Life Cycle Assessment (LCA) is a systematic, science-based methodology used to evaluate the environmental impacts associated with all stages of a product's life — from raw material extraction through processing, transportation, manufacturing, use, and end-of-life disposal or recycling. In the mining industry, LCA is applied to quantify and compare the environmental footprint of mining and mineral processing activities, including bauxite mining and alumina refining, gold mining and refining, iron ore mining and steel production, and diamond mining and processing.
The LCA methodology follows a standardized framework as defined by the International Organization for Standardization (ISO 14040 and 14044) and involves four main phases. The goal and scope definition phase establishes the purpose of the study, the system boundaries, and the functional unit (the reference basis for comparison). The life cycle inventory (LCI) phase involves the compilation and quantification of all inputs (energy, water, materials, land use) and outputs (products, waste streams, emissions to air, water, and soil) associated with each process stage. The life cycle impact assessment (LCIA) phase translates the inventory data into potential environmental impact indicators such as global warming potential (greenhouse gas emissions), water depletion, eutrophication, acidification, ecotoxicity, and land use. The interpretation phase synthesizes the results and draws conclusions relevant to the decision-making context.
In bauxite and alumina LCA studies, significant impact categories include bauxite residue (red mud) generation, energy consumption in digestion and calcination, and greenhouse gas emissions from the refining process. In gold mining, the energy intensity of grinding and cyanide-based leaching, as well as the land disturbance associated with large open-cut mines, are key impact categories. LCA supports sustainability reporting, environmental product declarations (EPDs), and the identification of hot spots for operational improvement.