Smelters matter to critical minerals beyond the metals on their labels
An IEA assessment highlights the by-products recovered at copper, zinc and lead plants.
A smelter built to process a base metal can also recover smaller quantities of materials that are hard to source elsewhere. The International Energy Agency's 2026 minerals outlook identifies copper, zinc and lead processing as important sources of several strategic by-products.
These materials have smaller markets than bulk metals. That can make a disruption at one processing hub significant even when the volume of the material lost looks modest.
The agency argues that new projects and investments in existing processing sites could diversify some supply chains. For minerals recovered as by-products, the investment decision may depend on whether the plant can separate and sell the additional material economically.