Towards waterless operations from mine to mill
Saija Luukkanen, Antti Tanhua, Zong‐Xian Zhang, Raul Mollehuara Canales, Ilpo Auranen
Abstract
To respond to the increased demand for commodities, increased volumes of primary ores need to be mined. This could lead to major challenges with water and tailings management since ore grades are low and many mining operations take place in high water stress areas. The current mineral processing methods used are highly water intensive and, consequently, there is increasing interest in finding alternative solutions to produce raw material concentrates using little or no water. Dry separation technologies capable of efficient recovery of commodities are relatively rare and highly dependent on the materials to be separated. Low-grade complex ores require energy-efficient solutions for liberating material. Controlled optimisation of the rock fragmentation chain from blasting to comminution can be seen as a viable option to reduce the need for energy-intensive grinding. Application of pre-concentration methods to remove barren waste prior to grinding, developing cost-efficient and energy-efficient methods for comminution, use of mechanical or chemical pre-treatment methods for modifying the mineral surfaces and replacing water with solvents for leaching are all good tools when considering the change from wet to non-aqueous processing. Nevertheless, considerable multidisciplinary research, along with many new methods and holistic, innovative solutions are required to enable the change.