Upgrading ventilation systems at Konkola mine, Zambia

Roman, W.; Guthrie, John; Ndhlovu, W

doi:10.1201/9781439833742.ch12

Cited by 3 publications

(2 citation statements)

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“…Engineers now have considered more factors in mining practices in addition to VOD (Ventilation on Demand) (Rocque and Sletmoen, 2002;Isaksson et al, 2009), such as hazards reduction (Rawlins, 2006;Brake, 2009;Panigrahi et al, 2009), and face ventilation layout (Zhang et al, 2009). To upgrade or optimize a mine ventilation system, some researchers also carried out a lot of work and obtained well outcomes (Myasnikov and Patrushev, 1981;Prosser et al, 2002;Roman et al, 2002;Loring and Nelson, 2006;Wallace and Sletmoen, 2009). For evaluating the system, back to 1960s or 1970s, only one or two single criteria was popular used to evaluate a system if it can be ventilated easily or not, such criteria including equivalent orifice (Murgue, 1883), total air quantity to working faces, ventilation efficiency, etc.…”

Section: Introductionmentioning

confidence: 97%

Comprehensive and Integrated Mine Ventilation Consultation Model – CIMVCM

Cheng

et al. 2015

Tunnelling and Underground Space Technology

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Section: Introductionmentioning

confidence: 97%

Comprehensive and Integrated Mine Ventilation Consultation Model – CIMVCM

Cheng

et al. 2015

Tunnelling and Underground Space Technology

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“…The re-entry time after blasting has also been studied in a room-and-pillar mine by considering the concentration of NOx released from an ANFO blast [ 30 ]. Currently, gas-monitoring systems in underground mines are used successfully to predict the re-entry times after blasting operations [ 31 ]. CFD numerical simulations are also carried out for evaluating the risk level in road tunnels under fire scenarios while considering natural ventilation [ 32 , 33 ].…”

Section: Introductionmentioning

confidence: 99%

Concentration, Propagation and Dilution of Toxic Gases in Underground Excavations under Different Ventilation Modes

Menéndez¹,

Merlé

Oro

et al. 2022

IJERPH

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The drill-and-blast method is widely used for the excavation of hard rock tunnels. Toxic gases such as carbon monoxide and nitrogen oxides are released immediately after blasting by the detonation of explosives. To provide a safe working environment, the concentration of noxious gases must be reduced below the threshold limit value according to health and safety regulations. In this paper, one-dimensional mathematical models and three-dimensional CFD numerical simulations were conducted to analyze the concentration, propagation and dilution of the blasting fumes under different operating conditions. Forced, exhaust and mixed ventilation modes were compared to determine the safe re-entry times after blasting in a 200 m-long tunnel excavated using the top-heading-and-benching method. Based on the numerical simulations, carbon monoxide was the most critical gas, as it required a longer ventilation time to reduce its concentration below the threshold limit value. The safe re-entry time reached 480 s under the typical forced ventilation mode, but was reduced to 155 s when a mixed ventilation system was used after blasting, reducing the operating costs. The reduction of the re-entry time represents a significant improvement in the excavation cycle. In addition, the results obtained show that 1D models can be used to preliminary analyze the migration of toxic gases. However, to reliably determine the safe re-entry times, 3D numerical models should be developed. Finally, to verify the accuracy of the CFD results, field measurements were carried out in a railway tunnel using gas sensors. In general, good agreements were obtained between the 3D numerical simulations and the measured values.

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