Nickel phytomining potential in serpentine soil of Sri Lanka: an implication for sustainable mining

The world is experiencing rapid growth of nickel (Ni) demand, especially for lithium-ion batteries used in electric vehicles, while high-grade Ni deposits are being depleted due to expanding economics, growing populations, and disorganized industrialization. Therefore, a major transformation from high-grade low-bulk ores to low-grade high-bulk ores is necessary to secure the future supply chain of Ni [1]. In this context, ultramafic soil is considered a low-grade high-bulk Ni ore, mostly found in tropical countries. However, conventional mining practices are high energy-consuming and generate a tremendous amount of waste, making it impracticable to recover Ni from ultramafic soil. Therefore, phytomining (or farming for metals) is identified as a viable and innovative method for Ni recovery from low-grade high-bulk sources such as ultramafic soil.