What is one way of extracting copper from low-grade ores?

Phytomining is an effective method for extracting copper from low-grade ores. In this process, certain plants are grown in soil that contains copper, and these plants absorb the copper through their root systems. Once the plants have matured, they are harvested, and the copper is extracted by burning the biomass, which concentrates the copper in the ash. This technique is particularly useful for ores that are too low in copper content to make traditional extraction methods economically viable. It is an environmentally friendly alternative that minimizes the impact on the land compared to conventional mining practices.

Other methods listed, such as hydraulic fracturing, boiling, and electrolysis, do not apply to the extraction of copper from low-grade ores in this context. Hydraulic fracturing is primarily used in the extraction of fossil fuels, boiling does not effectively separate copper from ores, and electrolysis typically requires a higher concentration of copper ions found in more refined ores or solutions rather than low-grade ores.