The economic efficiency of the enterprise and the length of its operation, the full utilization of mineral reserves and the total cost of operation depend on the selected depth and boundaries of opencast mining. In such conditions of the deposits' development it is necessary to evaluate the capabilities of the raw material base for the further development of the mining enterprise. The basis for determining of the border overburden ratio is on the condition that the price of manufactured marketable output of the designed enterprise should not exceed the price of the same marketable output in the world market. The realization of this condition is achieved analytically. This takes into account the impact of the rate of return on the final depth of the designed open pit. A new method of determining of the border overburden ratio is developed, which ensures the competitiveness of iron ore concentrate in the world market. The value of the border overburden ratio is developed for the Pershotravnevij open pit of the Northern mining and processing plant, depending on the situation of the iron-containing products' prices, which ensures the competitiveness of marketable iron-ore output in the domestic and world markets.

Further development of the open mining works on the domestic enterprises will be accompanied by the worsening of mining-geological conditions and declining of the quality of iron ore raw materials. In the same time, the accumulated mining wastes, that can make the technogenic deposits, pass into one of the important sources of the mineral raw materials. Taking into account this thing, the development and implementation of the modern technological circuits of the technogenic deposit development is an actual calling for mining industry, and determination and optimization of process conditions of the technogenic deposit development -is the scientific task of this publication. The obtained results of studies of the optimum step value of the ore chute transfer during the technogenic deposit development can be used by design organizations and mining enterprises for designing works. The obtained methodology and the proposed mathematical dependencies will reduce the cost of mining of the technogenic deposit due to the reasonable timely transfer of the open ore chute.

The article considers the determination of the final contours of the open pits. One of the problems of development of iron ore deposits at the present stage of development of opencast mining is described, which consists in the fact that in most open pits their working contours on the surface have reached final position. In these conditions, it is necessary to reevaluate the capabilities of the raw material base for further operation of mining enterprises. The analysis of scientific achievements in the decision of the final definition of the open pits` contours is executed. The well-known principle of determining the boundaries of opencast mining, the principle of which is to determine the boundaries based on a comparison of the allowable cost of ore production with the expected for the designed open pit. On the example of the open pits, which reflect the characteristic features of the development of steep-dipping deposits of Ukraine, the influence of current overburden ratio of the existing open pits on the economic overburden ratio, which serves as the main criterion in determining the boundaries of opencast mining for the designed open pits. A method for determining the boundaries of the open pits has been developed, which provides for the use of the economic overburden ratio of opening as a value not constant but variable over time, and one that depends on the change of current coefficients of opening in open pits-competitors. As a result, the theory in the field of determining the final contours of the open pits is improved. The new method differs from the known ones by taking into account the change in the economic overburden ratio over time, as well as determining the impact of technological indicators of open pits - competitors on the final depth of the designed open pit.

Introduction. Trends in developing Ukraine’s metallurgy in the context of using its mineral raw base indicate prospects for mining hematite quartzite deposits. Problem Statement. The problem of producing high-quality hematite ore concentrates is associated with the fact that aggregates of martite, goethite, marshallit quartz, and other low hard minerals can be easily reground while crushing and grinding. This results in increased content of fine particles (slimes), which decreases selectivity of separating ore and non-metallic minerals. One of the ways to solve this problem is gentle ore grinding Purpose. Developing a technology of dry and wet concentration for hematite quartzite from Kryvyi Rih Iron Ore Basin. Materials and Methods. While conducting the research, a set of methods are used including generalization of research data; chemical and mineral analysis of ore and concentration products prior to and after concentrating by magnetite and gravitation methods; mathematical modeling of processes; technological testing in laboratory and industrial conditions. Results. Magnetic and gravitation separation is used for hematite ore concentration. Sintering ore with Fe content of 55.1% and concentrates of 62.32-64.69% Fe have been produced from hematite ore. Iron extraction in marketable products makes up 73.6-80.49%. Conclusions. There have been developed technologies for dry and wet concentration for hematite quartzites of Kryvyi Rih Iron Ore Basin. For the first time, magnetic separation has been suggested to be used for hematite ore concentration. This has enabled producing concentrates with an iron content over 64.0%, decreasing ore grinding front by at least 40% as compared with the initial one, and reducing operation and capital expenses by over 30%.

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