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Rammelsberg Cobalt-Nickel Tailings Consortium

Ecological State ENGINEERED
Environment mine tailing
ENVO:00000072
Source File Rammelsberg_Cobalt_Nickel_Tailings.yaml

A mesophilic acidophilic bacterial consortium applied to bioleach cobalt, copper, and other valuable metals from sulfidic mine tailings at the Rammelsberg polymetallic massive sulfide deposit in the Harz Mountains, Germany. This consortium represents one of the only industrial-scale cobalt bioleaching processes globally and demonstrates exceptional efficiency in recovering critical battery materials from low-grade mine tailings. The adapted microbial community consists mainly of Acidithiobacillus ferrooxidans (iron-oxidizing) and Acidithiobacillus thiooxidans (sulfur-oxidizing), achieving 91% cobalt and 57% copper extraction from bulk tailings (Co 0.02%, Cu 0.12%) after 13 days in stirred tank reactors at 10% pulp density. The consortium exhibits synergistic cooperation between iron and sulfur oxidizers, where iron oxidation by At. ferrooxidans generates ferric iron that chemically oxidizes sulfide minerals, while sulfur oxidation by At. thiooxidans prevents elemental sulfur passivation and maintains low pH through sulfuric acid production. Mineralogical analysis revealed that cobalt occurs on the surface of framboidal pyrite and is mobilized through microbial attack. This system demonstrates the biotechnological potential for recovering critical materials (cobalt, copper, nickel) from mine waste through environmentally sustainable bioprocessing, addressing both resource recovery and mine tailings remediation challenges relevant to the circular economy and battery supply chains.

Taxonomy

Taxon Ontology ID Functional Roles Abundance
Acidithiobacillus ferrooxidans NCBITaxon:920
PRIMARY_DEGRADER
DOMINANT
Acidithiobacillus thiooxidans NCBITaxon:930
PRIMARY_DEGRADER SYNTROPHIC_PARTNER
DOMINANT

Ecological Interactions

Iron Oxidation and Ferric Iron Generation

COMMENSALISM

Source Taxon: Acidithiobacillus ferrooxidans

Metabolites: Fe(II) (CHEBI:29033), Fe(III) (CHEBI:29034), oxygen (CHEBI:15379)

Biological Processes:

Downstream Effects:
→ Cobalt and Copper Mobilization from Sulfide Minerals

Evidence

  • PMID:39770610 - SUPPORT (IN_VITRO)
    "It has emerged as a key player in biomining and bioleaching technologies thanks to its unique ability to mobilize a wide spectrum of elements, such as Li, P, V, Cr, Fe, Ni, Cu, Zn, Ga, As, Mo, W, Pb, U, and its role in ferrous iron oxidation and reduction"

Cobalt and Copper Mobilization from Sulfide Minerals

MUTUALISM

Metabolites: Fe(III) (CHEBI:29034), cobalt(2+) (CHEBI:48828), copper(2+) (CHEBI:29036), sulfate (CHEBI:16189)

Biological Processes:

Downstream Effects:
→ Iron Oxidation and Ferric Iron Generation
→ Sulfur Oxidation and Acid Generation

Evidence

  • doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO)
    "This material still contains several sulfide minerals (pyrrhotite, pyrite, sphalerite, pentlandite, violarite, chalcopyrite) and significant amounts of metals (Zn, Ni, Cu, Co, rare earth elements)"
  • doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO)
    "Mineralogical analysis showed that cobalt occurred on the surface of framboidal pyrite and was mainly leached by microbial attack"

Sulfur Oxidation and Acid Generation

MUTUALISM

Source Taxon: Acidithiobacillus thiooxidans

Metabolites: elemental sulfur (CHEBI:27568), sulfuric acid (CHEBI:26836), sulfate (CHEBI:16189)

Biological Processes:

Downstream Effects:
→ Iron Oxidation and Ferric Iron Generation

Evidence

  • PMID:39770610 - SUPPORT (IN_VITRO)
    "However, its use in biometallurgical applications poses environmental issues through its effect on the pH levels in bioleaching systems, which produce acid mine drainage in rivers and lakes adjacent to mines"
  • doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO)
    "In the framework of the European project NEMO (Near-zero-waste recycling of low-grade sulfidic mining waste for critical-metal, mineral and construction raw-material production in a circular economy), new ways to valorize sulfidic tailings are being developed through the recovery of valuable metals and critical raw materials and the transformation of the residual in clean mineral fraction to be used for the mass production of cement, concrete and construction products"

Autotrophic Carbon Fixation in Acidic Environment

COMMENSALISM

Metabolites: carbon dioxide (CHEBI:16526), ATP (CHEBI:15422)

Biological Processes:

Evidence

  • PMID:39770610 - SUPPORT (IN_VITRO)
    "ferrooxidans catalyzes the extraction of elements by generating iron (III) ions in oxic conditions, which are able to react with metal sulfides"

Environmental Factors

Factor Value Unit
pH 1.5-2.5 pH units
Temperature 30-35 °C
Pulp Density 10 % (w/v)
Reactor Configuration 2 L stirred tank reactors liters
Bioleaching Duration and Metal Recovery 13 days
Oxygen Supply Aerobic condition
Tailings Mineralogy and Metal Grades Framboidal pyrite with surface-associated cobalt N/A