How are cobalt sulfide ores processed before the metal is extracted?

To process cobalt sulfide ores, the material first undergoes conventional mineral processing to create a copper-cobalt concentrate. This concentrate is then treated using flotation, a method that utilizes pneumatic and mechanical agitation to create air bubbles. By applying specific reagents, cobalt minerals are made hydrophobic, allowing them to adhere to the bubbles and rise to the surface for collection as a cobalt-rich concentrate.12

Once separated, the cobalt-rich concentrate undergoes further treatment:

• Roasting: The sulfide concentrate is roasted under controlled conditions to transform most of the cobalt sulfide into a soluble sulfate while minimizing the conversion of copper and iron into water-soluble states.3
• Leaching: The roasted product is leached, and the resulting solution is treated to remove impurities like copper and iron.3
• Recovery: The cobalt is finally recovered in its metallic state through electrolysis.3