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What is black mass and why does everyone want it?

📅 July 29, 2026 🏷️ Process · Hydrometallurgy ⏱️ 4 min read

Inside every lithium battery there is a treasure you can grind. When an end-of-life battery is discharged, dismantled and its cells are milled, the result is a dark, dense powder: black mass. It is the emerging commodity of the energy transition, and at Ecobaterías we produce and process it in Chile.

Real black mass in a container, produced at our plant
Real black mass produced at our plant: the lithium, nickel and cobalt are in here.

What does it contain?

Black mass concentrates the cathode and anode materials. In an NMC chemistry (nickel-manganese-cobalt), typical of phones, laptops and electric vehicles, you will find approximately:

  • Nickel, cobalt and manganese: the highest unit-value metals.
  • Lithium: the one the industry is named after.
  • Graphite from the anode, and copper and aluminium remnants from the collectors.

Why is it so valuable?

Because it is an ore already "pre-concentrated" by industry: cobalt or nickel grades in black mass far exceed those of a natural deposit. That is why the European Union classified it as strategic waste and restricts its export, and why Asian refineries buy it avidly.

⚗️ The step that creates the value: black mass on its own is an intermediate. The value jump happens in hydrometallurgy — leaching, purification and crystallization — which turns it into industrial-grade salts, like the cobalt sulfate that Chile's copper industry already buys.

From grinding to sulfate

At our plant, black mass is dissolved in controlled leaching, the solutions are purified with per-batch analytical control, and finally crystallized into cobalt sulfate heptahydrate and nickel sulfate. You can see the full process, stage by stage and with real photos, on our process page.

Black mass NMC Hydrometallurgy