Justifying the parameters of dredging in various types of stopes and massive productive strata

Abstract

Introduction. Due to a wide variety of placer dredging conditions, traditional methods of dredging parameters calculation do not always take into account all aspects of productive strata mining. It is first of all true for deep placers operation and mining with side cuts. Research aim is to improve the methods of calculating dredging parameters and the capacity of pilesupported bucket chain dredgers. Methodology. Existing methods of calculating dredging parameters and dredgers capacity do not take into account the applied mining method, stope type, and upper stope cave-in conditions. The indicated factors greatly influence the parameters of productive strata excavation and washery refuse disposal. Taking these ISSN 0536-1028 «Известия вузов. Горный журнал», № 3, 2020 13 factors into account makes it possible to forecast the indicators of the pile-support dredgers more accurately. Results. Investigation of some aspects of dredging trenches and side cuts has made it possible to establish the dependence of dredger maneuvering angle in pit face and capacity on cutting depth when mining massive productive strata; spoil dumps parameters dependence on the type of stoping; the interrelation between the daily capacity and the width of the front bank under various vertical distribution of rock. The indicated dependences allow to determine dredging parameters and indicators for particular conditions. Summary. The proposed approach, which calculates dredging parameters when using side cuts and when mining deep placers with non-uniform thickness of sands, makes it possible to calculate the chips size, buckets filling ratio and sand fragmentation ratio in a more substantiated way; it makes it possible to more effectively manage the process of sand mining, thus increasing the capacity of dredges.