SUBSTANTIATION OF COUNTER BLASTING PARAMETERS IN DISTURBED MASSIVES OF SECONDARY CHAMBERS OF MINING SYSTEMS WITH FILLING
In the underground mining of copper pyrite deposits in the Urals by a floor-and-chamber mining system with gob filling, the issue of increasing the efficiency of self-propelled loading and delivery equipment at ore drawing is rather acute. The most negative factor in this case is a significant yield of oversized fractions during the production of explosive ore breaking, especially in second and third chambers. In compliance with growth of oversize fractions, tire wear is also significantly increasing as well as the cost of fuels and lubricants per ton of ore. In this paper, the main ways to reducing the oversize yield when mining secondary chambers based on various schemes of counter blasting are proposed and considered. As a result of the studies, the main technical and economic indicators of the considered schemes and substantiate counter blasting parameters - the distance between the working faces in the chamber, the angle of meeting of ore pieces and the line of least resistance.