Novikov L.A., Ishchenko K.S., Lohvyna L.O. Determination of the lifting height of dust particles after a mass explosion in an iron ore open pit

Geoteh. meh. 2023, 164, 126-134

https://doi.org/10.15407/geotm2023.164.126

 

DETERMINATION OF THE LIFTING HEIGHT OF DUST PARTICLES AFTER A MASS EXPLOSION IN AN IRON ORE OPEN PIT

Novikov L.A., Ishchenko K.S., Lohvyna L.O.

M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine

UDC [622.271.3:622.235.43]:622.807

Language: English

Abstract. Open pit mining is accompanied by emissions of fine dust and hazardous gases into the atmosphere. This is related to the operation of open pit transport, drilling and blasting operations. The release of harmful components into the quarry space and the increase in their concentrations has a negative impact on the health of working personnel and leads to pollution of the environment. In doing so, the nature of fine dust and gases pollution depends on the mining technology and meteorological factors. 
The problem of reduced effectiveness of dust suppression methods after mass explosions in open pits is relate to insufficient research into the formation of dust and gas cloud. Additional theoretical and experimental research into the dust dynamics of blasting operations is therefore need.
The article discusses the stages of formation of the dust and gas cloud after a mass explosion in an iron ore open pit. The results of experimental studies of the evolution of the dust and gas cloud at different points in time after the detonation of borehole charges are presented. Relations for determination of density and dynamic viscosity of gases, gas mixture and gas-dust aerosol are given. A formula for determining the time and height of ascent of spherical dust particles at the dynamic stage of dust and gas cloud formation is obtain. In this case, the assumption is madid that there is no mutual influence of the dynamic and thermal factors after detonation of the charges. The elevation of dust particles due to temperature differences during the heat stage of dust and gas cloud formation is determined. Based on the analysis of the calculation results, the duration of the dynamic stage of cloud formation is determined. It is established that, following the release of solid and gaseous detonation products into the atmosphere, a height distribution of dust particles is observed as a function of their diameter. That said during, the dynamic stage of dust and gas cloud formation, the height of dust particle lift is directly proportional to their diameter, while during the heat stage the inverse relationship is observe. That at the beginning of the thermal stage the deposition of coarse dust particles takes place are established. In this process, fine dust particles rise to a maximum height and are then carried outside the open pit by the airflow.
Keywords: dust and gas cloud, formation stage, dust particles, lifting height.

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About authors:

Novikov Leonid Andrііоvуch, Candidate of Technical Sciences (Ph.D.), Researcher in Department of Geomechanics of Mineral Opencast Mining Technology, M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine (IGTM of the NAS of Ukraine), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Ishchenko Kostiantyn Stepanovych, Doctor of Technical Sciences (D.Sc.), Senior Researcher in Department of Geomechanics of Mineral Opencast Mining Technology, M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine (IGTM of the NAS of Ukraine), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Lohvyna Liudmyla Oleksandrivna, Junior Researcherin in Department of Geomechanics of Mineral Opencast Mining Technology, M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine (IGTM of the NAS of Ukraine), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.