Concepts: - ![[Primary metal extraction]] - ![[Secondary metal extraction]] | Parameter | Primary Extraction (Virgin Ore) | Secondary Extraction (Recycling) | | -------------------------- | ------------------------------------------------------- | ---------------------------------------------------------------------------------- | | **Raw Material Source** | Geological ore deposits | Industrial scrap, end-of-life products | | **Pre-treatment Required** | [[Comminution]], concentration | Shredding, magnetic/sensor sorting, pyrolysis | | **Thermodynamic Step** | Highly endothermic reduction of oxides/sulfides | Phase transition (mostly melting of elemental metals) | | **Energy Consumption** | High (e.g., ~14,000 kWh/tonne for primary [[Aluminum]]) | Low (typically 5% to 10% of primary energy; e.g., ~700 kWh/tonne for secondary Al) | | **Carbon Footprint** | High (fossil-fuel reductants like coke are often used) | Generally lower (primarily dependent on the electricity source) | | **Solid Waste Generation** | Large volumes of [[mine tailings]] and slag | Slag and dust, but significantly lower volume overall | | **Impurity Profiles** | Well-defined gangue elements (e.g., silica, alumina) | Highly variable "tramp" elements (e.g., Cu in recycled steel) |