emission is important, um, because I see there is more when you start mining somewhere you need the uh, permission of the local authorities and I mean permission of local authorities. There is more and more the questions asked, what's the benefit for the local communities and what's the impact on local communities? And so coming up with saying, well, our operation will be net zero emission is of course a strong argument, uh, to say, well, the impact in your area will be minimal. I mean there will always be an impact. No doubt about that. Yeah. Um, but in the meantime, I mean big organizations like the European Union, um, want it to be net zero emission in total at the age at the year 2045. And so more and more, um, we understand that if we want to live, uh, in a world similar to what it is still now, uh, we need to do something. And uh, net zero emission is part of that. And this is our private responsibility. So we have to do something. Like I put already a photovoltaic on the roof of my house already 18 years ago. But it's also um, a um, responsibility of countries, governments, but also uh, big industry players. And um, yeah, as I mentioned, if we can actually, if a company can say, well, this operation will be net zero emission, the um, likelihood of getting a mining lease is of Course, much bigger. And the acceptance uh, will be bigger on the other side. I mean um, it also will boost the requirement for lithium for copper, for aluminium, which is all metals that we need for the electrification. And so it's just another opportunity for the mining industry. There will be more copper required, there will be lithium required. So it's other, maybe other areas to what we know at the moment, but there is still requirement for mining. Yeah, that's for sure.

Speaker A: Obviously you're a specialist in this area. Where do you see the industry in the sort of next 10 to 20 or even further out than that?

Speaker B: That's really a tricky question. Um, because what we see is um, I mean we see countries, the big countries like India having a plan to um, become a first world country. When they do, I think their 100 uh, years of anniversary, independence anniversary and that is in uh, 2048. And their plans, I've seen some plans saying okay, we still increase the um, mining of coal because we need it to trigger our industry but step by step. And I think they want to do it until the mid-30s and then they want to replace more and more with renewables. And so if I see this and other countries that are still in a development phase, I still believe in the next 10 years the demand for metals, the demand, what we need from mining industry will still increase. But on the other hand, I mean we also need to also the industry needs to be part of that um, change into renewables. And so in 20 years time I'm sure also the recycling area will start picking up and uh, not taking a big share at that time, but that share will become bigger and bigger. And um, if I'm not looking in the next 10 or 20 years, but I'm pretty sure um, recycling will actually take in 50 to 100 years a share that is somewhere at 80, 90%. But that can only be happen if we have one other factor in mind and that is worldwide population. I mean the demand also has to do with worldwide population. At the moment we are still almost in uncontrolled increase. And I mean if every, what is it, 15, 20 years or so, the population doubles, I mean then recycling can never pick up and the demand for mining will just grow and grow and grow and grow. The big question is how many people are healthy for the globe. And I think this is another area we talk about net zero emission. We also need to think about really controlling the population. And personally I believe it shouldn't be more than 10 billion on the word.

Speaker A: And if we conclude what would your Main message be regarding obviously the management of tailings. And also what advice would you give to someone who's involved uh, in the business?

Speaker B: Well, um, the message I would give is, I think I've mentioned that already before. Um, when we talk about tailing filtration. I mean there is the beautiful area of underground mining where they do mine backfill because then the tailing completely disappear in the underground. Uh, but uh, on a um, open pit operation you wouldn't basically do that. Um, my advice would be in those areas when you do tailing, stacking, um, in whatever way, wet or dry, um, do a life cycle calculation before you start. And do it on the basis of the modern technologies that are available. Um, and modern technologies. I mean our high performance disc filters is one of that. Because we minimize the um, pressure losses in the system. Uh, get a higher um, pressure difference at the filter cake. And by that really getting typically somewhere between 2 and 5% less moisture compared to standard design disk filters. And with that low moisture we are competing against filter presses. So really identify for your project, um, what equipments are suitable for your operation. Um and also what is the total cost. So include the property cost, include the um, rehabilitation cost and everything. And also the treatment of all your uh, water and filtration also reduces your water consumption. And water cost is also getting more and more so. And uh, just something I haven't mentioned yet, um, there is some initiatives talking about coarse flotation. And coarse flotation means that you reduce the milling um energy and you already separate um tailings and concentrates uh at a coarse basis. So you discard tailings without putting uh, by putting only 20% of the energy into it compared to what you do if you are milling oil to the ground. So all these new developments, if they are considered in a life cycle calculation, I think that that's the way to go. So that would be basically uh, my message and a um, final advice you ask for that. Um, I think when you are responsible for uh, the tailings management then just do it and thinking that this property where you put the tailings on is your own property. So what would you do on your own property? And then think about that your family is living downstream and operating a farm or whatever, just harvesting vegetables or uh, having uh, sheep or pigs or whatever. And so that any consequence, whatever you do wrong in your tailings management has direct impact on anything on all villages and farmlands uh, downstream. So if you keep that in mind and keep that as part of your decision making, I think then we would all be living in a, in a safer world.

Speaker A: Yeah, that's a great conclusion. Um, Jurgen, really appreciate your time. Thank you for telling us all about, uh, bocular and obviously talking about, uh, filtration, tailings, filtration, um, and educating our, uh, audience and the industry. Um, if our audience, uh, and anyone listening to this podcast or even watching on YouTube want to, um, reach out to you, obviously ask you questions, want to follow what the company's doing, um, how can they go about doing that, and what social media platform channels are you on?

Speaker B: I mean, I'm personally bookila as company and uh, I'm personally on LinkedIn. Um, but you can also, um, always visit our website which is www.bokehela.com. and um, if you want to contact me directly, um, as I said, you can actually contact me via LinkedIn or you just send me an email which is JFOR Jurgen Jhankela, uh.com and then you can send me directly an email. But, um, through the website you always can contact me as well.

Speaker A: Yeah, no worries. We'll include those in the show notes for easy access. So, uh, any other audience can reach out to you, um, follow the story and ask you any questions that they may have around tailings, filtration, etc. So really, thank you for your time, um, and keep up the good work.

Speaker B: Yeah, thanks Rob, for giving me that opportunity and um, I'm looking forward to any contacts that I get through that uh, podcast.

Speaker A: Yeah, certainly. Thank you for listening. Hope you enjoyed that episode. Um, this is obviously an educational episode, so appreciate if you can share this episode far and wide. Um, share it with people in operations, uh, for sure, but maybe also people that are designing mines, um, and designing tailings, um, because obviously this content, uh, could be relevant to them. So thank you again for listening. Please keep sharing these episodes far and wide. And until next time, happy mining.