DIRECTIONAL EXPLOSIVE-FREE BREAKAGE OF ROCK BY SOUNDLESS CHEMICAL DEMOLITION AGENTS
DOI:
https://doi.org/10.32782/3041-2080/2024-1-14Keywords:
soundless chemical demolition agent, direction rock breakage, stress concentrations, cartridge of soundless chemical demolition agent, trajectory of rock fracturing, rock breakage controlAbstract
The hard rocks breakage is one of the main processes in the modern mining and mineral recovery industry. The most common method breakage of hard rock’s with strength according to the scale of Prof. Protodiakonov more than 6 units, there is an explosive. Explosive breakage is associated with numerous harmful effects on the rock mass and the environment. In addition, conducting blasting operations is associated with risks of damage to equipment, devices, and communications located in the zone of impact of blasting. In some cases, explosive destruction cannot be used due to limitations of the dust-gas regime or other safety issues. Explosive-free technologies are an ecological alternative to traditional explosive methods of hard rock breakage. Among the various methods of explosive-free breakage, the method based on the use of soundless chemical demolition agents is promising. An unsolved issue of explosive-free rock breakage is directional fracturing. Control of the breakage direction is carried out mainly due to the optimization of the borehole’s layout. At the same time, natural defects, weakening and structural heterogeneities of rock mass are not taken into account. As a result, a “slope” of cracks from the design direction is observed. There are technical solutions aimed at eliminating the existing disadvantages of directed non explosive-free breakage based on the additional installation in the borehole cartridges. This paper discusses the method of directional fracturing of rocks, which is based on the creation of tensile stress concentrators on the borehole surface in the necessary places. The impact of an additional soundless chemical demolition agent cartridge installed in the borehole on the stress field nearby the borehole is considered. A modified design of the explosive-free cartridge is proposed, which allows to control the direction of rock breakage while adjusting the path of fracturing, which may not be a straight line.
References
Dai Y., Khandelwal M., Qiu Y., Zhou J., Monjezi M., Yang P. A hybrid metaheuristic approach using random forest and particle swarm optimization to study and evaluate backbreak in open-pit blasting. Neural Comput Appl. 2022. № 34. Р. 6273–6288. DOI: https://doi.org/10.1007/s00521-021-06776-z.
Harada T., Soeda K., Idemitsu T., Watanabe A. Characteristics of expansive pressure of an expansive demolition agent and the development of new pressure transducers. Doboku Gakkai Rombun-Hokokushu. Proceedings of the Japan Society of Civil Engineers. 1993. № 478. Р. 95–109. DOI: https://doi.org/10.2208/jscej.1993.478_91.
Natanzi A.S., Laefer D.F., Connolly L. Cold and moderate ambient temperatures effects on expansive pressure development in soundless chemical demolition agents. Constr Build Mater. 2016. № 110. Р. 117–127. DOI: https://doi.org/10.1016/j.conbuildmat.2016.02.016.
Hinze J., Brown J. Properties of Soundless Chemical Demolition Agents. J Constr Eng Manag. 1994. № 120 (4). Р. 816 DOI: 827. DOI: https://doi.org/10.1061/(asce)0733-9364(1994)120:4(816).
Laefer D., Natanzi A., Zolanvari S. Impact of thermal transfer on hydration heat of a soundless chemical demolition agent. Constr Build Mater. 2018. № 187. Р. 348–359. DOI: https://doi.org/10.1016/j.conbuildmat.2018.07.168.
Dessouki A., Mitri H. Rock Breakage Using Expansive Cement. Engineering. 2011. № 3 (2). Р. 168–173. DOI: https://doi.org/10.4236/eng.2011.32020.
De Silva V.R.S., Ranjith P.G., Perera M.S.A., Wu B., Rathnaweera T.D. The influence of admixtures on the hydration process of soundless cracking demolition agents (SCDA) for fragmentation of saturated deep geological reservoir rock formations. Rock Mech Rock Eng. 2019. № 52. Р. 435–454. DOI: https://doi.org/10.1007/s00603-018-1596-9.
Maneenoi N., Bissen R., Chawchai S. Influence of admixtures on the performance of soundless chemical demolition agents and implications for their utilization. J Sustain Min. 2022. № 21 (2). Р. 3. DOI: https://doi.org/10.46873/2300-3960.1350.
Пат. вин. № 100062, МПК (2006.01) E21С 37/06 Спосіб руйнування гірських порід невибуховими руйнуючимим складами й патрон для його реалізації / І.Г. Сахно, М.М. Касьян (Україна). a2011 00476; заявл. 17.01.2011, опубл. 12.11.2012, бюл. № 21. 5 с.
Sakhno S., Kobylianskyi В., Sakhno I. Destruction of rocks by the non-explosive depleting compounds during mining. Mining of Mineral Deposits. 2016. № 10 (1). Р. 25–30. DOI: http://dx.doi.org/10.15407/mining10.01.025.
