International Journal of Mining Reclamation and Environment · 2008 · 26 citations · 2 references
Environmental MonitoringEngineeringAir QualityGas Exchange ProcessTracer Gas MethodDiffusion CoefficientMine Ventilation MeasurementsMining EngineeringTransport PhenomenaAirflow RoutesAir SamplingMine VentilationVentilationTracer Gas MeasurementsEnvironmental EngineeringCivil EngineeringFansIndoor Air QualityAir PollutionTurbulent Diffusion Coefficient
The turbulent diffusion coefficient in mine airways is primarily influenced by the ratio of airway length to equivalent diameter, airway friction, and airflow mixing. Tracer‑gas measurements at the Pongkor underground gold mine were matched with advection‑diffusion simulations to determine airflow routes, flow rates, and turbulent diffusion coefficients, and to assess leakage reductions. Leakages of 26.7 and 36.7 m³ s⁻¹ were identified, and turbulent diffusion coefficients in simple airways matched the Taylor equation, whereas in complex mine airways they were 1.5–32 times larger, consistent with measurements from the Kushiro coal mine.
Tracer gas measurements have been carried out at the Pongkor underground gold mine, Indonesia, to evaluate mine ventilation flows and to investigate the effective turbulent diffusion coefficients in mine airways. The airflow routes and quantity, and the diffusion coefficient have been obtained by matching the measurements with numerical simulations using the advection-diffusion equation. Two leakages with flow quantity of 26.7 and 36.7 m3/s were detected. Reduction of leakages have been measured with the method after stopping the leakage routes. The turbulent diffusion coefficients for the simple airways have good agreement with the Taylor equation. However, for complex airways in operating mines, the coefficients show higher values (1.5 to 32 times) than that obtained by the Taylor equation and these have been compared with the data measured in the Kushiro coal mine, Japan. It is mainly affected by the ratio of airway length over equivalent diameter and airway frictions, but airflow mixing along the airway also has an effect on the diffusion coefficient.
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