Applications · Mining
Acid mine drainage treatment with less sludge and recoverable metals
Protected sulfate-reducing bacteria keep working at low pH and high metal loads, removing sulfate faster and recovering dissolved metals instead of burying them in lime sludge.
The challenge with lime dosing
Acid mine drainage (AMD) combines low pH, high sulfate concentrations and dissolved metals. Most sites treat it by chemical lime dosing, which generates large volumes of sludge and contributes 30–50% of operating costs (Wood, 2023).
The scale is significant: Australia alone spends up to AUD 650 million a year managing AMD, and the global market is estimated at USD 10–25 billion a year.
Why biological sulfate reduction often struggles
Sulfate-reducing bacteria (SRB) can treat AMD biologically, but free-floating bacteria are vulnerable to acidity, metal toxicity, temperature changes and washout. That makes performance hard to keep stable.
What entrapment changes
Immobilising SRB in a porous hydrogel protects them from these stresses and keeps them in the reactor. In laboratory trials this delivered:
Laboratory-scale results. See the publication on temperature disturbances.
Who this is for
- Mine operators managing AMD at active or closed sites
- Environmental and water-treatment teams looking to reduce lime use and sludge handling
- Operations interested in recovering metals, including critical minerals and rare earths, from mine water
- Engineering consultancies designing mine water treatment
We are seeking mining partners to host and co-develop pilot demonstrations. See partnership options.
Have a mine water challenge?
Tell us about your site's water chemistry and treatment goals. We are looking for pilot partners in the mining sector.