Metal transformations may be purely chemical or classified as biochemical when microbes are catalyzing some of the reactions.
Between solid and liquid phase
- Solid metal bearing materials may be dissolved by metal mobilization processes (Figure 1a).
- Metal ions in solution can turn into solid metal bearing material by metal immobilization processes (Figure 1c).
Within the aqueous phase by ions changing oxidation state
- Depending on the redox potential in solution metals may change from one oxidation state to another. A change in oxidation state can under certain conditions lead to precipitation and in other cases to dissolution of a metal or a metal compound. Changes in oxidation state can also occur within an aqueous phase (Figure 1b).
May be enhanced by microbes
- Microbial weathering of rocks
- Soil and sediment formation and transformation
- The genesis and degradation of minerals
Biohydrometallurgy and supporting technologies
One application is to minimize microbial activity to avoid acid rock generation and microbial corrosion.
Which of the enumerated transformations are metal mobilizations, immobilizations or state transformations?