Specific Features of Emulsion Explosives (EE) during the Development of Diamondiferous Deposits of Western Yakutia

摘要

The technology of emulsion explosives' application in ALROSA Co., Ltd. has been mastered today by two largest diamond-mining open cast mines: "Udachny" and "Yubileyny". "Dyno Nobel" company (USA) has acted as the supplier of EE application technology for both the deposits. The region of the deposits under mining is confined to the northern part of Middle-Siberian upland and represents poorly dissected gently ridged trappean plateau with absolute marks from 320 m (open pit "Udachny") to 620 m (open pit "Yubileyny"). The climate of the region is sharp continental with enduring winter period and short moderately warm summer. Absolute temperature maximum (up to+35°C) is recorded in July and absolute minimum (down to-65°C)-in January. Annual average is-11～-13°C. The depth of permafrost rocks (PFR) in the region of the deposits reaches 800 meters. The lowest temperatures of PFR zone -3.2～ -7.4°C at this are confined to subsurface part of the rock mass. The temperature of rocks at 200 m depth is -2.9～-3.0°C and at 500 m depth it is -1.1～-1.7°C. Seasonal thawing of rocks in August-September reaches the maximum value and constitutes 1.5～2.5 m. In winter period the temperature at the foot of the seasonal thawing layer descends to -12 ～ -17°C. Thus, negative temperatures prevail year-round in the exploded rock mass. During the process of mastering new technology for the purpose of providing security and required quality of rocks'breakage the works were performed according to the following trends: -revelation of dangerous factors (hazards) in the rock mass; -investigation of explosive characteristics of EE when applying nonporous ammonium nitrate (AN); -investigation of explosives (E) type effect on indications of man-caused damageability of diamonds; -determination of thermal regime of EE borehole charges; -optimization of EE borehole charges' construction. The article contains brief descriptions of performed according to engineering support works on EE application technology.