Irkutsk National Research Technical University, Irkutsk, Russia

N. V. Murzin, Associate Professor, Candidate of Engineering Sciences, murzinnv@istu.edu
B. L. Talgamer, Doctor of Engineering Sciences, Professor

The current economic situation with rising gold prices promotes exploitation of both primary and placer ore deposits with a low content of a valuable component, or located in difficult mining and geological conditions, including deep placers. Dredging method, which ensures the lowest cost of production, is particularly relevant in such conditions. At the same time, the almost complete absence of dredge engineering in the country determines the need to use existing dredges, which are not always able to develop deep placers and thick productive strata. In this regard, it is necessary to find new technologies for the development of such placers with existing dredges. In this paper, an analysis of the existing methods for developing deep placers with medium-capacity dredges is carried out, their disadvantages are identified, on the basis of which, a method and a technology for preparing and dredging productive deposits exceeding the limits of the dredge face are proposed. Mining of deep placers composed of thick productive strata can efficiently be implemented used small dredges, with vertical division of a stratum into two layers, and with sequential extraction of the layers. Initial dredging of the lower layer of the maximal possible thickness for a dredge, with the preliminary re-handling of the upper productive layer to a temporary storage beyond the limits of the dredge swing allows reducing essentially the scope and complexity of the first working, and enables decreasing the mining-disturbed land area. During backward dredging of the upper part of the productive layer stored in the planned dumps of the first course from the temporary storage, it is possible to re-extract the dredge dump material which is mostly rich with the unmined valuable component.

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