Intensification of Non-Ferrous Metals Leaching From Low-Grade Copper-Nickel Ores and Tailings

"The methods of heap leaching are considered to be the most promising for the low-grade copper-nickel raw materials. The article presents intensification capabilities of the process. Objects of research: the low-grade copper-nickel ores of Moncheplutone deposits (Moroshkovoye Lake, Nyud Terrasa, Nittis-Kumuzh’ya-Travyanaya (NKT), as well as the copper-nickel ore dressing tailings of the “Kola MMC” JSC. The following directions for the intensification of the low-grade copper-nickel raw materials heap leaching have been considered: preliminary electric pulse destruction (EPD) of ore; ore crushing and further sulfuric acid agglomeration. The impact of sulfuric acid concentration (1-3%) on the extraction of non-ferrous metals kinetics from the copper-nickel ore dressing tailings under various conditions of the percolation leaching has been studied. INTRODUCTION The low-grade grade sulfide ores at the abandoned and producing deposits, overburden rocks, mill tailings and non-ferrous slag are thought to be one of the large-scale sources for non-ferrous metals, on the one hand. On the other hand, they are known to be the subjects of emergency environmental danger. For this reason, the use of mine dumps and tailings, as well as the remained ores left in the ground as raw products, and at the same time decreasing the load on environment, are considered to be the pressing ecological and economic issue (Chanturia et al., 2012). Methods of heap hydrometallurgical and bacterial leaching are sure to be potentially productive for processing such low-grade and technogenic raw materials (Petersen, 2016). The early studies of hydrometallurgical method possibility to process copper-nickel ores of the Murmansk region deposits were launched in the seventies of the previous century (Golovko et al., 1978). For referencing purposes, the main types of impregnated ores from the deposits Zhdanovskoye, Kaula, Sopchinsky Plast and Lovnoozerskoye were selected. The metal content varied, as %: 0.46-1.49 of nickel, 0.01-0.62 of copper. In the first experiments, the solution containing 150g/l of H2SO4 and 135g/l of NaCl, was used in the capacity of leaching reagent. The possibility of underground metals leaching from the ores of the Lovnoozerskoye deposit was justified due to the performed laboratory and further large-sized tests."