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Leaching often involves redox reactions, where electrons are transferred between substances. This is where oxidants and reductants come in:
- Oxidants: These are substances that cause oxidation (loss of electrons) in other substances. In leaching, they help dissolve metals from their ores by changing their oxidation state. Common examples include:
- Oxygen (O₂)
- Hydrogen peroxide (H₂O₂)
- Ferric ions (Fe³⁺)
- Reductants: These substances cause reduction (gain of electrons) in other substances. While less commonly the primary drivers of leaching, reductants can play important roles:
- Enhancing the solubility of certain metals.
- Preventing the precipitation of unwanted compounds.
Why are they important?
Many metals in ores are in an insoluble form. Oxidants and reductants facilitate the chemical reactions that make them soluble, allowing them to be extracted by the leaching solution.
In essence, oxidants and reductants are the chemical tools that enable the dissolution of metals from their solid, often unreactive, state within the ore.
How do you optimize the use of oxidants and reductants to maximize metal recovery while minimizing reagent consumption?
Reference:
https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Supplemental_Modules_(Analytical_Chemistry)/Electrochemistry/Redox_Chemistry/Oxidation-Reduction_Reactions
