Nosov Magnitogorsk State Technical University, Magnitogorsk, Russia:
S. E. Gavrishev, Director of the Institute of Mining and Transport, Head of a Chair, Professor, Doctor of Engineering Sciences
K. V. Burmistrov, Associate Professor, Candidate of Engineering Sciences, burmistrov_kv@mail.ru
S. N. Kornilov, Head of a Chair, Professor, Doctor of Engineering Sciences
N. G. Tomilina, Senior Laboratory Assistant, Candidate of Engineering Sciences

In surface mining, the best part of minerals is abandoned beyond the project limits of open pits. It is highly important to evaluate extractability and profitability of such reserves at the closing stage of open pit mining. It may happen that extraction of these reserves using open pit mining method is impossible while construction of underground mine takes a long period of time and is low-efficient. Under such conditions, it is required to find such approaches to getting access and to extract mineral reserves both in pit walls and floor that allow commencement of mining at the earliest possible day and at the minimized financial investment. The earlier studies have proved expediency of getting access to pit wall and floor reserves from the open pit and of transporting recovered mineral using the open pit mine roads and dump trucks. However, considering high operation costs of dump trucks, the application of this approach is greatly limited. The article gives the resultant scientific estimates of the expediency of accessing mineral reserves beyond the ultimate pit limits with the help of steep open pit mine hoists. Construction of an underground mine from the mined-out open pit reduces the construction period and investment, while mineral transportation using the open pit hoist minimizes operational costs of elevating mineral to ground surface. These factors enable lower cost of mining, which, as a consequence, may sometimes result in higher efficiency of extracting reserves from pit walls and floor as compared with the conventional method of having access to mineral through vertical shafts drilled from ground surface. The use of steep open pit hosts, given shallow depth of mineral occurrence, allows avoiding access to mineral reserves in pit walls and floor from ground surface and widens previously determined application domain for getting access to mineral from mined-out open pit are and for using open pit hoists. In case of deeper level occurrence of mineral reserves beyond the ultimate pit limit, the proposed flow charts may be efficiently used in the early mining stages when sinking of principal shafts is in process.

1. Grigorev V. V. Obosnovanie sistem razrabotki pribortovykh zapasov mednokolchedannykh mestorozhdeniy pri proektirovanii kombinirovannoy geotekhnologii : avtoreferat dissertatsii … kandidata tekhnicheskikh nauk (Substantiation of development systems of near-edge reserves of copper-sulfur deposits during the combined geotechnology designing : thesis of inauguration of Dissertation … of Candidate of Engineering Sciences). Magnitogorsk : Nosov Magnitogorsk State Technical University, 2010. 20 p.
2. Gibadullin Z. R., Kalmykov V. N., Petrova O. V. Bases of efficient technological schemes of ore mass transportation during the underground mining of pit reserves. Tsvetnye Metally. 2013. No. 8 (848). pp. 9–13.
3. Volokhov A. V. Obosnovanie sposobov vyemki zakonturnykh zapasov, zalegayushchikh vyshe dna karera, pri razrabotke slozhnostrukturnykh mestorozhdeniy (na primere mestorozhdeniya Zabaykalya) : avtoreferat dissertatsii … kandidata tekhnicheskikh nauk (Substantiation of methods of excavation of edge reserves, deposited over the open pit bottom during the complex-structure deposit mining (on example of Transbaikalian deposit) : thesis of inauguration … of Candidate of Engineering Sciences). Irkutsk : Irkutsk State Technical University, 2006. 20 p.
4. Hustrulid W. A., Kuchta M., Martin R. K. Open Pit Mine Planning and Design. Third Edition. London, UK : Taylor & Francis plc., 2013.
5. Zobnin V. I., Koltsov P. V., Ivanov Yu. S. Vyemka zakonturnykh zapasov rudy na karerakh (Edge ore reserves excavation on open pits). Ekaterinburg : Publishing House of Ural State Mining University, 2012. 68 p.
6. Kidyaev V. A. Obosnovanie skhem vskrytiya karerov na zaklyuchitelnykh etapakh otkrytoy razrabotki pri osvoenii mestorozhdeniy otkryto-podzemnym sposobom : dissertatsiya … kandidata tekhnicheskikh nauk (Substantiation of open pit development mining schemes on the final stages of open-cast mining during the open-cast and underground mastering of deposits : dissertation … of Candidate of Engineering Sciences). Magnitogorsk, 2013. 142 p.
7. Spivakovskiy A. O., Dyachkov V. K. Transportiruyushchie mashiny (Transporting machines). Second edition, revised and enlarged. Moscow : Publishing House «Mashinostroenie», 1968. 504 p.
8. Grishko A. P., Sheloganov V. I. Statsionarnye mashiny i ustanovki: uchebnoe posobie dlya vuzov (Stationary machines and units: tutorial for universities). Moscow : Publishing House of Miscow State Mining University, 2004. 328 p.
9. Gavrishev S. E., Burmistrov K. V., Tomilina N. G. Design of technological schemes for deep benches stripping in pits at combined opencast and underground mining. Proceeding of the XII national conference with international participation of the open and underwater mining of minerals. Varna, Bulgaria, 2013. pp. 37–42.
10. Tomašková M., Sinay J. The Use of Screw Conveyors in Practical Applications. Applied Mechanics and Materials. 2014. Vol. 683. pp. 225–231.
11. Buchhorn W., Lorenz, W. POCKETROPE^®-conveyor fir vertikale Schittgutforderung bei grofen Forderhohenunterschieden, FH-Minster. Professor Ginther, 04/2003.
12. Awuah-Offei K., Checel D., Askari-Nasab. Evaluation of belt conveyor and truck haulage systems in an open pit mine using life cycle assessment. CIM Magazine. 2009. August. pp. 59–64.
13. Coal Production and Processing Technology. Ed. by M. R. Riazi, R. Gupta. Taylor&Francis Group, LLC, 2016. p. 535.
14. Parreiras T. M., Rocha A. V., Justino J. C. G., de Cardoso Filho B. J. True unit power factor active front end for high capacity belt conveyor systems. Industry Applications Society Annual Meeting, IEEE, 2015. pp. 1–9.
15. Lucio J. C., Senra C. T., Souza A. Paving the future — A case study replacing truck-and-shovels by shovel-and-conveyor continuous mining at Carajas open pit mines. Iron Ore 2009 Conference. Perth, WA, July 27-29, 2009. pp. 269–276.
16. Pikalov V. A., Sokolovskiy A. V., Vasilets V. N., Burmistrov K. V. Obosnovanie effektivnykh parametrov kombinirovannogo otkryto-podzemnogo sposoba razrabotki ugolnykh mestorozhdeniy (Substantiation of efficient parameters for hybrid open pit/underground mining of coal). Gornyi Zhurnal = Mining Journal. 2016. No. 1. pp. 67–72.
17. Rocha A. V., de Paula H., dos Santos M. E., de Cardoso Filho B. J. Increasing long belt-conveyors availability by using fault-resilient medium voltage AC drives. Part II. Reliability and maintenance assessment. Industry Applications Society Annual Meeting (IAS), IEEE, 2012. pp. 1–8.
18. Romakin N. E. Konstruktsiya i raschet konveyerov: spravochnik (Design and calculation of conveyors: tutorial). Staryy Oskol : TNT, 2012. 504 p.
19. Dyakov V. A., Shakhmeyster L. G., Dmitriev V. G. et al. Lentochnye konveyery v gornoy promyshlennosti (Belt conveyors in mining industry). Under the editorship of A. S. Spivakovskiy. Moscow : Nedra, 1982. 349 p.
20. Tomilina N. G. Povyshenie effektivnosti primeneniya karernykh podemnikov pri otkryto-podzemnoy razrabotke mestorozhdeniya (Increasing of efficiency of open-pit lifts application during opencast and underground deposit mining). Mashinostroenie : setevoy elektronnyy nauchnyy zhurnal = Russian Internet Journal of Industrial Engineering. 2013. No. 2. pp. 53–57.
21. Khokhryakov V. S. Otsenka effektivnosti investitsionnykh proektov otkrytykh gornykh razrabotok (Assessment of effi ciency of investment open-cast mining projects). Ekaterinburg : Ural State Mining Academy, 1996.
22. Shestakov V. A. Obosnovanie parametrov rudnikov i tekhnologii razrabotki rudnykh mestorozhdeniy : uchebnoe posobie (Substantiation of mine parameters and ore deposits mining technology : tutorial). Novocherkassk : Publishing House of Platov South Russian State Polytechnic University, 1979. 84 p.
23. Gavrishev S. E., Burmistrov K. V., Tomilina N. G. Klassifi katsiya tekhnologicheskikh skhem vskrytiya glubokikh gorizontov s primeneniem krutonaklonnykh podemnikov pri kombinirovannom sposobe razrabotki mestorozhdeniy (Classification of process flowsheets of deep horizons development mining with application of steeply inclined lifts with combined method of deposit mining). Izvestiya vuzov. Gornyy zhurnal = News of the Higher Institutions. Mining Journal. 2013. No. 7. pp. 9–15.
24. Gavrishev S. E., Kalmykov V. N., Burmistrov K. V., Tomilina N. G., Zalyadnov V. Yu. Otsenka effektivnosti skhem vskrytiya zakonturnykh zapasov s primeneniem karernykh podemnikov (Assessment of efficiency of schemes of edge reserves development mining with application of open-pit lifts). Vestnik Magnitogorskogo gosudarstvennogo tekhnicheskogo universiteta imeni G. I. Nosova = Vestnik of Nosov Magnitogorsk State Technical University. 2014. No. 1. pp. 8–12.
25. Kolga A. D., Rakhmangulov A. N., Osintsev N. A., Sladkowski A. V., Stolpovskikh I. N. Robotic transport complex of automotive vehicles for handling of rock mass at the process of open cast. Transport Problems. 2015. Vol. 10, No. 2. pp. 109–116.
26. Ivashov N. A. Obosnovanie sposobov vskrytiya zapasov za konturami karerov pri kombinirovannoy razrabotke mestorozhdeniy : dissertatsiya … kandidata tekhnicheskikh nauk (Substantiation of methods of reserves development mining over the open pit edges during the combined deposit mining : Dissertation … of Candidate of Engineering Sciences). Magnitogorsk, 2007. 169 p.