Green Manganese Technologies said it has successfully completed initial metallurgical test work demonstrating that its proprietary hydrometallurgical process can recover multiple critical metals from polymetallic nodules through a single, integrated process.
Polymetallic nodules, found resting unattached on the deep-ocean floor contain nickel, cobalt, copper, and manganese – core inputs for global battery, electronics, and defense supply chains.
As interest in ocean-based mineral resources grows, efficiently processing the complex matrix of metals contained in nodules remains a primary bottleneck to commercial deployment.
Unlike conventional processing flowsheets that rely on multi-stage pyrometallurgical smelting—sequentially calcining and smelting nodules to separate a nickel-copper-cobalt alloy from a manganese silicate slag—Green Manganese says its hydrometallurgical platform is engineered to extract all principal critical metals from polymetallic nodules in one integrated process.
By bypassing Submerged Arc Furnaces (SAF), electrolysis, and multi-phase converting steps entirely, Green Manganese said process consumes up to 5 times less energy while achieving greater than 90% recovery of manganese, nickel, cobalt, and copper simultaneously.
Selectively dissolving the manganese minerals releases associated critical metals into a unified process solution. Simultaneously, iron minerals are converted into hematite, simplifying downstream handling and creating an additional value stream to recover iron, titanium, and rare earth elements, maximizing overall resource utilization.
“What makes polymetallic nodules so compelling is that several critical metals are concentrated in a single rock,” Green Manganese Technologies CEO Alexey Demykin said.
“Instead of forcing a next-generation multi-metal feedstock into legacy technologies built for single ores, this new era of critical minerals demands a fundamental shift in processing,” Demykin said. “By extracting manganese, nickel, cobalt, and copper in one integrated hydrometallurgical circuit, we bypass energy-intensive thermal stages entirely—delivering a streamlined, low-emission pathway to multiple high-value products.”
Green Manganese said its hydrometallurgical platform uses specialized manganese chemistry to extract target metals from complex, manganese-bearing materials. As deep-sea resource developers move closer to commercial collection, the company said its results demonstrate a viable route to simplify nodule processing, establishing a foundation for further pilot-scale testing and commercial collaboration.
