Carbon Emissions

Carbon emissions, in the context of mining operations, refer to the release of greenhouse gases into the atmosphere — primarily carbon dioxide (CO₂) and methane (CH₄) but also nitrous oxide (N₂O), perfluorocarbons (PFCs), and other substances — resulting from the combustion of fossil fuels, industrial chemical processes, and biological decomposition associated with mining, mineral processing, and related activities. These emissions are collectively quantified and reported as tonnes of carbon dioxide equivalent (tCO₂e), using the global warming potential (GWP) of each gas over a standardized 100-year timeframe to express their relative climate impact in a common unit. In bauxite mining, significant carbon emissions arise from the combustion of diesel fuel in mining equipment and haul trucks, natural gas in alumina refinery calciners and digesters, and the generation of electricity consumed across operations. Iron ore mining and processing generate emissions from diesel consumption in open-pit and underground operations, fuel combustion in ore processing plants, and the large quantities of energy consumed in pelletizing and sintering. Gold mining often involves substantial diesel consumption, particularly in remote operations without grid electricity access, and generates process emissions from the oxidation of sulfidic refractory ores. Diamond mining emissions come primarily from diesel and electricity consumption in crushing, processing, and x-ray transmission sorting plants. Aluminum smelting, as the downstream transformation of alumina derived from bauxite, produces particularly significant emissions: the carbon anodes oxidize electrochemically, and anode effect events generate potent PFC gases (CF₄ and C₂F₆), making the aluminum sector one of the most emissions-intensive in the metals industry. Accurate measurement, reporting, and reduction of carbon emissions are central to industry sustainability commitments and regulatory compliance globally.