Conditions of leaching non-ferrous metals from non-commercial reserves
The relevance. Traditional technologies of underground development of ore deposits are characterized by irretrievable losses of noncommercial reserves in the ground. The alternative to traditional technologies is the technology of metals leaching in underground conditions without extracting the earth's surface, allowing production of non-commercial reserves. The aim of the study is to prove technical and economic feasibility of leaching metals from sub-standard metal-bearing minerals while solving the problems related to this. Method of the study problem is based on the analysis of the results of the industrial-experimental leaching non-commercial ores, and commercial ones on rocky fields with the investigation of metal extraction in product solution due to the technological exposure of a reagent solution on metal ores. Results. The authors have proposed the algorithm of combining the alternative technologies of underground mining with the development of a compensation space for crushing non-commercial ores by excavating commercial ones; justified the principle of combining the technologies of mine treatment in traditional way and underground one with selective extraction of a part of commercial ores and formation of the compensation space required for fragmentation, where the non-commercial ore is removed with further leaching. The paper introduces the detailed understanding of the main processes of a new technology: blasting, draw, irrigation and intensification of leaching, and demonstrates the benefits of engaging non-commercial ores in manufacture by a new technology, including the utilization of mineral resources, strengthening the resource base, reducing the burden on the environment. Conclusions. Combination of technologies which allows extracting a part of commercial ores for factory processing and averaging the content of non-commercial ores to the acceptable value within leaching, meets the interests of resource and nature preservation and it is a promising direction of strengthening the raw material base of mining industry, revitalizing the economy and addressing the environmental and social problems.