Sublevel stoping with applying artificial hardening stowing pillars for extraction of veins in complicated geotechnical conditions

Abstract

In the process of underground mining of deep levels rock pressure can appear in any form, creating a serious threat to the lives of miners, disrupting the normal course of mining works and reducing the efficiency of mining production. The solution of the problem of rock pressure control becomes very urgent for underground mines developing vein deposits at a depth of more than 250 m. The aim of the study is the development and justification of mining methods to provide safe and efficient mining of deposits in complicated mining and mechanical conditions. In this paper, the factors of redistribution and dangerous concentration of stresses in the mined ore mass were identified, the methods of rock mass management in complicated geotechnical conditions were studied, and their advantages and disadvantages were revealed. It was determined that the sublevel stoping with the combined use of existing methods of rock pressure control and applying selfpropelled mining machinery is currently one of the most promising method finding widening application scope. In the context of Zarmitan gold ore zone the options of technological schemes of the sublevel stoping method were considered, providing for a combination of different methods of rock pressure control, allowing to minimize the disadvantages of one method through using the advantages of other ones. We proposed sublevel stoping options with artificial polygonal pillars and with artificial columnar pillars, which allowed to reduce ore losses in inter-stope pillars, arch pillars, and secondary dilution. In addition, artificial pillars, taking compressive/tensile stresses, prevent their concentration and create safe conditions for extraction at adjacent and underlying levels.