Selection of environmentally safe open-pit technology for mining water-bearing deposits

Purpose. Substantiation of environmentally acceptable technologies for surface mining of water-bearing placer deposits, taking into account the parameters of mining systems elements and areas damaged during mining of mineral deposits. Findings. To conduct the research, we proposed to use index Δ whi...

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Дата:2017
Автори: Sobko, B., Drebenstedt, C., Lozhnikov, O.
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Опубліковано: УкрНДМІ НАН України, Інститут геотехнічної механіки НАН України 2017
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Цитувати:Selection of environmentally safe open-pit technology for mining water-bearing deposits / B. Sobko, C. Drebenstedt, O. Lozhnikov // Розробка родовищ: Зб. наук. пр. — 2017. — Т. 11, вип. 3. — С. 70-75. — Бібліогр.: 11 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
id nasplib_isofts_kiev_ua-123456789-145726
record_format dspace
spelling Sobko, B.
Drebenstedt, C.
Lozhnikov, O.
2019-01-27T20:25:43Z
2019-01-27T20:25:43Z
2017
Selection of environmentally safe open-pit technology for mining water-bearing deposits / B. Sobko, C. Drebenstedt, O. Lozhnikov // Розробка родовищ: Зб. наук. пр. — 2017. — Т. 11, вип. 3. — С. 70-75. — Бібліогр.: 11 назв. — англ.
2415-3435
DOI: https://doi.org/10.15407/mining11.03.070
https://nasplib.isofts.kiev.ua/handle/123456789/145726
622.271
Purpose. Substantiation of environmentally acceptable technologies for surface mining of water-bearing placer deposits, taking into account the parameters of mining systems elements and areas damaged during mining of mineral deposits. Findings. To conduct the research, we proposed to use index Δ which compares the actual position of inter-ramp angles and the inside dump angles with the maximum permitted values. The dependences of concentration degree KK and area of workings Str on index Δ allow to infer that the technological scheme with a rotary excavator is more environmentally sound than the scheme with hydraulic excavators. Application of the former technological scheme makes it possible to reduce the area of disturbed lands by 8%. In the proposed scheme of mining Motronivske placer deposit, the concentration degree KK reaches the maximum value 0.7, which corresponds to the minimum area of workings.
Мета. Обґрунтування екологічно безпечних технологій відкритої розробки обводнених розсипних родовищ з урахуванням параметрів елементів систем розробки і площ порушених земель при видобутку корисних копалин. Результати. Під час виконання досліджень запропоновано показник Δ, який оцінює існуюче положення кутів укосів робочого борту та внутрішнього відвалу з максимально допустимими значеннями. Залежність показників ступеня концентрації КК та площі гірничих виробок від показника Δ дозволяє визначити, що технологічна схема з застосуванням роторного екскаватора є більш екологічно безпечною, ніж схема з гідравлічними екскаваторами. Використання даної схеми дозволяє зменшити площу порушених земель відкритими роботами на 8%. При цій технологічній схемі розробки Мотронівського родовища ступінь концентрації КК досягає максимального значення 0.7, що відповідає мінімальній площі гірничих виробок.
Цель. Обоснование экологически приемлемых технологий открытой разработки обводненных россыпных месторождений с учетом параметров элементов систем разработки и площадей земель, нарушаемых при добыче полезного ископаемого. Результаты. При выполнении исследований предложен показатель Δ, который сравнивает существующее положение углов откосов рабочего борта и внутреннего отвала с максимально допустимыми значениями. Зависимость показателей степени концентрации KK и площади горных выработок Str от индекса Δ позволяет определить, что технологическая схема с применением роторного экскаватора более экологически безопасна, чем схема с гидравлическими экскаваторами. Применение данной схемы позволяет уменьшить площадь нарушенных земель открытыми работами на 8%. При этой технологической схеме разработки Мотроновского месторождения степень концентрации KK достигает максимального значения 0.7, что соответствует минимальной площади горных выработок.
The present research became possible due to initial preparation of application form for the grant of Volkswagen Stiftung in 2016. We express our sincere gratitude to Motronivske MPP for supplying our research with information about deposits geology, hydrogeology and mining technology.
en
УкрНДМІ НАН України, Інститут геотехнічної механіки НАН України
Розробка родовищ
Selection of environmentally safe open-pit technology for mining water-bearing deposits
Вибір екологічно безпечної технології відкритої розробки обводнених родовищ
Выбор экологически безопасной технологии открытой разработки обводненных месторождений
Article
published earlier
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
title Selection of environmentally safe open-pit technology for mining water-bearing deposits
spellingShingle Selection of environmentally safe open-pit technology for mining water-bearing deposits
Sobko, B.
Drebenstedt, C.
Lozhnikov, O.
title_short Selection of environmentally safe open-pit technology for mining water-bearing deposits
title_full Selection of environmentally safe open-pit technology for mining water-bearing deposits
title_fullStr Selection of environmentally safe open-pit technology for mining water-bearing deposits
title_full_unstemmed Selection of environmentally safe open-pit technology for mining water-bearing deposits
title_sort selection of environmentally safe open-pit technology for mining water-bearing deposits
author Sobko, B.
Drebenstedt, C.
Lozhnikov, O.
author_facet Sobko, B.
Drebenstedt, C.
Lozhnikov, O.
publishDate 2017
language English
container_title Розробка родовищ
publisher УкрНДМІ НАН України, Інститут геотехнічної механіки НАН України
format Article
title_alt Вибір екологічно безпечної технології відкритої розробки обводнених родовищ
Выбор экологически безопасной технологии открытой разработки обводненных месторождений
description Purpose. Substantiation of environmentally acceptable technologies for surface mining of water-bearing placer deposits, taking into account the parameters of mining systems elements and areas damaged during mining of mineral deposits. Findings. To conduct the research, we proposed to use index Δ which compares the actual position of inter-ramp angles and the inside dump angles with the maximum permitted values. The dependences of concentration degree KK and area of workings Str on index Δ allow to infer that the technological scheme with a rotary excavator is more environmentally sound than the scheme with hydraulic excavators. Application of the former technological scheme makes it possible to reduce the area of disturbed lands by 8%. In the proposed scheme of mining Motronivske placer deposit, the concentration degree KK reaches the maximum value 0.7, which corresponds to the minimum area of workings. Мета. Обґрунтування екологічно безпечних технологій відкритої розробки обводнених розсипних родовищ з урахуванням параметрів елементів систем розробки і площ порушених земель при видобутку корисних копалин. Результати. Під час виконання досліджень запропоновано показник Δ, який оцінює існуюче положення кутів укосів робочого борту та внутрішнього відвалу з максимально допустимими значеннями. Залежність показників ступеня концентрації КК та площі гірничих виробок від показника Δ дозволяє визначити, що технологічна схема з застосуванням роторного екскаватора є більш екологічно безпечною, ніж схема з гідравлічними екскаваторами. Використання даної схеми дозволяє зменшити площу порушених земель відкритими роботами на 8%. При цій технологічній схемі розробки Мотронівського родовища ступінь концентрації КК досягає максимального значення 0.7, що відповідає мінімальній площі гірничих виробок. Цель. Обоснование экологически приемлемых технологий открытой разработки обводненных россыпных месторождений с учетом параметров элементов систем разработки и площадей земель, нарушаемых при добыче полезного ископаемого. Результаты. При выполнении исследований предложен показатель Δ, который сравнивает существующее положение углов откосов рабочего борта и внутреннего отвала с максимально допустимыми значениями. Зависимость показателей степени концентрации KK и площади горных выработок Str от индекса Δ позволяет определить, что технологическая схема с применением роторного экскаватора более экологически безопасна, чем схема с гидравлическими экскаваторами. Применение данной схемы позволяет уменьшить площадь нарушенных земель открытыми работами на 8%. При этой технологической схеме разработки Мотроновского месторождения степень концентрации KK достигает максимального значения 0.7, что соответствует минимальной площади горных выработок.
issn 2415-3435
url https://nasplib.isofts.kiev.ua/handle/123456789/145726
citation_txt Selection of environmentally safe open-pit technology for mining water-bearing deposits / B. Sobko, C. Drebenstedt, O. Lozhnikov // Розробка родовищ: Зб. наук. пр. — 2017. — Т. 11, вип. 3. — С. 70-75. — Бібліогр.: 11 назв. — англ.
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fulltext Founded in 1900 National Mining University Mining of Mineral Deposits ISSN 2415-3443 (Online) | ISSN 2415-3435 (Print) Journal homepage http://mining.in.ua Volume 11 (2017), Issue 3, pp. 70-75 70 UDC 622.271 https://doi.org/10.15407/mining11.03.070 SELECTION OF ENVIRONMENTALLY SAFE OPEN-PIT TECHNOLOGY FOR MINING WATER-BEARING DEPOSITS B. Sobko1, C. Drebenstedt2, O. Lozhnikov3* 1Motronivske Mining Processing Plant, Vilnohirsk, Ukraine 2Institute of Surface Mining and Special Structure, TU Bergakademie Freiberg, Freiberg, Germany 3Surface Mining Department, National Mining University, Dnipro, Ukraine *Corresponding author: e-mail oleksii.lozhnikov@gmail.com, tel. +380681770095, fax: +380562470884 ВИБІР ЕКОЛОГІЧНО БЕЗПЕЧНОЇ ТЕХНОЛОГІЇ ВІДКРИТОЇ РОЗРОБКИ ОБВОДНЕНИХ РОДОВИЩ Б. Собко1, К. Дребенштедт2, О. Ложніков3* 1Мотронівський гірничо-збагачувальний комбінат, Вільногірськ, Україна 2Кафедра відкритої розробки та спеціального будівництва, ТУ “Фрайберзька гірнича академія”, Фрайберг, Німеччина 3Кафедра відкритих гірничих робіт, Національний гірничий університет, Дніпро, Україна *Відповідальний автор: e-mail oleksii.lozhnikov@gmail.com, тел. +380681770095, факс: +380562470884 ABSTRACT Purpose. Substantiation of environmentally acceptable technologies for surface mining of water-bearing placer deposits, taking into account the parameters of mining systems elements and areas damaged during mining of mineral deposits. Methods. Selection of the most environmentally safe technology of surface mining is carried out with the help of technical analytical method by way of establishing parameters of mine workings and determining the instant area of workings for each technological scheme. Findings. To conduct the research, we proposed to use index Δ which compares the actual position of inter-ramp an- gles and the inside dump angles with the maximum permitted values. The dependences of concentration degree KK and area of workings Str on index Δ allow to infer that the technological scheme with a rotary excavator is more environ- mentally sound than the scheme with hydraulic excavators. Application of the former technological scheme makes it possible to reduce the area of disturbed lands by 8%. In the proposed scheme of mining Motronivske placer deposit, the concentration degree KK reaches the maximum value 0.7, which corresponds to the minimum area of workings. Originality. The most environmentally efficient technological scheme of surface mining deposits is the scheme with the highest mining concentration factor. Practical implications. The results of the conducted research are of considerable practical value for the companies engaged in mining horizontal water-bearing deposits, which leads to disturbance of large land areas. In selecting a rational technological scheme for the surface mining of mineral deposits, it is proposed to consider not only econom- ic indicators, but also the possibility of the disturbed land areas reduction. Keywords: surface mining, mining technology, environmentally safe technology, water-bearing deposit, dredge 1. INTRODUCTION A considerable amount of mineral resources is con- centrated in deposits located in water-saturated soils. However, from year to year mining conditions become more difficult and environmental requirements get strong- er. Therefore, mining companies should pay more atten- tion to all economic, environmental, social, and legislative aspects of mining (Drebenstedt & Schmieder, 2005). There are many factors affecting mining methods due to which the procedure of making a decision about tech- nology to use is rather difficult (Gumenik, Lozhnikov, & Panasenko, 2013). These researches are aimed at the selec- tion of a surface mining method in terms of environmental aspects for the case when mineral deposits are located in water-saturated soils. The choice of available mining tech- nologies is based on the environmental impact, as well as economic and social aspects. Its implementation will ena- ble to improve decision-making mechanism, providing the best solutions for a mining region. Nowadays the problem of mining technology in wa- ter-saturated deposits in Ukraine is related to titanium ores exploration. The total reserves and resources of B. Sobko, C. Drebenstedt, O. Lozhnikov. (2017). Mining of Mineral Deposits, 11(3), 70-75 71 titanium ores exceed the world’s reserves of ilmenite. More than 40 deposits of titanium-zirconium ores were discovered in Ukraine, including the unique Malyshevske deposit. Up to 20 deposits of ilmenite and complex ores have been explored in the Volyn Region. They are con- fined to the northwestern part of Ukrainian crystalline shield within the Volodar-Volyn rocks massif. The Motronivske-Annovske placer deposit (MAP) is the part of Malyshevske deposit with huge mineral re- sources and significant advantages of geological and technological parameters in comparison with other il- menite deposits – it concerns particularly the thickness of the ore deposit in terms of proven reserves and ore min- erals grain size. The main feature of MAP is the fact that the ore seam is located below the groundwater level in the Neogene aquifer. Therefore, in conditions of placer deposit, implementation of technological schemes that are used on actual pits of Vilnohirsk mining processing plant (MPP) is complicated by the current ore properties and water-bearing rocks. It should be noted that hydrogeological conditions of the watered part of the Motronivske deposit are not fully studied. In this regard, all calculations of water in the future pit and the proposed drainage systems previ- ously carried out by various organizations were not well-grounded. The conducted research departs from the main meth- odological principles of the theory and practice of depos- its surface mining, taking into account the water- saturated rocks, as reflected in the scientific works of G. Nurok, M. Abzalov, J. Jansen, B. Weinrib and others (Weinrib, 2015; Abzalov, 2016; Jansen, 2016). Having analyzed mining methods of placer and wa- ter-bearing deposits described in these scientific works, we came to the conclusion that underwater ore mining is rather widely implemented in mining industry while the mechanical mining of overburden rocks does not affect underwater technology of ore mining. At the same time, currently there are no specific rec- ommendations for the use of hydro mechanization facili- ties for exploration of water-bearing deposits of titanium- zirconium ores characterized by specific water saturation and low water level. During the underwater mining, when ore is lying below the aquifer, it is necessary to study in detail how hydrogeological conditions change at different stages of the deposit development which is related to the problem of water-bearing deposits mining impact on the environment. That is why those pits should also be the subject of thorough research. The topicality of this problem arises from the necessi- ty to achieve cost efficiency of the titanium deposits development, given mining industry produces an essen- tial influence on GDP in Ukraine. However, the profit from the water-bearing deposit development should not be the only factor to consider when selecting a techno- logical mining scheme. The second criterion is to choose the environmental indicator of the technological scheme of placer deposit development, which takes into account the impact of mining on the environment. In this concern, it is important to use the experience of mining industry in Germany that is established as a leader in the safety and environmental standards worldwide. 2. THE MAIN PART OF THE ARTICLE In the process of selecting a mining technological scheme in terms of environmental evaluation of water- bearing deposits, the objective will be achieved by solv- ing the following tasks: determination of mining technol- ogies suitable for the development of water-saturated soils which include mechanical and hydromechanical methods of mining; determination of mechanical and hydromechanical mining methods efficiency by the CAPEX and OPEX; selection of theoretical methods for determination of technological, hydrogeological, and environmental parameters for conducting environmental and economical evaluation of mining in water-saturated soils; development of a comparative method integrating factors associated with the most rational mining scheme with minimum negative impact on the environment and maximum feasibility of mining; comparison of economic and environmental efficiency of the existing technologi- cal schemes of water-bearing deposits mining. Estimation of environmental risks and lands damage while mining water-saturated soils will be done via devel- opment of a method for the complex analysis of mining influence on the qualitative characteristics of groundwa- ter, stability of overall slope angles, areas of lands dam- aged by surface mining taking into account mining and geological conditions, as well as mining technology (Golovach & Volovik, 2008). The choice of the environmentally friendly mining method for deposits in water-saturated soils must be based on: hydrogeological evaluation of the deposit, stability of the overall pit and dump slopes, the area of land disturbed by workings, the possibility of storing overburden rocks in the gob, using of modern mining equipment, etc. We compared several schemes of mining deposits in water-saturated soils with available mechanical and hy- dromechanical mining (dredging) equipment. The as- sessment of environmentally-friendly mining machinery takes into account environmental effects, econom- ic/commercial and social aspects. These aspects are closely interrelated, as the lower environmental impact, the cleaner and healthier the workplace, and the fewer complaints from neighbors (Elsayed, 2013). As of today, there is no method for environmental evaluation of schemes for mining deposits in water- saturated soils. For the first time ever, the water-saturated soils will be considered as the main object for conducting complex technological, environmental, economic, and social assessment of mining (Pivniak, Gumenik, Drebenshtedt, & Panasenko, 2011). Implementation of the research results will allow to develop the choice method, which provides rational solutions in mining technology on the basis of input-output data analysis of the obtained models, taking into account mining and hydrogeological conditions of the deposit. During the research we estimated ecological efficien- cy of two most common titanium-zirconium ores mining technologies in water-saturated soils. Such water-bearing deposits can be mined by well-known methods: using mechanical with dewatering wells (dragline) and trucks haulage or hydromechanical mining equipment (dredge) with hydraulic haulage (Fig. 1). B. Sobko, C. Drebenstedt, O. Lozhnikov. (2017). Mining of Mineral Deposits, 11(3), 70-75 72 (а) (b) Figure 1. Schemes of mining in water-saturated soils: (a) mechanical mining method; (b) hydromechani- cal (combined) mining method; 1, 2 – overburden rocks; 3 – rocks with aquifer; 4 – mineral deposit; 5 – aquifer; 6, 7 – inpit dumps; 8 – rotary excavator; 9 – dragline; 10 – pumping well; 11 – dredge Each of them has its own advantages and disad- vantages in terms of economic and environmental im- pacts, so while choosing between two mining schemes it is necessary to conduct a detailed analysis. To justify the mining schemes (Fig. 1) and technolo- gies of water-bearing deposits mining using hydrome- chanical mining method, technological parameters of the following operations were determined: – working of the dry part of the soil massif by means of mechanical method; – working of the water-bearing part of the soil massif by means of hydromechanical method; – mining of mineral resources by means of hydrome- chanical method; – dumping of waste and clay slimes into the tailing pond; – dumping of sandy waste into the working; – formation of dumps in the working. For the purpose of the research we have used the fol- lowing equipment: suction dredges, bucket dredges, and other floating or land mounted mining machinery. The obtained results and calculation of capital and exploita- tion costs formed the basis for working out recommenda- tions on the use of hydromechanical mining method. Mining technology is justified by the results of study- ing geotechnical conditions for the case of the traditional opencast scheme of mining water-bearing deposits. On the basis of the data obtained, the influence of water on the opencast bench stability as well as the available method of quarry drainage can be estimated. Mining technology analysis is used as the basic com- ponent of the method for environmental evaluation of mining in water-saturated soils. This component will enable to conduct further environmental impact analysis (working parameters, surface land disturbance, etc.), and to establish economic indicators of mining (productivity, energy consumption, costs, etc.). Changes in qualitative characteristics of water body during mining are estimated on the basis of simulating water inflow, taking into account characteristics of the deposit (mining and hydrogeological conditions, for- mation flow characteristics, chemical content of soils, etc.) and mining technology (Sobko, Lozhnikov, Haidin, & Laznikov, 2016). Changes in surface and ground water conditions can influence the climate, deformation of the surface which sustains vitality of vegetation, yield per- formance, biodiversity. The assessment of an environmentally-friendly mining technique should take into account not only environmental effects, but also economic/commercial and social aspects. It should be also considered to what degree minimiza- tion takes into account social requirements to costs and environmental aspects, because an environmentally- friendly and cost-effective technique should be socially acceptable as well. Environmental, economic/commercial and social aspects are closely interrelated, because the lower the environmental impact, the cleaner and healthier the workplace, and the fewer complaints from the neigh- borhood. That is why cost efficiency is not the only crite- ria for surface mining. Evaluating environmental efficiency of technology for mining water-bearing deposits according to the listed crite- ria is a complex process and requires a large number of theoretical studies. However, it is irrefutable that the volume and extent of pollution caused by gobs are directly propor- tional to the area of workings or active area of the quarry. The preliminary research made it clear that mining of deposits in water-saturated soils implementing technological scheme based on the mechanical method of mineral extrac- tion is not economically feasible. In addition to significant pit drainage costs, operating costs for minerals haulage are several times higher than in the case of hydraulic haulage. The present research showed that net present value (NPV) for the technological scheme (Fig. 1b) with hy- dromechanical mining method is 4.02 times lower than NPV in the scheme where ore and lower rocks are exca- vated by draglines and trucks. We have conducted not only comparative technical and economic assessment of the technological schemes of mining operations efficiency but also calculated gen- eral discounted economic technical and economic indica- tors during the development of MAP. Comparison of the capital investments efficiency indicators in the process of selecting implementation technological scheme showed that schemes with hydromechanical method are the most effective for mining on the ore bench. To specify and determine a more efficient scheme for the development of the water-bearing deposit, the exist- ent scheme with the use of hydraulic excavators on over- burden benches was also considered. The advantage of this scheme is that the use of hydraulic excavators can significantly reduce capital costs, but the use of truck haulage significantly increases operating costs. There- fore, it is necessary to carry out additional technical and economic studies to select the most effective scheme. Two technological schemes for mining deposits in water-saturated soils were suggested. The first scheme is presented in Figure 1b, and the second scheme with hy- dromechanization method on ore bench and mechanical mining on overburden benches with hydraulic excavators is shown in Figure 2. B. Sobko, C. Drebenstedt, O. Lozhnikov. (2017). Mining of Mineral Deposits, 11(3), 70-75 73 Figure 2. Scheme of mining in water-saturated soils by hydro- mechanical (combined) mining method: 1 – overbur- den rocks are mined by the shovel excavator; 2 – overburden rocks with aquifer are mined by the dredge; 3 – mineral deposit; 4 – aquifer; 5, 6 – inpit dumps; 7 – hydraulic excavators; 8 – dredge The conducted research testified that operating costs for the scheme with rotary excavators and the dredge are 1.63 times lower than for the scheme with hydraulic excavators and the dredge. After determination of the two most cost-effective technological schemes for the development of Mo- tronivske pit, we analyzed the environmental effect pro- duced by each of them, taking into account the disturb- ance of the land area caused by mining operations. Hence, while studying the impact of mining on the ecological condition of the mining region, it is proposed to determine the total mining working area for each min- ing system with different equipment. For the purpose of comparing the first (Fig. 1b) and second schemes (Fig. 2) of mining in Motronivske pit according to the criterion of the quarry area, it is proposed to use the concentration degree index of mining opera- tions (Sobko, 2008). This indicator represents the ratio of the minimum permissible area of the pit working space according to the index of maximum overall slope stability to the actual, and comparing the area of pit working. This criterion has the advantage of taking into ac- count the main parameters of the pit working area. Change of those parameters influences the technological indicators, which are directly related to the economic evaluation of technological solutions. Concentration degree index is calculated by the formula: F МA К S SК = , (1) where: SMA – minimum permissible area of the pit workings at the condition of the slope stability, ha; SF – actual area of pit workings under condition of pit slope stability, ha. In order to calculate this index, it is necessary to es- tablish the minimum permissible angles of safety, dumps and pit slopes for the rotary and hydraulic excavator based technological schemes of mining. SMA area is calculated according to the formula: ( ) ( )( )аctgctghНLS РMA ++⋅+⋅= βϕ , ha, (2) where: LP – length of the working trench on the surface, m; Н – thickness of overburden rocks, m; h – thickness of the mineral deposit, m; φ – overall pit slope angle, degrees; β – overall slope angle of the inner dump, degrees; a – width of the pit floor, m. SF area is calculated according to the formula: ( ) ( )( )аctgctghНLS SSFF ++⋅+⋅= βϕ , ha, (3) where: LF – minimum permissible length of the working trench on the surface, m; φS – maximum steady overall pit slope angle, degrees; βS – maximum steady overall dump slope angle, degrees. The overall inter-ramp angle of the first and second schemes is calculated by the formula:   ++ += = == n i n i iР n i iPii P WctgHctgh hHarctg 1 11 γα ϕ , degrees, (4) where: n – number of benches; i – serial number of a bench; HP – height of the overburden bench, m; h – thickness of mineral deposit, m; α – inter-ramp angle, degrees; γ – dump slope angle, degrees; WP – road and ramp width, m. The overall slope angle of the internal dump for each technological scheme is calculated according to the fol- lowing formula: 32 1 ВВ n i iВ РВ WWctgH КHarctg i + + ⋅= = β β , degrees, (5) where: n – number of benches in the dumps; i – serial number of the dump; НВ – height of the dump, m; KP – coefficient of overlying rocks loosening; β – dump bench slope angle, degrees; WB – width of the dump bench working area, m. According to the results of the present research, it was determined that the maximum stable overall inter- ramp angle in conditions of Motronivske pit is 31.36° and overall dump slope angle – 18.37°. For the first technological scheme with the rotary ex- cavator on overburden benches, the overall slope angle of the pit working is 16.0° and for the dump – 14.8°. For the second scheme with hydraulic excavator on the overbur- den benches, the overall pit slope angle is 13.5° and the dump slope angle – 15.0°. In order to evaluate the considered technological schemes, it was proposed to use index Δ which compares the existent overall slopes of the pit working and internal dump with the maximum permissible angles. Those an- gles were determined by calculating concentration degree index of mining operations: ( ) ( )βϕβϕΔ +−+= SS . (6) Figure 3 shows the research results related to deter- mination of the dependence of the concentration degree index KK and the area of mining working Str on the index Δ for the two technological schemes. B. Sobko, C. Drebenstedt, O. Lozhnikov. (2017). Mining of Mineral Deposits, 11(3), 70-75 74 Figure 3. Dependence of the concentration degree index KK and the area of mining working Str on the index Δ for hydromechanization method for ore mining: Sc. 1 – mechanical method with rotary excavator on overburden benches; Sc. 2 – mechanical method with hydraulic excavator on overburden benches Analysis of the present research results (Fig. 3) shows that the first technological scheme of mining is the most effective for implementation in Motronivsky placer de- posit. If this scheme is applied, the concentration degree index KK achieves a maximum value 0.7, which corre- sponds to 57 hectares of mining workings. At the same time the second technological scheme has a concentra- tion degree index 0.64, while the area of mining working is 62 hectares. 3. CONCLUSIONS The study confirms that the technological scheme that includes mechanical method with rotary excavator for overburden rocks and hydromechanical method for ore excavation is 1.63 times more cost-effective and envi- ronmentally safe than the scheme with hydraulic excava- tor on overburden benches. Its implementation allows to increase the concentration degree index KK by 9%, as compared to the second technological scheme. The prac- tice of using the first scheme allows to reduce the area of disturbed lands by 8%. In conclusion, we should add that at the moment, it is not possible to estimate all effects of soil excavation or mining with available machinery. That is why, it is nec- essary to define at least peripheral conditions for the assessment. Thus, the present research considered only production costs and the environmental effects of water- bearing deposits mining as specific assessment criteria for the time being. ACKNOWLEDGEMENTS The present research became possible due to initial preparation of application form for the grant of Volkswagen Stiftung in 2016. We express our sincere gratitude to Motronivske MPP for supplying our research with information about deposits geology, hydrogeology and mining technology. REFERENCES Abzalov, M. (2016). Mineral Sands. Applied Mining Geology, 427-433. https://doi.org/10.1007/978-3-319-39264-6_35 Drebenstedt, C., & Schmieder, P. (2005) Environmental Evalu- ation of Mining Systems. In Sustainable Development Indi- cators in the Minerals Industry (pp. 973-992). Essen: Ver- lag Glückauf GmbH. Golovach, N. A., & Volovik, V.P. (2008). Substantiation of the Parameters of Mining in Irshansky Open Pits MPP in Ac- count with Environmental Requirements. In Forum Hirnykiv (pp. 158-163). Dnipropetrovsk: Natsionalnyi Hirnychyi Universytet. Gumenik, I., Lozhnikov, A., & Maevskiy, A. (2012). Methodo- logical Principles of Negative Opencast Mining Influence Increasing due to Steady Development. Geomechanical Processes During Underground Mining, 45-49. https://doi.org/10.1201/b13157-9 Gumenik, I.L., Lozhnikov, O.V., & Panasenko, A.I. (2013). Deliberate Dumping Technology for Mining Reclamation Effectiveness Improvement. Naukovyi Visnyk Natsional- noho Hirnychoho Universytetu, (5), 48-53. Elsayed, E. (2013). Environmental Balance of Technical Op- tions in Mining. Ph.D. Technische Universität Bergakade- mie Freiberg. Jansen, J.G.J. (2016). Dredge Mining Sequence Optimization: Maximizing the Net Present Value (NPV). Ph.D. Delft Uni- versity of Technology. Pivniak, H.H., Gumenik, I.L., Drebenshtedt, C., & Panasen- ko, A.I. (2011). Scientific Bases of Rational Nature Man- agement at the Deposits Open Cast Mining. Dniprope- trovsk: Natsionalnyi Hirnychyi Universytet. Sobko, B.E. (2008). Improvement of the Surface Mining Tech- nology of Placer Titanium-Zirconium Ores. Dniprope- trovsk: National Mining University. Sobko, B.Yu., Lozhnikov, O.V., Haidin, A.M., & Laznikov, O.M. (2016). Substantiation of Rational Mining Method at the Motronivskyi Titanium-Zirconium Ore Deposit Explora- tion. Naukovyi Visnyk Natsionalnoho Hirnychoho Univer- sytetu, (6), 41-48. Weinrib, B. (2015). Remote-Operated Submersible Gold Dredge. Sea Technology, 56(9), 21-23. ABSTRACT (IN UKRAINIAN) Мета. Обґрунтування екологічно безпечних технологій відкритої розробки обводнених розсипних родовищ з урахуванням параметрів елементів систем розробки і площ порушених земель при видобутку корисних копалин. Методика. Вибір найбільш екологічно безпечної технології відкритих гірничих робіт виконується методом техніко-аналітичного аналізу шляхом встановлення величини параметрів гірничих виробок і визначення безпо- середньої площі робочих траншей для кожної з технологічних схем. Результати. Під час виконання досліджень запропоновано показник Δ, який оцінює існуюче положення ку- тів укосів робочого борту та внутрішнього відвалу з максимально допустимими значеннями. Залежність показ- ників ступеня концентрації КК та площі гірничих виробок від показника Δ дозволяє визначити, що технологічна схема з застосуванням роторного екскаватора є більш екологічно безпечною, ніж схема з гідравлічними екска- ваторами. Використання даної схеми дозволяє зменшити площу порушених земель відкритими роботами на B. Sobko, C. Drebenstedt, O. Lozhnikov. (2017). Mining of Mineral Deposits, 11(3), 70-75 75 8%. При цій технологічній схемі розробки Мотронівського родовища ступінь концентрації КК досягає максима- льного значення 0.7, що відповідає мінімальній площі гірничих виробок. Наукова новизна. Найбільш екологічно ефективною технологічною схемою відкритої розробки родовища є схема із застосуванням гідромеханічного способу розробки корисної копалини та з найбільшим коефіцієнтом концентрації гірничих робіт. Практична значимість. Результати виконаних досліджень мають важливе практичне значення для підпри- ємств, які виконують розробку горизонтальних обводнених родовищ з порушенням великих площ землі. При виборі раціональної технологічної схеми розробки корисної копалини відкритим способом пропонується розрахо- вувати не тільки економічні показники, а також враховувати можливість скорочення площ порушених земель. Ключові слова: відкриті гірничі роботи, технологія видобування, екологічно-безпечні технології, обводнені родовища, драга ABSTRACT (IN RUSSIAN) Цель. Обоснование экологически приемлемых технологий открытой разработки обводненных россыпных месторождений с учетом параметров элементов систем разработки и площадей земель, нарушаемых при добы- че полезного ископаемого. Методика. Выбор наиболее экологически безопасной технологии открытых горных работ выполняется с использованием метода технико-аналитического анализа путем установления параметров горных выработок и определения непосредственной площади горных выработок для каждой из технологических схем. Результаты. При выполнении исследований предложен показатель Δ, который сравнивает существующее положение углов откосов рабочего борта и внутреннего отвала с максимально допустимыми значениями. Зави- симость показателей степени концентрации KK и площади горных выработок Str от индекса Δ позволяет опре- делить, что технологическая схема с применением роторного экскаватора более экологически безопасна, чем схема с гидравлическими экскаваторами. Применение данной схемы позволяет уменьшить площадь нарушен- ных земель открытыми работами на 8%. При этой технологической схеме разработки Мотроновского место- рождения степень концентрации KK достигает максимального значения 0.7, что соответствует минимальной площади горных выработок. Научная новизна. Наиболее экологически эффективной технологической схемой открытой разработки об- водненного месторождения является схема с применением гидромеханического способа разработки и наиболь- шим коэффициентом концентрации горных работ. Практическая значимость. Результаты выполненных исследований имеют важное практическое значение для предприятий, выполняющих разработку горизонтальных обводненных месторождений с нарушением больших площадей земель. При выборе рациональной технологической схемы разработки полезного ископае- мого открытым способом предлагается рассчитывать не только экономические показатели разработки, а также учитывать возможности сокращения площадей нарушенных земель. Ключевые слова: открытые горные работы, технология добычи, экологически безопасные технологии, обводненное месторождение, драга ARTICLE INFO Received: 14 August 2017 Accepted: 15 September 2017 Available online: 30 September 2017 ABOUT AUTHORS Borys Sobko, Doctor of Technical Sciences, Chief Process Engineer of the Motronivske Mining Processing Plant, 30a Molodizhna St, 3, 51700, Vilnohirsk, Ukraine. E-mail: sobko@maugok.com Carsten Drebenstedt, Dortor-Engineer, Professor of the Institute of Surface Mining and Special Structure, TU Bergakademie Freiberg, 1A Gustav-Zeuner Straße St, 09599, Freiberg, Germany. E-mail: Carsten.Drebenstedt@mabb.tu-freiberg.de Oleksii Lozhnikov, Candidate of Technical Sciences, Associate Professor of the Surface Mining Department, National Mining University, 19 Yavornytskoho Ave., 7/407, 49005, Dnipro, Ukraine. E-mail: oleksii.lozhnikov@gmail.com