Improvement of combined technologies of underground block leaching of metals from out of balance and unconditioned ores

The object of the research is technologies and technical means for combined leaching of metals from hard ores in installations mounted in underground leaching blocks (BWB) with their preliminary crushing by explosives (BV). One of the most problematic places is the difficulty of achieving the specified quality of crushing, as well as the necessary height of ore storage in the chamber for further leaching of metals and the coefficient of loosening, taking into account the management of the energy of explosive destruction of rock ores. In the course of the study, the following were used: data from literary sources and patent documentation in the field of technologies and technical means for PBV of metals from ores in energy-disturbed massifs, substantiation of technological parameters of operational units; laboratory and production experiments; physical modeling of metal extraction from ores from the average linear size of a piece of blasted ore. Analytical studies, comparative analysis of theoretical and practical results using standard and new methods were performed with the participation of the authors. It was established that the most intense infiltration leaching occurs in the size class of ore pieces –100+0 mm. For the Michurynske deposit, Ukraine, during leaching, it is recommended that the yield of such a fraction in the reflected ore is about 90%. Metals are extracted less intensively and longer from fractions of –200+100 mm. It has been proven that the main place in PBV should be occupied by the explosive preparation of ore, which ensures effective extraction of metal from stored ores with a loosening coefficient of 1.15 > Kr < 1.20, which is regulated by the volume of ore released from the block (up to 30%) and parameters cameras (length, width and height). The extraction of metal ξ, %, which significantly depends on the average linear size of a piece of blasted ore dср and with a high degree of reliability (R2 = 0.97), was established. Due to the involvement in the production of substandard and off-balance ores, the raw material base of metal extraction at existing mines and those that are being built again can be increased by 1.4–1.6 times. Research results can be used during the underground development of ore deposits of off-balance and non-conditional ores of complex structure.