Contemporary Research and Developments in the Low-Toxic Chelating Reagents for the Extraction of Non-Ferrous and Noble Metals from Poor Polymetallic Ores and Processing Tailings

An urgent technological, economic and environmental task of mining and metallurgical enterprises is to involve poor, off-balance and hard-to-beneficiate ores in the technological process, as well as accumulated and current waste from mining and metallurgical industries. As the reserves of developed deposits are depleted, technogenic objects may become a priority, and in some cases the only, source of mineral raw materials. Mining wastes represent a large reserve of raw materials for the extraction of non-ferrous and precious metals, and at the same time, they are centers of local or regional environmental pollution. Stale waste re-processing may promote territorial cultivation and reduce the environmental burden. The conventional methods of poor ore and waste treatment do not fully provide for a sufficient separation degree of high metal extraction, and lead to significant valuable ore losses, while the quality of the obtained concentrates often does not meet the requirements for subsequent technological process. In this regard, the development of novel chelating agents with specific functional groups that can selectively adsorb on the mineral surface, change the contrast of chemical surface composition and improve the flotation properties of mineral complexes, is an innovative solution for increasing their flotation selectivity. Furthermore, the synthesis and application of novel flotation reagents may help to replace toxic reagents by ecologically friendly or less-toxic ones.