Why is it necessary to remove gangue from the ore before metal extraction?

Removing gangue from the ore before metal extraction is essential because gangue materials are non-valuable and can dilute the concentration of the desired metal or mineral. Extracting metals from ore involves various processes like smelting or leaching, where the goal is to obtain the metal in a pure form. Gangue not only decreases the efficiency of these processes but also increases the energy consumption and environmental impact. Separating gangue from the ore improves the overall ore grade, allowing for more efficient extraction of valuable metals, reducing waste, and minimizing the environmental footprint associated with the extraction and processing of large volumes of non-valuable materials.