VostNII Science Center, Kemerovo, Russia

Prokopenko S. A., Leading Researcher, Professor, Doctor of Engineering Sciences, sibgp@mail.ru
Ludzish V. S., Scientific Consultant, Professor, Doctor of Engineering Sciences,
Sementsov V. V., Head of Laboratory, Candidate of Engineering Sciences

Kuzbass State Technical University, Kemerovo, Russia¹ ; Kuzbass State Agricultural Academy, Kemerovo, Russia²
Ravochkin N. N.^1,2, Associate Professor, Doctor of Philosophical Sciences

The evaluation of reusability of conventional one-piece picks in manufacturing recyclable modular tools necessitated modeling the pick head wear. This article proposes a space–time model of the pick wear dynamics, representing the pick head in the initial condition and at the key stages of deformation depending on geological conditions of the tool operation. The model images the wear dynamics of the nose bit and steel body of picks. It allows predicting a wear stage (half-wear, pre-wear, normal wear and over-wear) of the pick heads, and determining the time of this stage. It becomes possible to find the limits of the tool wear by the criterion of reusability of the pick residues. The implemented wear analysis of picks of JOY 4LS-20 Longwall Shearer in operation in a Kuzbass mine shows that in coal cutting, the half-wear stage comes on the 6^th–7^th day of operation, at the residual length of the head of 76 mm, and the pre-wear stages comes on the 11^th–12^th day of operation, at the residual length of 67 mm. After operation for 15 days, the nose bit 28 mm long becomes totally worn, and the head length decreases from 90 to 62 mm, but the pick preserves a high potential for being reused in rock breaking. The wear limits are evaluated for the picks by the criterion of their reusability. The range and limits of wear on conventional picks by the criterion of strength of a modular structure are justified and tested. The results open prospects for multiple recycling of rock breaking tools of mining machines.

1. Talerov M. P., Bolobov V. I. Life and failures of tangential-rotary picks. Gornyi Zhurnal. 2018. No. 4. pp. 77–81.
2. Bolobov V. I., Chupin S. A., Akhmerov E. V., Plaschinskiy V. A. Comparative wear resistance of existing and prospective materials of fast-wearing elements of mining equipment. Materials Science Forum. 2021. Iss. 1040. pp. 117–123.
3. Gabov V. V., Zadkov D. A., Nguyen Van Xuan, Hamitov M. S., Molchanov V. V. To the problem of improving the working tools of mining excavation machines. GIAB. 2022. No. 6-2. pp. 205–222.
4. Yasar S., Yilmaz A.O. Drag pick cutting tests: A comparison between experimental and theoretical results. Journal of Rock Mechanics and Geotechnical Engineering. 2018. Vol. 10. рр. 893–906.

5. Shemyakin S. A., Shishkin E. A. Physical and mathematical model of rock destruction by a milling machine cutter. Journal of Mining Institute. 2021. Vol. 251. pp. 639–647.
6. Krauze K., Mucha K., Wydro T., Pieczora E. Functional and operational requirements to be fulfilled by conical picks regarding their wear rate and investment costs. Energies. 2021. Vol. 14, Iss. 12. ID. 3696.
7. Cheluszka P., Mikuła S., Mikuła J. Conical picks of mining machines with increased utility properties — selected construction and technological aspects. Acta Montanistica Slovaca. 2021. Vol. 26(2). рp. 195–204.
8. Jeong H., Jeon S. Characteristic of size distribution of rock chip produced by rock cutting with a pick cutter. Geomechanics and Engineering. 2018. Vol. 15, Iss. 3. рp. 811–822.
9. Bolobov V. I., Gabov V. V., Talerov M. P., Talerov K. P. Composite cutter for mining machines. Patent RF, No. 2448247. Applied: 30.11.2010. Published: 20.04.2012. Bulletin No. 11
10. Shishlyannikov D. I., Sukhanov A. E., Vasilev A. L., Borisov A. V., Gribov D. S. Composite cutter with mounting device on operating member of machine. Patent RF, No. 2755106. Applied: 14.12.2020. Published: 13.09.2021. Bulletin No. 26
11. Bołoz L. Directions for increasing conical picks’ durability. New Trends in Production Engineering. 2019. Vol. 2(1). рр. 277–286.
12. Bołoz L., Kalukiewicz A., Galecki G., Romanyshyn L., Romanyshyn T. Conical pick production process. New Trends in Production Engineering. 2020. Vol. 3(1). рр. 231–240.
13. Prokushenko S. I., Kalinin V. V., Dvornikov L. T. Dismountable rotary pick for mining machines. Patent RF, No. 54093. Applied: 15.06.2005. Published: 10.06.2006. Bulletin No. 16
14. Prokopenko S. A., Ludzish V. S., Li A. A. Recycling possibilities for reducing waste from cutters on combined cutter-loaders and road builders. Waste Management & Research. 2017. Vol. 35, Iss. 12. pp. 1278–1284.
15. Prokopenko S. A., Vorobiev A. V., Andreeva L. I., Janočko J. Waste cutters utilization in underground coal mining. Acta Montanistica Slovaca. 2017. Vol. 22, No. 1. рр. 81–89.
16. Bolobov V. I., Chupin S. A., Bochkov V. S., Mishin I. I. Service life extension for rock cutters by increasing wear resistance of holders by thermomechanical treatment. Gornyi Zhurnal. 2019. No. 5. pp. 67–71.
17. Krestovozdvizhenskiy P. D. Some observations over operation of shearing machines in mines in Kuzbass. GIAB. 2009. No. 6. pp. 120–123.
18. Khoreshok A. A., Tsekhin A. M., Kuznetsov V. V., Borisov A. Yu., Krestovozdvizhenskiy P. D. Field Experience of the working tools on effectors of mining machines on mines of Kuzbass. Mining Equipment and Electromechanics. 2011. No. 4. pp. 8–11.
19. Bolobov V. I., Akhmerov E. V., Rakitin I. V. Influence of rock type on regularities of excavator bucket tooth crown wear. GIAB. 2022. No. 6-2. pp. 189–204.
20. Bolobov V. I., Chupin S. A., Bochkov V. S., Akhmerov E. V., Plaschinskiy V. A. The effect of finely divided martensite of austenitic high manganese steel on the wear resistance of the excavator buckets teeth. Key Engineering Materials. 2020. Vol. 854, Iss. 10. pp. 3–9.
21. Gabov V. V., Zadkov D. A., Lykov Yu. V., Gurimsky A. I., Shpil’ko S. I. Exploiting heading machines at Vorkutaugol JSC mines. Mining Equipment and Electromechanics. 2008. No. 12. pp. 2–6.
22. Prokopenko S. A., Ludzish V. S., Kurzina I. A. Improvement of cutting tools to increase the efficiency of destruction of rocks tunnel harvesters. Journal of Mining Science. 2016. Vol. 52, No. 1. pp. 153–159.