- Data is presented from the mine perspective. Physical production parameters are provided, including ore mined, heap leached and/or milled, ore grades, strip ratios and co/by-product metal production
- For mines that produce silver in a base metal concentrate, GHG emissions relating to the freight, smelting and refining of the concentrate are apportioned to the primary metal in that concentrate: silver is effectively 'free carried'. Emissions from refining of anode slimes derived from the smelting of concentrates are allocated to silver
- Silver production and emission data is provided by mine, company or country
- Allocation of emissions by company is according to equity ownership of asset, including emissions for minority shareholdings, which are often excluded from company sustainability reports)
Emission data is presented as total tonnes of CO2e and tonnes of CO2e per equivalent ounce of refined silver.
Skarn recommends CO2e per equivalent ounce of refined silver as the most suitable metric for comparing operations.
For silver, E0 and E1 emissions are defined as follows:
E0: Scope 1 and 2 emissions at mine site.
E1: E0 emissions, plus emissions from dore and concentrate freight, smelting and refining.