Technology of Blasting of Strong Valuable Ores with Ring Borehole Pattern
Abstract
The ores of non-ferrous and precious metals, represented by hard rocks, has a peculiar feature, that is the effect of segregation, that is the tendency of ore minerals to break down into small size classes, which in the underground mining method accumulate in significant quantities on uneven surface of bottom layers and subsequently are lost. When mining valuable non-metallic materials, there is an acute problem of overgrinding, when fines do not meet the requirements for the quality of the final product. It is well known that the granulometric composition of the ore depends mainly on the technology and parameters of drilling and blasting operations. In underground mining of ore deposits, the main method of drilling and blasting is the borehole blasting with continuous construction charges with the ring pattern. The main drawbacks of the method are: uneven distribution of the explosive along the plane of the broken layer and the expenditure of a significant part of the blast energy of the charges of the continuous structure on the blasting effect, necessarily associated with over-grinding the ore. To solve these problems, the authors proposed a blasting technology, the essence of which lies in the fact that the uniform distribution of the energy concentration of explosives in the broken layer is ensured by the dispersion of charges by air gaps and a certain order of their placement in the ring plane. For the practical implementation of the technology, a method has been developed to form dispersed charges in deep boreholes that do not require a significant increase in labor costs and additional special means. A special technique has been created that allows defining the dispersion parameters, ensuring the sustained specific consumption of explosives over the entire plane of the broken layer. Experimental studies of the proposed technology in the natural conditions of an underground mine for the extraction of valuable granulated quartz were carried out. As a result, the possibility of a significant reduction in the specific consumption of explosives (by 42 %) has been established. At the same time, the yield of the commercial product increased by 10.7 % in total, and the yield of the fraction most favorable for further processing increased by 33.7 %.
References
- Grishin A.N., Matrenin V.A., Muchnik S.V. The method of forming dispersed borehole charges. Gornyi zhurnal. 2007. N 4, p. 55-57 (in Russian).
- Zharikov I.F. Energy-saving technologies for blasting in open pits. Vzryvnoe delo. 1998. N 91(48), p. 191-195 (in Russian).
- Kutuzov B.N., Belin V.A. Design and organization of blasting operations. Moscow: Gornaya kniga, 2012, p. 416 (in Russian).
- Leshchinskii A.V., Shevkun E.B. Dispersion of borehole charges. Khabarovsk: Izd-vo Tikhookean. gos. un-ta, 2009, p. 154 (in Russian).
- Lomonosov G.G., Turtygina N.A. The phenomenon of segregation of the ore mass and its impact on the formation of the quality of mining products. Gornyi informatsionno-analiticheskii byulleten'. 2014. N 6, p. 37-40 (in Russian).
- Test results of Canadian-made equipment at OJSC Mine Karalveem. Gornaya promyshlennost'. 2012. N 3 (103), p. 42-43 (in Russian).
- Sitnikov R.V. Hydromechanical cleaning of ore fines as an effective way to reduce ore losses. Vestnik ChitGU. 2010. N 2 (59), p. 18-22 (in Russian).
- Smirnov A.A., Rozhkov A.A. Investigation of the action of the explosion of the ring borehole pattern. Vzryvnoe delo. 2018. N 119-76, p. 118-128 (in Russian).
- Sokolov I.V., Smirnov A.A., Rozhkov A.A. Improving the efficiency of quartz mining using a flat system of dispersed charges. Izvestiya vuzov. Gornyi zhurnal. 2018. N 1, p. 56-65 (in Russian).
- Shalaev M.S., Paramonov G.P. On the issue of increasing the stability of the pit walls during contour blasting due to the use of gel explosives. Zapiski Gornogo instituta. 2009. Vol. 180, p. 217-220 (in Russian).
- Bhandari S. Engineering rock blasting operations. Rotterdam: Dalkema Publishers. 1997, p. 375.
- Vokhmin S.A., Kurchin G.S., Kirsanov A.K., Shigin A.O., Shigina A.A. Destruction of rock upon blasting of explosive agent. ARPN Journal of Engineering and Applied Sciences. 2017. Vol. 12, p. 3978-3986.
- Yue Z.W., Yang R.S., Chen G., Pan C.C., Meitan X. Dynamic test on siltcharge blasting of air-deck charge. Journal of the China Coal Society. 2011. Vol. 36(3), p. 398-402.
- Götze J., Möckel R. Quartz: Deposits, Mineralogy and Analytics. Berlin, Heidelberg: Springer. 2012, p.360.
- Jhanwar J.C. Theory and Practice of Air-Deck Blasting in Mines and Surface Excavations: A Review. Geotechnical and Geological Engineering. 2011. N 29, p. 651-663.
- Melnikov N.V., Marchenko L.N. Effective methods of application of explosive energy in mining and construction. In Twelfth Symposium on Dynamic Rock Mechanics. New York: AIME, 1971, p. 350-378.
- Müller A., Wanvik J.E., Ihlen P.M. Petrological and chemical characterization of high-purity quartz deposits with examples from Norway. In Quartz: Deposits, Mineralogy and Analytics. Berlin, Heidelberg: Springer. 2012, p. 71-118.
- Onederra I.A., Furtney J.K., Sellers E., Iverson S. Modelling blast induced damage from a fully coupled explosive charge. International Journal of Rock Mechanics and Mining Sciences. 2013. Vol. 58, p. 73-84.
- Sokolov I.V., Smirnov A.A., Antipin Yu.G., Baranovsky K.V., Rozhkov A.A. Optimal combination technology for high-grade quartz production based on modeling. Journal of Mining Science. 2016. Vol. 52. N 6, p. 1159-1167.
- Götze J., Pan Y., Müller A., Kotova E.L., Cerin D. Trace Element Compositions and Defect Structures of High-Purity Quartz from the Southern Ural Region, Russia. Minerals. 2017. Vol. 7, p. 189.
- Yang G.L., Yang R.S., Jiang L.L. Pressure distribution along borehole with axial air-deck charge blasting. Explosion and Shock Waves. 2012. N 32 (6), p. 653-657.