05.09.2025
No More Lost Gold – Alchemist Recovers Gold from Process Water
Endomines and Sofi Filtration have successfully completed the first pilot of the Alchemist technology at the Pampalo gold mine. With this innovative solution, up to 99% of the gold contained in the plant’s filter water was recovered.
Endomines and the Finnish water purification technology company Sofi Filtration carried out the pilot at the Pampalo mill. Alchemist, developed by Sofi Filtration, is an advanced filtration system designed to treat mining side streams – the excess water from production processes – and recover valuable minerals that would otherwise be lost.
“It’s widely known that after the final flotation stage in the concentration process, the filter water still contains 1–20% of fine concentrate. With Alchemist, we can recover on average 98% of that. The exact percentage depends on the site. In the Endomines pilot, we achieved up to 99% gold recovery,” says Nina Harjula, Marketing Director at Sofi Filtration.
A Step Toward More Sustainable Mining
Alchemist operates without chemicals or disposable filters and can separate particles as small as 0.3 microns. The system is self-cleaning and does not interfere with the main production process. At Pampalo, Alchemist ran seamlessly alongside the concentration process throughout the entire production cycle.
“We’re very pleased with the results of the pilot. Naturally, we want to recover every bit of gold we possibly can. More efficient gold recovery from filter water improves resource efficiency and ensures cleaner water. Every step toward more sustainable mining is significant,” says Ilkka Räty, COO, at Endomines.
Sofi Filtration and Endomines will continue their collaboration to maximize the value of process water. The goal is to recover every last speck of gold from mining wastewater – while also reducing environmental impact.