INFLUENCE OF INTENSITY OF ORE DRAWING ON LOSSES IN SUBLEVEL CAVING IN PERMAFROST ZONE
Underground mining of ore deposits in the north-east of Russia currently features high costs, which affects profitability of ore production. Application of sublevel caving systems enables reduction in costs of ore haulage and ground control as well as considerable improvement of safety and productivity of mine personnel. At the same time, mining in permafrost zone requires taking into account possible adfreezing of broken ore in stopes, which complicates operation. The influence of adfreezing on ore losses was studied at various intensity of drawing and moisture content of ore during sublevel caving. Physical simulation of adfreezing-inclined ore drawing was executed on laboratory test bench, in a cryo-cell reproducing temperature conditions of underground mining in the Nezhdaninsky gold deposit. Ore drawing was carried out from single stope at the temperature of 5–7 ˚С below zero, which conformed with temperature conditions in stopes in permafrost zone. Intensity of ore drawing was varied by increasing quantity of discharge. The experimental drawing was continued until the limiting dilution of 50% per draw batch. The broken ore loss was determined as the difference between the discharged ore quantity and its mass in the test bench. The experimental studies find that under conditions of negative temperatures and varying moisture content of ore from 0 to 1.0%, the increase in the ore draw batch (intensity) by 2 times (from 150 to 300 t/shift) reduces the ore loss due to adfreezing by 14% (from 33 to 19%). Undoubtedly, the research findings are only valid for the specific test conditions. At the same time, they make it possible to estimate qualitatively the change in ore loss in adfreezing in stopes as function of ore drawing intensity in underground mining in permafrost zone. The resultant qualitative dependences of ore drawing intensity and ore loss in adfreezing in stopes will be used in recommendations on improvement of sublevel stoping efficiency in the conditions of permafrost zone.
For citation: Zubkov V. P., Petrov D. N. Influence of intensity of ore drawing on losses in sublevel caving in permafrost zone. MIAB. Mining Inf. Anal. Bull. 2019;(8):5-13. [In Russ]. DOI: 10.25018/02361493-2019-08-0-5-13.
: Zubkov V. P., Petrov D. N.
V.P. Zubkov, Cand. Sci. (Eng.), Senior Researcher,
Deputy Director for Science, e-mail: zubkov @ igds.ysn.ru,
D.N. Petrov, Cand. Sci. (Eng.), Head of Laboratory, e-mail: firstname.lastname@example.org,
Federal Research Centre The Yakut Scientific Centre,
Chersky Mining Institute of the North, Siberian Branch,
Russian Academy of Sciences,
677980, Yakutsk, Republic of Sakha (Yakutia), Russia.
Corresponding author: D.N. Petrov, e-mail: email@example.com.Key words
Underground mining, ore deposits, permafrost zone, sublevel caving, ore drawing, intensity, adfreezing, losses.References
1. Shekhar G., Gustafson A., Schunnesson H. Draw control strategy and resource efficiency in sublevel caving. State-of-the-art. Research report. Luleå University of Tecnology, Luleå 2017, 96 p.
2. Golik V. I., Belodedov A. A., Logachev A. V., Shurygin D. N. Improvement of parameters of production of ores at the subfloor collapse with face release. Izvestiya Tul'skogo gosudarstvennogo universiteta. Nauki o Zemle. 2018, no 1, pp. 150—159. [In Russ].
3. Nordqvist A., Wimmer X. Holistic approach to study gravity flow at the Kiruna sublevel caving mine. In Seventh International Conference and Exhibition on Mass Mining (Mass Min 2016). Sydney: The Australian Institute of Mining and Metallurgy. Pp. 401—414.
4. Rana Gruber. Sublevel caving. URL: http://www.ranagruber.no/index.php?id=40 (accessed 03.04.2019).
5. Matthews T. Dilution and ore loss projections: Strategies and considerations. SME Annual Conference and Expo and CMA 117th National Western Mining Conference — Mining: Navigating the Global Waters. Denver, United States. 15— 18 February 2015. Pp. 529—532.
6. Evertovskiy V. M. Underground mining method with ore bulk caving. Zolotodobycha. 2014, no 193, December. URL: http://zolotodb.ru/news/11164 (accessed: 17.06.2017). [In Russ].
7. Skawina B., Greberg J., Salama A., Gustafson A. The effects of orepass loss on loading, hauling, and dumping operations and production rates in a sublevel caving mine. Journal of the Southern African Institute of Mining and Metallurgy. April 2018, Vol. 118, pp 409—418.
8. Tapsiev A. P., Uskov V. A. Development of mining method for the thawed zone of the Nezhdaninskoye deposit. Interekspo Geo-Sibir'. 2014, no 4. Vol. 2. URL: http://cyberleninka.ru/article/n/razvitie-sistem-razrabotki-dlya-usloviy-talikovoy-zony-nezhdaninskogo-mestorozhdeniya#ixzz43bh7luxr (accessed: 30.03.2019). [In Russ].
9. Petrov D. N., Neobutov G. P. Experience and prospects of sublevel caving mining of ore deposits in Yakutia. Gornyy informatsionno-analiticheskiy byulleten’. 2017. Special edition 24, pp. 211—219. [In Russ].
10. Bakhmutov V. M. Tekhnologicheskiy reglament dlya razrabotki tekhnicheskogo proekta Nezhdaninskogo GOKa v Yakutskoy ASSR po tekhnologii podzemnykh gornykh rabot [Technological regulations for the development of a technical project for Nezhdaninskiy GOK in the Yakut ASSR on the technology of underground mining], Chita, CHF VNIPIGortsvetmet, 1986, 76 p.
11. Bechaev M. D., Artemonov S. V. Razrabotka effektivnoy tekhnologii otrabotki rudnykh tel Nezhdaninskogo mestorozhdeniya: otchet o NIR [Development of an effective technology for mining ore bodies at the Nezhdaninskoe deposit: Research report], Chita, Giprotsvetmet, 1989, 120 p.
12. Shekhovtsov V. S. Osnovy nauchnykh issledovaniy v gornom dele: uchebnoe posobie. Izd. 2-e [Fundamentals of scientific research in mining: Educational aid, 2nd edition], Novokuznetsk, SibGIU, 2006, 136 p.
13. Imenitov V. R., Kovalev I. A., Uralov V. S. Modelirovanie obrusheniya i vypuska rudy [Simulation of the caving and ore drawing], Moscow, MGI, 1961, 151 p.
14. Savich I. N., Mustafin V. I. Prospects of application and substantiation of design solutions for level and sublevel discharge. Gornyy informatsionno-analiticheskiy byulleten’. 2015. Special edition 1, pp. 419—429. [In Russ].
15. Bashkov V. I., Kopytov A. I. Calculation of parameters and constructive design options of developing sublevel caving with mechanical release of ore. Vestnik Kuzbasskogo gosudarstvennogo tekhnicheskogo universiteta. 2015, no 2, pp. 75—77. [In Russ].