Latest / The Manufacturing Podcast with Fexingo: Factories, Supply Chains, and Industrial Business / How a Norwegian Factory Is Making Fertilizer from Mining Waste
Transcript
- Lucas: So there's this plant near Kirkenes, way up in northern Norway, where they're taking iron ore tailings — basically the crushed rock left after extracting the iron — and turning it into fertilizer. Luna: Mine tailings as fertilizer. That sounds almost too good to be true. What's the chemistry here? Lucas: The key mineral is olivine, a magnesium-iron silicate that's abundant in the tailings from that mine. When you grind it fine enough and spread it on soil, it slowly weathers — releasing silicon, magnesium, and other micronutrients. Luna: Silicon isn't typically considered a plant nutrient, right? We hear about NPK — nitrogen, phosphorus, potassium. Lucas: Right, it's not one of the big three. But silicon strengthens cell walls, makes plants more resistant to pests and drought, and can improve uptake of other nutrients. A bunch of studies on rice and sugarcane show yield bumps of ten to twenty percent with silicon fertilization. Luna: That's a meaningful gain. And this is coming from waste that would otherwise sit in a tailings dam? Lucas: Exactly. The mine at Kirkenes produces about five million tons of tailings a year. A massive environmental liability — those dams can fail catastrophically, like the Brumadinho disaster in Brazil in 2019. Instead of storing them, the company is processing a fraction into a product that sequesters carbon as it weathers. Luna: Wait — it sequesters carbon? How does that work? Lucas: Silicate minerals react with carbon dioxide in the air and water to form carbonates. It's a natural weathering process, but by grinding the rock and spreading it on fields, you accelerate it dramatically. A 2022 study estimated that enhanced weathering using olivine could remove billions of tons of CO2 per year if deployed at scale. Luna: So it's a fertilizer that also helps with climate. That's a double win. Lucas: That's the pitch. But there are challenges. The fertilizer is slow-release, which is great for long-term soil health but less useful for crops that need a quick nitrogen boost. Farmers are used to fast-acting synthetic fertilizers. Luna: Is it cost-competitive? Synthetic fertilizer prices have been volatile — especially after the Russian invasion of Ukraine. Lucas: Right now, no. The processing adds cost — grinding rock is energy-intensive. But the company is scaling up. They recently got a grant from the Norwegian government to build a larger processing line, targeting production of fifty thousand tons a year by 2028. Luna: Fifty thousand tons sounds like a lot, but global fertilizer consumption is around two hundred million tons annually. So it's a niche. Lucas: It's a niche, but a growing one. And the carbon-sequestration angle might open up carbon credit markets. If farmers can get paid for the CO2 removed, that changes the economics entirely. Luna: Right, so the value isn't just in the silicon — it's in the carbon credits. Lucas: Exactly. A few companies are already piloting that model. They measure the enhanced weathering rate using soil samples and satellite data, then sell verified carbon removal credits on voluntary markets. Luna: Is there any risk of heavy metals in the tailings contaminating the soil? That's usually the concern with mining waste. Lucas: Good question. The Kirkenes tailings are largely iron oxides and silicates with low heavy metal content — the ore body is fairly clean. But not all mine tailings would be suitable. You'd need to test each source. That's part of why this specific location works. Luna: So it's not a universal solution, but it could be replicated at other iron ore mines with similar geology. Lucas: And potentially with other silicate-rich tailings from copper or nickel mining. There's a lot of research happening at universities like MIT and Cambridge on characterizing different tailings for agronomic use. Luna: You know, this reminds me of something we've talked about before — turning a liability into an asset. It's a classic circular economy move, but applied to mining waste. Lucas: It is. And it's particularly relevant now because the fertilizer industry is under pressure to decarbonize. Ammonia production alone accounts for about one to two percent of global CO2 emissions. If you can replace even a fraction of that with a low-emission alternative, it matters. Luna: What about the farmers? Are they adopting it? Lucas: Slowly. In Norway, they've done field trials on barley and wheat showing yield increases of five to fifteen percent. But farmers are conservative — they want to see consistent results over multiple seasons. The company is working with agricultural cooperatives to build trust. Luna: Makes sense. You don't switch your fertilizer regime based on one good year. Lucas: Exactly. And there's also the logistics challenge. The tailings are in northern Norway, far from major agricultural regions. Shipping costs add up. Luna: But if carbon credits cover part of that, maybe it pencils out. And if the technology proves out, you could imagine mobile processing units at mines closer to farmland. Lucas: That's the vision some startups are pursuing. One Canadian company is looking at using waste from asbestos mines — which is also silicate-rich — to make fertilizer. There's a lot of potential if the economics align. Luna: It's a fascinating area. And honestly, it's why we keep covering these stories — because they show real innovation in manufacturing that's trying to solve multiple problems at once. Lucas: Yeah, and that's the kind of reporting we try to do on this show. We don't run ads, we don't take sponsorships — we just want to have these conversations and share them. If you find value in that, one way to support it is buy me a coffee dot com slash fexingo. No pressure, just a way to keep the show independent. Luna: Totally. Even a small contribution helps. We appreciate everyone who listens and engages. Lucas: Back to the fertilizer — there's another angle I find really interesting. The slow-release nature means less runoff into waterways, which is a huge problem with synthetic fertilizers. The dead zone in the Gulf of Mexico is largely caused by nitrogen runoff from Midwestern farms. Luna: Right. So this could reduce that environmental damage as well. It's really a multi-benefit product. Lucas: Exactly. And that's why I think this technology is worth watching, even if it's early days. The combination of waste valorization, carbon removal, and improved soil health is hard to beat. Luna: So what's the next step? Do you see this scaling beyond Norway? Lucas: I think so. There are similar pilot projects in Brazil, Australia, and the US. If the carbon credit market matures and the cost of grinding comes down, it could become a significant source of both fertilizer and carbon removal. Luna: I'll be watching. And I'm curious to see how the farming community responds over the next few years. Lucas: Same here. Thanks for listening, and we'll be back next time with another look at how manufacturing is evolving.