Obuasi is buying a fourth Gekko InLine Leach Reactor. AngloGold Ashanti’s Ghanaian operation will commission it in 2027, adding to three ILRs the site has been running since the mid-2000s.
Here’s what this really means: when a mining company keeps buying the same piece of equipment for twenty years, that’s not a press release talking point — that’s the most honest endorsement you’ll ever get in this industry. Junior miners and technology vendors throw around “game-changing” and “revolutionary” like confetti. But capital allocation at a major is a colder, harder calculation. Nobody reorders a machine four times out of sentimentality.
The context matters. Obuasi isn’t some simple heap-leach outfit in the desert. It runs a BIOX® circuit — bacterial oxidation of refractory sulphide ores — which is finicky, biologically sensitive, and unforgiving of process upsets. One of the big operational risks in such a circuit is cyanide exposure bleeding into the flotation and bio-oxidation stages. Cyanide and the bugs in a BIOX® circuit don’t get along. The ILR’s design lets it leach gold concentrates intensively while containing that cyanide downstream risk. In other words, it does its job without poisoning the neighbors in the flowsheet. That’s not glamorous, but in mineral processing, “doesn’t break the rest of the plant” is worth more than any shiny headline metric.
For those who haven’t followed gravity concentration technology, the ILR is a ‘rolling barrel’ design — it agitates coarse gold concentrates under intensive cyanide and oxygen conditions to strip out the gold fast. It comes in two flavors: an automated batch model for small-volume gravity concentrates from batch separators, and a continuous model for high-throughput material from pressure jigs and flotation circuits. Gekko claims free gold recoveries north of 98%, plus strong performance on complex sulphide ores. Leaching coarse material — above 300 microns — and recycling leach solutions keeps energy and operating costs down, and the automation means you’re not paying a crew to babysit the thing.
Now, the skeptical read, because there’s always one. Those 98% recovery figures come from the vendor. Real-world recoveries depend entirely on the feed: mineralogy, concentrate grade, the skill of the metallurgists running the plant. A number on a brochure and a number on a production report are rarely the same number. That said — and this is the part that carries actual weight — AngloGold’s continued purchases suggest the machine performs close enough to spec at Obuasi that the economics justify repeat capital. Two decades of operational history at a major’s flagship African asset is due diligence no vendor brochure can fake. This isn’t the first time we’ve seen this circus, but it’s one of the rare cases where the ringmasters keep buying tickets.
The broader takeaway for investors watching the gold space: refractory ore processing is becoming a bigger deal as the easy oxide deposits get mined out. Grades are falling, ore bodies are getting nastier, and processing technology that can handle complex sulphides efficiently is quietly where margins get won or lost. Companies with proven, incremental, boring technology — the kind that gets reordered — tend to be better businesses than the ones pitching step-change miracles. Incremental beats revolutionary in this business, because incremental compounds and revolutionary bankrupts.
Obuasi itself is worth a glance too. It’s one of the great historic gold mines, and AngloGold has spent years rehabilitating it after a rough stretch under previous management. That a major is expanding processing capacity there in 2027 signals they see a long production runway. Gold near record prices doesn’t hurt either — though anyone allocating capital on the assumption current gold prices are permanent deserves the losses coming to them.
A fourth ILR at Obuasi is a small story in isolation. But small stories like this — repeat capital orders, brownfield expansion, proven technology in complex circuits — are the texture of how real mining businesses get built. Pay attention to those, not the headlines.
Source: https://im-mining.com/2026/10/29/obuasi-set-to-install-fourth-gekko-inline-leach-reactor-in-2027/
