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Purpose. The research is aimed at substantiation of the effective method for mining thin slope ore bodies occurring in soft unstable host rocks by optimizing the breaking process, while determining the patterns of blast energy impact on the disturbed mass by explosive charges with controllable density, taking into account the geomechanical rock mass state. Methods. The research uses a comprehensive approach, including analysis of literature sources, practical experience of mining the slope ore bodies in difficult mining-geological conditions, modeling of the energy characteristics of blasts and wave action on the mass using software, as well as conducting experimental-industrial tests in the Akbakai mine. Findings. An innovative method for effective and safe ore mining from thin slope ore deposits in masses with weakened host rocks has been substantiated and developed. It implies the use of a new construction and location in the blast-holes of a charge consisting of mixed low-density explosives with widely controllable characteristics and with which the blast-holes are charged in two layers with different densities of explosives and detonated at different delay intervals. The optimum delay intervals have been determined, which improve the conditions for controlling the blast energy by changing the direction of the blast action vector towards the newly outcropped surfaces formed in the rock mass after the blasting the first stage charges. The main factors influencing the ore delivery range when mining thin slope ore bodies with blast delivery system have been revealed and methods for increasing this process efficiency are proposed. Originality. New parameters of drilling and blasting operations have been determined for the conditions of mining thin slope ore bodies of the Akbakai deposit: a rational charge construction with controllable blast characteristics has been developed; the optimum range of blast-hole charging density with mixed low-density explosives and delay intervals have been substantiated; a new exponential dependence of the ore delivery range on the specific blasting agent consumption and the angle of the ore body occurrence has been revealed. Practical implications. Practical significance is in increasing the efficiency of blast breaking of minerals, improving the quality of blast delivery of broken ore to loading sites while maintaining the host rock mass continuity and reducing the ore mass dilution, eliminating the formation of large-sized pieces that complicate the blast delivery of the broken ore. [ABSTRACT FROM AUTHOR]

Purpose is to select the optimal composition of the mixed low-density explosive (Es) applied in the form of blasthole charges which provide high efficiency of blasting operations while mining of thin ore deposits. The abovementioned becomes possible while studying features of the foamed polystyrene chemical decomposition and gasification; role of additional water components as well as catalyzator being sodium carboxymethyl cellulose; and analysis of explosive characteristics of the compositions. Methods. The research involved lab-based experiments to define application efficiency of the recommended low-density blasting agents through identification of the basic explosive characteristics of the model mixed Es. Findings. The optimal composition of the mixed low-density Es has been developed. It consists of ammonia nitrate, diesel fuel, granulated foamed polystyrene, water, and sodium carboxymethyl cellulose to be used to break thin ore bodies. Owing to it, the possibility has arisen to control over a wide range both detonation velocity and pressure of blasting fumes during the charge density increasing or decreasing. The main detonative characteristics of the proposed compositions of low-density Es have been determined helping perform explosive rock mass loading in terms of extremely low values of both energy and explosive characteristics. The developed composition of the mixed low-density Es makes it possible to control quantity of Es energy in a volume well unit by means of increase or decrease in the charge energy concentration depending upon the changes in the rock mass resistance; in such a way, efficient breakage of thin ore bodies is provided inclusive of less dilution indicators. Originality. For the first time, dependence of the relative efficiency of the mixed low-density Es upon the foamed polystyrene volume content has been identified as well as dependence of pressure of blasting fumes upon the charging density. Practical implications are the development of procedures for blasting operations while thin ore body mining. The procedures are based upon formulating of the optimal composition of low-density Es differing in its simplicity, safety, and efficiency; and helping reduce prime cost of the extracted mineral at the expense of the decreased degree of the ore dilution. An empiric formula to define specific consumption of the low-density Es has been proposed for Akbakay mine. [ABSTRACT FROM AUTHOR]

In this article, methods of reducing landslide phenomena and collapse of career of slopes, in the extraction of minerals with the open-pit mining approach are set out. The ways of uncovering upper argillaceous acclivities with the creation of buttresses made from rocky minerals are suggested. Also, technological frameworks of the establishment of acclivities of benches in primary resources, with preliminary conduct of the research on the deformation of the minerals from the drilling-andblasting activities are offered. On the basis of the dynamic processes of blasting and resistance of the massif to the breakage, there is a formula offered, for determining the rate of fracturing, and the methodology of calculation of the specific charge of the blasting substance, including and excluding the fracturing of the massif is substantiated. The technique of defining the parameters of buttresses, used in strengthening of the acclivities, piled with unstable argillaceous and friable minerals, is also suggested.