Bioleaching and phytomining are two innovative methods for extracting metals from low-grade ores using biological processes.

Bioleaching involves the use of bacteria to extract metals from their ores. As a branch of biomining, bioleaching harnesses biological processes to recover valuable elements from ores. In this process, bacteria metabolize the low-grade ores, producing a leachate—a solution that contains the desired metal. This leachate is then collected, and the metal is subsequently extracted from it. Bioleaching is particularly effective for obtaining metals such as copper and gold.

In contrast, phytomining employs plants to extract metals from low-grade ores. Certain plants, referred to as hyperaccumulators, possess the unique ability to absorb metals from the soil through their root systems. These plants are cultivated on low-grade ore deposits, and as they grow, they uptake the metal from the soil. Once the plants reach maturity, they are harvested and incinerated. The resulting ash contains a higher concentration of the metal, which can then be extracted. Phytomining is often used for extracting nickel.

Both bioleaching and phytomining are considered more environmentally friendly alternatives to traditional mining methods. These techniques do not necessitate extensive land excavation or the use of harmful chemicals. However, they are generally slower processes and may not be suitable for all types of ores. They are most effective for recovering metals from low-grade ores, where conventional mining methods may be economically unfeasible.