Improvement of Blasting in Underground Development of Iron Ore Deposits of Siberia

摘要

Underground mining of iron ore deposits has been blessed with some advances in drilling and blasting are-a. Improvements affected virtually all constituents of the drilling and blasting system, including the engineering aspects of mining methods, reduction of the share of manual labor, and productivity enhancement in all processes of explosives fabrication and treatment, decreased borrowing of the workforce engaged in some other processes and the restricted admission to work with explosives, safer and healthier working environment It is known that in blasting practice of the mining industry underground mineral mining involves the application of borehole explosive charges, as well as blasthole and chamber (mine) charges set in chambers, stopes and mine holes. The largest share of rock mass blasting is currently provided by borehole explosive charges. The increase of mining depth and rock pressure is accompanied by a number of challenges, in particular, increased mine workings maintenance costs, particularly those for the lower drilling horizon in blocks under development; the number of shifted holes in the clusters of closely spaced boreholes, inefficiency of explosives in 105 mm diameter holes due to excessive compaction of a charge while loaded into rising hole clusters and overwetting of explosives in downholes. For mines of Mountain Shoria, Khakassia and the Urals a long-term production modernization program has been developed with the comprehensive coverage of the interaction of the essential components of the mining system, namely, rock mass, explosives and priming facilities, bulk blast action control system for geotechnologjes, machinery and equipment for mechanization of drilling and blasting processes. For example, for the last of the mentioned components the program envisages the application of standard mechanization patterns for underground conditions with the use of the available equipment and piece-by-piece installation of new and upgraded equipment for some processes aiming at complete mechanization of the entire chain of explosive preparation-from a truck to a firing face. Other components of the system cover the aspects of the theory of blast action control at different scales of rock mass disintegration by blast, present new results in various aspects of blasting operations and their effect on ore dressing. In general, the implementation of new ideas, scientific findings and engineering developments, which are in detail discussed in this paper, will enhance the efficiency of blasting processes in underground ore mines of Siberia.