Survey of underground geotechnology for mining of inclined low thickness ore body

Abstract

The purpose of this work is to justify and selection of a safe and effective option of the technology for experimental block during the pilot development of the «Skalistoe» deposit. Based on the researches determined that the projected system for the development of sub-floor caving with the accepted parameters does not guarantee the completeness of the extraction of reserves and the efficiency of mining. Project indicators for ore extraction using the technology of sub-floor caving with face ore output are overstated and difficult to achieve in these mining and geological conditions (a combination of low width and insufficiently steep angle of incidence of the ore body); The projected scheme for the delivery and transportation of rock mass is characterized by a significant amount of excavation, increased costs for the transportation of ore and is impractical in conditions of low productivity of the mine. For low power and not enough steep angle of incidence of the field with a high content of useful component, the most suitable options are the chamber development system, the system of sub-floor caving and horizontal layers. Based on this, seven technically rational variants of development systems were constructed: five variants of a sub-floor-chamber development system with the subsequent collapse of the pillars and two variants of a horizontal layer system with a dry (rock) backfill. For the conditions of mining the «Skalistoe» deposit according to the results of economic and mathematical modeling, the optimal technology for profit attributed to 1 ton of redeemable balance of ore reserves is a variant of the technology of sub-floor-chamber excavation with dual chambers, mechanical production of ore with remote control load-andhaul machines and subsequent the collapse of pillars, as having the highest profit by decreasing volume of preparating works on the block by 34%, the cost of ore mining by 12%, losses and dilution of ore by 2 and 2,9 times, accordingly. In particular, the proposed scheme for the delivery and transportation of rock mass can reduce the volume of tunneling by 25% and the average transportation length by 10-15% compared with the projected scheme.