Low-grade ores are undesirable because extracting the metals requires more energy per pound than high-grade ores.

Question

Quizplus · Accepted Answer

Low-grade ores have a low concentration of the desired metal, which means that a large amount of ore must be processed to extract a small amount of metal. This requires more energy per pound of metal compared to high-grade ores, which have a higher concentration of the desired metal and require less processing. Therefore, low-grade ores are generally considered undesirable.

Low-Grade Ores Are Undesirable Because Extracting the Metals Requires More