INCREASING THE EFFICIENCY AND ENVIRONMENTAL SAFETY OF COMBINED GEOTECHNOLOGIES FOR LEACHING METALS FROM AND OFF-BALANCE ORES

Abstract Goal. Increasing the efficiency and environmental safety of geotechnologies of solid ore extraction with their preliminary grinding with explosives according to traditional technologies and leaching of metals from substandard ores in installations installed in mining workings of the operational block. This will ensure the protection and rational use of the subsoil, increasing the economic efficiency and environmental safety of the mining of poor, substandard and out-of-balance ores in terms of metal content. Method. The article examines literary sources and patent documentation in the field of geotechnology and technical means of leaching metals from hard ores in energy-disturbed massifs. The technological and geomechanical parameters of operational blocks, laboratory and production experiments, physical modeling of metal extraction from ores of average linear size of a piece of blasted ore mass are substantiated. The theoretical generalization of the process of explosive destruction of rock ores is made, the results of which are laid down in the basis of the technology of breaking for high-quality preparation of ore for leaching in place of its occurrence. The combined method of uranium mining is recommended for use as the most effective. The existing methodology is analyzed and the definition of the parameters of drilling and blasting destruction of ores with a given quality of crushing for preparation for leaching of metal in place of its occurrence is substantiated. The results. On the basis of research and industrial tests at the Ingul Mine of the State Enterprise "SkhidGZK" of the Michurinsk deposit (Ukraine) of the development of the experimental unit 5–86, the technological operations of the formation of cut-off gaps and compensation spaces are recommended. This will ensure optimal loosening of stored ore under the condition of effective leaching (the loosening coefficient is within 1.15< Kr < 1.2), as well as structural stable parameters of the chambers: height - 20 m; width – 16 m; length - 24 m. It is shown that the most intensive infiltration leaching occurs in the size class of ore pieces - 100 + 0 mm. The specified PBV technology will allow to extract reserves of poor, substandard and off-balance, in terms of mineral content, ores and expand the available raw material base of the mining industry by 1.4-1.6 times, as well as ensure environmental safety of the combined development of strong poorly penetrated ores. Scientific novelty. It was established that the extraction of metal ξ, %, significantly depends on the average linear size of a piece of mined ore dsr and with high reliability according to the Fisher criterion (R2 = 0.97) is described by an aesthetic dependence of the type A distinctive feature of the proposed method of determining rock destruction parameters at a given quality of grinding of strong ores for leaching is finding the necessary explosion energy, taking into account the maximum energy consumption for crushing the rock. It has also been established that the ratio of the average linear size of a piece of crushed ore mass to the diameter of the borehole (ds'), required by the condition of maximum leaching of metal, is achieved by matching the level of energy of the explosion, which is transformed into a destroyed massif, with the kinetic energy of the pieces of rock that fly apart, is a logarithmic function of the specific consumption of explosives (qEV) for primary crushing according to the refined formula: ds'= – 0,553ln qEV + 2,1145. Practical significance. It is also recommended to organize hydrogeological monitoring of groundwater sampled through observation wells drilled in the bottom of the production block and to contacts with the ore body, as well as zones of fracture and hydrogeological rupture of rocks. On the basis of the received positive results of the research and implementation of technologies of PBV of metals from rock ores during the development of block 5-86, in accordance with the issued recommendations, scientific support was carried out during the development of blocks 5-84-86 and 5-88-90, as well as industrial and experimental block 1-75-79.