Justification of parameters and technology for safe extraction of gold ore reserves from pillars during underground mining

Aimed to replenish the resource base during mining of Vetrenskoe gold deposit, the geological exploration revealed promising and mineable reserves in several ore bodies on the lower horizons of the underground mine. Due to the increase in the mining depth, it was necessary to determine the stable design parameters of the sublevel mining system, namely, dimensions of the level and rib pillars. As a result, the sizes of the pillars were determined depending on the thickness and dip angle of the ore body and the application range of this technology was defined. For the mining conditions of a representative ore body, a version of the sublevel mining system with establishment of level and rib pillars was designed. Extraction of ore reserves from the pillars is carried out by their bulk caving to the bottom of stopes with ore drawing under caved rocks. The measures are proposed to reduce the loss of ore in the caved rock crests between haulage entries. Since there is practically no experience of bulk caving of pillars in the mine, the calculations of the boundaries of the hazardous zone of the shock wave impact were performed. The dependence of the excess pressure at the front of the air shock wave on the distance from the massive explosion site is determined. Taking into account the fact that mining of the deposit is carried out in the permafrost zone and with the open stoping system, the calculated value of the excess pressure at the front of the air shock wave without regard to local drags was chosen as a determining factor. In order to prevent accidents during massive blasting, all people are evacuated from the mine to ground surface to a distance of at least 50 m from the adit mouth.

Rozhkov A. A., Baranovsky K. V., Smirnov A. A., Solomein Yu. M. Justification of parameters and technology for safe extraction of gold ore reserves from pillars during underground mining. MIAB. Mining Inf. Anal. Bull. 2021;(5—1):41—54. [In Russ]. DOI: 10.25018/0236_1493_2021_51_0_41.

The research was carried out within the framework of State Task No. 07500581-19-00. Topic No. 0405-2019-0005.

Rozhkov A. A.¹, Cand. Sci. (Eng.), Senior Researcher at the Laboratory of Underground Geotechnology, geotech@igduran.ru;
Baranovsky K. V., Cand. Sci. (Eng.), Senior Researcher at the Laboratory of Underground Geotechnology
Smirnov A. A., Cand. Sci. (Eng.), Senior Researcher at the Laboratory of Underground Geotechnology
Solomein Yu. M., Researcher at the Laboratory of Underground Geotechnology
¹ Institute of Mining, Ural Branch, Russian Academy of Sciences, Ekaterinburg, Russia.

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